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LEACHATE, GROUNDWATER, SURFACE STREAM, TREATED LEACHATE, GROUNDWATER, SURFACE STREAM, TREATED LEACHATE, GROUNDWATER, SURFACE STREAM, TREATED LEACHATE, GROUNDWATER, SURFACE STREAM, TREATED WATER AND SOIL WATER AND SOIL WATER AND SOIL WATER AND SOIL CHARACTERISTICS OFCHARACTERISTICS OFCHARACTERISTICS OFCHARACTERISTICS OF THE VICINITY OF A THE VICINITY OF A THE VICINITY OF A THE VICINITY OF A MUNICIPAL SOLID WASTE DUMPSITE AT UYO METROPOLIS, MUNICIPAL SOLID WASTE DUMPSITE AT UYO METROPOLIS, MUNICIPAL SOLID WASTE DUMPSITE AT UYO METROPOLIS, MUNICIPAL SOLID WASTE DUMPSITE AT UYO METROPOLIS,
AKWA AKWA AKWA AKWA –––– IBOM STATE, NIGERIA.IBOM STATE, NIGERIA.IBOM STATE, NIGERIA.IBOM STATE, NIGERIA.
BYBYBYBY
MONECHOTMONECHOTMONECHOTMONECHOT,,,, WALTERSWALTERSWALTERSWALTERS,,,, ORUORUORUORU REG NO: PG/MSREG NO: PG/MSREG NO: PG/MSREG NO: PG/MScccc/09/50796/09/50796/09/50796/09/50796
A PROJECT SUBMITTED IN PARTIAL FULFILLMENT OF THE A PROJECT SUBMITTED IN PARTIAL FULFILLMENT OF THE A PROJECT SUBMITTED IN PARTIAL FULFILLMENT OF THE A PROJECT SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENT FOR THE AWARD OF THE MASTER OF REQUIREMENT FOR THE AWARD OF THE MASTER OF REQUIREMENT FOR THE AWARD OF THE MASTER OF REQUIREMENT FOR THE AWARD OF THE MASTER OF
SCIENCE DEGREE (MSSCIENCE DEGREE (MSSCIENCE DEGREE (MSSCIENCE DEGREE (MScccc) IN ANALYTICAL CHEMISTRY IN ) IN ANALYTICAL CHEMISTRY IN ) IN ANALYTICAL CHEMISTRY IN ) IN ANALYTICAL CHEMISTRY IN THE DEPARTMENT OF PURE AND INDUSTRIAL CHEMISTRY, THE DEPARTMENT OF PURE AND INDUSTRIAL CHEMISTRY, THE DEPARTMENT OF PURE AND INDUSTRIAL CHEMISTRY, THE DEPARTMENT OF PURE AND INDUSTRIAL CHEMISTRY,
FACULTY OF PHYSICAL SCIENCES, UNIVERSITY OF FACULTY OF PHYSICAL SCIENCES, UNIVERSITY OF FACULTY OF PHYSICAL SCIENCES, UNIVERSITY OF FACULTY OF PHYSICAL SCIENCES, UNIVERSITY OF NIGERIA NSUKKA.NIGERIA NSUKKA.NIGERIA NSUKKA.NIGERIA NSUKKA.
NOVEMBERNOVEMBERNOVEMBERNOVEMBER, 2012, 2012, 2012, 2012
ii
DECLARATION DECLARATION DECLARATION DECLARATION
I hereby declare that this project contains the report of my
research work and has not been presented in any previous
application for a higher degree. All information from other
sources have been acknowledged by means of reference.
__________________ __________________ Monechot, Walters Oru Date PG/MSc/09/50796 Student
iii
CERTIFICATION CERTIFICATION CERTIFICATION CERTIFICATION
This is to certify that, the project entitled “Leachate,
groundwater, surface stream, treated water and soil
characteristics of the vicinity of a municipal solid wastes
dumpsite at Uyo metropolis, Akwa-Ibom State, Nigeria” by
Monechot Walters Oru meets the regulation governing the award
of degree of master of science of the University of Nigeria,
Nsukka and it is approved for its contribution to scientific and
literary presentation.
____________________________________________________________ ____________________________________________________________ Prof. P.O. Ukoha Prof. P.O. Ukoha Prof. P.O. Ukoha Prof. P.O. Ukoha Date Date Date Date Project SupervisorProject SupervisorProject SupervisorProject Supervisor ____________________________________________________________ ____________________________________________________________ Prof. P.O. Ukoha Prof. P.O. Ukoha Prof. P.O. Ukoha Prof. P.O. Ukoha Date Date Date Date Head of Department Head of Department Head of Department Head of Department
iv
DEDICATIONDEDICATIONDEDICATIONDEDICATION
I dedicate this piece of work to God Almighty for inspiring
me and being with me day by day until this success have been
recorded. May his Holy name be exalted above every other name.
v
ACKNOWLEDGEMENTSACKNOWLEDGEMENTSACKNOWLEDGEMENTSACKNOWLEDGEMENTS
No man is an island of knowledge and entire of itself. It
should be fraudulent to claim that this work has been completed
by me without the assistance of others who have had a part in
making this academic dream a reality and success. These are
known and unknown friends, my lecturers at the University of
Nigeria Nsukka (UNN), supervisor, gentle critics, family members
and others I can’t mention. I wish to express my profound
gratitude to Almighty God for his protection, guidance and
blessing throughout the research period.
I wish to acknowledge the exemplary supervision of Prof. P.
O. Ukoha who enthusiastically gave me his precious time and
made invaluable encouragement, corrections, suggestions and
penetrating contributions as well as constructive criticism at
every stage of this work. All these rekindled me a sense of
responsibility, reliability and attention to details.
I am equally indebted to all my lecturers in the department
of Pure and Industrial Chemistry University of Nigeria Nsukka.
I am very grateful and thankful to Dr. B. O. Ekpo for his
advise and amiable support; morally, financially and otherwise.
I extend my profound gratitude and love to my beloved
family members; my father Mr. Monechot Joseph Orock and
mother Philomina Eta-Akeyuk, my beloved and caring Aunty,
madam Philomina Orock Bate, my brothers and sisters, especially
Clement Aje-Ndep whom in the presence of nothing, showed
brotherly love to me financially and otherwise.
I am also extremely appreciative of the love,
encouragement, patience, understanding, material and moral
support which I have received from my beloved fiancée Yvonne
vi
Anom Owor and the entire Owor’s family throughout the period of
this work.
I also wish to acknowledge the staff and the management of
Gifted College Calabar for the spirit of hard work they have
instilled in me, as well as their moral support and advise as each
day passes on.
I wish to acknowledge my friends in the department of Pure
and Industrial Chemistry University of Nigeria Nsukka for their
encouragement, words of advise and constructive criticism
during this period.
I also wish to express my gratitude to the 46 Webber family
for their love, care, encouragement and support in one way or the
other.
Finally I extend my sincere appreciation to my dutiful,
hardworking, understanding, and serious minded typist Mrs.
Enubiak for giving her valuable time all to make sure that this
work is transformed from the handwriting from to this form.
May God bless and reward them abundantly forever, Amen.
vii
AbstractAbstractAbstractAbstract
These findings documented the physical, chemical and heavy metal contents in leachate, borehole water, surface stream, treated water and soil samples around the municipal solid waste dumpsite at Uyo metropolis, Akwa-Ibom State, Nigeria. Samples were collected during the wet and dry seasons 2010/2011. The samples were analysed for the following parameters: heavy metals (Fe, Cu, Mn, Zn, Cr, Cd, Pb), anions (PO3
4,SO2-4,Cl
-, NO-3, NH
+4-N), essential metals (Na, K, Ca, Mg), total
dissolved solids (TDS), dissolve oxygen (DO), Chemical oxygen demand (COD), pH, salinity, turbidity and conductivity. The results revealed that most of the parameters recorded for the leachate samples significantly exceeded the WHO international standards for drinking water in both seasons. Fe (47.33 and 113.13mg(L), Cd (2.29 and 14.47mg/l), Cu (5.78 and 35.87mg/l), Cr (1.63 and 7.63mg/l), Pb (12.33 and 31.13mg/l), Zn (17.33, and 34.5mg/l), BOD (52.2 and 159.6mg/l), Cl- (284.37 and 536mg/l), NO-
3 (74.03 and 87.83mg/l), TDS (1709.5 and 2043mg/l) and DO (1.73 and 2.73mg/l). In leachate, all the heavy metals, Cl-, COD, salinity, and conductivity contents showed significant increase (P<0.05) while SO2-
4 recorded significant decrease (P<0.05) during the dry season. The physico-chemical contents recorded for the borehole water and treated water samples in both seasons agree with the international standards for drinking water, except for high PO4
3- content (1.13 to 2.17mg/l) recorded for the borehole water samples in both seasons which exceeded the WHO permissible limit of 0.1mg/l for drinking water. The borehole water sample recorded significant increase (P<0.05) in Fe, Mn, Na, K. and a significant decrease in SO2-
4 contents during the dry season. The stream water sample recorded high Fe (0.61 and 2.5mg/l) content in both seasons and high Mn (2.37 mg/l), Cr (0.42mg/l), Cd (0.46mg/l) and Cu (3.95mg/l) contents during the dry season which exceeded the WHO international standard for drinking water. The stream water samples recorded significant increase in BOD5, Cu, Mn, Cd and Cr contents during the dry season (P<0.05). The heavy metal contents recorded for soil samples from the dumpsite, from 10 and 20m east, west, south and north of the dumpsite and from the control site were all within the WHO international standards in both seasons. The heavy metal contents in the dumpsite soil sample in both seasons were significantly higher; pb (9.90 and 11.82mg/kg), Zn (1370 and 146mg/kg), Ni (12.56 and 11.82mg/kg), Cr (3.60 and 4.05mg/kg) Cd (9.05 and 12.2mg/kg) and Mn (94.0 and 91.2mg/kg) In both seasons than the control; Pb (3.78mg/kg) Zn (50.90mg/kg), Ni (2.19mg/kg), Cr (1.06mg/kg), Mn (44.27mg/kg), and Cd (1.09mg/kg). Heavy metal contents for soil samples 10 and 20m east of the dumpsite were also significantly higher (P<0.05) than that of the control. This study infer that the solid waste dumpsite is affecting the natural quality of the ambient environment. Therefore indiscriminate dumping of solid waste at the dumpsite should be prohibited.
viii
TABLE OF CONTENTSTABLE OF CONTENTSTABLE OF CONTENTSTABLE OF CONTENTS
Title Page - - - - - - - - i
Declaration - - - - - - - - ii
Certification - - - - - - - - iii
Dedication - - - - - - - - iv
Acknowledgements - - - - - - - v
Abstract - - - - - - - - vii
Table of contents - - - - - - - viii
List of Tables - - - - - - - - xiii
List of Figures - - - - - - - - xv
List of plates - - - - - - - - xvii
CHAPTER ONECHAPTER ONECHAPTER ONECHAPTER ONE
1.1 Background of the study - - - - 1
1.2 Statement of the problem - - - - 7
1.3 Objectives of study - - - - 8
1.3.1 General objectives - - - - 8
1.3.2 Specific objectives - - - - 8
1.4 Expected benefits of the study - - - - 9
1.5 Research questions - - - - 9
1.6 Scope of the study - - - - 10
CHAPTER TWOCHAPTER TWOCHAPTER TWOCHAPTER TWO
2.1 Meaning of waste - - - - 11
2.1.1 Solid waste - - - - 11
ix
2.2 Solid waste dumpsite - - - - - 14
2.2.1 Open dumps system - - - - - 14
2.2.2 Sanitary landfill system - - - - - 15
2.3 Waste management - - - - - 15
2.3.1 Landfills - - - - - 16
2.3.2 Incineration - - - - - 16
2.3.3 Recycling - - - - - 17
2.4 Leachate - - - - - 17
2.4.1 Leachate production - - - - - 20
2.4.1.1 Influence of Source - - - - - - 20
2.4.1.2 Processes - - - - - - 20
2.4.1.3 Timing of landfill stabilization - - - - 22
2.5 Pollution - - - - - - - - 23
2.5.1 Ancient culture - - - - - 23
2.5.2 Official acknowledgement - - - - 23
2.5.3 Modern awareness -- - - - - 25
2.5.4 Forms of Pollution - - - - - 27
2.6 Water Pollution - - - - - 28
2.6.1 Water pollution Categories - - - - 29
2.6.1.1. Surface Water pollution - - - - - 29
2.6.1.2 Groundwater pollution - - - - - 31
2.6.2 Causes of water pollution - - - - - 31
2.6.2.1 Pathogens - - - - - - 32
x
2.6.2.2 Chemical and other contaminants - - 33
2.6.3 Measurement of water pollution - - 34
2.7 Water quality - - - - - - - 34
2.8 Soil/land pollution - - - - - 33
2.8.1 Causes of soil pollution - - - - 36
2.8.2 Effects - - - - - - - 36
2.8.2.1 Health effects - - - - - - 36
2.8.2.2. Ecosystem effects - - - - - 37
2.8.2.3 Clean up options - - - - - 38
2.9 Review of related studies - - - 39
CHAPTER THREECHAPTER THREECHAPTER THREECHAPTER THREE
3.1 The study area - - - - - 45
3.2 Material and methods - - - - - 47
3.2.1 Sampling - - - - - - - 47
3.2.2 Samples treatment - - - - - - 51
3.2.2.1 Treatment of water samples - - - - 51
3.2.3 Treatment of leachate sample - - - - 51
3.2.4 Treatment of soil sample - - - - - 52
3.2.5 Preparation of stock solutions - - - 52
3.2.6 Chemical analysis - - - - - 52
3.2.6.1 Determination of pH and temperature - 53
3.2.6.2 Determination of chemical oxygen demand (COD) 53
3.2.6.3 Determination of Dissolved oxygen (DO) - - 53
xi
3.2.6.4 Determination Biochemical Oxygen demand (BOD) 54
3.2.6.5 Determination of total dissolved solids (TDS) - 54
3.2.6.6 Determination of Major Anions - - - 55
3.2.6.6.1 Determination of Phosphate (PO43-) - - 55
3.2.6.6.2 Determination of Nitrate (NO3-) - - - 55
3.2.6.6.3 Determination of Sulphate (SO42-) - - 55
3.2.6.6.4 Determination of Chloride (Cl-) - - - 56
3.2.6.6.5 Determination of nitrite (NO2) - - - 56
3.2.6.6.6 Determination of Ammonium Nitrogen - - 57
3.2.7 Determination of Sodium (Na) and Potassium (K) 57
3.2.8 Determination of heavy metals - - - 57
3.3 Data Analysis Technique - - 57
CHAPTER FOURCHAPTER FOURCHAPTER FOURCHAPTER FOUR: RESULTS AND DISCUSSION : RESULTS AND DISCUSSION : RESULTS AND DISCUSSION : RESULTS AND DISCUSSION
4.1 Means and standard deviations of some physic- chemical contents in leachate ground water, stream water and treated water samples - 58
4.1.1 Mean concentrations of pH temperature turbidity
salinity and conductivity in leachate, groundwater, stream water and treated water samples - - 58
4.1.2 Mean concentrations of DO, BOD, COD,
Total suspended solids (TSS) and Total dissolved solids (TDS) in leachate groundwater, stream water and treated water samples - 69
4.1.3 Mean concentrations of some major anions
In leachate, groundwater, stream water and treated Water samples - - - - - - - 79
4.1.4 Mean concentrations of essential cations in leachates,
Ground water, treated water and stream water samples 87
xii
4.1.5 Mean concentrations of heavy metals in leachate Groundwater stream water and treated water Samples - - - - - - - - 93
4.2 Mean concentrations of heavy metals in soil along
Wastes and non wastes disposal sites - - - 100 4.3 Discussion - - - - - - - 115 4.3.1 Physico-chemical characteristics of leachate,
groundwater, stream water and treated water samples 115 4.3.2 Heavy metal characteristics of soil samples
along wastes and non-wastes disposal sites - - 137
4.4 Spiked samples - - - - - - - 144 CHAPTER FIVE: SUMMARY AND CONCLUSION CHAPTER FIVE: SUMMARY AND CONCLUSION CHAPTER FIVE: SUMMARY AND CONCLUSION CHAPTER FIVE: SUMMARY AND CONCLUSION
5.1 Summary and conclusions - - - - - 150
5.2 Recommendations - - - - - 152
5.3 Contribution to knowledge - - - - - 153
5.4 Suggestion for further works - - - - 153
References
xiii
LIST OF LIST OF LIST OF LIST OF TABLESTABLESTABLESTABLES Table 2.1: Nigerian urban cities; project volume of city depot/ dumpsite (1982-2000). - - - - - 13 Table 2.2: Water quality of two rivers in Nigeria before
and within the City. - - - - - 30 Table 4.1: Selected physical parameters of leachate, ground water, surface stream and treated water samples during the wet season. - - - - - 59 Table 4.2: Selected physical parameters of leachate, ground water, surface stream and treated water samples during the dry season. - - - - - 60 Table 4.3: Mean concentrations of selected physical
Parameters in leachate, groundwater, surface stream and treated water samples during the wet season. - - - - - - 70
Table 4.4: Mean concentrations of selected physical
Parameters in leachate, groundwater, surface stream and treated water samples during the dry season. - - - - - - 71
Table 4.5: Mean concentrations of anions in leachate, ground water, stream water and treated water samples during the wet season. - - - - 80 Table 4.6: Mean concentrations of anions in leachate, ground water, stream water and treated water samples during the dry season. - - - - 81 Table 4.7: Mean concentrations of essential cations in
leachate, groundwater, surface stream and treated water samples during the wet season. 88
Table 4.8: Mean concentrations of essential cations in
leachate, groundwater, surface stream and treated water samples during the dry season. - 89
Table 4.9: Mean concentrations of heavy metals in leachate, ground water, stream water and treated water Samples during the wet season. - - - 94
xiv
Table 4.10: Mean concentrations of heavy metals in leachate, ground water, stream water and treated water Samples during the dry season. - - 95 Table 4.11: Mean concentrations of heavy metals in soil along waste and non-waste disposal sites during the wet season. - - - - - - 101 Table 4.12: Mean concentrations of heavy metals in soil along waste and non-waste disposal sites during the dry season. - - - - - - 102 Tables 4.13 and 4.14 Recovery analysis during the wet
Season for leacheate, borehole water, stream water and treated water samples - - - - 146
Tables 4.15. and 4.16 Recovery analysis during the dry
Season for leacheate, borehole water, stream water and treated water samples - - - - 147
xv
LIST OF FIGURESLIST OF FIGURESLIST OF FIGURESLIST OF FIGURES Figure 3.1: The map of Uyo Municipality showing the dumpsite 46 Figure 3.2: Sketch map of the study area - - - 48 Figure 4.1: Comparison of pH in leachate, groundwater, surface Stream and treated water samples in wet and dry Seasons - - - - - - - 64 Figure 4.2: Comparison of temperature in leachate, groundwater,
surface Stream and treated water samples in wet and dry Seasons - - - - - 65
Figure 4.3: Comparison of turbidity in leachate, groundwater,
surface Stream and treated water samples in wet and dry Seasons - - - - - - 66
Figure 4.4: Comparison of salinity in leachate, groundwater,
surface Stream and treated water samples in wet and dry Seasons - - - - - - 67
Figure 4.5: Comparison of conductivity in leachate, groundwater,
surface Stream and treated water samples in wet and dry Seasons - - - - - - 68
Figure 4.6: Comparison of dissolved oxygen in leachate, groundwater, surface Stream and treated water samples in wet and dry Seasons - - - 74
Figure 4.7: Comparison of chemical oxygen demand in leachate,
groundwater, surface stream and treated water samples in wet and dry Seasons - - - 75
Figure 4.8: Comparison of biochemical oxygen demand in
leachate, groundwater, surface Stream and treated water samples in wet and dry Seasons - - 76
Figure 4.9: Comparison of total suspended solids in leachate,
groundwater, surface Stream and treated water samples in wet and dry Seasons - - - 77
xvi
Figure 4.10: Comparison of total dissolved Solids in leachate, groundwater, surface Stream and treated water samples in wet and dry Seasons - - - 78
Figure 4.11: Comparison of nitrate in leachate, groundwater,
surface Stream and treated water samples in wet and dry Seasons - - - - - - 85
Figure 4.12:Comparison of phosphate in leachate, groundwater,
surface Stream and treated water samples in wet and dry Seasons - - - - - - 86
Figure 4.13:Comparison of calcium in leachate, groundwater,
surface Stream and treated water samples in wet and dry Seasons - - - - - - 92
Figure 4.14:Comparison of iron in leachate, groundwater, surface
stream and treated water samples in wet and dry seasons - - - - - - 98
Figure 4.15:Comparison of manganese in leachate, groundwater,
surface stream and treated water samples in wet and dry seasons - - - - - - 99
Figure 4.16: Comparison of Iron in soils along waste and non-
waste disposal site in wet and dry seasons - 103 Figure 4.17:Comparison of lead in soils along waste and non
waste disposal site in wet and dry seasons - 105 Figure 4.18: Comparison of zinc in soil along waste and non-waste
disposal site in wet and dry seasons - - 106
Figure 4.19: Comparison of nickel in soil along waste and non-waste disposal site in wet and dry seasons - 108
Figure 4.20:Comparison of chromium in soil along waste and non-waste disposal site in wet and dry seasons - 110
Figure 4.21:Comparison of cadmium in soil along waste and non-waste disposal site in wet and dry seasons - 111
Figure 4.22:Comparison of manganese in soil along waste and
non-waste disposal site in wet and dry seasons - 113
xvii
List of plates List of plates List of plates List of plates
Plate 1 : Cross section of the Barracks road dumpsite - 49 Plate 2: Cross section of the surface stream in the vicinity of the dumpsite - - - - - - 50
1
CHAPTER ONECHAPTER ONECHAPTER ONECHAPTER ONE
INTRODUCTIONINTRODUCTIONINTRODUCTIONINTRODUCTION
1.11.11.11.1 Background of the studyBackground of the studyBackground of the studyBackground of the study
The municipal solid waste dumpsite (MSWD) examined is
located within the barrack’s road street at Uyo Metropolis; Akwa -
Ibom State. The dumpsite examined contains both biodegradable
and non biodegradable materials of all sorts. The different waste
materials may contain different physical, chemical and
biochemical properties. In the presence of atmospheric water,
high temperature and high microbial populations, these waste
materials may decompose and get dissolved in the presence of
water to generate a waste liquid substance called leachate. This
waste water produced may infiltrate into the ground water
aquifer, it may be washed into a near by surface stream and it
may affect the soil properties. When humans come into direct
contact with such contaminated samples, it may lead to many
health problems.
Pollution occurs when a product added to our natural
environment adversely affects nature’s ability to dispose it off. A
pollutant is something which adversely interferes with health,
comfort, property or environment of the people. Generally, most
pollutants are introduced in the environment as seawage, waste,
accidental discharge and as compounds used to protect plants
and animals. There are many types of pollution such as air
pollution, water pollution, soil pollution, nuclear pollution and oil
pollution (Misra and Mani, 1991).
Solid wastes other than hazardous and radioactive
materials are often referred to as Municipal Solid Waste (MSW).
Municipal solid waste is useless unwanted material discharged as
a result of human activity. Most commonly, they are solids, semi-
solids or liquids in containers thrown out of houses, commercial
2
or industrial premises (Nyangababo and Hamya, 1980). Municipal
solid waste varies in composition, which may be influenced by
many factors, such as culture affluence, location etc. Municipal
solid waste management depends on the characteristics of the
solid wastes including the gross composition, moisture contents,
average particle size, chemical composition and density, in which
knowledge of these usually helps in disposal plans (Sally, 2000).
In Nigeria, agencies like the Federal Environmental
Protection Agencies (FEPA), Ministry of environment,
Environmental Sanitation Authorities, for example Akwa Ibom
State Environmental Protection Agency (AKSEPA) and even local
authorities are responsible for planning a defined line of action for
the disposal of waste generated on daily basis in our society.
The report that refuse dumps have caused traffic delays in
some strategic parts of our urban centers and cities is an
example of poor management of refuse dumps in Nigerian towns
and cities (Umaakuta and Mba, 1999). According to Eddy,
Odoemelem and Mbaba (2006), the series of problems are as a
result of lack of designed strategies that can be based on
scientific principles and approach.
However, human endeavours, such as technology,
industrialization, construction, trade, commerce, as well as
nutrition have rendered the whole environment system a “throw
away society”. This is true because indiscriminate disposal of
waste coupled with increasing world population and urbanization
have combined to worsen the situation day in, day out (Eddy et
al., 2006).
According to Holmes (1992), site selection for waste
disposal is generally based on geographic rather than geological
and hydro geological considerations, that is the closer the site to
the source of the waste the better in terms of transport cost
3
reduction. It is not uncommon therefore to find waste disposal
sites within municipal boundaries and surrounded by residential
areas. Clearly such sites pose-serious health risk just in terms of
problems associated with litter, stray dogs, scavenging birds,
rats and air borne contaminants from mobilization of fine
particulate matter.
Despite the best attempts at waste avoidance reduction,
reuse and recovery (recycling, compositing and energy
recovery), landfills and waste disposal sites are still the principal
focus for ultimate disposal of residual wastes and incineration
residues world-wide (Waite, 1995). The placement and
compaction of municipal wastes in land fills facilitates the
development of facultative and an aerobic conditions that
promotes biological decomposition of land filled wastes. Hence,
leachates of diverse composition are produced, depending on
site construction and operational practices, age of the landfill,
landfill method, climatic and hydro geological conditions and
surface water ingress in to the landfill (Campbell, 1993).
A landfill is an engineered waste disposal site facility with
specific pollution control technology designed to minimize
potential impacts. Landfills are usually either placed above
ground or contained within quarries pits. Landfills are sources of
groundwater and soil pollution due to the production of leachates
and its migration through refuse (Christensen and Stengmann,
1992).
According to Amina, et al., (2004), leachate corresponds to
atmospheric water that has percolated through waste, interacting
with bacteriological activity and especially organic substances.
Its composition is a function of the nature and age of the land fill,
type of waste, the method of burying, the geological nature of the
site and climate.
4
Leachate pollution is a result of mass transfer process.
Waste entering the landfill reactor undergoes biological, chemical
and physical transformations, which are controlled among other
influencing factors, by water input fluxes. In the reactor, three
physical phases are present; the solid phase (waste), the liquid
phase (leachate) and the gaseous phase. In the gaseous phase,
mainly carbon (prevalently in the form of CO2 and CH4) is present.
The main environmental aspects of landfills leachate are the
impacts on surface water quality, ground water quality as well as
soil quality, if leachate is discharging into these bodies
(Christensen et al., 1992).
According to Paster, et al., (1993); De-vare and Bahadir,
(1994), uncontrolled leachates may exert deleterious effects on
the environment, especially the input of high concentrations of
organic leachate and inorganic solutions of metals at low
oxidation states into water course which apparently depletes the
dissolved oxygen content of the water and ultimately lead to
extinction of all oxygen depending life. Also the non-
biodegradable organic compounds in the leachate will persist for
a long time. These compounds may adversely affect aquatic
species when they are assimilated into food chains.
Ground water is that portion of subsurface water which
occupies that part of the ground that is fully saturated and flows
into a hole under pressure greater than atmospheric pressure.
Groundwater occurs in geological formations called aquifer. An
aquifer (gravel/sand) may be defined as a geological formation
that contains sufficient permeable materials that yield significant
quantities of water to wells and springs; this implies an ability to
store and transmit water (Chae, 2000).
Groundwater is an important source of drinking water for
human kind. It contains over 90% of the fresh water resources
5
and is an important reserve of good quality water. Groundwater,
like any other water resource, is not just of public health and
economic value it also has an important ecological function
(Armon and Kitty, 1994). Groundwater contamination by landfill
leachate is increasingly recognized as a serious problem
(Hussan, et al., 1989; Loizidous and kapetanois, 1993;
kwanchanawong and Kootlakers, 1993; Al-Muzains and
Muslamani, 1994).
Soil is the collection of natural materials occupying part of
the earth surface that may support plant growth, and which
reflects the pedogenetic processes acting over time under the
associated influences of climate, relief, living organisms, and
parent materials. Soil pollution is caused by the removal or
addition of substances and factors that decreases its
productivity, quality of plants and ground water. Landscape
pollution is simply the conversion of fertile land to barren one by
dumping wastes over it.
Indiscriminate dumping of refuse can influence soil physico-
chemical properties, but can still be used for farming provided
the risks associated with its usage are continuously assessed and
controlled. The introduction of metal contaminants into the
environment could result from various sources; a few of which
are application of sea wage materials, and leaching of garbage.
The impact on man would be felt if the metals enter into the food
chain and accumulate in living organisms (Moore and
Ramamoorthy, 1984; Altundogan, et al., 1998).
Continuous disposal of municipal wastes in soil may
increased heavy metal concentrations. Heavy metals may have
harmful effects on soils, crops, and human health. However, there
is generally not strong relationship between the concentration of
heavy metals in soils and plants because it depends on many
6
factors such as soil metal bioavailability, plant growth, and metal
distribution to plants parts.
Apart from the contamination of soil, water and agricultural
land by other elements, lead alone has a poisoning effect.
According to Akaeze (2001), the toxicity of lead could lead to
encephalopathy, renal effect, and hematological effect. The WHO,
had confirmed the effects of lead intake to include, abortion,
infant mortality, malformation of foetus, genetic mutation,
retarded growth, intoxication, depression of respiration and
chromosomal aberrations. Smith, (1976), stated that heavy metals
can be introduced into the environment through high tension
electricity supply lines, municipal solid wastes and building
materials. Sommers, et al., (1976), explains that copper is an
essential constituent of all organisms, but if the copper
concentration is increased above normal level, it becomes highly
toxic. An increase in concentration of copper in the ocean by one
part per billion has resulted in the death of several species of
phytoplankton and the eggs of some fishes of open oceans.
Based on these, researchers have opted to suggest ways of
controlling the generation of wastes and effects on the
environment.
Akpan (2001) observed that the major cause of land
degradation in Uyo is solid waste, and on the characteristics of
wastes, papers, food remains, metal scraps, tins, cans, rubber
containers, plastics, cellophane bags, worn-out tyres, and tubes
were identified as the major components of solid waste. Apart
from the fact that solid waste degrade the environment, and pose
problems to the aesthetic value of the environment, Etekpo (1999)
has confirmed that health hazards associated with improper
disposal of solid waste include;
7
- harbouring and favouring rodents breeding and other
harmful reptiles
- empty can which favour mosquito breeding
- putrescible wastes emit offensive odour thus polluting
the air.
1.21.21.21.2 Statement of the problemStatement of the problemStatement of the problemStatement of the problem
Humans and other living organisms depend on a healthy
environment for good health. The Barrack’s road dumpsite
examined is situated very close to residential areas. These areas
use borehole water, and a nearby stream located closed to the
dumpsite for drinking and for other domestic activities. Soil
around the dumpsite is used for farming activities. Rapid
population growth and industrialization, coupled with
indiscriminate dumping of solid wastes at the site, with little or no
sound solid waste management plants at the study area have
contributed to increase the volume of solid wastes at the
dumpsite in an alarming rate. The different wastes types at the
dumpsite, possess different physical, chemical and biochemical
properties. The waste water produced from the decomposed
wastes materials each times it rains, may drain into the nearby
surface stream, may leach into the sub-surface soil and then into
the groundwater aquifers. During this process, the boreholes,
stream water and soil samples around the dumpsite may become
contaminated. This may be very possible in the study area
because the soil texture show that soil around the dumpsite and
even outside the dumpsite show very high percentage coarse
sand which is highly conducive to leachate transport. When
humans and other animals come into direct contact with the
contaminated samples they may face serious health challenges.
With the desire to know the present quality of the borehole water,
8
surface stream and soil around the dumpsite, the researcher
deemed it necessary to determine the physio-chemical
characteristics of leachate from the dumpsite, the borehole
water, surface stream and soil sample around the solid wastes
dumpsite which are known to impact on human health. The
results of this findings may reveal the present qualities of the
boreholes, surface stream and soil around the dumpsite.
1.31.31.31.3 Objective of studyObjective of studyObjective of studyObjective of study
1.3.11.3.11.3.11.3.1 General objectiveGeneral objectiveGeneral objectiveGeneral objective
To characterize leachate, groundwater, stream water and
soil in the vicinity of a municipal dumpsite at Uyo metropolis to
determined the level of impact of the dumpsite on the ambient
environment.
1.3.21.3.21.3.21.3.2 Specific objectiveSpecific objectiveSpecific objectiveSpecific objective
1) To assess and compare the physic-chemical properties of
leachate, borehole, surface stream and treated water
samples around the barrack’s road dumpsite with the
international standard for drinking water.
2) To assess and compare the heavy metal contents of soil
samples from the dumpsite, samples from the control site
(800m) and samples from 10 and 20m outside the dumpsite
in the north, south, west and east transects with the internal
standards.
3) To compare the physic-chemical contents and heavy metals
recorded for leachate, borehole water, surface stream
treated water and soil samples during the wet and dry
seasons.
9
1.41.41.41.4 Expected benefits of the studyExpected benefits of the studyExpected benefits of the studyExpected benefits of the study
This study is necessary because it is hoped that through its
outcome, the magnitude of the environmental contamination in
the study area will be highlighted.
To the author, this work is so important since it serves as a
medium through which he can address the numerous problems
associated with the waste dump site.
The outcome of this study may ginger the government to
adopt appropriate waste management strategies and control
measures over indiscriminate dumping of waste.
Further more, it is hoped that the findings of this study will
motivate other interested researchers in and outside the study
area; thus helping to broaden our knowledge which is a
prerequisite to formulation of effective control strategies in the
future.
Finally, the result of this findings will be included into the
limited literature of pollution studies in the study area, and to the
numerous existing literatures on studies around waste dumpsites.
1.51.51.51.5 Research questionsResearch questionsResearch questionsResearch questions
1) Why did you embark on pollution studies in the vicinity of
the chosen dumpsite?
2) Was the levels of physico-chemical parameters and
heavy metal in all the samples analysed within the
permissible limits?
3) Was there any variation in physico-chemical parameters
in all the samples analysed during the wet and dry
seasons?
4) Was there any significant difference in heavy metal
concentrations in soil at dumpsite compared with soil
outside the dumpsite?
10
1.61.61.61.6 Scope of the studyScope of the studyScope of the studyScope of the study
These findings, examined the physico-chemical and heavy metal
characteristics of leachate, borehole water, treated water,
stream water and soils at the vicinity of a municipal solid wastes
dumpsite at Uyo metropolis, Akwa-Ibom State, SE Nigeria, during
the wet and dry seasons.
11
CHAPTER TWOCHAPTER TWOCHAPTER TWOCHAPTER TWO
LITERATURE REVIEWLITERATURE REVIEWLITERATURE REVIEWLITERATURE REVIEW
Numerous scholars from various fields made a lot of
contributions on the issues of environmental impact of waste
through sound programs or studies. In the quest for previous
knowledge, the investigator attempted to review a number of
these literatures from journals, books, electronic devices,
newspapers and magazines.
2.12.12.12.1 Meaning of wasteMeaning of wasteMeaning of wasteMeaning of waste
Waste is anything which has no use or is not profitable to
the disposer. Nevertheless, anything produced in excess, be it
food remains, metal scrabs, papers, plastics, cans etc.
2.1.12.1.12.1.12.1.1 Solid wasteSolid wasteSolid wasteSolid waste
The United States Environmental Protection Agency (EPA),
defined solid waste as “any useless, unwanted or discarded
materials with insufficient liquid content to be free flowing.
According to Federal Environmental Protection Agency (FEPA)
(1995), solid wastes are useless, unwanted or discarded
materials that arise from man’s activities and cannot be
discarded through sewer pipe.
Solid wastes can be classified in a number of ways, on the
basis of source, environmental risk, utility and physical property.
On the basis of source which is commonly used, solid waste are
classified as municipal solid waste, industrial solid waste,
agricultural waste, healthcare waste, radioactive waste, human
and animal waste.
The generation of solid wastes from household, industries,
market, abattoir, and shops result in improving the standard of
12
living of the inhabitants. These solid wastes can as well
contaminate groundwater.
Although solid waste is an asset when properly managed,
its volume has continued to increase tremendously in recent
times in Nigeria as a result of socio-economic development
including wage increases. In Nigeria, much has been and is being
invested on municipal solid waste in cities. But little progress,
has been made because of several financial, technological and
institutional constraints within the public and the private sectors
apart from erratic growth of housing unit in the inner core of
urban cities (Ojestina, 1999 and Sridhar et al., 1985).
Solid waste problem has received attention by many
environmental scientists and appreciable researchers have been
carried out on solid waste. Gilbert (1987) explained that most of
the studies on solid waste are aimed at evaluating the potential
problems associated with solid wastes and their impact on the
environment. Some of these efforts have brought lime-light on the
issues while others failed perhaps due to some short coming or
setback during the study.
In recent times, Awake Magazine (2000) alerted that New
York city alone produced enough garbage each year to bury the
city’s huge central park under four meters of refuse. The same
warning notes were made of the quantity of garbage produced by
the people of Germany annually. In India, the generation stood at
between 300 to 600g per person per day resulting in 850 to 1200
million Rupees being spent every year for waste disposal /
management.
Okpala (1986) in his study, correlated increase in solid
waste generation in the urban centers in Nigeria with increase in
population and finally discovered and concluded that there is a
direct relationship.
13
The Federal Ministry of Health (FMH) estimated that the
quantities of solid waste generation in some cities in Nigeria are
on the increase as shown in Table 1
TabTabTabTable 1 Nigerian Urban Cities; Projectle 1 Nigerian Urban Cities; Projectle 1 Nigerian Urban Cities; Projectle 1 Nigerian Urban Cities; Project
Volume of City Depot/Dumpsites (1982Volume of City Depot/Dumpsites (1982Volume of City Depot/Dumpsites (1982Volume of City Depot/Dumpsites (1982----2000)2000)2000)2000)
CityCityCityCity 1982198219821982 Tone/YearTone/YearTone/YearTone/Year
1985198519851985 Tone/YearTone/YearTone/YearTone/Year
1990199019901990 Tone/YearTone/YearTone/YearTone/Year
2000200020002000 Tone/YearTone/YearTone/YearTone/Year
Lagos 55991 61183 104305 106816
Ibadan 55221 60345 89687 91846
Kano 39855 43583 76553 82305
Kaduna 20019 21875 19212 57853
Onitsha 34785 38010 56493 64806
Port
Harcourt
51390 56155 60277 104943
Aba 54458 59508 92995 28631
Jos 18792 21438 24262 28631
Warri 43336 48747 42977 50886
Gasau 7671 8382 9261 9797
Potiskum 2761 3017 2498 2774
Uyo 5100 5573 3313 4453
Suleja 1227 1380 1376 1793
New Bussa 1726 1887 1165 4198
Source: (Akaeze 2001).
Natural water is inflicted with a wide variety of inorganic,
organic and biological pollutants, a significant fraction of which
come from improper wasted disposal. In Nigeria, a variety of
wastes originating from domestic and industrial sources find their
way into streams and rivers due to a weak enforcement of
existing legislation and lack of basic infrastructure, such as
sewers and hygienic disposal facilities (Sridhar and Ademoroti,
1984).
14
The non-free flowing or sticking nature of the solid wastes
gives rise to the accumulation of solid waste on some habitable
parts of the earth. Places with accumulated solid wastes are
called refuse dumps or a designed place for dumping of refuse is
known as sanitary landfill. (Eddy, et al., 2006).
2.22.22.22.2 Solid waste dumpsiteSolid waste dumpsiteSolid waste dumpsiteSolid waste dumpsite
A solid waste dump site is a selected site for the disposal of
solid waste. Open dumps and sanitary landfill are the most
peferred places for the disposal of solid waste.
2.2.12.2.12.2.12.2.1 Open dumps systemOpen dumps systemOpen dumps systemOpen dumps system
Open dumps are the oldest and most common way of
disposing of solid waste and although in recent years thousands
have been closed, many still are being used. In many cases, they
are located wherever land is available, without regard to safety,
health and aesthetic degradation. The waste is often piled as high
as equipment allows. In some instances, the refuse is ignited and
allowed to burn. In others, the refuse is periodically leveled and
compacted. As a general rule, open dumps tend to create a
nuisance by being unsightly, breeding pest, creating a health
hazard, polluting the air and sometimes polluting groundwater
and surface water (Keller, 1982).
In the developing world the prevailing method for the
disposal of municipal and domestic refuse is usually open
dumping, often coupled with waste burning with minimal effort
directed towards land filling practice e.g the use of daily cover
(Me-Stuart and Klinck, 1998).
15
2.2.22.2.22.2.22.2.2 Sanitary landfill systemSanitary landfill systemSanitary landfill systemSanitary landfill system
The term “sanitary landfill” was first used in the 1930s to
refer to the compacting of solid waste materials. Initially adopted
by New York City and Fresno, California, the sanitary landfill used
heavy earth moving equipment to compress waste materials and
then cover them with soil. The practice of covering solid waste
was evident in Greek civilization over 2,000 years ago, but the
Greek did it without compacting (Krug and Ham, 1997).
The term landfill refers to the physical facility, which has
been specifically designed, constructed and operated for the
disposal of waste. From the past to the present, disposal of waste
into landfills has been the preferred method of waste disposal
both from an economic and environmental point of view. Even
where well planned waste reduction, recycling and
transformation are in place. The residual waste from such
operations still ends up on a landfill. Therefore, landfills will
remain an integral part of the integrated waste management
strategy for a long time (Ejlertsson and svenssor, 1997).
2.32.32.32.3 Waste managemWaste managemWaste managemWaste managementententent
Waste year after year, decade after decade, more and more
is generated. And, as this precious time progresses, precious
space for it decreases. But some communities clearly identify
this problem, and they are saving space and saving money, and
therefore saving the environment as well. Waste management is a
vital component of the environmental movement. Everyone on the
planet contributes to the problem; therefore, everyone on the
planet can help contribute to the solution. That solution is, very
simply, land filling, reducing, reusing, and recycling and
composting of wastes.
16
2.3.1 Landfills2.3.1 Landfills2.3.1 Landfills2.3.1 Landfills
There are several different ways to manage the solid waste
produced in mining, processing, manufacturing and using
resources, but most can be categorized into two different
approaches. The high waste approach involves leaving it
somewhere, burning it or burying it (in a sanitary landfill or any
hole in the ground) the low-waste approach is two fold;
attempting to produce as little solid waste as possible, and
diverting as much solid waste away from landfills and incinerators
(Miller, 1990). Over the past few years, the former has been
viewed as cheap and irresponsible, and the latter has been
viewed as initially expensive but morally gratifying.
In Canada, many cities have several options besides land
filling (which is, unfortunately, the most popular method).
Recycling, composting, and incineration systems are working
now in various provinces (Anonymous, 1992).
2.3.22.3.22.3.22.3.2 Incineration Incineration Incineration Incineration
Incineration is the burning of solid waste in incinerators.
Burning solid waste in incinerators kills disease carrying
organisms and reduces the volume of waste by 90% and weight
by 75% in waste-to-energy incinerators, the heat released from
the burning of solid waste can be used to heat nearby buildings,
or sold to generate electricity. Unfortunately, the good news
ends there. Municipal solid waste (MSW) incinerators emit small
but noticeable amount of lead, cadmium, mercury and other toxic
substances into the air we breathe. The most frightening item
piped into the atmosphere are dioxins, which are carcinogenic
(Miller, 1990).
17
2.3.32.3.32.3.32.3.3 RecyclingRecyclingRecyclingRecycling
Recycling is the process of converting useless material into
a form that is useful. A mere 13% of American waste is recycled.
An equal amount is burned in incinerators, and the rest heads to
the dump (Anonymous, 1992). But recycling remains the most
popular environmental activity among the peoples of
industrialized nations, simple because we do it often as we throw
something away. Recycling programs are springing up in every
corner of the globe, recycle goods are being utilized and recycled
again, and Americans are at least doing something environmental
on a regular basis. These resource recovery programs extend the
globe’s mineral supply by reducing the amount of virgin materials
that need to be removed from the globe to meet the demand.
Resource recovery saves energy, causes minimal population and
land disruption, cuts waste disposal costs, and extends the life of
land fills by preventing waste from residing there. Once an item
has been used, recycled, and reprocessed, and appears on the
shelf a second time, It is said to be in its second life. Glass and
aluminum have unlimited lives – theoretically, they can be
recycled and reused forever. Plastic has approximately four
lives; usually beverage and laundry containers see their third or
fourth life in other forms, such as plastic picnic bench or plastic
park benches. Recycled paper, after the de-inking process, can
go about three lives; after that, the pulp fibres within the paper
degrade.
2.42.42.42.4 LeachatesLeachatesLeachatesLeachates
On the basis of numerous studies, it has been established
that as a result of biochemical decomposition of organic
substances and washing out of soluble minerals and organic
fractions contained in the waste materials on a landfill site by
18
precipitation and run-off waters, leachate is formed. Their
physical and chemical composition is determined by among other
things, deposited waste type, their properties and landfill
operation time and type (Bogchi, 2004; McBean, et. al., 1995.
Inspite of many safety devices (subsoil sealage, drainage)
leachate can get outside landfill area and penetrate the
aquiferous layer. The result of pollution can be visible even at
long distances from the landfill for many years (El-Fadel Bou-Zeid
and Chahine, 2002).
According to Ekpo et al., (1999), leachate can flow away
from the surface through fissures and coarse sediments or move
more slowly in an unsaturated zone consisting of intergranular
pathways, before entering ground water.
Leachate consists of high concentrations of physico-
chemicals which can pollute the soil, surface water and ground
water (Esmail et al., 2009).
Christensen et al., (1994) have identified the following
principal groups:
(a) Inorganic macro components calcium, magnesium,
sodium, potassium, ammonium, iron, manganese,
chloride, sulphate and bicarbonate.
(b) Heavy Metal; Cadmium (Cd), Chromium (Cr),
Copper (Cu), Lead (pb), nickel (Ni) and Zinc (Zn) in
trace amounts.
(c) Dissolved organic matter expressed as chemical
oxygen demand (COD) or total organic carbon
(TOC), including methane and volatile fatty acids.
(d) Anthropogenic organic compounds associated with
household and industrial use are generally present
in very low concentration these compounds
19
include, among others, aromatic hydrocarbons,
chlorinated solvents and phenols.
Temperature, pH, and dissolved oxygen (DO)
concentrations have an influence on the degree of toxicity on a
particular aquatic species. Helma, et al., (1996) revealed that
leachate in comparison to other industrial waste water,
groundwater and drinking water samples have shown the highest
genotoxic potentials. According to Ekpo, and Ibok (1999) once
groundwater and surface waters have been polluted by leachate,
it may be unsuitable as a source of portable water supply for
drinking and irrigation purposes.
Christensen et al., (1994) are of the opinion that pathogens
are not important in leachates. This conclusion appears to be
based on the published results of the very few investigations that
have focused on the occurrence and survival of pathogenic
bacteria in leachate and associated contaminant plumes.
Andreottaha and Cannas (1992) noted that the presence of faecal
indicator bacteria generally decreases with increasing landfill
age and that growth is inhibited at temperatures greater than
60oC. The study of Robinson (1996) indicated that the existence
of pathogens in properly operated landfill sites is unlikely to
constitute a major environmental or public health hazard. The
results of the present study tend to indicate that thermotolerant
bacteria, an indicator of faecal contamination, are generally
present in very low concentrations in the leachate investigated.
However, there is compelling evidence that caliform bacteria
rapidly multiply where leachate is entering a shallow, oxygenate
ground water system. This strongly suggest that the leachate may
be a source of pathogenic contamination given suitable aquifer
conditions (Mathess et al., 1988).
20
2.4.12.4.12.4.12.4.1 Leachate productionLeachate productionLeachate productionLeachate production
2.4.1.12.4.1.12.4.1.12.4.1.1 Influence of sourceInfluence of sourceInfluence of sourceInfluence of source
In the developing world municipal solid waste (MSW) tend to
have a very high content of putrescibe materials compared to a
typical developed city in the Western world (Klinck, Crawford and
Noy, 1995). Ultimately it is the waste composition that influences
the chemistry of the leachate generated. Waste density is
between 2 and 5 times higher than industralised countries and
moisture content is well in excess of 30% i.e the waste is
generally at field capacity and any infiltration produces leachate.
Indeed, Blight et al., (1989) and Blight et al., (1992) have shown
that even in water deficient areas there is a potential to generate
leachate because of high organic matter contents. The
widespread practice of informal recycling may explain to some
extend this very high organic matter content too. This recycling
process often begins even before the waste leaves its point of
origin.
2.4.1.22.4.1.22.4.1.22.4.1.2 ProcessesProcessesProcessesProcesses
Leachate quality varies throughout the operation life of a
landfill and long after its closure. There are three broad and
overlapping phases of waste decomposition, in which chemical
and biological processes give rise to both landfill gas, and
leachate during and beyond the active life of the site (Robinson,
1996);
Phase 1: oxygen present in the waste is rapidly consumed
by aerobic decomposition. This phase typically lasts less than one
month and is normally relatively unimportant interms of leachate
quality. This phase is exothermic and high temperatures may be
produced. This speeds up the later phase if some heat is
retained.
21
Phase 2: anaerobic and facultative micro-organisms
hydrolyze cellulose and other putrescible materials such as
complex carbohydrates fats and proteins to soluble compounds.
These hydrolysis products are then fermented during
acidogenesis to various intermediates such as fatty acids and
alcohol. Finally, these intermediate are converted during
acetogenesis to acetic acid, carbondioxide and hydrogen. The
high putrescible material in the waste may sustain acidogenic
conditions for quite some time and provide a rich feed stock for
methanogens subsequently. Leachate from this acidic phase
typically contains a high concentration of free fatty acids. It
therefore has low pH of 5 or 6 and will dissolve other components
of the wastes, such as the alkaline earths and heavy metals,
which can mobilize in the leachate, possibly as fatty acid
complexes Christensen et al., (1994) and Gintalltas and Huyck
(1993). The leachate also contains high concentrations of
ammonical nitrogen and has both high organic carbon
concentrations and a biochemical oxygen demand (BOD).
Phase 3: Conditions become more anaerobic as waste
degradation and methanogenic bacteria gradually become
established. These start to consume the simple organic
compounds producing a mixture of carbon dioxide and methane
that is released as landfill gas. The carbondioxide tends to
dissolve producing the very high bicarbonate concentrations
typical of phase 3 leachate. The rate at which this phase
becomes established is controlled by a number of factors,
including the content of readily putrescible waste. Since the
majority of the organic compounds are high molecular weight
humic and fulvic acids, the leachates are characterized by
relatively low BOD values. Amnoniacal nitrogen continues to be
released by areas of the waste phase 2 is continuing, and
22
generally remains at high concentrations in the leachate. Falling
redox potential immobilizes many metals as sulphides in the
waste (Pohland, et al., 1993; Belevi and Baccini, 1992).
2.4.1.32.4.1.32.4.1.32.4.1.3 Timing of landfill stabilizationTiming of landfill stabilizationTiming of landfill stabilizationTiming of landfill stabilization
Data collected from a large number of sites in Wisconsin
(King and Ham, 1997) suggested that the leachate tended to
remain in the acidogenic phase during active operation of the
site, but that leachate concentrations tended to be very variable.
After site closure a clearer pattern was followed indicating the
onset of the methonogenic phase. The conductivity continue to
rise during the life time of the landfill and then remains more or
less constant, probably for at least 10 years. Chloride
concentrations, which is a major contributor of the conductivity
(SEC) responded in a similar manner. BOD, and to a lesser
extend COD, tends to fall rapidly within the first few years after
closure. The pH tends to be very variable but generally reaches 7
or more within 4 years of closure. Heavy metals concentration
e.g cadmium tends to decrease after about three years. Overall
individual sites appear to move from acidogenic to anaerobic
conditions in an average of 4 years after closure or 10 years after
waste was first placed, with small sites taking only 4 to 7 years.
The speed at which waste degradation proceeds is a function of
moisture content (thought to be the most important),
temperature, waste density, age, composition, waste particle
size, substrate availability, pH, microbial population and microbial
nutrient availability. Sub tropical and tropical arid regions are
found in many developing countries and the presence of large soil
moisture deficits means that the potential for leachate generation
may be quite low. The lack of moisture may also permit the
ingress of oxygen, delaying the onset of anaerobic conditions,
23
and inhibit bacterial movement; movement of nutrients, buffering
reactions, substrate dissolution and cellulose swelling. All of
these factors may delay the onset of methanogenic conditions
and production of less toxic leachate, while at the same time
increase time to stabilization.
2.52.52.52.5 PollutionPollutionPollutionPollution
According to the Meriam – Webster online Dictionary,
pollution is the introduction of contaminants into an environment
that causes instability, disorder, harm or discomfort to the
ecosystem i.e physical system or living organisms.
Pollution can take the form of chemical substances or
energy, such as noise, heat, or light. Pollutants, the elements of
pollution can be foreign substances or energies, or naturally
occurring; when naturally occurring, they are considered
contaminants, when they exceed natural levels. Pollution is often
classed as point source or non point source pollution.
2.5.12.5.12.5.12.5.1 Ancient culturesAncient culturesAncient culturesAncient cultures
Air pollution has always been with us soot found on ceilings
of prehistoric caves provides evidence of the high levels of
pollution associated with inadequate ventilation of open fires
(Spengle, John and Sexton, 1983). The forgoing of metals appear
to be a key turning point in the creation of significant
environmental pollution.
2.5.22.5.22.5.22.5.2 Official acknowledgementOfficial acknowledgementOfficial acknowledgementOfficial acknowledgement
The earliest known writings concerned with pollution were
written between 9th and 13th centuries by Persian scientists such
as Muhammad ibn Zakarija Razi (Rhazes), Ibn Sina (Avicenna),
and al-Masihi or were Arabic medical treatises written by
24
physicians such as al-kindi (Alkindus), Qustaibn Luga (Costa ben
Luca), Ibn Al-Jazzar, al-Tamini, Ali ibn Ridwan, Ibn Jumay, Isaac
Israeli ben Solomon, Abd-el-latif, Ibn al-Quff, and Ibn al-Nafis.
Their works covered a number of subjects related to pollution
such as air contamination, water contamination, soil
contamination, solid waste mishandling, and environmental
assessments of certain localities (L-Gari, 2002).
King Edward 1 of England banned the burning of sea-coal
by proclamation in London in 1272, after its smoke had become a
problem (David Urbinato, 1994; Deadly Smog, 2003). But the fuel
was so common in England that this earliest of names for it was
acquired because it could be carted away from some shores by
the wheelbarrow. Air pollution continue to be a problem in
England, especially later during the industrial revolution, and
extending into the recent past with the Great Smog of 1952. This
same city also recorded one of the earlier extreme cases of water
quality problems with the Great stink on the thames of 1858,
which led to construction of the London seawage system soon
after wards.
It was the industrial revolution that gave birth to
environmental pollution as we know it today the emergence of
great factories and consumption of immense quantities of coal
and other fossil fuels gave rise to the unprecedented air pollution
and the large volume of industrial chemical discharges added to
the growing load of untreated human waste. Chicago and
Cincinnati were the first two American cities to enact laws
ensuring cleaner air in 1881 other cities followed around the
country until early in the 20th century, when the short lived office
of Air pollution was created under the Department of the interior.
Extreme Smog events were experienced by the cities of Los
25
Angeles and Donara, Pennsylvania in the late 1940s, serving as
another public reminder (James and Berthany 2006).
2.5.32.5.32.5.32.5.3 Modern awarenessModern awarenessModern awarenessModern awareness
Pollution become a popular issue after World War II, due to
radioactive fallout from atomic warfare and testing then a non-
nuclear event, the Great Smog of 1952 in London, killed at least
4000 people BBC News (1952).
This prompted some of the first major modern
environmental legislation, the clean Air Act of 1956. Pollution
began to draw major public attention in the United States
between the 1950s and early 1970s, when congress passed the
Noise Control Act, the clean Air Act; the clean water Act and the
National Environmental policy Act. Bad bouts of local pollution
help increase consciousness. PCB dumping in the Hudson River
resulted in a ban by the Environmental Protection Agency (EPA)
on consumption of its fish in 1974. Long term dioxin
contamination at love canal starting in 1947 became a national
news story in 1978 and led to the super fund legislation of 1980.
Legal proceeding in the 1990s helped bring to light chromium – 6
releases in California, the champions of whose victims became
famous. The pollution of industrial land gave rise to the name
brown field, a term now common in city planning. DDT was
banned in most of the developed world after the publication of
Rachel Carson’s silent spring.
The development of nuclear science introduced radioactive
contamination, which can remain lethally radioactive for
hundreds of thousand of years. Lake Karachay, named by the
world watch institute as the “most polluted spot” on earth, served
as a disposal site for the Soviet Union throughout the 1950s and
26
1960s. Second place may go to the area of Chelyabinsk U.S.S.R
(Environmental performance report, 2001).
Nuclear weapons continued to be tested in the cold war,
sometimes near inhabited areas, especially in the earlier stages
of their development. The toll on the worst affected populations
and the growth since then in understanding about the critical
threat to human health posed by radioactivity has also been a
prohibitive complication associated with nuclear power. Though
extreme care is practiced in that industry, the potential for
disaster suggested by incidents such as those at three Mile Island
and Chernobyl pose a lingering specter of public mistrust. One
legacy of nuclear testing before most forms were banned has
been significantly raised levels of background radiation.
International catastrophes such as the wreck of the Amoco Cadiz
oil tanker off the coast of Brittany in 1978 and the Bhopal disaster
in 1984 have demonstrated the universality of such events and
the scale on which efforts to address them needed to engage. The
borderless nature of atmosphere and oceans inevitably resulted
in the implication of pollution on a planetary level with the issue of
global warming. Most recently the term persistent organic
pollutant (POP) has come to describe a group of chemicals such
as PBDES and PFCs among others. Though their effects remain
somewhat less well understood owing to lack of experimental
data, they have been detected in various ecological habitats far
removed from industrial activity such as the Arctic,
demonstrating diffusion and bioaccumulation after only a
relatively brief period of wide spread use.
Growing evidence of local and global pollution and an
increasingly informed public over time have given rise to
environmentalism and environmental movement, which generally
seek to limit human impact on the environment.
27
2.5.42.5.42.5.42.5.4 Forms of pollutionForms of pollutionForms of pollutionForms of pollution
The major forms of pollution are listed below along with
particular pollutants relevant to each of them.
• Air pollution, the release of chemicals and particulars into
the atmosphere. Common gaseous air pollutants include
carbon dioxide sulphur dioxide, chloro fluorocarbons
(CFCS) and nitrogen oxides produced by industry and motor
vehicles. Photochemical ozone and Smog are created as
nitrogen oxides and hydrocarbons react to sunlight.
Particulate matter, or fine dust is characterized by their
micrometer size. PM10 to PM25
• Light pollution; includes light trespass, over illumination and
astronomical interference.
• Noise pollution, which encompasses roadway noise, aircraft
noise, industrial noise as well as high-intensity sonar.
• Soil contamination; occurs when chemicals are released by
spill or underground leakage. Among the most significant
soil contaminants are hydrocarbon, heavy metals,
herbicides, pesticides, and chlorinated hydrocarbons.
• Radioactive contamination; result from 20th century
activities in atomic physics, such as nuclear power
generation and nuclear weapons research, manufacture
and deployment.
• Thermal pollution, is a temperature change in natural water
bodies caused by human influence, such as use of water as
coolant in a power plant.
• Visual pollution, which can refer to the presence of
overhead power lines, motorway bill board, scarred
landforms (as from strip mining), open storage of trash or
municipal solid waste.
28
• Water pollution, by the release of waste products and
contaminants into surface runoff into river drainage
systems, leaching into ground water, liquid spills,
wastewater discharges, eutrophication and littering.
2.62.62.62.6 Water pollutionWater pollutionWater pollutionWater pollution
Water pollution is the contamination of water bodies (e.g
lakes, rivers, oceans and ground water). Comprising over 70% of
the Earth’s surface, water is undoubtedly the most precious
natural resource that exists on our planet. Without the seemingly
invaluable compound comprised of hydrogen and oxygen, life on
Earth would be non existent. It is essential for everything on our
planet to grow and prosper. Although we humans recognize this
fact, we disregard it by polluting our rivers, lakes, oceans, and
streams. Subsequently, we are slowly harming our planet to the
point where organisms are dying at a very alarming rate. In
addition to innocent organisms dying off, our drinking water has
become greatly affected as its our ability to use water for
recreational purposes. In order to combat water pollution, we
must understand the problems and become part of the solution.
In addition to the acute problems of water pollution in
developing countries, industrialized countries continue to
struggle with pollution problems as well. In most recent national
reports on water quality in the United States, 45% of assessed
stream miles, 47% of assessed lakes and 32% of assessed bay
and estuarine square miles were classified as polluted (United
States Environmental Protection Agency Report, 2007).
29
2.6.12.6.12.6.12.6.1 Water pollution categoriesWater pollution categoriesWater pollution categoriesWater pollution categories
Surface waters and groundwater have often been studied
and managed as separate resources, although they are
interrelated.
2.6.1.12.6.1.12.6.1.12.6.1.1 Surface water pollution Surface water pollution Surface water pollution Surface water pollution
Any water body occurring on land surface is referred to as
surface water. Examples are; streams, rivers, lakes, seas and
oceans. Domestic, municipal, trade, industrial and agricultural
wastes are factors causing surface water pollution. The
magnitude of the wastes dumped into water bodies increases
during rainy season. Most of the municipal wastes, particularly
the solids, which are left scattered here and there during dry
season, are flushed by storm water during rainfall and are carried
enmass into nearby rivers/streams which flow into larger river
and finally into seas/oceans. Liquid waste from chemical
industries and agricultural run off flow through drains into rivers
or streams to cause pollution.
When rivers and streams flow through cities and receive
liquid and solid wastes, their qualities become poor due to
pollution by the wastes; the greater the pollution load, the poorer
the water quality.
30
Table 2.0 shows the water quality of two rivers in Nigeria before
and within the city.
S/N Rivers Temperature (oC)
pH Values
Suspended Particles
Dissolved Solids, Mg/L
BOD Mg/L
Total Coliform Per 100ml
1
Ogun River (Abeokuta) Before entering town
28.0
7.5
49.0
7.2
3.1
12x103
2 Within the town
28.0
7.1
126.0
2.8
12.1
38x107
1
Ogun pa river (Ibadan) Before entering town
24.6
6.9
14.0
6.7
3.1
3.7 x 103
2 Within the town
26.4
7.2
118.0
0.0
73.8
32.2x106
Source:Source:Source:Source: Ademoroti (1980)Ademoroti (1980)Ademoroti (1980)Ademoroti (1980)
31
2.6.1.22.6.1.22.6.1.22.6.1.2 Groundwater pollutionGroundwater pollutionGroundwater pollutionGroundwater pollution
Ninety five percent of all fresh water on earth is
groundwater. Groundwater is found in natural rock formations.
These formations, called aquifers, are a vital natural resource
with many uses. Nationally, 53% of the population relies on
groundwater as a source of drinking water. In rural areas, this
figure is even higher. Eighty one percent of community water is
dependent on ground water. Analysis of groundwater
contamination may focus on the soil characteristics and site
geology, hydrogeology, hydrology and the nature of the
contaminants.
2.6.22.6.22.6.22.6.2 Causes of water pollutionCauses of water pollutionCauses of water pollutionCauses of water pollution
The specific contaminants leading to pollution in water
include a wide spectrum of chemicals, pathogens, and physical or
sensory changes such as elevated temperature and
discolouration. While many of the chemicals and substances that
are regulated may be naturally occurring (Cadmium, sodium, iron,
manganese etc) the concentration is often the key in determining
what is a natural component of water, and what is a contaminant.
Oxygen depleting substances may be natural materials such as
plant matter (e.g leaves and grass) as well as man – made
chemicals. Other natural and anthropogenic substances may
cause turbidity (cloudiness) which block light and disrupt plant
growth, and clogs the gills of some fish species (EPA Report,
2005)
Many of the chemical substances are toxic. Pathogens can
produce water borne diseases in either human or animal host (C.
Michael Hogan, 2010). Alteration of water’s physical chemistry
include acidity (change in pH), electrical conductivity,
temperature, and eutrophication. Eutrophication is an increase in
32
the concentration of chemicals nutrients in an ecosystem to an
extend that increases in the primary productivity of the
ecosystem. Depending on the degree of eutriphication,
subsequent negative environmental effects such as anoxia
(oxygen depletion) and severe reduction in water quality may
occur, affecting fish and other animal populations.
2.6.2.12.6.2.12.6.2.12.6.2.1 PathPathPathPathoooogens gens gens gens
Coliform bacteria are commonly used bacterial indicator of
water pollution, although not an actual cause of disease. Other
microorganisms sometimes found in surface waters which have
caused human health problems include:
• Burkholderia pseudomallei
• Crytosporidium parvum
• Giardia lamblia
• Salmonella
• Novo virus and other viruses
• Parasitic worms (helminthes). (Reston, VA, 2001; Schueler,
Thomas R, 2000).
High levels of pathogens may result from inadequately treated
sewage discharges (EPA, 2009). Thus can be caused by a sewage
plant designed with less than secondary treatment (more typical
in less developed countries). In developed countries, older cities
with aging infrastructure may have leaky sewage collection
systems (pipes, pumps, values), which can cause sanitary sewer
overflows. Some cities also have combined sewers, which may
discharge untreated sewage during rain storms (EPA, Report
2004). Pathogen discharges may also be caused by poorly
managed livestock operations.
33
2.6.2.22.6.2.22.6.2.22.6.2.2 Chemical and other contaminantsChemical and other contaminantsChemical and other contaminantsChemical and other contaminants
Contaminants may include organic and inorganic substances.
Organic water pollutants include:
• Detergents
• Disinfection by –products found in chemically disinfected
drinking water, such as chloroform
• Food processing waste, which include oxygen demanding
substances, fats and grease.
• Insecticides and herbicides, a huge range of organohalides
and other chemical compounds
• Petroleum hydrocarbons, including fuels (gasoline, diesel
fuel, jet fuels, and fuel oil) and lubricants (motor oil) and fuel
combustion by products, from storm water run off (Allen
and Robert 2001).
• Tree and bush debris from logging operations
• Volatile organic compounds (VOCs), such as industrial
solvents, from improper storage. Chlorinated solvents,
which are dense non-aqueous phase liquids (DNAPLS), may
fall to the bottom of reservoirs, since they don’t mix well
with water and are denser.
• Various chemical compounds found in personal hygiene and
cosmetic products.
Inorganic water pollutants include:
• Acidity caused by industrial discharges (especially sulfur
dioxide from power plants).
• Ammonia from food processing waste
• Chemical waste as industrial by-products
• Fertilizers containing nutrients like nitrates and
phosphates, which are found in storm-water run off from
agriculture, as well as commercial and residential use
34
• Heavy metals from motor vehicles (via urban storm run off)
(Allen and Robert, 2001; Schueler, Thomas, 2000).
2.6.32.6.32.6.32.6.3 Measurement of water pollution Measurement of water pollution Measurement of water pollution Measurement of water pollution
Water pollution may be analysed through several broad
categories of methods; physical, chemical and biological.
Most involve collection of samples, followed by specialized
analytical tests. Some methods may be concluded in situ, without
sampling, such as temperature. Government agencies and
research organizations have published standardized, validated
analytical tests methods to facilitate the comparability of results
from disparate testing events (Clescerl, et al., 2001).
Physical testing involves common physical tests of water
temperature, solids concentration like total suspended solids
(TSS) and turbidity. Chemical testing involves the test of pH,
biochemical oxygen demand (BOD), chemical oxygen demand
(COD), nutrients (nitrate and phosphorus compounds), metals
(including copper, zinc, cadmium, lead and mercury, oil and
grease, total petroleum hydrocarbon (TPH), and pesticides.
Biological testing involves the use of plant, animal, and /or
microbial indicators to monitor the health of an aquatic
ecosystem.
2.2.2.2.7777 Water qualityWater qualityWater qualityWater quality
Water quality is closely linked to water use and to the state
of economic development. In industrialized countries bacterial
contamination of surface water caused serious health problems
in major cities throughout the mid 1800s (Mac Donnell, 1996). The
term water quality is a universally used expression which has an
enormous meaning and explanation. Each person has put interest
in water for his particular use which could involve domestic,
35
commercial industrial or recreational pursuit. Since the desirable
characteristics of water vary with its intended use, there is
frequent unsatisfactory relationship among the users of water
where quality is concerned. As such, in discussing a public
supply, a housewife may declare the water to be suitable quality
while and industrialist may find that quality unfit. Thus the
paramount aim of water treatment is to produce an adequate and
continuous supply of the desired quality for the purpose of water
required (Oni, 1980).
All other water uses must be subordinate to one’s need for a
healthy fluid for his consumption. Water for drinking and food
preparation must be free from mineral and organic substances
producing adverse physiological effect. To encourage man to
drink this health promoting liquid, the water must be aesthetically
acceptable. For example it should be free from apparent
turbidity, colour, odour and from any objectionable taste. These
properties are caused by inorganic salts, decaying vegetation
and dissolved gases.
2.82.82.82.8 Soil/Land pollutionSoil/Land pollutionSoil/Land pollutionSoil/Land pollution
Soil pollution refers to the alteration in soil caused by
removal or addition of substance and factors that decreases its
productivity, quality of plants and ground water. Negative soil
pollution is the reduction in soil productivity due to erosion and
over-use while positive soil pollution is reduction in soil
productivity due to addition of undesirable substances.
Landscape pollution is the conversion of fertile land into barren
one by dumping wastes over it.
36
2.8.12.8.12.8.12.8.1 Causes of soil pollutionCauses of soil pollutionCauses of soil pollutionCauses of soil pollution
Soil contamination is caused by the presence of xenobiotic
(Human made) chemicals or other alteration in the natural soil
environment. This type of contamination typically arises from the
rupture of underground storage tanks, application of pesticides,
percolation of contaminated surface water to subsurface strata,
oil and fuel dumping, leaching of leachates from landfills or direct
discharge of industrial waste to the soil, as well as excessive use
of agricultural fertilizers. The most common chemicals involve
are petroleum hydrocarbons, solvents pesticides, lead and other
heavy metals.
The occurrence of this phenomenon is correlated with the
degree of industrialization and intensities of chemical usage.
According to Snyder (2005), treated sewage sludge, known in the
industry as biosolids, has become controversial as a fertilizer to
land. As it is the by-product of sewage treatment, it generally
contains contaminants such as organisms, pesticides, and heavy
metals than other soil. There is also controversy surrounding the
contamination of fertilizers with heavy metals; (Davenport et al.,
2005).
2.8.22.8.22.8.22.8.2 EffectsEffectsEffectsEffects
2.8.2.12.8.2.12.8.2.12.8.2.1 Health eHealth eHealth eHealth effectsffectsffectsffects
Contaminated or polluted soil directly affects human health
through direct contact with soil or via inhalation of soil
contaminant which have vaporized. Potentially greater threats
are posed by the infiltration of soil contaminants into groundwater
aquifers used for human consumption, sometimes in areas
apparently far removed from any apparent source of above
ground contamination.
37
Health consequences from exposure to soil contamination
vary greatly depending on pollutant type, pathway of attack and
vulnerability of the exposed population. Chronic exposure to
chromium, lead, and other metals petroleum solvents and many
pesticides and herbicides formulations can be carcinogenic, and
cause congenital disorder, or can cause other chronic health
conditions. Industrial or man-made concentrations of naturally
occurring substances, such as nitrate and ammonia associated
with livestock manure from agricultural operation have also been
identified as health hazards in soil and groundwater.
Chronic exposure to benzenes at sufficient concentrations
is known to be associated with higher incidence of leukemia.
Mercury and Cyclodienes are known to induce higher incidence
of kidney damage, some irreversible Cyclodienes is linked to liver
toxicity. Organophosphates and carbonates can induce a chain of
responses leading to neuro-muscular blockage. Many
chlorinated solvents induce liver changes, kidney changes and
depressed of the central nervous system. There is an entire
spectrum of further health effect such as headache, fatigue, eye
irritation and skin rash for the above cited and other chemicals.
At sufficient dosage a large number of soil contaminants can
cause death via direct contact, inhalation or ingestion of
contaminants in ground water contaminated through soil (Article
on soil contamination in China, 2009).
2.8.2.22.8.2.22.8.2.22.8.2.2 Ecosystem effectsEcosystem effectsEcosystem effectsEcosystem effects
Not unexpectedly, soil contaminants can have significant
deleterious consequences for ecosystem. (Michael, et al, 1973).
There is radical soil chemistry changes which can arise from the
presence of many hazardous chemicals even at low
concentrations of the contaminant species. These changes can
38
manifest in the alteration of metabolism of endemic
microorganisms and arthropods resident in a given soil
environment. The result can be virtual eradication of some of the
primary food chain; which in turn have major consequences on
predators or consumer species. Even if the chemical effect on
lower life is small, the lower pyramid levels of the food chain may
ingest alien chemicals, which normally become more
concentrated for each consuming rung of the food chain. Many of
these effects are now well known, such as the concentration of
persistent DDT material for avain consumers, leading to
weakening of egg shells, increased chick mortality and potential
extinction of species.
2.8.2.32.8.2.32.8.2.32.8.2.3 Clean up optionsClean up optionsClean up optionsClean up options
Clean or remediation is analysed by environmental
scientists who utilize field measurement of soil chemicals and
also apply computer models for analyzing transport and fate of
the soil chemicals (Crupta, et al., 1982). There are several
principal strategies for remediation.
• Excavate soil and take it to a disposal site away from ready
path ways for human or sensitive ecosystem. This
technique also applies to dredging of bay muds containing
toxins.
• Aeration of soils at the contaminated site (with attendant
risk of creating air pollution).
• Thermal remediation by introduction of heat to raise
temperatures subsurface sufficiently high to volatilize
chemical contaminants out of the soil for vapour extraction.
• Bioremediation, involve microbial digestion of certain
organic chemicals. The techniques used in bioremediation
39
includes land farming, biostimulation and bioaugmenting
soil biota with commercially available microflora.
• Extraction of groundwater or soil vapour with active electro
chemical system, with subsequent stripping of the
contaminants from the extract.
• Phyto remediation, or using plants (such as willow) to
extract heavy metals.
2.92.92.92.9 Review of Related Literature Review of Related Literature Review of Related Literature Review of Related Literature
Christensen et al., (1992), Ehrig (1989), Aminia et al., (2004)
and Banar et al., (2006) examined the physico-chamical
parameters in leachate from various dump sites. Their results
revealed high electrical conductivities (EC), chemical oxygen
demand (COD), Biological oxygen Demand (BOD), high anions
concentrations including ammonia nitrogen (NH3-N). The heavy
metals concentrations varied amongst the different leachates
examined. Some of the leachate samples recorded low heavy
metals contents whereas leachate from other dumpsites
recorded high heavy metals contents.
Abdulahi (2000), in his finding on the physico-chemical
parameters of leachate revealed, low anions concentrations.
Yoshida et al., (2002) recorded low electrical conductivities (EC),
BOD and COD values. The findings of Abdulahi (2000) and
Yoshida et al., (2002) contradicts the mean concentrations
recorded by Christensen et al., (1992), Ehrig (1989), and Banar et
al., (2006).
Esmail et al., (2009), also examined the physiochemical
parameters of leachates in land fills at Yemen city Romania. The
results revealed that most of the leachates examined recorded
high physico-chemical parameters, with high heavy metal
contents, high anions, total dissolved solids (TDS), biochemical
40
oxygen demand (BOD), total suspended solids (TSS) and low
dissolved oxygen concentrations. Similar results were reported
by Ekpo et al., (1999), Christensen et al., (1992), Ehrig (1989)
Aminia et al ., (2004) and Banar et al ., (2006).
Talalaj and Dziens (2006) examined the physico chemical
contents in leachates from wastes dumpsites in Bialystock,
Poland. The results revealed the following trend: Cl > NH4+ > dry
residue > TDS > total hardness > calcium hardness > Mg hardness
> SO42- > PO43- Fe> B> CN > heavy metals. The contents for heavy
metals were ordered as follows: Zn> Ni> Cu> Cd.
The above series were closed to the ones obtained by
Szymanski (1998), in his study on leachates on Sianonwo landfill
of Koszalin. It was also noted that some leachates analysed at the
Bialystock landfill had lower NO-3, ���, TDS and Zn contents
compared to other landfill leachate in Poland.
Nubi, et al., (2008) also examined the physico-chemical
parameters in leachates from the Akpanran dumpsite. The results
revealed that the leachates samples analysed was generally high
in all the assessed physico-parameters; with relatively low pH of
4-7. The heavy metals contents in the leachate showed the
following trend: Zn> pb> Cr > Cu> Ni> Cd.
Another findings on the physico-chemical characterization
of leachate was carried by Aluko, et al., (2003). The results
revealed variations in turbidity, suspended solids (SS) and
biochemical oxygen demand (BOD) during the wet and dry
season. The leachate sample recorded high SS, BOD and
ammonia nitgrogen (NH3N) which exceeded permissible limits
and low SO42-, NO3- and PO43- which were below the
recommended range. Except for iron (Fe), the heavy metals
concentration in the leachates were below the normal range.
41
Esmail et al., (2009) examined the physico-chemical
parameters in ground water around some waste dumpsites in
Yemen city, Romania. The results revealed that four out five
examined boreholes recorded high heavy metals contents; Pb, Ni,
Cu, Cd, and high Ca, Mg, NH3, hardness and TDS concentrations.
The examined boreholes also recorded very high coliform
organisms which exceeded the permissible limits for portable
water.
Talalaj et al., (2006) examined the physico-chemical
parameters in ground water around a solid waste dumpsite at
Bialystock, Poland. The results revealed high cadmium (Cd),
Copper (Cu) and Zinc (Zn) concentrations. Abu and Osoma (2001)
also investigated the effects of leachate from major landfills in
northern Jordan on groundwater. The results revealed high
physico-chemical parameters in ground water samples.
Omofonmwan and Esiegbe (2009) also examined ground
water sample, around selected waste disposal sites in Benin
Metropolis, Nigeria. The results revealed, showed variations
amongst the different boreholes sample examined. Some of the
boreholes recorded low physico-chemicals parameters while
others recorded high concentrations for some parameters which
exceeded permissible limits.
Ekpo, et al., (1999) investigated the physico-chemical
contents in ground water around two wastes dumpsites at
Calabar Metropolis, Nigeria. The results revealed low physico-
chemical parameters for the examined boreholes.
Earnest, et al., (2010) also examined groundwater in
selected wastes dumpsite areas in Warri, Nigeria. The results
revealed, mild to high iron concentrations and acidity. Longe and
Enekwechi (2007) recorded high anions and heavy metals
42
contents in ground water down gradient of the solid waste
dumpsite.
Nubi et al., (2008) examined the impact assessment of
dumpsite leachates on the quality of surface water in Ona-Ara
Local Government, Oyo State, Nigeria. The findings revealed high
BOD, COD, PO43-, SO42- and high metal contents for the upstream
region. The metals concentrations recorded by Nubi et al., (2008)
for the assessed surface water samples were higher than the
metals concentrations recorded for some streams and lakes in
Ibadan as reported by Mombeshora, et al., (1981).
Adefemi and Awokunmi (2009) studied the impact of
municipal solid waste on soils around Ado-Ekiti metropolis, Ekiti
state, Nigeria, the results revealed high Fe, Pb and Zn contents in
soil at the center of the dumpsite and lower heavy metals
concentrations for soils at 20m away from the dumpsite. Similar
observations have been reported by Alloway (1971) and Amusan,
Ige and Olawafe (2005) on the Bodeosi dumpsite and Obafemi
Awolowo University Central refuse dumpsite respectively.
Among all the parameters examined, Iron recorded the highest
mean concentrations. Amusan et al., (2005) have reported earlier
that iron is the most abundant mineral in Nigeria soil.
The results of Adefemi et al., (2009) indicated that due to the
upland location of the examined dumpsite, the low land
community recorded high levels of physico-chemical parameters.
This may cause a significantly environmental impact particularly
to the lowland community.
Elaigwu, et al., (2007) studied the impact of municipal solid
waste dumpsite on the surrounding soil. The results revealed high
soil pH, soil organic matter and cation exchange capacity (CEC),
the levels of cadmium (Cd), Copper (Cu), lead (Pb) and Iron (Fe)
recorded in some waste disposal sites were above the
43
permissible limits given by international environmental protection
agencies. (EPA)
Similar results for heavy metals on wastes dumpsite soils have
been reported by Adefemi et al., (2009), on soils around selected
dumpsites in Ado-Ekiti and Alloway (1971) and Amusen et al.,
(2005) on the Bodeosi dumpsite and Obafemi Awolowo, University
dumpsite.
Nduka, et al., (2006) examined soils around five dumpsite in
Awka. It was noticed that sites A and C recorded high levels of
arsenic and lead respectively. Site D had high level of iron (Fe)
and Sodium (Na). Generally, the metals levels exceeded the limits
set forth by the US environmental protection agencies.
Anikwe and Nwobodo (2001) examined the long term (20
years) effects of municipal solid waste dumpsite on soil
properties in Abakiliki. The results recorded high physico-
chemical parameters in dumpsite soil compared to non-dumpsite
soil. This therefore, indicates that long term dumping of waste
may influence soil properties and productivity.
Eddy et al., (2006) also examined the elemental composition
of soil in selected dumpsite within Ikot Ekpene. The results
revealed that the concentrations of micro-nutrients, heavy
metals, exchangeable cations (Na and K) and essential non-
metals Phosphorus and nitrogen, were higher than the WHO
recommended limit for soil at the center of the dumpsite
compared to soils outside the dumpsite.
Akpan (2001) in his study compared the results of the
analysis of soil extracted from Uyo municipality with the WHO and
Food and Agricultural organization (FAO) (1996) standards and
admitted that soils from Uyo metropolis were polluted because of
waste dumps on the land. Akaeze (2001) on the analysis of soil
samples from Uyo metropolis revealed that Lead, Copper and Iron
44
were present in high concentrations in the soil and thus may also
contaminate soil water.
Stephens et al., (1972) reported the presence of heavy
metals As, Cr, and Cu in the soil to be associated with sludge
incineration, Smith (1996) stated that heavy metals can be
introduced into the environment through high tension cables,
municipal solid wastes and building materials. According to Smith
et al., (1996), Continuous disposal of municipal solid wastes on
soil may increased heavy metal contents in it. Thus heavy metals
may have harmful effects on soil organisms, crops and human
health.
45
CHAPTER THREECHAPTER THREECHAPTER THREECHAPTER THREE
MATERIALS AND METHODS MATERIALS AND METHODS MATERIALS AND METHODS MATERIALS AND METHODS
3.13.13.13.1 The study areaThe study areaThe study areaThe study area
The Map of Uyo municipality showing the study area is
indicated in Figure 1. Uyo municipality is the capital territory of
Akwa-Ibom State, South Eastern Nigeria. Apart from being a
booming businesses center in the state, it also links Akwa-Ibom
State with Abia, Imo, Cross River and Rivers States, South
Eastern Nigeria. The location matrix, is between latitude 5o and
5o171, and longitude 7o and 7o501. The Uyo municipal dumpsite is
located at the Barracks road area. It is an open dump sited in an
upland area, with the east transect located low land of the
dumpsite. The area is located in the sub-equatorial belt
characterized by the wet and dry seasons. The wet season begins
in April and ends in September with a peak in June and July, while
the dry season starts from October and ends in March. Its
topography is basically plane except a few sloppy terrain which
ends in a ravine. The area lacks functional drainage system, and
it is always flooded each time it rains heavily. Due to poor
disposal of solid wastes, the area is faced with the problem of
indiscriminate dumping of wastes on streets and roads. The
vegetation is however, affected by activities like agriculture,
construction and urbanization. Apart from the wind system, other
climatic parameters such as mean annual rainfall and
temperature, global radiation reflections coefficient to mention a
few also influence the study area.
46
Figure 3.1: Map of Uyo Urban showing Dump Site
Source : Culled from Akwa Ibom State Map (2006)
47
3.23.23.23.2 Materials and methodsMaterials and methodsMaterials and methodsMaterials and methods
3.2.13.2.13.2.13.2.1 SamplingSamplingSamplingSampling
The map of the study area and the photographs showing a
section of the dumpsite and the stream water examined, are
shown in Figures 2, 3 and 4. The scale and range of pollution in
the examined area have been observed in leachates, soil, ground
and surface water samples in the vicinity of the solid waste dump
site. Samples were collected in the months of July, August and
September (2010) during period of heavy rainfall representing
wet season and in December, 2010, January, 2011 and February
2011 during period of high sun shine (Dry season). Leachate
monitoring station within the dumpsite was constructed
according to that designed by Ekpo et al., (1999). Leachate
sample was collected at the dumpsite itself, stored in 500ml
polyethylene bottle for physico-chemical characterization.
Groundwater, surface stream and treated water samples were
also collected into 500ml sterile bottles, and a few drops of
concentrated nitric acid was added to all the samples for heavy
metal analysis. Soil samples were collected from ten different
points, at the dumpsite (DS) itself, at 10 and 20m north, South,
East and West transects of the dumpsite, and from 800m away
from the dumpsite to serve as control. These soil samples were
placed inside polyethylene bags and covered with aluminium foil.
All the samples were then transported in a cool box to be stored
under suitable temperature until analysis. Tables 3 to 9 shows the
locations and characteristic features of the sampling points.
FIG. 3.2FIG. 3.2FIG. 3.2FIG. 3.2: SKETCH MAP OF THE STUDY AREA: SKETCH MAP OF THE STUDY AREA: SKETCH MAP OF THE STUDY AREA: SKETCH MAP OF THE STUDY AREA: SKETCH MAP OF THE STUDY AREA: SKETCH MAP OF THE STUDY AREA: SKETCH MAP OF THE STUDY AREA: SKETCH MAP OF THE STUDY AREA
48
49
Plate 1: Cross Section of the Barracks Road solid wastes
dumpsite at Uyo Metropolis Akwa Ibom State, Nigeria
Plate 2: A cross section of the surface stream in the vicinity of
the solid waste dumpsite
A cross section of the surface stream in the vicinity of
the solid waste dumpsite
50
A cross section of the surface stream in the vicinity of
51
3.2.23.2.23.2.23.2.2 Samples treatmentSamples treatmentSamples treatmentSamples treatment
Samples were treated and concentrated into small volumes
to increase the sensitivity of the method of determination.
3.2.2.13.2.2.13.2.2.13.2.2.1 Treatment of water samples for Treatment of water samples for Treatment of water samples for Treatment of water samples for heavy metal analysisheavy metal analysisheavy metal analysisheavy metal analysis
100ml of the water sample from different locations were
measured into a digestion flask, 5ml of concentrated
tetraoxosulphate (VI) acid was added to the sample and heated in
a hot plate for 1 hour. The digested sample was then cooled and
thereafter quantitatively transferred to 100ml volumetric flask
and the volume adjusted to 100ml with distilled water (Ekpo et al.,
1999). The digested sample was taken for the determination of
the heavy metal contents using Atomic Absorption
Spectrophotometer (AAS).
3.2.33.2.33.2.33.2.3 Treatment of leachate sampleTreatment of leachate sampleTreatment of leachate sampleTreatment of leachate sample
Leachate sample was digested according to the method
recommended by Radiojevic and Bashkin (1999), Ekpo et al.,
(1999). This method is fast, cheap, simple and suitable. 100ml of
the leachate sample was transferred into a beaker and 5ml
concentrated HNO3 was added. The beaker and its content was
placed on a hot plate and evaporated down to 20ml. The beaker
was cooled and another 5ml concentrated HNO3 was added and
heated until the solution appeared light coloured or clear, this
was done in a fume cupboard. The beaker wall and watch glass
were washed with distilled water and the solution filtered to
remove some insoluble materials. The volume was adjusted to
100ml mark with distilled water.
52
3.2.43.2.43.2.43.2.4 Treatment of Soil SamplesTreatment of Soil SamplesTreatment of Soil SamplesTreatment of Soil Samples
The soil particulates samples were air dried and then
passed through 1mm stainless steel sieve. One gram of each
sample was put into 150ml conical flask, a mixture of
concentrated HN03: HClO4: HF in the ratio 3:1:3 was added
(Nwajei and Gagophien, 2000). The mixture was placed on a hot
plate for three hours at 80oC. The digest was filtered into 100ml
standard flask and made to mark with deionized water.
3.2.53.2.53.2.53.2.5 Preparation of stock solutions (1000ppm)Preparation of stock solutions (1000ppm)Preparation of stock solutions (1000ppm)Preparation of stock solutions (1000ppm)
Weighed masses of salts of different metals each was used
to prepare a stock solution of (1000ppm). Each mass of salt was
dissolved in distilled water or in dilute acid or base for salts which
were insoluble into 100ml distilled water. The solution in the
beaker was transferred into 1000ml standard flask and made up
to the mark with 1:1 HCl solution to obtain 1000ppm solution of
the metal. Varying volumes of the stock solutions were
transferred into 1000ml standard flask to prepare working
solution of different concentrations in ppm. The absorbances of
the standard solutions were used to plot the calibration curves,
which were used to determine the concentrations of the sample
solutions by extrapolation.
3.2.63.2.63.2.63.2.6 Chemical analysisChemical analysisChemical analysisChemical analysis
The dependent variables analysed were pH, temperature,
conductivity, salinity, dissolved oxygen (DO), biochemical oxygen
demand (BOD5), chemical oxygen demand (COD), total dissolved
solid (TDS), total suspended solid (TSS), nitrate, nitrite,
phosphate, sulphate, chloride, calcium, potassium, magnesium,
sodium, and heavy metals concentrations. Sample measurements
were done in replicates.
53
3.2.6.13.2.6.13.2.6.13.2.6.1 Determination of pHDetermination of pHDetermination of pHDetermination of pH and temperatureand temperatureand temperatureand temperature
pH and temperature were determine using WTW pH
Electrode. The pH meter was calibrated using HACH (1997)
buffers of pH 4.0, 7.0, and 10,0; according to the manufacturer
specifications.
3.2.6.23.2.6.23.2.6.23.2.6.2 Determination of chemical oxygen demand (COD)Determination of chemical oxygen demand (COD)Determination of chemical oxygen demand (COD)Determination of chemical oxygen demand (COD)
Chemical oxygen demand was determined by titration method
Procedure:
(i) Take reflux flask to it 1ml of concentrated H2SO4 and
20ml of sample and mix.
(ii) Add 10ml of potassium dichromate (K2Cr2O7)
(iii) Mix the content thoroughly and reflux for 2 hours.
(iv) Cool and wash down the condenser. Dilute the mixture to
100ml by adding distilled water.
(v) Add 3 drops of ferroin indicator and titrate with ferrous
ammonium sulphate solution, till the color change from
green to red. Which is the end point.
(vi) Perform the same procedure with “blank” using distilled
water instead of the sample.
COD = (V1-V2) X Normality of X 8000 (mg/l) __ ammonium sulphate_______ Volume of sample
Where V1 is the volume at end point for sample titration, and
V2 is the volume at end point for blank titration.
3.2.6.33.2.6.33.2.6.33.2.6.3 Determination of dissolved oxygen (DO) concentrationDetermination of dissolved oxygen (DO) concentrationDetermination of dissolved oxygen (DO) concentrationDetermination of dissolved oxygen (DO) concentration
Dissolved oxygen was measured with Jenway Model 1970
waterproof DO meter. Dissolved oxygen meter was calibrated
prior to measurement with appropriate traceable calibration
54
solution of (5% HCl) in accordance with the manufacturers
specifications. This was measured on site by direct reading. The
probe was immerse into the water sample, the switch was turned
on. The display was allowed to show a stable value and result was
recorded in mg/L.
3.2.6.43.2.6.43.2.6.43.2.6.4 Determination of biochemical Determination of biochemical Determination of biochemical Determination of biochemical oxygen demand (BODoxygen demand (BODoxygen demand (BODoxygen demand (BOD5555) ) ) )
concentrationconcentrationconcentrationconcentration
Biochemical oxygen demand (BOD5) was determined as the
difference in dissolved oxygen (DO) before and after incubation of
the water sample at 20oC for 5 days.
Calculation
BOD5 = X – Y mg/l
Where X = Initial dissolved oxygen in the water sample
Y = Final dissolved oxygen in the water sample
3.2.6.53.2.6.53.2.6.53.2.6.5 Determination of total dissolved solidsDetermination of total dissolved solidsDetermination of total dissolved solidsDetermination of total dissolved solids,,,, conductivity and conductivity and conductivity and conductivity and salinity.salinity.salinity.salinity.
Conductivity and salinity were determined using a CO150
conductivity meter according to the manufacturer specification.
The conductivity meter was calibrated using the potassium
chloride solution as provided by the manufacturer (HACH, 1997).
55
3.2.6.63.2.6.63.2.6.63.2.6.6 Determination of major anions concentrationsDetermination of major anions concentrationsDetermination of major anions concentrationsDetermination of major anions concentrations
The concentrations of phosphate (PO43-), nitrate (NO3-),
nitrite (NO2-) and ammonium nitrogen (NH4+-N) were determined
using a DR/2010 HACH portable Data logging UV
spectrophotometer according to the manufacturer specifications.
3.2.6.6.13.2.6.6.13.2.6.6.13.2.6.6.1 Determination of phosphate (PODetermination of phosphate (PODetermination of phosphate (PODetermination of phosphate (PO44443333----) concentration) concentration) concentration) concentration
Phosphate was determined colorimetrically by the
spectrophotometric method.
Procedure: To 50ml of filtered sample, 5ml of mixed molybdenum
blue reagent was added and shaken immediately. After 15 minute
preferably, the absorbance of the blue colour solution was
measured against a blank at 470nm and the concentration in mg/l
noted.
3.2.6.6.23.2.6.6.23.2.6.6.23.2.6.6.2 Determination of nitrate (NODetermination of nitrate (NODetermination of nitrate (NODetermination of nitrate (NO3333----) concentrations) concentrations) concentrations) concentrations
Nitrate was determined colorimetrically by the
spectrophotometric method according to the manufacturer
specification.
Procedure: To the 50ml prepared solution, 2ml of
phenoldisulphonic acid reagent was added and mixed thoroughly
and allowed for 5 minutes. 1ml of 1-naphthyl ethylene diamine-
(NED) reagent was then added and the absorbance was
measured after 15-20 minutes at 540nm against a blank and the
concentrations taken in mg/l.
3.2.6.6.33.2.6.6.33.2.6.6.33.2.6.6.3 DeDeDeDetermination of sulphate termination of sulphate termination of sulphate termination of sulphate (SOSOSOSO44442222----) concentrations) concentrations) concentrations) concentrations
Sulphate was determined by spectrophotometric method
using Ba(NO3)2 as precipitant (APHA, 1998).
Procedure: 100cm3 of sample was measured into a beaker,
2ml conditioning reagent was added and the solution was stirred
56
for 1 minute at constant speed. 5g of Ba(NO3)2 salt was weighed
and added to the mixture with a constant stirring for 1 minute. At
the end of the stirring, the solution was turned into a cuvette for
the measurement of SO42- concentration at a wavelength of
420nm against a blank.
3.2.6.6.43.2.6.6.43.2.6.6.43.2.6.6.4 Determination of chlorides (CDetermination of chlorides (CDetermination of chlorides (CDetermination of chlorides (Cllll----) Concentrations) Concentrations) Concentrations) Concentrations
Chloride was determined by titration with AgNO3 solution
using potassium chromate as indicator (APHA, 1998).
Procedure: 100ml of sample was measured into a conical
flask, 1ml of hydrogen peroxide was added to hinder SO32- or
thiosulphate interferences. The solution was adjusted to pH of 8
with NaOH solution. 1ml of dichromate indicator was added to the
solution and titrated with silver nitrate solution to the pinkish
yellow end point. A blank titration was also carried out.
Hence, the chloride determination was calculated as
follows:
Mg/L = (B-A) X N
Volume of sample (ml)
Where A = ml titration for the blank sample
B = ml titration for the sample
N = normality of silver nitrate
3.2.6.6.53.2.6.6.53.2.6.6.53.2.6.6.5 Determination of NitriteDetermination of NitriteDetermination of NitriteDetermination of Nitrite
50ml of samples was measured into a beaker and the pH
was adjusted to 7, 1ml of sulfanilamide solution was added and
allowed to stand between 2-8 minutes. 1ml 1-naphthyl ethylene
diamine (NED) reagent was added to the mixture and allowed to
stand for 20 minutes. The mixed solution was them transferred
into a cuvette and the wavelength of the spectrophotometer was
adjusted to 543nm for the nitrite concentration determination.
57
3.2.6.6.6 Determination of Ammo3.2.6.6.6 Determination of Ammo3.2.6.6.6 Determination of Ammo3.2.6.6.6 Determination of Ammonium (Direct Neslerization)nium (Direct Neslerization)nium (Direct Neslerization)nium (Direct Neslerization)
2ml of Nessler reagent was added to 50ml of sample. The
mixture was mixed thoroughly well and left to stand for 10
minutes. The concentration of ammonium was read at 425nm
against a blank.
3.2.73.2.73.2.73.2.7 Determination of Sodium (Na) and Determination of Sodium (Na) and Determination of Sodium (Na) and Determination of Sodium (Na) and Potassium (Potassium (Potassium (Potassium (KKKK) ) ) ) concentrations.concentrations.concentrations.concentrations.
Sodium and potassium concentrations were determined
using flame photometer (PFP7). According to the standard
methods of (APHA, 1998) and Ekpo et al., (1999).
3.2.83.2.83.2.83.2.8 Determination of heavy metals concentrationsDetermination of heavy metals concentrationsDetermination of heavy metals concentrationsDetermination of heavy metals concentrations
Heavy metals (Fe, Mn, Co, Zn, Cu, Cr, Cd, Pb) were
determined using Atomic Absorption spectrophotometer (AAS,
Unicom 969) according to the standard methods of (APHA, 1998)
and Ekpo et al., (1999). The spectrophotometer was checked for
malfunctioning by passing standard solutions of all the
parameters to be measured; Blank samples (deionized water)
were passed between every three successful measurements to
check for any eventual contamination or abnormal response of
the equipment.
3.33.33.33.3 Data Analysis TechniquesData Analysis TechniquesData Analysis TechniquesData Analysis Techniques
The data obtained from this study was analysed using spss
soft wear version 15. The mean values were used to compare with
the WHO (2004) standards whereas the independent t-test values
were used to compare the mean values obtained during the dry
season with values obtained during the wet season, and also to
compare mean values obtained for soil at dumpsite with soil
outside the dumpsite at P<0.05.
58
CHAPTER FOURCHAPTER FOURCHAPTER FOURCHAPTER FOUR
RESULTS AND DISCUSSIONRESULTS AND DISCUSSIONRESULTS AND DISCUSSIONRESULTS AND DISCUSSION
4.14.14.14.1 Means and standard deviations of physical, chemiMeans and standard deviations of physical, chemiMeans and standard deviations of physical, chemiMeans and standard deviations of physical, chemical,cal,cal,cal, and and and and heavy metal contents iheavy metal contents iheavy metal contents iheavy metal contents in leachate, groundwater, stream n leachate, groundwater, stream n leachate, groundwater, stream n leachate, groundwater, stream water and treated water samples during wet and dry water and treated water samples during wet and dry water and treated water samples during wet and dry water and treated water samples during wet and dry seasons.seasons.seasons.seasons.
The means and standard deviations of selected physic-
chemical and heavy metal contents in leachate, groundwater,
stream water and treated water samples during the wet and dry
seasons in the vicinity of the waste disposal site are as shown in
Tables 3 to 8.
4.1.14.1.14.1.14.1.1 MeanMeanMeanMean concentrations of pH, temperature, turbidity, concentrations of pH, temperature, turbidity, concentrations of pH, temperature, turbidity, concentrations of pH, temperature, turbidity, salinity and conductivity in leachate, ground, stream salinity and conductivity in leachate, ground, stream salinity and conductivity in leachate, ground, stream salinity and conductivity in leachate, ground, stream and treatment water samples.and treatment water samples.and treatment water samples.and treatment water samples.
Tables 4.1 and 4.2 shows the means and standard deviation
of pH, temperature, salinity and conductivity in leachate,
groundwater, stream and treated water samples during wet and
dry seasons. The mean pH recorded in leachate sample range
from 5.13 to 7.55 during the dry and wet season. The highest
mean pH value was recorded in leachate sample during the wet
season (7.55) while the lowest pH value was measured in
leachate sample during the dry season (5.13). The mean pH
values recorded for all the boreholes during the wet season range
between 5.54 to 6.09 whereas during the dry, the values
decreased slightly to 5.40 to 5.67. Stream water sample recorded
a mean pH value which range from 6.50 to 6.67 during the dry and
wet season while the treated water sample used as a control
recorded values of 6.10 to 6.40 during the dry and wet seasons
(Tables 4.1 and 4.2). There was no significant difference (p > 0.05)
in pH values between the wet and dry season for all the samples
analyzed.
59
TABLETABLETABLETABLE 4444.1:.1:.1:.1: Physical parameters of leachate, surface waterPhysical parameters of leachate, surface waterPhysical parameters of leachate, surface waterPhysical parameters of leachate, surface water (SW), borehole water (BH) (SW), borehole water (BH) (SW), borehole water (BH) (SW), borehole water (BH) and treated waterand treated waterand treated waterand treated water(TW)(TW)(TW)(TW) during wet seasonduring wet seasonduring wet seasonduring wet season
(WET SEASON)(WET SEASON)(WET SEASON)(WET SEASON)
ParameterParameterParameterParameter Location and Location and Location and Location and CoordinatesCoordinatesCoordinatesCoordinates
pHpHpHpH TemperatureTemperatureTemperatureTemperature ((((ooooCCCC))))
TurbidityTurbidityTurbidityTurbidity (FTU)(FTU)(FTU)(FTU)
SalinitySalinitySalinitySalinity (mg/l)(mg/l)(mg/l)(mg/l)
ConductivityConductivityConductivityConductivity (µs/cm)(µs/cm)(µs/cm)(µs/cm)
Leachate Barrack Rd. Dumpsite 05o02’34”N 07o56’01”E
7.55 ± 1.10 24.73 ±1.10 141.46±29.52 3.51 ± 0.56 2518.2 ± 40.75
BH1 Udo Street 05o02’28”N 07o56’01”E
6.09 ± 0.30 24.3 ± 0.67 0.48 ± 0.19 0.22 ± 0.08 62.9 ± 38.3
BH2 Old Stadium Rd 05o02’22”N 07o55’55”E
6.03 ± 0.34 23.73 ± 0.21 0.75 ± 0.19 0.18 ± 0.09 37.4 ± 4.79
BH3 Effiong Udo Street 05o02’20”N 07o55’51”E
5.69 ± 0.17 23.7 ± 0.21 1.25 ± 0.54 0.19 ± 0.07 46.0 ± 5.0
BH4 Effiong Udo Street 05o02’21”N 07o55’49”E
5.54 ± 0.33 24.1 ± 0.28 0.45 ± 0.48 0.19 ± 0.08 39.97 ± 3.49
Stream water (SW)
Along Udo village Road 05o03’08”N 07o56’11”E
6.67 ± 0.35 24.2 ± 0.54 1.95 ± 0.43 0.3 ± 0.01 79.2 ± 12.1
Treated water (TW)
Imatan Street 05o02’23”N 07o55’53”E
6.40 ± 0.31 23.97 ± 0.12 0.05 ± 0.006 0.08 ± 0.01 32.7 ± 5.1
BH = Borehole
60
TABLE 4TABLE 4TABLE 4TABLE 4.2:.2:.2:.2: Physical parameters of leachPhysical parameters of leachPhysical parameters of leachPhysical parameters of leachate, surface water, borehole water ate, surface water, borehole water ate, surface water, borehole water ate, surface water, borehole water and treated water during dry and treated water during dry and treated water during dry and treated water during dry
seasonseasonseasonseason
(DRY SEASON)(DRY SEASON)(DRY SEASON)(DRY SEASON)
ParameterParameterParameterParameter pHpHpHpH Temperature (Temperature (Temperature (Temperature (0000c)c)c)c) TurbidityTurbidityTurbidityTurbidity
(FTU)(FTU)(FTU)(FTU)
SalinitySalinitySalinitySalinity
(mg/l)(mg/l)(mg/l)(mg/l)
ConductivityConductivityConductivityConductivity
(µs/cm)(µs/cm)(µs/cm)(µs/cm)
Leachate 5.13 ± 0.09 26.53 ± 0.05 171.17 ± 8.22 7.24 ± 0.26 2946.3 ± 64.10
BH1 5.53 ± 0.25 26.02 ± 0.35 0.65 ± 0.12 0.65 ± 0.03 47.8 ± 3.39
BH2 5.67 ± 1.07 25.8 ± 0.62 0.62 ± 1.08 0.5 ± 0.06 46.17 ± 4.77
BH3 5.4 ± 0.33 25.83 ± 0.62 0.73 ± 0.16 0.59 ± 0.01 42.33 ± 4.26
BH4 5.67 ± 0.09 25.97 ± 0.05 0.77 ± 0.09 0.55 ± 0.05 46.97 ± 2.86
Stream water 6.5 ± 0.36 26.1 ± 0.79 3.82 ± 1.0 0.98 ± 0.16 58.9 ± 6.90
Treated water 6.10 ± 0.1 25.33 ± 0.41 0.06 ± 0.01 0.06 ± 0.01 26.83 ± 1.17
61
The mean temperature values recorded for the leachate
samples range between 24.73 to 26.53oC during the wet and dry
seasons. The highest mean temperature values was recorded for
the leachate sample during the dry season (26.53oC) while the
lowest mean temperature value (23.73oC) was obtained in
borehole 2 (BH2) during the wet season. The mean temperature
values recorded for all the boreholes range from 23.70 to 24.3oC
during the wet season, while during the dry season the mean
temperature values range between 25.8 to 26.02oC. Stream
water samples recorded mean temperature values which range
between 24.2 to 26.1oC during the wet and dry seasons, while
treated water samples measured mean temperature values which
range from 23.97 to 25.33oC during the wet and dry seasons
(Tables 4.1 and 4.2). There was a significant increase in (p< 0.05)
the mean temperature values recorded during the dry season for
leachate, all the boreholes and treated water samples (fig. 4.2).
The mean turbidity values in leachates range from 141.46 to
171.17FTU during the wet and dry seasons. The highest mean
turbidity value was recorded for the leachate samples
(171.17FTU) while the lowest turbidity value was obtained in
treated water samples (0.05 FTU). The mean turbidity values
recorded for all the boreholes samples during the wet season
range from 0.45 to 1.25 FTU, while during the dry season, the
mean turbidity values range between 0.62 to 0.77 FTU. Stream
water samples measured turbidity values which range from 1.95
to 3.82 FTU during the wet and dry seasons, while treated water
samples measured values which range between 0.05 to 0.06 FTU
during the wet and dry seasons (Tables 4.1 and 4.2). Generally,
all the boreholes, stream water and treated water samples
62
measured very low turbidity values compared to leachate
samples in both seasons. There was no significant difference
(p>0.05) in turbidity values between the wet and dry season for
the leachate and water samples.
The mean salinity concentrations in leachate range between
3.51 to 7.24mg/l during the wet and dry seasons. The highest
mean salinity value was obtained in leachate sample (7.24mg/l)
while the lowest mean salinity value was recorded for the treated
water sample (0.08mg/l). All the boreholes recorded mean salinity
values which range from 0.18 to 0.22mg/l during the wet season
whereas during the dry season, the mean salinity values
increased to a range of 0.50 to 0.65mg/l. Stream water samples
measured salinity values which ranged from 0.30 to 0.98mg/l
during the wet and dry seasons, while treated water samples
recorded very low values which range between 0.06 to 0.08mg/l
during the dry and wet seasons (Tables 4.1 and 4.2). There was a
significant increase (p<0.05) in the salinity values during the dry
season for leachate, boreholes and stream water samples (fig.
4.4).
Leachate samples showed very high conductivity values.
Which range from 2518.2 to 2946.3 µs/cm during the wet and dry
seasons, while the treated water samples recorded the lowest
mean conductivity values which range from 26.83 to 32.7µs/cm
during the dry and wet seasons. All the boreholes measured
mean conductivities values which range from 37.4 to 62.9µs/cm
during the wet season, while during the dry season the range
values increased to a range of 42.33 to 47.80 µs/cm. The mean
conductivity values in the stream water samples range between
58.9 to 79.2µs/cm during the dry and wet seasons. There was a
63
significant increase (p<0.05) in mean conductivity values during
the dry season in the leachate sample.
The trend for pH in leachate, borehole water (BH), stream
water (SW) and treated water (TW) samples in the wet season is
as follows: Leachate > SW > BH1 > BH2 > TW > BH3 > BH4. During
the dry season, the trend was; SW > TW> BH2 > BH4 > B1 > BH3 >
leachate. For conductivity the trend recorded was; leachate > SW
> BH1 > BH3 > BH4 > BH2 > TW during the wet season, while during
the dry season, the trend was; leachate > SW > BH1 > BH4 > BH2 >
BH3 > TW. The trend for salinity in the samples was; leachate >
SW > BH1 > BH3 > BH4 > BH2 TW during the wet season, while in
the dry season, the trend is; leachates > SW > BH1 > BH3 > BH4 >
BH2 > TW. This trend is similar to the one recorded in the wet
season. The trend for turbidity in the samples was recorded as
follows; leachate > SW > BH3 > BH2 > BH1 > BH4 > TW. In the wet
season while during the dry season, the trend was, leachate > SW
> BH4 > BH3 > BH1 > BH2 > TW.
These trends revealed that the perameters compared
among the samples recorded very high concentration in leachate
followed by the stream water samples, and with low
concentrations in the treated water samples in both seasons.
These parameter vary among the different boreholes in both
seasons.
The comparisons of pH, temperature, turbidity, salinity and
conductivity are shown in figures 4.1– 4.5.
64
0
1
2
3
4
5
6
7
8
Leachate BH1 BH2 BH3 BH4 SW TW
pH
Water type
Fig. 4.1 Comparison of the pH of leachate, groundwater, stream water and treated water in
wet and dry season. Values are mean + SD, n = 3.
Wet
DryWHO standrd = 6.5 to 9.5
65
0
5
10
15
20
25
30
Leachate BH1 BH2 BH3 BH4 SW TW
Te
mp
era
ture
(D
eg
ree C
els
ius
)
Water type
Fig. 4.2 Comparison of the temperature of leachate, groundwater, stream water and treated water in
wet and dry season. Values are mean + SD, n = 3. *P<0.05 vs wet season.
Wet
Dry
* * * ***
WHO standard = 12 to 250C
66
0
20
40
60
80
100
120
140
160
180
200
Leachate BH1 BH2 BH3 BH4 SW TW
Tu
rbid
ity (
FT
U)
Water type
Fig. 4.3 Comparison of the turbidity of leachate, groundwater, stream water and treated water in
wet and dry season. Values are mean + SD, n = 3.
Wet
Dry
WHO standard = 25 FTU
67
0.0
1.0
2.0
3.0
4.0
5.0
6.0
7.0
8.0
9.0
Leachate BH1 BH2 BH3 BH4 SW TW
Sa
lin
ity (
pp
t)
Water type
Fig. 4.4 Comparison of the salinity of leachate, groundwater, stream water and treated water in
wet and dry season. Values are mean + SD, n = 3. *P<0.05 vs wet season.
Wet
Dry*
*
****
68
0
20
40
60
80
100
120
140
160
180
200
Leachate BH1 BH2 BH3 BH4 SW TW
Tu
rbid
ity (
FT
U)
Water type
Fig. 4.5 Comparison of the turbidity of leachate, groundwater, stream water and treated water in
wet and dry season. Values are mean + SD, n = 3.
Wet
Dry*
WHO standard = 1400µs/cm
69
4.1.24.1.24.1.24.1.2 Mean concentrations of DO, BODMean concentrations of DO, BODMean concentrations of DO, BODMean concentrations of DO, BOD5555 COD,TSS, TDS in leachate, COD,TSS, TDS in leachate, COD,TSS, TDS in leachate, COD,TSS, TDS in leachate,
groundwater, stream water and treated water samples in both groundwater, stream water and treated water samples in both groundwater, stream water and treated water samples in both groundwater, stream water and treated water samples in both
seasons.seasons.seasons.seasons.
Tables 4.3 and 4.4 shows the Means and standard deviations of
DO, BOD5, COD, TSS, and TDS in leachate, groundwater, stream water
and treated water samples in both seasons.
Leachate samples recorded the lowest mean value of DO in both
seasons. These mean values range between 1.73 to 2.77mg/l during the
wet and dry seasons. The highest mean DO values was measured in
treated water samples in both seasons. These values range between
6.23 to 6.6mg/l during the dry and wet seasons. Borehole samples
recorded mean DO concentrations which ranged from 5.13 to 6.1mg/l
during the wet season, while during the dry season, the DO
concentrations range between 5.43 to 5.77mg/l. The mean DO
concentrations recorded for the stream water samples range between
4.33 to 5.80mg/l during the dry and wet season (Tables 4.3 and 4.4).
There was no significant difference (p>0.05) observed between the
mean DO concentrations recorded during the wet and dry seasons for
all the samples analyzed.
The COD values recorded for the leachate samples (Tables 4.3
and 4.4) were higher than that recorded for the other samples
analysed. During the wet and dry seasons, the mean COD values
measured in the leachate samples range between 12.44 to 17.7mg/l.
Treated water samples recorded the lowest COD values which were
the same in both seasons (0.02mg/l). Boreholes samples recorded
mean COD concentrations which range from 0.09 to 0.12mg/l during
the wet season while during the dry season the values decreased to a
range of 0.06 to 0.08mg/l. The mean COD concentrations in the stream
water sample (Tables 4.4 and 4.4) range between 0.28 to 0.78mg/l.
There was a significant increase (p<0.05) in the mean COD
concentrations in leachate samples during the dry seasons (fig. 4.7).
Boreholes, stream water and treated water samples did not show any
significant difference in COD concentrations in both seasons.
70
TABLE 4.3TABLE 4.3TABLE 4.3TABLE 4.3: Mean: Mean: Mean: Meanssss and Standard and Standard and Standard and Standard ddddeviationeviationeviationeviationssss of some physical parameters of some physical parameters of some physical parameters of some physical parameters in Leachates, boreholein Leachates, boreholein Leachates, boreholein Leachates, borehole water, stream water, stream water, stream water, stream
water and Treated waterwater and Treated waterwater and Treated waterwater and Treated water samples samples samples samples during wet seasonduring wet seasonduring wet seasonduring wet season
(WET SEASON)(WET SEASON)(WET SEASON)(WET SEASON)
ParameterParameterParameterParameter DO (mg/l)DO (mg/l)DO (mg/l)DO (mg/l) COD (mg/l)COD (mg/l)COD (mg/l)COD (mg/l) BODBODBODBOD5555 (mg/l)(mg/l)(mg/l)(mg/l) Total Total Total Total Suspended Suspended Suspended Suspended
Solid (mg/l)Solid (mg/l)Solid (mg/l)Solid (mg/l)
TotalTotalTotalTotal Dissolved Dissolved Dissolved Dissolved
Solids(mg/l)Solids(mg/l)Solids(mg/l)Solids(mg/l)
Leachate 1.73 ± 0.56 12.44 ± 1.75 52.2 ± 11.9 125.2 ± 8.87 1709.5±19.2
BH1 5.93 ± 0.42 0.09 ± 0.03 0.68 ± 0.15 0.40 ± 3.64 55.16 ± 7.20
BH2 6.0 ± 0.28 0.11 ± 0.06 0.67 ± 0.32 0.31 ± 0.13 59.3 ± 6.47
BH3 5.13 ± 0.62 0.11 ± 0.09 0.74 ± 0.27 0.45 ± 0.26 51.17 ± 8.19
BH4 6.1 ± 0.29 0.12 ± 0.07 0.75 ± 0.01 0.40 ± 0.22 43.85±15.25
Stream water 5.8 ± 0.52 0.28 ± 0.25 1.32 ± 0.05 1.39 ± 1.00 63.28 ± 4.10
Treated water 6.6 ± 0.14 0.02 ± 0.41 0.81 ± 0.34 0.05 ± 0.03 41.16 ± 6.76
71
TABLE 4.4TABLE 4.4TABLE 4.4TABLE 4.4: Means : Means : Means : Means and and and and sssstandard tandard tandard tandard ddddeviationeviationeviationeviationssss of some physical parametersof some physical parametersof some physical parametersof some physical parameters in Leachates, in Leachates, in Leachates, in Leachates, boreholeboreholeboreholeborehole water, stream water, stream water, stream water, stream
water and Treated water water and Treated water water and Treated water water and Treated water samples samples samples samples during dry seasonduring dry seasonduring dry seasonduring dry season
(DRY SEASON)(DRY SEASON)(DRY SEASON)(DRY SEASON)
ParameterParameterParameterParameter DO (mg/l)DO (mg/l)DO (mg/l)DO (mg/l) COD (mg/l)COD (mg/l)COD (mg/l)COD (mg/l) BODBODBODBOD5555 (mg/l)(mg/l)(mg/l)(mg/l) Total Total Total Total ssssuspended uspended uspended uspended
Solid (mg/l)Solid (mg/l)Solid (mg/l)Solid (mg/l)
Total Total Total Total ddddissolved issolved issolved issolved
Solids(mg/l)Solids(mg/l)Solids(mg/l)Solids(mg/l)
Leachate 2.77 ± 0.26 17.7 ± 0.70 76.17 ± 7.34 159.61 ± 8.16 2043.2±67.77
BH1 5.77 ± 0.61 0.07 ± 0.01 0.51 ± 0.07 0.37 ± 0.04 53.3 ± 1.71
BH2 5.73 ± 0.38 0.07 ± 0.01 0.50 ± 0.05 0.38 ± 0.08 52.3 ± 1.63
BH3 5.43 ± 0.37 0.08 ± 0.010 0.50 ± 0.02 0.36 ± 0.02 51.27 ± 4.98
BH4 5.73 ± 0.94 0.06 ± 0.010 0.53 ± 0.08 0.44 ± 0.05 49.47 ± 1.52
Stream water 4.33 ± 0.23 0.78± 0.30 2.57 ± 0.12 4.53 ± 0.57 72 ± 7.28
Treated water 6.23 ± 0.21 0.02 ± 0.01 0.19 ± 0.03 0.07 ± 0.01 25.8 ± 0.85
72
The highest mean BOD5 concentrations (Tables 4.3 and 4.4)
was recorded for the leachate samples in both season with a
range of 52.2 to 76.17mg/l, while the treated water samples
recorded the lowest mean BOD5 concentrations which range
between 0.19 to 0.81mg/l during the dry and wet seasons.
Boreholes samples recorded mean BOD5 Concentrations which
range between 0.67 to 0.75mg/l during the wet season, while
during the dry season, the mean BOD5 values range between 0.50
to 0.53mg/l. Stream water sample recorded mean BOD5 values
which range from 1.32 to 2.57mg/l in both seasons.
The highest mean total suspended solids (TSS)
concentration was recorded for the leachate samples in both
seasons, with a range of 125.2 to 159.61mg/l. All the boreholes
and treated water samples recorded quite low TSS
concentrations. During the wet and dry season, the mean TSS
values recorded for the treated water samples range from 0.05 to
0.07mg/l (tables 4.3 and 4.4). Borehole samples during the wet
season measured mean TSS values which range between 0.40 to
0.45mg/l, and 0.37 to 0.44mg/l during the dry season. The mean
TSS values recorded for the stream water samples range
between 1.39 to 4.53mg/l during the wet and dry seasons. There
was no significant difference (p>0.05) in the mean TSS
concentrations recorded during the wet and dry seasons for
leachate, boreholes, stream water and treated water samples.
The mean values recorded for total dissolved solids (TDS) in
all the samples were higher than to the TSS values recorded in
both seasons. The highest mean TDS values was recorded for the
leachate samples during the wet and dry seasons with a range of
1709.5 to 2043.2mg/l, while the treated water samples, recorded
73
the lowest values during the wet and dry seasons, with mean
values ranging between 25.8 to 41.16mg/l. The mean TDS
concentrations in the borehole samples range between 43.85 to
59.3mg/l during the wet season while during the dry seasons, the
mean TDS values range between 49.47 to 53.3mg/l. The stream
water samples during the wet and dry season measured mean
TDS values which range between 63.28 to 72.0mg/l. Only the
leachate samples showed significant increase (p<0.05) in TDS
concentrations during the dry season (fig. 4.10). The general
trend for DO, BOD5 and COD in leachate, borehole, surface
stream and treated water samples in both seasons are as follows:
for leachate samples in both seasons it was; BOD5 > COD > DO.
For boreholes samples in both seasons the trend was; DO > BOD5,
> COD. Treated water and stream water samples in both seasons,
recorded similar trends to those in the borehole samples. The
comparisons of the TDS, DO, TSS, BOD5 and COD in leachate,
groundwater, stream water and treated water samples in both
seasons are shown in Figures (4.6 - 4.10) in both seasons.
74
0.0
1.0
2.0
3.0
4.0
5.0
6.0
7.0
8.0
Leachate BH1 BH2 BH3 BH4 SW TW
Dis
so
lve
d O
xyg
en
(m
g/L
)
Water type
Fig. 4.6 Comparison of the dissolved oxygen content of leachate, groundwater, stream water and treated water in
wet and dry season. Values are mean + SD, n = 3. *P<0.05 vs wet season.
Wet
Dry
*
WHO standard = 4.0mg/l
75
0
2
4
6
8
10
12
14
16
18
20
Leachate BH1 BH2 BH3 BH4 SW TW
CO
D (
mg
/L)
Water type
Fig. 4.7 Comparison of the COD of leachate, groundwater, stream water and treated water in
wet and dry season. Values are mean + SD, n = 3. *P<0.05 vs wet season.
Wet
Dry
*
76
0
10
20
30
40
50
60
70
80
90
Leachate BH1 BH2 BH3 BH4 SW TW
BO
D (
mg
/L)
Water type
Fig. 4.8 Comparison of the BOD5 of leachate, groundwater, stream water and treated water in
wet and dry season. Values are mean + SD, n = 3. *P<0.05 vs wet season.
Wet
Dry
*
WHO standard = 0.5mg/l
77
0
20
40
60
80
100
120
140
160
180
Leachate BH1 BH2 BH3 BH4 SW TW
To
tal S
us
pe
nd
ed
So
lid
s (
mg
/L)
Water type
Fig. 4.9 Comparison of the total suspended solids in leachate, groundwater, stream water and treated water in
wet and dry season. Values are mean + SD, n = 3.
Wet
Dry
78
0
500
1000
1500
2000
2500
Leachate BH1 BH2 BH3 BH4 SW TW
To
tal D
iss
olv
ed
So
lid
s (
mg
/L)
Water type
Fig. 4.10 Comparison of the total dissolved solids in leachate, groundwater, stream water and treated water in
wet and dry season. Values are mean + SD, n = 3. *P<0.05 vs wet season.
Wet
Dry
*
*
WHO standard = 500mg/l
79
4.1.34.1.34.1.34.1.3 Mean concentrations of Mean concentrations of Mean concentrations of Mean concentrations of selectedselectedselectedselected anions in leachate, anions in leachate, anions in leachate, anions in leachate,
groundwater, stream water and treated water samples during the groundwater, stream water and treated water samples during the groundwater, stream water and treated water samples during the groundwater, stream water and treated water samples during the
wet and dry season:wet and dry season:wet and dry season:wet and dry season:
Tables 4.5 and 4.6 shows the means and standard deviations
of selected anions in leachate boreholes, stream water and treated
water samples during the wet and dry seasons.
The highest mean nitrate concentration was recorded for the
leachate samples during the wet and dry season (Tables 4.5 and 4.6)
with a range of 74.03 to 87.83mg/l, whereas the lowest mean nitrate
concentrations was measured in the treated water samples with a
range of values between 3.33 to 3.37mg/l in the wet and dry
seasons. The mean nitrate concentrations measured in the borehole
samples during the wet season range from 4.27 to 4.80mg/l, while
during the dry season, these values slightly increased to a range of
5.6 to 6.20mg/l. Stream water samples recorded mean nitrate
concentrations which range from 6.57 to 7.67mg/l in the wet and dry
season. There was no significant difference (p>0.05) in nitrate
concentrations recorded for the leachate, groundwater, stream
water and treated water samples during the wet and dry seasons.
The highest mean nitrite concentration was recorded for the
leachate samples during the wet and dry seasons (Tables 4.5 and
4.6) with values ranging from 6.13 to 6.17mg/l, whereas the lowest
mean nitrite concentrations was recorded for the treated water
sample with a value of 0.01mg/l in both seasons. All the borehole
samples recorded very low nitrite concentrations like the treated
water samples with a mean concentration of 0.01mg/l in both
seasons. The mean nitrite concentrations recorded for the stream
water sample range between 0.04 to 0.07mg/l during the wet and dry
seasons. There was no significant difference (p>0.05) in nitrite
concentrations in leachate, groundwater, stream water and treated
water samples during the wet and dry seasons.
80
TABLE 4.5TABLE 4.5TABLE 4.5TABLE 4.5: Means and standard deviations : Means and standard deviations : Means and standard deviations : Means and standard deviations of mof mof mof major anions in leachate, borehole water, stream water ajor anions in leachate, borehole water, stream water ajor anions in leachate, borehole water, stream water ajor anions in leachate, borehole water, stream water and and and and
treated water treated water treated water treated water samples samples samples samples in wet season.in wet season.in wet season.in wet season.
ParameterParameterParameterParameter NitrateNitrateNitrateNitrate
(mg/l)(mg/l)(mg/l)(mg/l)
NitriteNitriteNitriteNitrite
(mg/l)(mg/l)(mg/l)(mg/l)
Ammonium Ammonium Ammonium Ammonium
(mg/l)(mg/l)(mg/l)(mg/l)
PhosphatePhosphatePhosphatePhosphate
(mg/l)(mg/l)(mg/l)(mg/l)
SulphateSulphateSulphateSulphate
(mg/l)(mg/l)(mg/l)(mg/l)
ChlorideChlorideChlorideChloride
(mg/l)(mg/l)(mg/l)(mg/l)
Leachate 74.03±4.64 6.17±0.56 2.80 ± 0.54 146.53±15.31 148.2±2.77 284.37±53.08
BH1 4.53 ± 0.54 0.01 0.38 ± 0.04 1.95 ± 0.11 3.32 ± 0.62 3.09 ± 0.13
BH2 4.27 ± 6.18 0.01 0.31 ± 0.07 2.17 ± 0.13 3.37 ± 0.53 3.17 ± 0.32
BH3 4.67 ± 0.47 0.01 0.38 ± 0.04 1.82 ± 0.29 3.55 ± 0.49 2.97 ± 0.10
BH4 4.80 ± 0.43 0.01 0.38 ± 0.02 1.94 ± 0.05 3.04 ± 0.12 3.03 ± 0.14
Stream water 6.57 ± 0.58 0.07±0.64 0.57 ± 0.06 4.21 ± 1.13 5.24 ± 0.44 2.97 ± 0.69
Treated water 3.33 ± 0.74 0.01 0.26 ± 0.04 0.04 ± 0.02 1.38 ± 0.48 2.43 ± 0.88
81
TABLE 4.6TABLE 4.6TABLE 4.6TABLE 4.6: Means and standard deviations : Means and standard deviations : Means and standard deviations : Means and standard deviations of major anions in leachate, of major anions in leachate, of major anions in leachate, of major anions in leachate, borehole waterborehole waterborehole waterborehole water, stream water, and , stream water, and , stream water, and , stream water, and
treated watertreated watertreated watertreated water samplessamplessamplessamples in dry season.in dry season.in dry season.in dry season.
ParameterParameterParameterParameter NitrateNitrateNitrateNitrate
(mg/l)(mg/l)(mg/l)(mg/l)
NitriteNitriteNitriteNitrite
(mg/l)(mg/l)(mg/l)(mg/l)
Ammonium Ammonium Ammonium Ammonium
(mg/l)(mg/l)(mg/l)(mg/l)
PhosphatePhosphatePhosphatePhosphate
(mg/l)(mg/l)(mg/l)(mg/l)
SulphateSulphateSulphateSulphate
(mg/l)(mg/l)(mg/l)(mg/l)
ChlorideChlorideChlorideChloride
(mg/l)(mg/l)(mg/l)(mg/l)
Leachate 87.83 ± 11.52 6.13±1.05 6.20 ± 3.16 126.2 ± 5.6 144.97±8.83 536 ± 52.5
BH1 6.10 ± 0.70 0.01 0.62 ± 0.40 1.19 ± 0.45 0.89 ± 0.41 4.25 ± 0.69
BH2 5.60 ± 0.59 0.01 0.66 ± 0.14 1.13 ± 0.62 1.45 ± 1.04 4.08 ± 0.52
BH3 6.20 ± 0.59 0.01 0.59 ± 0.19 1.15 ± 0.57 1.36 ± 0.79 3.80 ± 0.74
BH4 5.80 ± 1.00 0.01 0.63 ± 0.05 1.14 ± 0.48 1.19 ± 0.37 3.87 ± 0.98
Stream water 7.67 ± 2.08 0.04±0.01 1.79 ± 0.74 5.96 ± 4.26 4.98 ± 0.50 6.25 ± 2.40
Treated water 3.37 ± 0.82 0.01 0.09 ± 0.03 0.08 ± 0.09 0.08 ± 0.03 1.51 ± 0.07
82
The highest mean ammonium ion concentration (Tables 4.5
and 4.6) was recorded for the leachate sample during the wet and
dry seasons, with mean values ranging from 2.80 to 6.13mg/l,
while the lowest mean ammonium ion concentrations was
obtained in treated water samples during the dry and wet
seasons with mean values ranging from 0.09 to 0.26mg/l.
Borehole samples recorded mean ammonium ion concentrations
which range between 0.31 to 0.38mg/l during the wet season,
while during the dry season, the mean values slightly increased to
the range of 0.59 to 0.66mg/l. The mean ammonium ion
concentrations measured in the stream water samples range
between 0.57 to 1.79mg/l in the wet and dry seasons. There was
significant increase (p<0.05) in the mean concentrations of
ammonium ions in all the borehole water, stream water and
treated water samples during the dry season.
The mean phosphate concentrations recorded (Tables 4.5
and 4.6) was highest in leachate samples in both seasons with
mean values ranging from 126.2 to 146.53mg/l, whereas the
lowest mean concentrations of phosphate ions was measured in
the treated water samples with mean values ranging between
0.04 to 0.08mg/l during the wet and dry seasons. Borehole
samples during the wet season recorded mean phosphate
concentrations which range between 1.82 to 2.17mg/l, and 1.13 to
1.19mg/l during the dry season. Stream water sample measured
mean phosphate concentrations which range between 4.21 to
5.96mg/l during the wet and dry seasons. There was no
significant difference (p>0.05) in phosphate concentrations in
leachate, boreholes, stream water and treated water samples
during the wet and dry seasons.
83
The highest mean sulphate ion concentrations was obtained
in leachate samples (Tables 4.5 and 4.6) during the wet and dry
seasons, with mean values ranging from 144.97 to 148.2mg/l,
while the lowest mean sulphate concentration was recorded for
the treated water samples during the dry and wet seasons, with
mean values ranging from 0.08 to 1.33mg/l. Borehole samples
recorded mean sulphate concentrations which range from 3.04 to
3.37mg/l during the wet season, and 0.89 to 1.45mg/l during the
dry season. Stream water sample recorded mean sulphate
concentrations which range from 4.98 to 5.24mg/l during the wet
and dry seasons. Treated water and borehole samples showed
significant decrease (p<0.05) in sulphate concentrations during
the dry season.
Among all the major anions determined (Tables 4.5 and 4.6)
chloride ion measured the highest concentration in leachates in
both seasons with mean values ranging between 284.37 to
536mg/l. The lowest mean chloride concentration was recorded
for the treated water samples in both seasons with mean values
ranging from 1.51 to 2.43mg/l during the wet and dry seasons.
Boreholes samples measured mean chloride ion concentrations
which range from 2.97 to 3.03mg/l during the wet season, and
3.80 to 4.25mg/l during the dry season. The mean chloride ion
concentration recorded for the stream water samples range from
2.97 to 6.25mg/l during the wet and dry seasons. The leachate
sample recorded a significant increase (p<0.05) in chloride ion
concentrations during the dry season. The general trend for the
major anions in leachate, boreholes, stream water and treated
water samples during the wet and dry seasons are shown as
follows: for leachate, the trend was; chloride (Cl�) > sulphate
(SO42-) > phosphate (PO43- )> nitrate (NO-3) > nitrite (NO-2) >
ammonium nitrogen (NH4+-N) during the wet season. During the
84
dry season, the trend was similar to that of the wet season except
for the changes in concentrations of nitrite (NO-2) and `ammonium
nitrogen. (NH4+-N) For borehole samples, the trend recorded was
Nitrate (NO-3) > sulphate (SO42-) > chloride (Cl-) > ammonium
nitrogen (NH4+-N) > Nitrite (NO-2) during the wet season, while
during the dry season, the trend recorded were similar except for
changes in the concentrations of sulphate (SO42-) and chloride
(Cl-) in both seasons. For stream water sample, the trend
recorded was similar to the one obtained for all the borehole
samples in the wet season while during the dry season, the trend
showed slight variation as shown; Nitrate (NO-3) > chloride (Cl-) >
Phosphate (PO43- ) > Sulphate (SO42-) > ammonium nitrogen (NH4+-
N) > nitrite (NO-2). The comparison of the nitrate and phosphate
concentrations in leachate, boreholes, stream water and treated
water samples during the wet and dry seasons are shown in
Figures 4.11- 4.12.
85
0
20
40
60
80
100
120
Leachate BH1 BH2 BH3 BH4 SW TW
Nit
rate
(m
g/L
)
Water type
Fig. 4.11 Comparison of nitrate levels in leachate, groundwater, stream water and treated water in
wet and dry season. Values are mean + SD, n = 3.
Wet
Dry
WHO standard = 45.0mg/l
86
0
20
40
60
80
100
120
140
160
Leachate BH1 BH2 BH3 BH4 SW TW
Ph
os
ph
ate
(m
g/L
)
Water type
Fig. 4.12 Comparison of phosphate levels in leachate, groundwater, stream water and treated water in
wet and dry season. Values are mean + SD, n = 3.
Wet
Dry
WHO standard = 0.1mg/l
87
4.1.44.1.44.1.44.1.4 Mean concentrations of essential cations in leachate, Mean concentrations of essential cations in leachate, Mean concentrations of essential cations in leachate, Mean concentrations of essential cations in leachate,
boreholes, stream water and treated water samples during the boreholes, stream water and treated water samples during the boreholes, stream water and treated water samples during the boreholes, stream water and treated water samples during the
wet and dry season.wet and dry season.wet and dry season.wet and dry season.
Tables 4.7 and 4.8 shows the means and standard deviations of
essential cations in leachate, borehole, stream water and treated water
samples during the wet and dry seasons. The highest mean calcium
concentration was recorded for the leachate samples with mean values
from 221.8 to 364-23mg/l during the wet and dry seasons, whereas the
treated water samples recorded the lowest mean calcium
concentrations which range between 5.13 to 14.53mg/l during the wet
and dry seasons. All the boreholes recorded mean calcium
concentrations which range from 10.87 to 13.9mg/l during the wet
season, and 10.8 to 11.3mg/l during the dry season. The mean calcium
concentrations recorded for the stream water samples during the wet
and dry seasons range between 14.0 to 14.97mg/l. There was a
significant increase (p<0.05) in the mean concentrations of calcium
recorded during the dry season for the leachate samples only.
The highest mean magnesium concentration (Tables 4.7 and 4.8)
was recorded for the leachate samples in both seasons, with a range of
values between 38.07 to 49.37mg/l whereas the lowest mean
magnesium concentration was obtained in treated water sample with
values ranging between 1.47 to 7.7mg/l during the wet and dry season.
All the borehole samples recorded mean magnesium concentrations
which range between 5.03 to 6.23mg/l during the wet season, 5.50 to
5.97mg/l during the dry season. The mean magnesium concentration
recorded for the stream water samples during the wet and dry seasons
(Tables 4.7 and 4.8) range from 7.20 to 13.97mg/l. There was no
significant difference (p>0.05) in mean magnesium concentrations in all
the boreholes, leachate, stream water and treated water samples
during the wet and dry seasons.
88
Table 4.7Table 4.7Table 4.7Table 4.7: Means and standard deviations of major cations in leachate, : Means and standard deviations of major cations in leachate, : Means and standard deviations of major cations in leachate, : Means and standard deviations of major cations in leachate, borehole waterborehole waterborehole waterborehole water, stream water and , stream water and , stream water and , stream water and
treated water samples (wet season)treated water samples (wet season)treated water samples (wet season)treated water samples (wet season)
Parameter Calcum (mg/L) Magnesium (mg/L) Potassium (mg/L) Sodium (mg/L)
Leachate 221.86±18.31 38.07±3.31 143.33±5.51 23.87±1.85
BH1 13.9±1.39 5.67±0.82 2.85±0.14 1.60±0.70
BH2 11.47±1.06 6.23±0.86 2.5±0.37 1.78±0.22
BH3 11.7±1.53 5.2±0.59 2.47±0.92 1.94±0.9
BH4 10.87±1.33 5.03±1.25 2.27±0.17 1.38±0.36
Stream water 14.0±1.76 13.97±4.77 3.37±0.97 1.54±0.28
Treated Water 14.53±1.60 77±4.18 2.83±0.17 1.06±0.67
89
Table 4.8Table 4.8Table 4.8Table 4.8: Means and standard deviations of major cations in leachate, : Means and standard deviations of major cations in leachate, : Means and standard deviations of major cations in leachate, : Means and standard deviations of major cations in leachate, borehole waterborehole waterborehole waterborehole water, stream water and , stream water and , stream water and , stream water and
treated water samples (dry season)treated water samples (dry season)treated water samples (dry season)treated water samples (dry season)
Parameter Calcum (mg/L) Magnesium (mg/L) Potassium (mg/L) Sodium (mg/L)
Leachate 364.23±15.97 49.37±5.78 41.37±9.86 68.93±27.0
BH1 10.87±1.70 5.5±0.57 3.13±0.52 5.57±0.78
BH2 10.86±1.80 5.67±0.11 3.27±0.52 4.33±1.27
BH3 11.3±1.20 5.97±0.86 3.33±0.62 5.07±0.54
BH4 11.0±0.75 5.8±0.75 3.33±0.34 5.8±0.43
Stream water 14.97±0.88 7.2±0.82 5.0±0.43 6.5±1.28
Treated Water 5.13±2.88 1.47±0.12 1.93±0.77 2.43±0.54
90
The mean concentration of potassium (Tables 4.7 and 4.8)
was highest in leachate samples in both seasons, with mean
values ranging from 41.37 to 143.33mg/l whereas the lowest
mean concentration of potassium was obtained in the treated
water samples with mean values ranging between 1.93 to
2.83mg/l in both seasons. Borehole samples recorded low mean
potassium concentrations which range between 2.27 to 2.85mg/l
during the wet season, and 1.93 to 3.33mg/l during the dry
season. The low mean potassium concentrations obtained in the
stream water samples during the wet and dry seasons range from
3.37 to 5.0mg/l. There was a significant increase (p<0.05)
observed in the concentration of potassium ions in leachate
sample during the dry season.
The highest mean sodium concentration was recorded for
the leachate samples in both seasons (Tables 4.7 and 4.8), with
mean values ranging between 23.87 to 68.93mg/l while the lowest
mean sodium concentration was obtained in treated water
sample in both seasons, with the mean values ranging between
1.06 to 2.43mg/l during the wet and dry seasons. Borehole
samples recorded low mean sodium concentrations with mean
values ranging between 1.38 to 1.94mg/l during the wet season,
and 4.33 to 5.80mg/l during the dry season. Stream water
samples measured mean sodium concentrations which range
between 1.54 to 6.5mg/l in both seasons. Only the borehole
samples showed significant increase (p<0.05) in mean sodium
concentration during the dry season.
The general trend for the essential cations in leachate,
boreholes, treated water and stream water samples in both
season (Tables 4.7 and 4.8) are shown as follows: for leachate
sample during the wet season, the trend recorded was; calcium>
potassium> magnesium> sodium, while during the dry season, the
91
trend was; calcium> potassium> sodium> magnesium. For the
borehole samples, the trend recorded was; calcium>
magnesium> potassium> sodium> during the wet season,
whereas in the dry season similar trend compared to that of the
wet season was recorded. For the stream water sample, the trend
was; calcium (Ca)> magnesium (Mg)> potassium (K)> sodium
(Na)> during the wet season, while during the dry season, the
trend was; calcium> magnesium> sodium> potassium>. For
treated water sample, the trend was calcium> potassium>
magnesium> sodium> iron.
The comparisons of mean concentrations of calcium in
leachate, borehole stream water and treated water samples
during the wet and dry season are shown in Figure 4.13.
92
0
50
100
150
200
250
300
350
400
450
Leachate BH1 BH2 BH3 BH4 SW TW
Ca
lciu
m (
mg
/L)
Water type
Fig. 4.13 Comparison of calcium levels in leachate, groundwater, stream water and treated water in
wet and dry season. Values are mean + SD, n = 3. *P<0.05 vs wet season.
Wet
Dry
*
*
WHO standard = 100mg/l
93
4.1.54.1.54.1.54.1.5 Mean Concentrations of selectedMean Concentrations of selectedMean Concentrations of selectedMean Concentrations of selected heavy metals in leachate, heavy metals in leachate, heavy metals in leachate, heavy metals in leachate, boreholes, stream water and treated water samples during boreholes, stream water and treated water samples during boreholes, stream water and treated water samples during boreholes, stream water and treated water samples during the wet and dry season.the wet and dry season.the wet and dry season.the wet and dry season.
Tables (4.9 and 4.10) shows the means and standard
deviations of some heavy metals in leachate, borehole water,
stream water and treated water samples in both seasons.
Leachate sample recorded high heavy metal concentrations than
the rest of the samples, whereas boreholes water and treated
water samples measured the lowest concentrations of heavy
metals in this study. The highest mean concentration of iron was
obtained in leachate sample (Tables 4.9 and 4.10), with mean
values ranging from 47.33 to 133.13mg/l during the wet and dry
seasons, whereas the lowest mean concentration of iron was
measured in the treated water samples, with mean values ranging
between 0.02 and 0.13mg/l in both seasons. Boreholes samples
measured very low mean iron concentrations which range from
0.03 to 0.08mg/l, during the wet season and 0.33 to 0.36mg/l
during the dry season. The mean iron concentration recorded for
the stream water samples in both seasons range between 0.60 to
2.35mg/l. There was a significant increase (p<0.05) in mean iron
concentrations in leachate, boreholes, and treated water samples
during the dry season.
94
Table 4.9Table 4.9Table 4.9Table 4.9: Means and standard deviations of heavy metals in leachate, : Means and standard deviations of heavy metals in leachate, : Means and standard deviations of heavy metals in leachate, : Means and standard deviations of heavy metals in leachate, borehole borehole borehole borehole water, stream water and water, stream water and water, stream water and water, stream water and
treated water samples (wet season)treated water samples (wet season)treated water samples (wet season)treated water samples (wet season)
Parameter Iron (mg/L) Manganese
(mg/L)
Copper
(mg/L)
Cadmium
(mg/L)
Chromium
(mg/L)
Zinc (mg/L) Lead (mg/L)
Leachate 47.33±71 39.76±6.50 5.78±033 2.29±0.80 1.63±0.73 17.33±2.57 12.33±8.62
BH1 0.08±0.05 0.04±0.02 nd nd nd nd nd
BH2 0.08±0.05 0.02±0.01 nd nd nd nd nd
BH3 0.03±0.01 0.01±0.01 nd nd nd nd nd
BH4 0.04±0.03 0.02±0.01 nd nd nd nd nd
Stream
water
0.61±0.48 0.08±0.03 0.32±0.35 0.005 0.004 0.12 0.002
Treated
water
0.02±0.08 0.01±0.01 nd nd nd nd nd
ND = No detection
95
Table Table Table Table 4.104.104.104.10: Means and standard deviations of heavy metals in leachate, : Means and standard deviations of heavy metals in leachate, : Means and standard deviations of heavy metals in leachate, : Means and standard deviations of heavy metals in leachate, borehole waterborehole waterborehole waterborehole water, stream water and , stream water and , stream water and , stream water and
treated water samples (dry season)treated water samples (dry season)treated water samples (dry season)treated water samples (dry season)
Parameters Iron (mg/L) Manganese
(mg/L)
Copper (mg/L) Cadmium
(mg/L)
Chromium
(mg/L)
Zinc (mg/L) Lead (mg/L)
Leachate 113.13±17.0 57.2±7.24 35.87±18.2 14.47±5.14 7.67±1.23 34.5±6.02 31.13±2.53
BH1 0.33±0.07 0.15±0.03 nd nd nd nd nd
BH2 0.36±0.12 0.13±0.03 nd nd nd nd nd
BH3 0.34±0.07 0.12±0.03 nd nd nd nd nd
BH4 0.35±0.13 0.11±0.02 nd nd nd nd nd
Stream water 2.35±0.79 2.37±0.63 3.95±1.44 0.42±0.25 0.46±0.36 4.46±1.44 0.04±0.01
Treated water 0.13±0.01 0.05±0.01 nd nd nd nd nd
96
Manganese recorded the highest mean concentration in
both seasons in leachate samples with mean concentrations
ranging between 39.79 to 57.2mg/l, while the lowest mean
manganese concentration was obtained in treated water samples
with mean values ranging between 0.01 to 0.05mg/l during the
wet and dry seasons. The mean manganese concentration
recorded in the boreholes water samples range from 0.01 to
0.04mg/l during the wet season, and 0.11 to 0.15mg/l during the
dry season. Stream water samples measured mean manganese
concentrations which range between 0.08 to 2.37mg/l during the
wet and dry seasons. There was a significant increase (p<0.05) in
the mean concentration of manganese in leachate, borehole
water stream water and treated water samples during the dry
season. Copper, cadmium, chromium, zinc and lead were not
detected in the borehole water and treated water samples in both
seasons. The mean copper concentration recorded was highest
in the leachate samples, with mean values ranging from 5.78 to
35.87mg/l during the wet and dry season. The stream water
samples recorded copper concentrations ranging from 0.32 to
3.95mg/l during the wet and dry season. The mean cadmium
concentration recorded was highest in the leachate samples with
mean values ranging from 2.29 to 14.47mg/l during the wet and
dry seasons while in the stream water sample the mean cadmium
values range between 0.005 to 0.69mg/l. In the leachate samples,
the mean chromium concentration range from 1.63 to 7.67mg/l
during the wet and dry seasons, whereas the stream water
samples measured mean chromium concentrations which range
from 0.004 to 0.36mg/l in both seasons. The highest mean
concentration of zinc was obtained in leachate samples in both
seasons, with mean values ranging between 17.33 to 34.5mg/l
during the wet and dry seasons whereas the stream water
97
samples recorded mean zinc levels which ranged between 0.12 to
4.46mg/l in both seasons. Lead recorded the highest mean
concentration in leachate samples in both seasons, with mean
values ranging between 12.93 to 31.13mg/l during the wet and dry
seasons while stream water sample measured mean lead
concentrations which ranged from 0.002 to 0.04mg/l. during the
wet and dry seasons. There was significant increase (p<0.05) in
the mean concentrations of copper, cadmium, chromium, zinc,
and lead in leachate and stream water samples during the dry
season. The comparison of iron and manganese concentrations
in leachate, borehole water, stream water and treated water
samples during the wet and dry seasons are shown in Figures
4.14 - 4.15.
98
0
20
40
60
80
100
120
140
Leachate BH1 BH2 BH3 BH4 SW TW
Iro
n (
mg
/L)
Water type
Fig. 4.14 Comparison of iron levels in leachate, groundwater, stream water and treated water in
wet and dry season. Values are mean + SD, n = 3. *P<0.05 vs wet season.
Wet
Dry
*
* * * * *
WHO standard = 0.3mg/l
99
0
10
20
30
40
50
60
70
80
Leachate BH1 BH2 BH3 BH4 SW TW
Ma
ng
an
es
e (
mg
/L)
Water type
Fig. 4.15 Comparison of manganese levels in leachate, groundwater, stream water and treated water in
wet and dry season. Values are mean + SD, n = 3. *P<0.05 vs wet season.
Wet
Dry
*
*****
WHO standard = 0.05mg/l
100
4.24.24.24.2 Mean concentrations Mean concentrations Mean concentrations Mean concentrations of heavy metals in soils along of heavy metals in soils along of heavy metals in soils along of heavy metals in soils along waste and nonwaste and nonwaste and nonwaste and non----waste disposal sites during the wet and waste disposal sites during the wet and waste disposal sites during the wet and waste disposal sites during the wet and dry season.dry season.dry season.dry season.
Tables (4.11 and 4.12) show the mean and standard deviations
of heavy metals in soil during the wet and dry season. The mean
concentrations of iron in soil samples from the dumpsite range
between 1804 to 1813mg/kg in both seasons. The highest
concentration of iron was recorded for soil sample 20m west of the
dumpsite (SSW2) (2505mg/kg) during the wet season, while the
lowest concentration was recorded for the control sample
(1797.56mg/kg). At 10 and 20m north, south, west and east outside
the dumpsite, the mean iron concentrations in the soil range from
1837.55 to 2007-50mg/kg and 1846-50 to 2505mg/kg during the wet
season, while during the dry season, the mean iron concentrations
range from 1845.50 to 2002.mg/kg and 1886.0 to 2430.mg/kg.
(Tables 4.11 and 4.12). Soil samples from 20m west of the dumpsite
(SSW2) recorded significant increase (p<0.05) in iron contents in
both seasons compared with the control sample. Soil Sample from
20m east (SSE2) of the dumpsite recorded significant decrease
(p<0.05) in iron contents during the dry season (fig. 4.16).
101
Table 4Table 4Table 4Table 4.1.1.1.11111
Heavy metal contents of soils sampled along wastes and non-waste dumpsites, Uyo, Akwa Ibom State during wet seasons.
Values are mean ±±±± SEM, n=2.
Location Coordinates DCP
(m) Fe (mg/kg)
Pb (mg/kg)
Zn (mg/kg)
Ni (mg/kg)
Cr (mg/kg)
Cd (mg/kg)
Mn mg/kg)
SSC 05o02’30”N
007o56’48”E
800 1797.56
±2.000
3.78
±0.05
50.90
±3.00
2.19
±0.03
1.06
±0.02
1.09
±0.03
44.27
±4.50
SS0 05o02’34”N
007o56’01”E
0.00 1813.00
± 3.00
9.90
±0.70
137.00
±3.00
12.56
±1.53
3.60
±0.20”
9.05
±0.15
94.00
±2.00
SSE1 05o02’31”N
007o56’04”E
10.0 1837.55
±4.45
8.47
±0.34
153.00
±1.00
10.15
±0.16
2.90
±0.10
8.75
±0.75
82.68
±1.52
SS E2 05o02’29”N
007o56’06”E
20.0 1846.50
±3.50
8.80
±0.20
161.40
±0.60
10.62
±0.59
3.18
±0.10
7.50
±0.10
91.03
±1.00
SSS1 05o02’35”N
007o56’03”E
10.0 2000.55
±1.45
5.65
±0.55
69.00
±1.00
3.10
±0.10
1.13
±0.02
1.87
±0.06
49.10
±0.00
SSS2 05o02’33”N
007o56’05”E
20.0 1894.90
±3.50
6.35
±0.25
70.05
±1.15
2.90
±0.10
2.00
±0.12
2.01
±0.10
49.45
±0.65
SSW1 05o02’30”N
007o56’03”E
10.0 1999.90
±0.10
5.70
±0.10
68.05
±0.25
3.20
±0.20
1.51
±0.05
1.81
±0.05
59.20
±1.00
SSW2 05o02’24”N
007o56’07”E
20.0 2505.00
±5.00
6.60
±0.50
60.32
±0.08
3.10
±0.11
1.74
±0.14
1.80
±0.09
55.50
±0.50
SSN1 05o02’23”N
007o55’53”E
10.0 2007.50
±7.50
4.50
±0.30
56.65
±1.55
4.55
±0.55
1.64
±0.36
1.75
±0..05
70.40
±0.40
SSN2 05o02’21”N
007o55’50”E
20.0 1999.52
±0.52
4.00
±0.00
64.65
±0.55
4.00
±0.20
1.60
±0.10
1.77
±0.05
62.80
±0.50
Values are expressed as mean ±±±± SEM, ∗= significant at a<0.05 compared with control. DCP = Distance from centre point of dumpsite SSC = Soil samples from control site SSO = Soil samples from dumpsite SSE = Soil samples from east of the dumpsite SSS = Soil samples from south of the dumpsite SSW = Soil samples from west of the dumpsite SSN = Soil samples from north of the dumpsite
102
Table 4.12 Heavy metal contents of soils sampled along wastes and non-waste dumpsites, Uyo, Akwa Ibom State during dry seasons.
Values are mean ± SEM, n=2. Location Fe Pb Zn Ni Cr Cd Mn
SSC 1797.56
±2.000
3.78
±0.05
50.90
±3.00
2.19
±0.03
1.06
±0.02
1.09
±0.03
44.27
±4.50
SS0 1804.00
± 4.00
8.70
±0.50
146.00
±2.00
11.82
±1.00
4.05
±0.05
12.21
±0.19
91.20
±0.80
SSE1 1845.50
±2.50
8.65
±0.25
149.00
±1.00
10.40
±0.20
3.18
±0.06
6.72
±0.52
89.12
±1.08
SS E2 1866.00
±4.00
8.93
±0.27
159.60
±0.40
10.85
±0.65
3.15
±0.14
6.90
±0.10
92.03
±1.97
SSS1 1994.00
±4.00
5.45
±0.55
71.10
±0.90
2.90
±0.10
1.95
±0.25
2.09
±0.21
46.65
±0.65
SSS2 1899.60
±0.40
6.20
±0.20
72.35
±1.05
2.40
±0.30
1.92
±0.12
1.90
±0.10
46.50
±0.50
SW1 2002.00
±2.00
5.15
±0.15
61.25
±1.05
3.05
±0.04
1.65
±0.15
1.81
±0.01
51.65
±1.45
SSW2 2430.00
±30.00
5.53
±0.33
60.57
±0.27
2.95
±0.05
1.63
±0.03
1.82
±0.02
54.50
±0.50
SSN1 2001.00
±7.50
4.50
±0.30
56.65
±1.55
4.55
±0.55
1.64
±0.36
1.75
±0..05
70.40
±0.40
SSN2 1999.50
±0.50
4.00
±0.00
64.55
±0.45
3.85
±0.05
1.55
±0.05
1.73
±0.01
62.75
±0.45
Values are expressed as mean ±±±± SEM, ∗= significant at a<0.05 compared with control.
103
0
500
1000
1500
2000
2500
3000
Fe (
mg
/kg
)
Location
Fig. 4.16 Iron (Fe) contents of soils sampled along wastes and non-waste dumpsite, Uyo, Akwa Ibom State
during dry and wet seasons. Values are mean + SEM, n = 2.
Dry
WetWHO standard = 3000 to 250000mg/kg
104
The mean lead concentrations in the dumpsite soil range
from 8.70 to 9.90mg/kg in both seasons. The highest
concentration of lead was recorded for the dumpsite soil sample
during the wet season (9.90mg/kg) while the lowest concentration
of lead was recorded for the control sample (3.78mg/kg). At 10
and 20m north, west, south and east outside the dumpsite, the
mean lead concentrations in the soil range from 4.50 to
8.47mg/kg and 4.00 to 8.80mg/kg during the wet season while
during the dry season, the mean lead contents in the soil range
from 4.0 to 8.65mg/kg and 4.0 to 8.93mg/kg. Soil samples from the
dumpsite and from the east transect recorded significance
increase (p<0.05) in lead contents in both seasons compared with
soil samples from the control site (fig. 4.17). Soil samples from the
different sites did not show any significant difference (p>0.05) in
lead contents in both seasons.
The mean zinc contents in the dumpsite soil range from 137.0 to
140mg/kg in both seasons. The highest concentration of zinc was
recorded for soil sample 20m east of the dumpsite (161.4mg/kg) during
the wet season while the lowest content of zinc was recorded for the
control (50.90mg/kg). At 10 and 20m north south, west and east of the
dumpsite, the mean zinc contents in the soil range from 56.65 to
153mg/kg and 60.32 to 161.40mg/kg during the wet season while
during the dry season, the zinc contents in the soil range from 63.60 to
149.0mg/kg and 60.57 to 159.60mg/kg. (Tables 4.11 and 4.12). Soil
samples from the dumpsite and from the east transect, recorded
significant increase (p<0.05) in zinc contents in both seasons
compared with the zinc contents recorded for the control sample.
105
0
2
4
6
8
10
12P
b (
mg
/kg
)
Location
Fig. 4.17 Lead (Pb) contents of soils sampled along wastes and non-waste dumpsite, Uyo, Akwa Ibom State
during dry and wet seasons. Values are mean + SEM, n = 2.
* = significant at p<0.05.
Dry
Wet
*
*
WHO standard = 15 to 25mg/kg
*
**
106
0
20
40
60
80
100
120
140
160
180
Zn
(m
g/k
g)
Location
Fig. 4.18 Zinc (Zn) contents of soils sampled along wastes and non-waste dumpsite, Uyo, Akwa Ibom State
during dry and wet seasons. Values are mean + SEM, n = 2.
Dry
Wet
WHO standard = 20 to 300mg/kg
* *
*
107
The mean nickle contents recorded for the dumpsite soil in
both seasons range from 11.82 to 12.56mg/kg. The highest
concentration of nickle was recorded for soil samples from the
dumpsite (12.56mg/kg) during the wet season while the lowest
nickel concentration was recorded for the control sample
(2.19mg/kg). At 10 and 20m north, south, west and east of the
dumpsite, the nickle contents range from 3.10 to 10.5mg/kg and
3.10 and 10.62 during the wet season while during the dry season
the nickle contents range from 2.90 to 10.4mg/kg and 2.4 to
10.85mg/kg (Tables 4.11 and 4.12). Soil samples from the dumpsite
and from the east transect recorded significant increase (p<0.05)
in nickle contents in both seasons compared to soil samples from
the control site. Soil samples from the control site did not record
any significant difference compared with samples from the north,
south and west of the dumpsite.
108
0
2
4
6
8
10
12
14
Ni (m
g/k
g)
Location
Fig. 4.19 Nickel (Ni) contents of soils sampled along wastes and non-waste dumpsite, Uyo, Akwa Ibom State
during dry and wet seasons. Values are mean + SEM, n = 2.
Dry
Wet
WHO standard = 0 to 100mg/kg
*
* *
109
The mean chromium contents recorded for soil from the
dumpsite soil range from 3.6 to 4.05mg/kg in both seasons. The highest
content of chromium was recorded for the dumpsite soil (4.05mg/kg)
during the wet season while the lowest content of chromium was
recorded for the control (1.05mg/kg).
At 10 and 20m north, south, west and east of the dumpsite, the mean
contents of chromium range from 1.13 to 2.90mg/kg and 1.60 to
3.18mg/kg during the wet season while during the dry season, the
mean chromium contents range from 1.65 to 3.18 and 1.55 to
3.15mg/kg. Soil samples from the dumpsite and from the east transect
recorded significant increase (p<0.05) in chromium contents compared
with samples from the control site. Soil samples from the west, north
and south of the dumpsite did not record any significant difference
compared with soil samples from the control site.
The mean cadmium content recorded for the dumpsite soil range
from 9.05 to 12.21mg/kg in both seasons. The highest cadmium content
was recorded for soil samples from the dumpsite (12.21mg/kg) during
the wet season while the lowest cadmium content was recorded for the
control sample (1.09mg/kg). At 10 and 20m east, west, south and north
of the dumpsite, the cadmium contents range from 1.75 to 8.75mg/kg
and 1.77 to 7.50mg/kg during the wet season while during the dry
season, the cadmium contents in the soil samples range from 1.75 to
6.72mg/kg and 1.73 to 6.90mg/kg. Soil samples from the dumpsite (SS0)
and from the east transect recorded significant increase (p<0.05) in
cadmium content in both seasons compared with the control sample.
The cadmium contents in soil samples from 10 and 20m west, south
and north of the dumpsite agree with that of the control sample in both
seasons.
110
0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
Cr
(mg
/kg
)
Location
Fig. 4.20 Chromium (Cr) contents of soils sampled along wastes and non-waste dumpsite, Uyo, Akwa Ibom State
during dry and wet seasons. Values are mean + SEM, n = 2.* = significance compared with control sample
Dry
Wet
WHO standard = 0 to 85mg/kg*
* *
*
*
111
0
2
4
6
8
10
12
14
Cd
(m
g/k
g)
Location
Fig. 4.21 Cadmium (Cd) contents of soils sampled along wastes and non-waste dumpsite, Uyo, Akwa Ibom State
during dryand wet seasons. Values are mean + SEM, n = 2.* = significance compared with control sample
Dry
Wet
WHO standard = 0 to 30mg/kg
*
*
* *
*
*
112
The mean manganese contents recorded for the dumpsite
soil range from 91.20 to 94.0mg/kg in both seasons. The highest
manganese concentration was recorded for the dumpsite soil
(94.0mg/kg) during the wet season, while the lowest manganese
concentration was recorded for the control sample (44.27mg/kg).
At 10 and 20m north, south, west and east outside the dumpsite
the manganese contents range from 49.01 to 82.68mg/kg and
49.45 to 91.03mg/kg during the wet season while during the dry
season, the manganese values range from 46.68 to 89.12mg/kg
and 46.50 to 92.03mg/kg. Soil samples from the dumpsite and
from 10 and 20m east, and north of the dumpsite recorded
significant increase (p<0.05) in manganese contents compared
with samples from the control site (fig. 4.22). Samples from 10
and 20m north of the dumpsite did not recorded any significant
difference (p>0.05) compared with the control. There was
significant decrease in manganese contents in soil from 10m west
(SSW1) of the dumpsite during the dry season.
113
0
10
20
30
40
50
60
70
80
90
100
Mn
(m
g/k
g)
Location
Fig. 4.22 Manganese (Mn) contents of soils sampled along wastes and non-waste dumpsite, Uyo, Akwa Ibom State during dry and wet seasons. Values are mean + SEM, n = 2.* = significance compared with control sample** = significance compared with the wet seas
Dry
Wet
WHO standard =200 to 9000mg/kg
*
* *
*
**
114
The results in Tables 4.11 and 4.12 show that soil samples
from the dumpsite and from 10 and 20m east of the dumpsite
recorded the highest mean concentrations of heavy metals
determined. The soil parameters determined at dumpsite
correlated positively with soil at the east transect of the dumpsite.
Whereas samples obtained from at the control site, west, south
and north transects recorded lower physico-chemical values
compared to soil samples from the dumpsite and from the east
transect of the dumpsite, which is located at the low land portion
of the dumpsite.
The general trend for the heavy metals in the soil samples is
Fe> Zn> Mn> Pb> Ni> Cd> Cr. This trend revealed that, the soil at
the dumpsite and outside the dumpsite recorded the highest
mean concentration of Iron, while chromium recorded the lowest
mean concentration in all the soil samples analyzed in both
seasons.
115
DISCUSSIONDISCUSSIONDISCUSSIONDISCUSSION
4.3 4.3 4.3 4.3 Discussion Discussion Discussion Discussion
4444.3.3.3.3.1.1.1.1 Physical, chemical and Physical, chemical and Physical, chemical and Physical, chemical and heavy metal characteristicsheavy metal characteristicsheavy metal characteristicsheavy metal characteristics of of of of leachate, boreholes water, stream water and treated leachate, boreholes water, stream water and treated leachate, boreholes water, stream water and treated leachate, boreholes water, stream water and treated water samples.water samples.water samples.water samples.
The mean concentrations of selected physical, chemical
and heavy metal contents in leachate, boreholes water, stream
water and treated water samples in both seasons have been
shown in Tables 3 to 8. The results reveal that leachate from the
dumpsite recorded the highest mean concentrations, whereas
treated water sample in the study area recorded the lowest mean
concentrations.
The high mean concentrations of the assessed parameters
in leachate is as a result of the types of waste and their chemical
compositions present at the dumpsite. The Barracks road
dumpsite wastes are characterized by both biodegradable and
non-biodegradable wastes of all sort: abandoned metal bearing
wastes, such as metal scraps, dysfunctional electrical
equipments, food cans, waste batteries (dry and wet cells), paint
pigments that contain heavy metals, polyethelene material, nylon,
household waste and waste from food preparation, builders
rubbles, wastes from photographic laboratories, papers, plastics
etc, made up the bulk of the wastes at the dumpsite.
pHpHpHpH
The mean pH values recorded for leachate in both seasons
were in agreement with the values obtained by Ehrig et al.,
(1989); Christensen et al., (1992) and Saleh, et al., (1995). The
normal range of pH in water is between 6.5 – 9.5. The mean pH
value recorded in leachate during the wet season agree with the
normal range, while during the dry season, the pH value recorded
was slightly below the normal range in drinking water. This low
116
pH value in leachate during the dry season may indicate
increased concentrations of free fatty acid, and inorganic acids
solutions produced during acidogenesis of waste at the dumpsite
due to bacteria activities. Fresh leachate is generally alkaline in
nature, its pH value lies between 7.3 – 7.5. However, as
temperature increases, pH value tend to fall due to production of
acids by bacterial action, and the leachate tends to become
acidic.
The pH values recorded for all the borehole water samples
during the wet season agrees with the WHO (2004) permissible
limits, while during the dry season the values were slightly lower
than the normal range. This indicates that the borehole water
samples were slightly acidic during the dry season. The mean pH
values recorded for the stream water and treated water samples
in both seasons agrees with the normal range.
The pH value denotes hydrogen ion concentration in the
liquid and is the measure of acidity or alkalinity of the liquid. The
pH of the leachate sample depends not only on the concentration
of acid present, but also on the partial pressure of carbon (iv)
oxide gas present in the dumpsite gas that is in contact with the
waste water (leachate). According to Atxotegi et al., (2003), no
health base guideline value is proposed for pH; and although pH
has no direct impact on consumers, it is one of the most
operational water quality parameter. Omofonmwan et al., (2009)
indicated that water with high pH value may cause taste and
corrosion of metals. pH> 7 may indicate that the water is hard and
contains calcium and magnesium ions.
TemperatureTemperatureTemperatureTemperature
The normal range of temperature in water is 12oC-25oC. The
mean temperature recorded for the leachate samples during the
wet season agrees with the normal range, while during the dry
117
season, the mean temperature was slightly above the normal
range. This high value may depend on the environmental
conditions during the period of sampling. The mean temperature
values in leachate in both seasons agreed with the mean value
obtained by (Esmail et al., 2009). On the contrary, these values
were lower than the temperature value recorded by (Ekpo et al.,
1999). The mean temperature values recorded for all the
boreholes, stream water and treated water samples agreed with
the normal range during the wet season while during the dry
season, the mean temperature values slightly exceeded the
normal range. The significant increase in the mean temperature
values recorded during the dry season for all the samples
analyzed may be due to the seasonal differences in physio-
geographic conditions.
ConductivityConductivityConductivityConductivity
The WHO (2004) permissible limit for conductivity in water is
1400 µs/cm. The mean conductivity values recorded for the
leachate samples in both season exceeded normal limit. This
indicate high dissolve salts in the leachate and strong inorganic
pollution. The mean electrical conductivity values recorded for
the borehole water samples, stream water and treated water
samples in both seasons were lower than the normal range. This
reveals the presence of low dissolved inorganic species or total
concentration of ions. These low electrical conductivity values
may suggest that the borehole water, stream water and treated
water samples were pure, portable and did not pose any
significant water quality problem. Conductivity is an index of
salinity, i.e it depends on the amount of dissolve salts present in
the liquid (Bhatia, 2005). The significant increased in electrical
conductivity value during the dry season for leachate sample may
118
be due to increase in concentrations of inorganic ions owing to
the decrease in the pH and volume of leachate generated.
Turbidity:Turbidity:Turbidity:Turbidity:
The normal limit of turbidity in portable water is 25 FTU the
mean turbidity value recorded in leachate samples in both
seasons exceeded the normal range. This indicate that the
leachate sample contain high concentration of colloidal and
anthropogenic substances. The turbidity of water depends on the
quantity of solid matters present in the suspension state. The
stronger and more concentrated is the water, the higher is its
turbidity. Turbidity is a measure of light emitting properties of
water. The mean turbidity values obtained in the borehole water,
stream water and treated water samples in both seasons were
quite lower than the permissible limit. These low values reflects
that ground water, stream and treated water samples were quite
clear. The significant increase in turbidity value for the leachate
sample during the dry season was due to the low pH, decrease
volume and high concentration of the leachate generated. The
stronger and more concentrated the leachate, the higher is its
turbidity.
Dissolved Oxygen (DO):Dissolved Oxygen (DO):Dissolved Oxygen (DO):Dissolved Oxygen (DO):
The WHO (2004) permissible limit for dissolve oxygen in
portable water is 4.0mg/l. Dissolved oxygen determination is very
important for drinking water. It is an indication of purity of water.
If DO is less than the required limit, it indicates pollution. The
saturation limit of oxygen in water depends upon temperature,
altitude above sea level and purity of the water itself. The
maximum value of DO in water is 14.6mg/l at temperature of 8oC
at mean sea level (Bhatia, 2005). The mean DO recorded for the
leachate samples in both seasons were lower than the
permissible limits. This low DO values in leachates indicate high
119
microbial activities and strong organic pollution by leachate. All
the borehole water, stream water and treated water samples in
both seasons recorded mean DO values which agreed with the
permissible limit. This indicates that ground water, stream water,
and treated water samples were pure and did not pose any
significant water quality problem in both seasons. The significant
decrease in DO concentrations in stream water during the dry
season may indicate high concentration of biodegradable organic
matters and high microbial activities which may be due to
leachate migration from the body of the dumpsite. The DO values
recorded in this study for leachate agrees with the values
obtained by (Ekpo et al., 1999 and Nubi et al., 2008). On the
contrary, these values were higher than the DO values recorded
by Esmail et al., (2009). The presence of DO in water is desirable
because it prevents the formation of noxious odour. According to
Bhatia (2005), the actual quantity of DO in water is governed by (i)
solubility of oxygen (ii) partial pressure of oxygen in atmosphere
(iii) the temperature, and (iv) purity (salinity, suspended solids).
Chemical Oxygen Demand (COD):Chemical Oxygen Demand (COD):Chemical Oxygen Demand (COD):Chemical Oxygen Demand (COD):
Chemical oxygen Demand corresponds to the amount of
oxygen required to oxidize the organic fraction of a sample which
is susceptible to tetraoxo–manganate (vii), permanganate or
heptaoxo-chromate (vi) (dichromate) oxidation in an acid solution.
The WHO permissible limit for COD in portable water is 250mg/l.
The mean COD values in leachate in both seasons were lower
than the normal limit. This suggests low industrial wastes at the
dumpsite. These values were lower than the COD values
recorded for leachate by Christensen et al., (1992); Ehrig (1989),
Amina et al., (2004), and Yoshida et al., (2002)
The mean COD values recorded for the stream water,
boreholes water and treated water samples in both seasons were
120
quite lower than the normal limits. The significant increase in COD
values during the dry season for leachate may be due to the
seasonal variation in the volume and pH of leachate generated.
The decreased pH and volume of leachate produced during the
dry season may lead to an increase in concentrations of dissolved
organic and inorganic matters.
Biochemical oxygen demand (BODBiochemical oxygen demand (BODBiochemical oxygen demand (BODBiochemical oxygen demand (BOD5555):):):):
The biochemical oxygen demand (BOD5) is a measure of the
oxygen required to oxidized the organic matter present in a
sample, through the action of micro-organisms contained in the
sample of waste water under aerobic conditions at standard
temperature. This test is very important as it indicates the amount
of decomposable organic matter present in the wastes. The
greater the BOD value, the more is the nuisance potential, or the
strength of the leachate produced. The WHO (2004) permissible
limit for BOD5 in portable water is 30mg/l. The mean BOD5 values
recorded for the leachate samples in both seasons exceeded the
permissible limits. This reflects high amounts of biodegradable
organic waste at the dumpsite, and also indicate strong leachate
pollution. Similar BOD5 values for leachate were recorded by
Ekpo et al., (1999) and Amina et al., (2004).
The mean BOD5 values recorded for the boreholes water,
stream water and treated water samples were quite lower than
the permissible limits in both seasons. This suggests that ground
water, stream water and treated water samples did not pose any
significant water quality problems in both seasons.
The significant increase in BOD5 value for stream water
sample during the dry seasons was due to the increase in
concentrations of biodegradable organic matters as a result of
the decrease in the volume of water in the stream and decrease in
the water flow rate due to evaporation.
121
Biochemical oxygen demand (BOD5) is the most widely used
parameter of organic pollution applied to both waste water as
well as surface water. According to Christensen (1994), low pH in
leachate may lead to high organic carbon, BOD5, essential
elements and heavy metals.
Total suspended solids (TSS):Total suspended solids (TSS):Total suspended solids (TSS):Total suspended solids (TSS):
Suspended solids are those solids which can be filtered out
on an asbestos mat or filter papers, ie, suspended solids are non-
filtrable solids. The permissible limit of TSS in drinking water is
25mg/l. The mean TSS values recorded for leachate in both
seasons were quite higher than the permissible limits. This
reflects high concentration of non-filtrable solids, in the leachate
samples. The mean TSS values recorded for all the borehole
water, stream water and treated water samples in both seasons
were quite lower than the normal limits for drinking water. This
reflects purity of groundwater, stream water and treated water
samples in both seasons and suggested that these samples did
not pose any significant water quality problems in both seasons.
According to Omofonmwan (2009), high TSS in water may
lead to high turbidity, taste and gastro-intestinal irritation. The
significant increase in TSS in leachate sample during the dry
season may depend on the seasonal variation in the volume and
pH of leachate produced. In the dry season decreased and more
concentrated form of leachate is produced. This therefore leads
to an increase in total suspended solids (TSS).
Total Dissolved Solids (TDS):Total Dissolved Solids (TDS):Total Dissolved Solids (TDS):Total Dissolved Solids (TDS):
The solids which are in dissolved form go into solution, even
after filtration. These solids are filtrable and can be separated
from others through filtration using filter paper. The WHO (2004)
permissible limits for TDS in drinking water is 500mg/l. The mean
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TDS values recorded for leachate in both seasons were higher
than the permissible limits. These mean values agreed with the
range values of 450-3000mg/l required for treated waste water
discharge determined by Esmail et al., (2009). This high value
characterized the leachate as polluted, with high concentration of
dissolved organic and inorganic matters. The mean TDS values
recorded for the boreholes water, stream water and treated
water samples in both seasons were quite lower than the normal
range. This characterized the water samples as pure with
absence of objectionable taste, low salinity and conductivities.
The significant increase in TDS concentration in leachate during
the dry season may be due to the decreased in pH and volume of
leachate generated which causes the dissolved substances to
become more concentrated.
Nitrate (NONitrate (NONitrate (NONitrate (NO3333----))))
The presence of nitrates in waste water indicate the
presence of fully oxidized nitrogeneous matters. They indicate the
most stable form of nitrogenous matter contained in the leachate
(Bhatia, 2005). Nitrogen can enter the ground water from several
sources. Certain plants such as legumes fix atmospheric nitrogen
and transfer it to the soil by the help of nitrifying bacteria, where it
is used by plants. Some of the surplus nitrogen is removed in
solution in the form of nitrate by percolating soil water. Natural
nitrate concentration in ground water ranged from 0.1 to 10mg/l
(Adeyemo et al., 2002). Nitrate in concentration greater than
45mg/l is undesirable in domestic water supplies because of the
potential toxic effect on young infants (Adeyemo et al., 2002).
Nitrate by itself is not dangerous. It is converted to highly toxic
dioxonitrate (iii), NO-2 by certain bacteria commonly found in the
intestinal tract of infants. Nitrite has a great affinity for
haemoglobin in the blood stream than does oxygen, and when
123
NO-2 replaces oxygen, a condition known as methemoglobinemia
results. The resulting oxygen starvation causes a bluish
discolouration of the infant; hence, it is commonly referred to as
the “blue baby” syndrome. In extreme cases, the victim may die
from suffocation. The syndrome may not occur after the child has
exceeded six months of age (Bahatia, 2005). The WHO (2004)
permissible limits for nitrate in drinking water is 45mg/l. The mean
nitrate concentration recorded for the leachate samples in both
seasons were quite higher than the recommended limits. This
suggests the presence of fully oxidized nitrogenous matter in the
dumpsite leachate and characterized the leachates as polluted.
The mean nitrate concentration, recorded for leachate in this
study were similar to the values recorded by Amina et al., (2004).
On the contrary, these mean values in both seasons were higher
than the mean values obtained by Ehrig et al., (1989), Ekpo et al.,
(1999), and Nubi et al ., (2008). The mean nitrate concentrations
recorded for the boreholes water, stream water and treated
water samples in both seasons were quite lower than the normal
limits. This suggests that they water samples were not affected by
leachate from the body of the dumpsite. Ekpo et al ., (1999) and
Omofonmwan (2009) recorded quite lower nitrate concentrations
compared to the nitrate values recorded for all the boreholes in
both seasons in this study. On the contrary, the mean nitrate
concentrations recorded by Esmail et al., (2009) for boreholes
water samples were quite higher than the mean nitrate values in
this study.
Nitrite: (NONitrite: (NONitrite: (NONitrite: (NO2222----))))
The highest nitrite concentration was recorded in leachate
the sample. These concentrations in both seasons were higher
than WHO (2004) permissible limit of 0.1mg/l. Nitrite indicates the
presence of partly decomposed organic matters. The presence of
124
nitrite, in leachate indicates that oxidation is in progress. Nitrite
nitrogen is relatively unimportant in waste water pollution studies
because its unstable and can easily be oxidized to nitrate form.
This reduces its concentration in water as time passes away.
Other sources of soil nitrogen may be decomposing plant and
animal debris, waste from homes, business areas, hospitals,
agricultural activities etc. During treatment of waste water, the
presence of nitrite indicates incomplete oxidation and suggest
the waste water as being stale. It is an indicator of past pollution
in water samples. The mean nitrite concentrations for all the
boreholes water, stream water and treated water samples in both
seasons were far below the permissible limit of 0.1mg/l.
AmmonAmmonAmmonAmmonium Nitrogen (NHium Nitrogen (NHium Nitrogen (NHium Nitrogen (NH4444++++----N)N)N)N)
Ammonia nitrogen exist in solution as either the ammonium
ion or ammonia, depending upon the pH of the solution in
accordance with the following equilibrium reaction:
NH3+ H20↔NH� + OH�.
When pH > 7, the equation displaces to the left while for P< 7 the
ammonium ion predominates. The WHO (2004) permissible limit
for ammonium ions in drinking water is 0.5mg/l. The mean
concentration of ammonium ion recorded for leachate in both
seasons were higher than the permissible limits. This suggest the
presence of high ammonium waste at in the dumpsite. The
production of CO2, NH3, H20, during aerobic respiration taking
place in the waste; produce acid solutions which reduces the pH
of the leachate and influences the formation of ammonium ions
from the ammonia produced. This may also cause the high
concentration of ammonium ions in leachates sample especially
during the dry season according to the equation
NH3+H+ ↔NH4+.
125
Similar concentrations were recorded by Ekpo et al., (1999),
Esmail et al 2009). The mean ammonium ion concentrations in the
borehole water samples during the wet season were below the
normal range, during the dry season the mean values increase
slightly above the normal range. This might indicate the presence
of nitrogenous contaminants which could have come from human
faeces. The ammonium concentration becomes so intense during
the dry season for all the boreholes samples because of
excessive evaporation of water from the soil which have caused
the groundwater to become more concentrated.
The stream water samples in both seasons recorded high
mean values of ammonium Irons than the permissible limits. This
may suggest leachate seepage from the body of the dumpsite or
the presence of human sewage, death plants and animals
remains. Treated water samples in both season recorded mean
values lower than the permissible limits.
Phosphate ions (POPhosphate ions (POPhosphate ions (POPhosphate ions (PO44443333----))))
The maximum permissible level of phosphate in drinking
water is 0.1mg/l. The mean phosphate concentration recorded for
the leachate sample in both seasons were above the permissible
level. This implies that the dumpsite contains high phosphate
waste which may impact negatively on soil, ground water and
stream water. All the boreholes in both seasons recorded high
mean values of phosphate which exceeded the permissible limits.
This may suggest the presence of high phosphate bearing rocks
in the groundwater aquifers. The mean phosphate concentrations
recorded for the stream water in both seasons were higher than
the permissible limits. This may suggest the presence of high
phosphate bearing rocks in the soil or the influence of leachate
from the body of the dumpsite. Excessive use of inorganic
126
fertilizers on soil may also lead to ground water and surface
water contamination. Phosphate is required in the body for the
building of bones and teeth. It is also required for the building of
shell in animals.
Sulphate (SOSulphate (SOSulphate (SOSulphate (SO44442222----))))
Sulphates are formed due to the decomposition of various
sulphur containing substances present in the waste. The sulphur
required for the synthesis of protein in plants is released during
degradation process. Sulphate is a naturally occurring anion
found in all kinds of natural water, in high concentrations. The
discharge of industrial waste, domestic waste and seawage into
water bodies may also increase the sulphate concentration in
water. High sulphate concentrations in water may give offensive
odour, objectional taste and laxative effects. It may also lead to
crown corrosion in sewers. (Bhatia 2005). The WHO (2004)
permissible limit for sulphate in drinking water is 150mg/l. The
mean sulphate concentration recorded for the leachate sample in
both seasons were lower than the permissible limit for drinking
water. The low sulphate concentration in leachate may be due to
the anaerobic decomposition of sulphates in the waste water by
bacteria to sulphides and hydrogen sulphide according to the
equation below:
SO2-4 + organic matter bacteria S2-+H20+ CO2(g)
S2- +2H H2S(g).
This low value may also suggest low solubility of sulphate
compounds in the generated leachate. The mean sulphate
concentrations recorded for the boreholes, treated water and
stream water samples in both seasons were quite lower than the
permissible limit. This characterized the boreholes water, treated
water and stream water samples as uncontaminated with high
sulphate ions. Similar sulphate concentrations were recorded by
127
Ekpo et al .,(1999) and Omofonmwan et al., (2009). On the
contrary, high sulphate concentrations in the groundwater
samples were recorded by Esmail et al., (2009). The significant
decrease in sulphate concentrations in the boreholes water
samples during the dry season may be due to the low solubility of
sulphate salts. During the dry season some of the sulphate
compounds may have been precipitate out of solution as insoluble
sulphates compounds as ground water infiltrate into the aquifer.
Thus causing a significant decrease in the concentration of
sulphate in the groundwater and surface water samples.
The significant decrease in sulphate ion concentration in
treated water sample during the dry season may depend on the
seasonal variation in the levels of treatment of hardness of water.
The low sulphate concentrations in the stream water, borehole
water and treated water samples suggest that they do not pose
any significant water quality problem.
Chloride (ClChloride (ClChloride (ClChloride (Cl----))))
Chlorides are mineral salts and therefore are not affected
by biological actions. Chlorides in natural water results from the
leaching of chlorides containing rocks and soils with which the
water comes into contact. In water, chlorides ions are usually
present as NaCl, MgCl2, and CaCl2. Chloride concentration of
250mg/l and above, impart a particular taste to water. The WHO
(2004) permissible limit for chloride in drinking water is 250mg/l.
The mean chloride ion concentrations recorded for leachate
samples in both seasons were higher than the permissible limit.
This suggests the presence of dissolve salts of strong basis in the
leachate sample and characterized the leachate as polluted. The
mean chloride concentrations in leachates in both seasons were
similar to the values recorded by Esmail et al., (2009). On the
contrary, these mean values for leachate were higher than the
128
values obtained by Nubi et al., (2008). This variation may be due
to the differences in the wastes composition, the operational
pattern, age of the dumpsite, the size and capacities of the
dumpsites as well as their locations from the wastes sources.
The significant increase in the chloride ion concentration during
the dry season may be due to the seasonal variation in the pH and
volume of leachate generated. High chloride ions in water may
cause taste, and corrosion in hot water systems (Omofonmwan,
2009).
The mean chloride ion concentrations in the boreholes
water, stream water and treated water samples in both seasons
were quite lower than the permissible limits. These low values
correlate positively with the low conductivities, and salinities
recorded for the stream water, boreholes water and treated
water samples. This characterized the water samples as
uncontaminated by leachate from the body of the dumpsite. The
mean chloride ion recorded in the boreholes water samples in
both seasons agrees with the mean values recorded by Ekpo et
al., (1999). According to Trembley et al., (1973), chloride ion
concentrations > 40mg/l in coastal aquifers may indicate salt
water contamination.
Calcium Calcium Calcium Calcium
Calcium in water is probably gotten from silicates and
fluorspars. Calcium is an important ingredient in the diet of men,
animals and plants. Lack of calcium will impair life. In man,
calcium deficiency will inevitably lead to physical defects. In the
case of minor deficiency, tooth decay is a common result. If there
is a major lack of calcium in the human diet, the bones are
affected with diseases such as Rickets as a result. The WHO
(2004) permissible limits for calcium in drinking water is 100mg/l.
The mean calcium concentration measured in the leachate
129
samples in both seasons were higher than the permissible limit.
This suggest the presence of high calcium wastes at the
dumpsite. The mean calcium values obtained for leachates in this
study were similar to the mean values obtained by Ehrig et al.,
(1990); Nubi et al., (2008) and Esmail et al., (2009). On the
contrary, these mean calcium values were higher than the mean
values recorded by Ekpo et al., (1999). The variations in calcium
concentration for leachates may be due to the different waste
composition, the age and location of the respective waste
dumpsite. The mean calcium concentrations obtained in the
borehole water, stream water and treated water samples in both
seasons agrees with the acceptable limits. This characterized
the boreholes water, stream water and treated water samples as
soft, with less hardness related problems.
The significant increase in calcium concentration in the
leachate sample during the dry season may suggest the seasonal
variation of the pH and volume of leachate produced.
Magnesium Magnesium Magnesium Magnesium
The WHO permissible limit of magnesium in drinking water
is 30.0mg/l. The mean magnesium concentrations recorded for
leachates in both seasons were higher than the permissible limit.
This shows that the dumpsite contained significant magnesium
wastes. The boreholes, treated water and stream water samples
in both seasons, show very low concentrations of magnesium
which were below the permissible limits. This suggest that the
samples were soft and may not pose any hardness related
problems. According to Omofonmwan (2009), magnesium and
calcium has some undesirable effects. They may cause
permanent and temporary hardness of water, and gastro-
intestinal irritations if sulphate is present in the water sample.
130
Magnesium in water may naturally have been derived from
dissolution of carbonate bearing rocks. (Ekpo et al., 1999).
Potassium Potassium Potassium Potassium
The mean potassium concentrations in leachates in both
seasons were within the permissible limits. This suggests the
presence of low potassium containing waste at the dumpsite. The
mean potassium concentrations obtained in both seasons for the
boreholes, stream water and treated water samples were
negligible compared to the permissible limits. These low values
reflect low dissolve salts, and low salinity with absence of
objectionable taste. The significant decrease in potassium
concentration in leachate samples during the dry season may
depend on the high solubility of potassium salts. Also during the
wet season, much of the potassium compounds present in the
waste must have been leached away into the ground by
percolating rain water due to high solubility of potassium
compounds. This may give rise to the low potassium
concentration recorded during the dry season.
Sodium Sodium Sodium Sodium
The mean concentrations of sodium in the leachate samples
in both seasons were lower than the permissible limit of 200mg/l.
This suggests that the dumpsite wastes contain little sodium
waste. Also the high solubility of sodium salts coupled with the
high permeability of the dumpsite soil may influence the low
sodium in the examined leachate. The mean sodium
concentration recorded for leachate samples in both seasons
were considerable lower than the mean values recorded by Ekpo
et al., (1999). On the contrary, these mean values agree with the
ranged values recorded by Ehrig el at., (1989). The mean
concentrations of sodium in the boreholes, stream water and
treated water samples, were negligible compared with the WHO
131
standard of 200mg/l. A comparison of the concentrations of the
major elements in groundwater, stream water and treated water
samples with WHO (2004) permissible levels revealed that these
water samples were not polluted. They were soft, portable and
suitable for domestic and other purposes. This indicates that the
leachate apparently do not affect the groundwater.
Ekpo et al., (1999) recorded mean values for sodium in
boreholes which agrees with the mean values obtained in this
study. The significant increase in sodium concentrations in the
dry season for all the boreholes may be due to the presence of
sodium bearing rocks in the soil in which the water comes into
contact. Also, the decrease in the volume of water in the stream
due to evaporation and slow flow rate of the surface stream
during dry season significantly increased the concentrations of
calcium salts.
HeHeHeHeavy Metalsavy Metalsavy Metalsavy Metals
Heavy metals such as copper, cadmium, zinc, lead and
chromium recorded low concentration in leachates, and stream
water samples, whereas in the boreholes and treated water
samples, the mean heavy metals concentrations were negligible
compared to the recommended limits. Iron and manganese
recorded very high concentrations in leachate sample in both
seasons compared with other heavy metals examined.
IronIronIronIron
Ground water in excessive rainfall areas contains iron in toxic
amount of 20mg/l. The maximum permissible limit of iron in
drinking water is 0.3mg/l. The mean concentrations of iron
recorded for the leachate samples in both seasons were
considerably higher than the recommended limits. This indicates
high iron containing waste at the dumpsite and characterized the
leachate as strongly inorganic polluted. Some example of iron
132
bearing wastes materials include: abandon metals Scraps,
dysfunctional electrical equipments, waste from building
activities and other sources. The mean iron concentration
recorded for leachate contradicts the findings of Aluko et al.,
(2007). This variation may depend on the waste composition at
the dumpsite as well as the ages and locations of the respective
dumpsites. The stream water samples also recorded mean iron
concentrations which were slightly above the recommended limit
in both seasons. This may reflect leachate migration from the
body of the dumpsite into the stream water and characterized it
as contaminated. All the boreholes recorded quite low
concentrations of iron in both seasons which were below the
normal range. This indicates that ground water samples in both
seasons were not affected by leachate from the dumpsite. The
mean values for iron in boreholes agrees with the findings of Ekpo
et al., (1999) and Omofonmwan et al., (2009). The significant
increase in iron concentrations in all the boreholes in the dry
season may reflect the presence of significant iron bearing rocks
beneath the boreholes acquifer. Iron has been reported to be the
most abundant element in the earth’s Crust Eddy et al., 2004).
Also, the significant increase in the mean iron concentration in
the leachate sample may depend on the seasonal variation in the
pH and volume of leachate generated. According to Omofonmwan
(2009) water with high iron concentration may cause taste,
discolouration, corrosion of pipes and utensils.
ManganeseManganeseManganeseManganese
The permissible limit for manganese in drinking water is
0.05mg/l. The mean manganese concentration in leachate in both
seasons were higher than the normal range. This suggests
strong leachate pollution due to significant manganese containing
waste at the dumpsite. Examples of manganese containing
133
wastes include; abandoned dry cell batteries, broken glasses,
leather and textile materials etc. The concentration of manganese
in the stream water samples was slightly higher than the
permissible limits in both seasons. This suggests the migration of
leachates and manganese containing wastes from the body of the
dumpsite into the surface stream. Thus, this characterized the
stream water as contaminated. The boreholes water samples in
both seasons recorded negligible manganese concentrations,
and therefore, pose no significant water quality problem as well
as the treated water samples.
Manganese resembles iron in its chemical behaviour and its
occurrence in ground water is less abundant than iron. It is found
to be lower than iron although in deep wells, manganese may
reach concentrations of 2 to 3mg/l (Bhatia, 2005). Manganese
occurs in water as soluble manganese bicarbonate, which
changes to insoluble manganese hydroxide when it reacts with
atmospheric oxygen. Stains produced by manganese, are more
objectionable and harder to remove than iron (Omofonmwan,
2009).
CopperCopperCopperCopper
The mean copper concentrations in leachates in both
seasons were higher than the permissible limit of 1.0mg/l. This
high values indicate significant copper containing waste at the
dumpsite. Some examples of copper containing waste are
dysfunctional copper wires, electrical equipments in which
copper is used as anti-corrosive agent, discarded dry cells and
wet cells. This characterized the leachate at the dumpsite as
polluted. Stream water samples in the wet season recorded mean
copper concentrations which agreed with the permissible limits
whereas in the dry season the copper content exceeded the
permissible limits. Copper concentrations in the groundwater
134
samples and treated water samples in both seasons, agree with
the WHO standards for drinking water.
CCCCadmium admium admium admium
The mean cadmium concentrations recorded for the
leachate sample exceeded the normal range of 0.005mg/l in both
seasons. This suggests the presence of significant cadmium
containing waste at the dumpsite. Some examples of cadmium
containing waste may include, abandon poly vinyl chloride (PVC)
material, nickle – cadmium batteries, plastics in which cadmium is
used as stabilizers and pigments and other cadmium compounds
used in metal electroplating as well as in making cans, packs and
pipes. This characterized strong leachate pollution. The stream
water sample measured mean cadmium concentration in the wet
season which agrees with the normal range, whereas in the dry
season the mean value recorded exceeded normal range of
0.005mg/l. This high value may be due to leachate migration or
runoffs from the dumpsite. As the volume of water and the flow
rate of the stream decreases during the dry season due to
surface evaporation, the concentration of cadmium became
higher than the permissible limit. The sources of cadmium in
water may include the use of galvanized pipes, cisterns and
cadmium containing solder in water hectares. Cadmium ingestion
by human beings may also occur through drinking cadmium
contaminated drinks and water (Bhatia 2005). The concentrations
of cadmium in the boreholes water and treated water samples in
both seasons were quite negligible compared to the permissible
limits. This suggests that ground water was not contaminated by
leachate from the body of the dumpsite.
ZincZincZincZinc
The mean concentration of zinc in the leachate samples in
both seasons were higher than the normal range of 5.0mg/l.
135
Stream water samples in both seasons recorded mean zinc
concentrations which agrees with the normal range. The high zinc
concentrations in the leachate suggest the presence of high zinc
containing waste at the dumpsite. The sources of zinc containing
waste at the dumpsite may be dysfunctional batteries, electrical
equipments, metal cans and packs in which zinc is used as alloy.
Discarded rubbles from construction work. This high value
characterized the leachate as strongly polluted. Zinc
concentrations in all the boreholes water and treated water
samples in both seasons were quite lower than the permissible
limit. This indicates that groundwater and treated water in the
study area are safe for drinking and other domestic purposes.
LeadLeadLeadLead
Leachate samples recorded mean lead concentrations
which were slightly above the normal range of 0.05mg/l. This
suggests the presence of significant lead waste at the dumpsite.
Some examples of lead containing wastes at the dumpsite may be
dysfunctional lead crystal glasses, plastics fishing tools,
ceramics, solders, lead pipes, lead-acid accumulators as well as
discarded paint pigment, cathode ray tubes and containers in
which lead is used as a component. The mean concentrations of
lead in stream water samples in both seasons agrees with the
permissible limit. All the boreholes and treated water samples
recorded mean concentrations of lead in both seasons, which
were quite negligible compared to the local and the international
standards. Lead contamination of water results from the release
of lead containing industrial waste into the soil and water bodies
and the use of lead in plumbing systems which becomes
dissolved by soft water. The mean concentration of lead recorded
in this study for leachates and ground water were lower than the
mean values obtained by Esmail et al., (2009). On the contrary,
136
these mean values were higher than the values of lead recorded
by Ehrig et al., (1989), Christensen et al (1992), Aminia et al.,
(2004) and Yeshida et al., (2002). The effects of lead on the mental
development of children causes the most concern. It has been
calculated that lead can cause a reduction of between 5-15% of a
child’s intelligence depending on the amount found in water
(Esamil et al., 2009).
137
4.3.24.3.24.3.24.3.2 Heavy metal characteristics Heavy metal characteristics Heavy metal characteristics Heavy metal characteristics of soil samples along waste of soil samples along waste of soil samples along waste of soil samples along waste and non waste disposal sites and non waste disposal sites and non waste disposal sites and non waste disposal sites The physico-chemical characteristics in soils at the
biodegradable waste dumpsite and along non-waste dumpsites
indicate that there is an evidence of relative increase in the mean
concentrations of heavy metals in soil at the dumpsite and at the
east of the dumpsite compared with soil samples from the control
site, south, north and west transects of the dumpsite. The
existing soil characteristics at the dumpsite, coupled with
biological and chemical reactions taking place in the waste matrix
may influence the mobility of constituents or by products leading
to high physico-chemical properties in this areas. Therefore, the
properties of soil that require evaluation depend upon the waste
composition and the type of land fill disposal method, as well as
the topography of the area.
The iron contents in soil samples from the dumpsite, from
the control site and from 10 and 20m north, south, west and north
of the dumpsite were below the international limits in both
seasons (3000 to 250,000mg/kg). The significant increase in iron
content in soil samples from west, east, south and north of the
dumpsite compared with the control may suggests significant
amount of iron containing materials which may have come from
the dumpsite. The low iron content in the dumpsite soil may be
due to high permeability of the dumpsite soil and the incline
nature of the dumpsite which may favour the washing away of
wastes components from the dumpsite to the low land
communities.
138
Ademority (1996); Aluko et al., (2003); Dara, (1993) and
Eddy, (2004) reported that natural soils contain significant
concentration of iron. Eddy et al., (2004) suggested that pollution
of the environment by iron cannot be conclusively linked to waste
materials alone but other natural sources of iron must be taken
into consideration. Besides, iron has earlier been reported to be
the most abundant element in Nigeria soil (Amusen et al., 2005).
This agrees with the high iron concentration recorded for soils at
dumpsite and outside dumpsite compared to other metals. The
results of iron recorded by Udeme (2001) and Akaeze (2001) were
considerably higher than the iron concentration recorded in soil
at dumpsite in this study. This variation may depend on the waste
compositions at the dumpsites, the capacity and locations of the
different dumpsites investigated and also on the background
concentrations of iron in soils at different locations.
The lead contents recorded for soil samples from the
dumpsite from the control site and from 10 and 20m outside the
dumpsite in both seasons were below the normal range (15 to
25mg/kg). The significant increase in lead contents of soil
samples from the dumpsite and from the east transect in both
seasons compared with the control may be due to the presence of
significant proportion of lead containing waste at the dumpsite.
There has been increased concern about lead in the environment,
which comes mainly from the use of lead as anti-knock additive to
petrol or in the use of lead in battery accumulators, ceramics,
solders, lead pipes, paint, glasses and plastics.
Lead is toxic even at low concentration and has no known
function in the biochemical process (Haggins and Burns 1995).
The mean concentration of lead in soil at the dumpsite in this
study were lower than the lead values recorded by Eddy et al.,
(2006). Aluko et al (2003) reported mean lead concentration in
139
soil at Ibadan dumpsite to range from 1.34 to 1.69mg/kg. This
values were lower than the lead values obtained in this study for
dumpsite soil.
The zinc contents recorded for dumpsite soil, control soil
sample and soil samples from 10 and 20m north, south, west and
east of the dumpsite in both seasons were below the WHO
international limits (20 to 300mg/kg). The significant increase in
zinc contents for the dumpsite soil and samples from the east
transect in both seasons compared with the control may indicate
significant proportion of zinc waste at the dumpsite waste, which
may affect the soil property negatively. The significant decrease
in zinc content in soil samples from 10m west during the dry
season may indicate that during the wet season some of the zinc
containing compounds along that portion may have been washed
away thereby causing a decrease during the dry season.
Aluko et al (2003) reported low zinc concentrations ranging
from 1.42 to 2.42mg/kg for soils in Ibadan dumpsites. These
range values were significantly lower than the zinc
concentrations recorded for dumpsite soil in this study. The
incorporation of zinc in the manufacture of tyres is a good source
of zinc from tyre abraision Nriagu (1988).
The nickle contents recorded for the dumpsite soil samples,
control sample and soil samples from 10 and 20m east, west,
south and north of the dumpsite in both seasons were all within
the WHO permissible limits (0 to 100mg/kg). The significant
increase in nickle contents of soil samples from the dumpsite and
from 10 and 20m east of the dumpsite in both seasons compared
with the control sample may be due to the presence of significant
proportion of nickle containing waste at the dumpsite.
Nickle can be added into the soil through different solid
wastes materials like dysfunctional ceramics, storage batteries,
140
coloured glasses, textiles, leather, stainless steel, discarded
electrical equipments as well as wearing of mechanical parts. The
concentrations of nickle recorded for the dumpsite soil in this
study in both seasons were higher than the values obtained by
Eddy et al., (2006). A proven source of nickle in the soil is the
wearing of mechanical parts of vehicles (Evans et al., 1980).
The manganese contents records for the dumpsite soil
samples, control and soil samples from 10 and 20m north, south,
west and east of the dumpsite in both seasons were lower than
the WHO international standards (200 to 9000mg/kg). The
significant increase in manganese contents in soil samples from
the dumpsite, from 10 and 20m east and north of the dumpsite in
both seasons compared with the control may reflect significant
proportion of manganese containing waste at the dumpsite which
may affect the soil properties negatively. From the findings at
Elelewo dumpsite reported by Akaeze (2001), the concentration
of manganese were relatively lower than the values recorded in
this study. Udeme (2001) reported concentrations in the range of
263.95 to 406.00mgkg-1 at dumpsite and a range of 19.21 to
485.00mgkg-1 100m away from the dumpsite located within Akwa
Ibom State. Although the range values of manganese reported
for dumpsite soil by Udeme (2001) fall within the normal range of
concentration in soil, there are relatively high compared to the
results obtained for dumpsite soil in this study.
The mean chromium contents recorded for the dumpsite
soil, control soil and soil samples from 10 and 20m east, west,
south, and north of the dumpsite in both seasons were within
international standards (0 to 35mg/kg). The significant increase in
Chromium content of soil samples from the dumpsite and from the
east transect in both seasons compared with the control sample
indicate the presence of significant proportion of chromium
141
containing wastes at the dumpsite which may affect the
surrounding soil properties. The source of chromium in soil may
be attributed to waste like chrome pigment containers as well as
dysfunctional boilers in which chromium is used as anticorrosive
agent.
The mean cadmium contents recorded for the dumpsite soil
samples, control sample and soil samples from 10 and 20m north,
south, west and east of the dumpsite in both seasons were within
the permissible limits (0 -30mg/kg). The significant increase in
cadmium contents in soil sample from the dumpsite and from the
east transect in both seasons compared with the control sample
may suggest significant proportion of cadmium containing waste
at the dumpsite
The positive correlation of the toxic heavy metals in soils at
the dumpsite compared with soil at the east transect may be due
to leaching of leachates and washing away of wastes
contaminants from the dumpsite to the east transect located low
land of the dumpsite. This reflects evidence of impact of the
dumpsite on the ambient environment. Heavy metals such as
chromium, cadmium are added into the soil through rechargeable
batteries, stainless steel tanned leather, fabrics, dysfunctional
electrical equipment such as alloys, and in waste materials in
which chromium and cadmium are used as anti-corrosive agents.
Lead can be added into the soil through discarded paint
materials, aviation fuel and still in some countries gasoline.
Chronic exposure to chromium, cadmium, lead and other heavy
metals in soil may lead to congenital disorder, or can cause other
chronic health conditions.
Many studies internationally and locally have reported high
physico-chemical concentration in leachate, groundwater,
142
surface water and soil samples around solid wastes disposal
sites.
However, the leachate examined in this study in both
seasons recorded high levels of the assessed physico-chemical
parameters, with slightly alkaline pH of 7.50 during the wet
season, low pH of 5.31 during the dry season and low dissolved
oxygen in both seasons. This high parameters may be due to the
presence of different wastes materials at the dumpsite. Similar
finding on leachate were reported by Ehrig et al., (1989)
Christensen et al (1992), Ekpo et al., (1999), Amina et al (2008)
and Esmail et al., (2009). On the other hand this findings
contradicts the findings of Aluko et al., (2003) and Abduhali et al.,
(2000) which revealed low SO42, NO3- and PO43- concentrations
and Yoshida et al., (2002)which reported low electrical
conductivity (EC), low biochemical oxygen demand (BOD) and low
chemical oxygen demand (COD) concentrations. The variations in
the levels of physico-Chemical parameters recorded in the
examined leachate compared to others studies cited above in the
literature may be due to the types of wastes at the dumpsites,
their chemical compositions, the operational pattern and age of
the respective dumpsites as well as the sizes, capacities and
locations of the different dumpsites.
Comparing the physcio-chemical parameter in leachates in
both season revealed significant differences in the mean
concentrations of some of the assessed parameters. The
significant increase in the mean concentrations for some of the
assessed parameters may be due to the increase in the
concentrations of the leachate produced, and decrease in the pH
will enable much of the wastes components to be decomposed
and dissolved into the small volume of the generated leachate.
143
The characteristic of the groundwater (borehole) samples
around the examined solid waste dumpsite revealed low levels of
physico-chemical parameters below the international and local
standards except for phosphate concentration which slightly
exceeded the permissible limits in both seasons. The low levels of
the physico-chemical parameters in the examined boreholes may
be due to the upland location of the boreholes and the dumpsite
respectively. The locations of the boreholes and dumpsite,
influences ground water and leachate flow directions down
gradient. Any infiltrating leachate into the groundwater aquifer is
washed down gradient due to the ground water flow direction.
Salinity, NO3-, NH4+-N, Na, Fe, and Mn showed significant
increase in mean concentrations during the dry season. Similar
observations and results on the physico-chemical characteristics
of groundwater were reported by Ekpo et al (1999) and
Omofonmwan (2009) on ground water samples around solid
waste dumpsites in Calabar and Benin Metropolis. The low
physico-chemical parameters in the groundwater samples in this
study contradicts the high levels recorded by Abu et al (2000),
Talalaj et al (2006), Esmail et al (2009) and Earnest et al (2010).
Also, it contradicts the high levels of the physico-chemical
parameters reported by Longe et al (2007) for ground water
samples located down gradient of an examined dumpsite.
The stream water samples in both seasons recorded high
phosphate, NH4+-N and heavy metals concentrations; Fe, Mn, Cd,
Cu, and Cr, above the permissible limits. Physico-chemical
parameters such as; salinity, DO, BOD5, TSS, Mn, Cd, Fe, Cu, Cr,
and Zn, had significant increase in mean concentrations during
the dry season.
144
The low anions; SO42-, PO4
3-,BOD and COD concentrations in
the examined surface stream in both seasons in this study
disagrees with the high levels of SO42-, PO43-, BOD and COD
recorded by Nubi et al (2008) for river water samples collected
upstream. However, the difference in the levels of the physico-
chemical parameters in the examined surface water samples may
be due to the variations in the volume of the leachate draining into
each surface water, as well as the volume of water in the surface
water.
The heavy metal contents for soil samples from the
dumpsite in both seasons were within the international standards.
These low heavy metal contents contradicts the high heavy metal
contents recorded for dumpsite soil in Nigeria by Alloway (1971),
Amusen et al., (2005) Eddy et al., (2006) and Adefemi et al.,
(2009). However the low heavy metal contents recorded for the
dumpsite soil in both seasons in this study may be due to the
proportion of heavy metal containing wastes at the dumpsite, high
permeability of the dumpsite soil which may be conducive for
leachate infiltration, and also the inclined nature of the dumpsite
which may influence wastes and leachate migration down to the
low land portions.
The general trend for the heavy metal contents in this study
for all the samples examined is as follows: leachate > soil >
stream water > borehole water > treated water.
4444.4.4.4.4 SpikeSpikeSpikeSpikedddd samplessamplessamplessamples
Leachate, borehole water, stream water and treated water
samples were spiked with standard solutions of the heavy metals
analysed. 0.02mg of each of the heavy metal in 4ml of 5mg/l was
mixed with 50ml of each sample before treatment. The prepared
samples were analysed using atomic absorption
145
spectrophotometeric method. The percentage recoveries
recorded in both seasons range between 85 to 113% (Tables 4.13,
4.14, 4.15 and 4.16). The presence of interferences in the
samples may have significantly interfered with the percentage
recovery result recorded in both seasons.
Percentage (%) recovery = spiked result X spike volume X 100 expected result sample volume 1
Expected result = sample result + standard concentration.
For borehole 1 (BH1) the percentage recovery for iron (Fe) in the
wet season was calculated as follows. (Table 9.1a).
Spike results = 0.40mg/l., 0.38mg/l, 0.42mg/l
Expected results = 0.44mg/l, 0.45mg/l, 0.55mg/l.
Standard concentration = 5mg/l X 4ml = 0.4mg/l 50ml
Spike average = 0.40±.0.02mg/l
Expected average = 0.47±0.16mg/l
% recovery (1) = 0.4 X 54 X 100 = 98% 0.44 50 1 % recovery (2) = 0.38 X 54 X 100 = 91% 0.45 50 1 % recovery (3) = 0.42 X 54 X 100 = 82.5% 0.55 50 1 Average = 98+.91+82.5 3
=90±6%
146
Table Table Table Table 4.134.134.134.13:::: Recovery analysis for heavy metals in spiked leachate, groundwater, stream water and treated water samples during Recovery analysis for heavy metals in spiked leachate, groundwater, stream water and treated water samples during Recovery analysis for heavy metals in spiked leachate, groundwater, stream water and treated water samples during Recovery analysis for heavy metals in spiked leachate, groundwater, stream water and treated water samples during
wet season.wet season.wet season.wet season.
Parameter
Iron (Fe) mg/l). Manganese (mn) mg/l) Copper (Cu) mg/l) Cadmium (Cd) mg/l)
Expected
result
Spike
result
%
Recovery
Expected
Result
Spike
result
%
Recovery
Expected
result
Spike
result
%
Recovery
Expected
result
Spike
result
%
Recovery
Leachate 47.6±7 45.3±8 103±7% 39.9±6 37.4±5 101±2% 6.2±0.3 5.6±0.3 97±0.01% 3.8±0.9 3.6±07 101±1%
BH1 0.47±0.16 0.40±0.02 90±6.6% 0.44±0.02 0.40±0.01 97±3.4% 0.4 0.32±0.01 86±3.4% 0.4 0.36±0.02 97±4%
BH2 0.48±0.04 0.42±0.03 96±5.3% 0.42±0.02 0.36±0.02 91±4.3% 0.4 0.32±0.02 86±5.6% 0.4 0.34±0.02 91±3.2%
BH3 0.47±0.02 0.46±0.04 106±5.% 0.41±0.02 0.38±0.01 100±2% 0.4 0.35±0.02 95±4% 0.4 0.360±02 97±5.6%
BH4 0.44±0.03 0.38±0.01 94±12% 0.41±0.01 0.38±0.01 98±3% 0.4 0.37±0.01 100±5% 0.4 0.37±0.04 101±10%
SW 0.88±0.2 0.86±0.2 105±4% 0.48±0.03 0.46±0.02 102±081% 0.71±035 0.65±0.3 99±3 0.4 0.34±0.01 93±3%
TW 0.42±0.01 0.37±0.02 96±3% 0.41±0.01 0.34±0.02 90±6% 0.4 0.34±0.01 92±4% 0.4 0.33±0.02 89±5.5%
147
Table Table Table Table 4.144.144.144.14:::: Recovery analysis for heavy metals Recovery analysis for heavy metals Recovery analysis for heavy metals Recovery analysis for heavy metals in spiked leachate, groundwater, stream water and tin spiked leachate, groundwater, stream water and tin spiked leachate, groundwater, stream water and tin spiked leachate, groundwater, stream water and treated reated reated reated
water samples during wetwater samples during wetwater samples during wetwater samples during wet season.season.season.season.
Parameter
Chromium (Cr) mg/l). Zinc (Zn) mg/l) Lead (Pb) mg/l)
Expected
Result
Spike
result
%
Recovery
Expected
Result
Spike
Result
% Recovery Expected
result
Spike
result
%
Recovery
Leachate 2. ±1 1.9±1 98±2% 17.7±2.6 16.8±2 103±0.01% 13.2±9 12±8 99±3%
BH1 0.4 0.35±0.01 95±3% 0.4 0.34±0.03 91±7.8% 0.4 0.37±0.008 100%
BH2 0.4 0.39±0.01 105±4.% 0.4 0.38±0.02 103±5% 0.4 0.35±0.03 95±5.%
BH3 0.4 0.38±0.02 102±5% 0.4 0.39±0.02 105± 0.4 0.35±0.02 94±4%
BH4 0.4 0.39± 105±8% 0.4 0.34±0.02 92±6% 0.4 0.31±0.02 85±5%
SW 0.4 0.36±0.01 98±2% 0.4 0.33±0.03 89±4% 0.4 0.34±0.02 93±1%
TW 0.4 0.33±0.02 88±6% 0.4 0.34±0.01 93±3% 0.4 0.33±0.01 90±7%
148
Table Table Table Table 4.154.154.154.15:::: Recovery analysis for heavy metalsRecovery analysis for heavy metalsRecovery analysis for heavy metalsRecovery analysis for heavy metals in spiked leachate, groundwater, stream water and treated in spiked leachate, groundwater, stream water and treated in spiked leachate, groundwater, stream water and treated in spiked leachate, groundwater, stream water and treated
water samples during dry season.water samples during dry season.water samples during dry season.water samples during dry season.
Parameter
Iron (Fe) mg/l). Manganese (Mn) mg/l) Copper (Cu) mg/l) Cadmium (Cd) mg/l)
Expected
result
Spike
result
%
Recovery
Expected
result
Spike
result
%
Recovery
Expected
Result
Spike
result
%
Recovery
Expected
Result
Spike
result
%
Recovery
Leachate 114.8±2.1 112.66±1.63 106±3% 48.66±0.83 46.16±0.56 103±2.1% 37.1±0.71 35.0±0.46 108±4% 15±0.30 14.0±0.25 104±6%
BH1 0.73±0.01 0.62±0.3 94±1.8% 0.13±0.01 0.11±0.01 94±1.5% 0.40 0.33±0.02 89±2% 0.4 0.34±0.08 92±3%
BH2 0.49±0.03 0.41±0.01 89±3% 0.53±0.02 0.46±0.01 96±4% 0.4 0.34±0.03 93±2% 0.4 0.33±0.04 92±3%
BH3 0.38±0.01 0.32±0.01 94±0.8% 0.52±0.05 0.48±0.02 98±1.2% 0.4 0.35±0.04 94±2% 0.4 0.39±0.01 104±6%
BH4 0.75±0.05 0.68±0.03 101±4% 0.51±0.02 0.44±0.01 94±1.% 0.4 0.37±0.01 100% 0.4 0.35±0.02 94±4%
SW 2.75±0.04 2.70±0.02 111±2% 2.81±0.01 2.68±0.02 103±3% 4.35±0.05 4.03±0.03 102±3% 1.009±0.02 0.99±0.01 100%
TW 0.53±0.01 0.47±0.01 96±1% 0.45±0.03 0.41±0.01 100% 0.4 0.36±0.0l 97±4% 0.4 0.35±0.01 94±0.8%
149
Table Table Table Table 4.164.164.164.16:::: RecoveryRecoveryRecoveryRecovery analysis for heavy metals analysis for heavy metals analysis for heavy metals analysis for heavy metals in spiked leachate, groundwater, stream water and treated in spiked leachate, groundwater, stream water and treated in spiked leachate, groundwater, stream water and treated in spiked leachate, groundwater, stream water and treated
water samples during water samples during water samples during water samples during dry dry dry dry season.season.season.season.
Parameter
Chromium mg/l). Zinc (Zu) (mg/l) Lead (pb) mg/l)
Expected
result
Spike
result
% Recovery Expected
result
Spike
result
% Recovery Expected
result
Spike
result
% Recovery
Leachate 77±0.03 7.30±0.01 103±5% 0.4 32.6±0.6 102±6% 31±0.05 26.8±0.04 93±3%
BH1 0.4 0.32±0.07 86±4% 0.4 0.33±0.03 89±2% 0.4 0.35±0.02 94±6%
BH2 0.4 0.32±0.01 87±4% 0.4 0.34±06 92±5% 0.4 0.33±0.01 90±1%
BH3 0.4 0.37±0.08 100% 0.4 0.36±0.10 97±3% 0.4 0.35±0.2 95±4%
BH4 0.4 0.33±0.03 91±3% 0.4 0.35±0.05 95±1% 0.4 0.33±0.01 90±3%
SW 0.76±0.01 0.67±0.03 100% 4.85±0.1 4.31±0.09 93±2% 0.4 0.35±0.05 95±2%
TW 0.4 0.36±0.03 98±3% 0.4 0.35±0.01 95±1% 0.4 0.36±0.02 96±3%
150
5.1 Summary and ConclusionSummary and ConclusionSummary and ConclusionSummary and Conclusion
The results of the parameters analysed in this study reveal
that leachate from the barracks road dumpsite recorded pH
values of 7.55 and 5.13 during the wet and dry seasons. It
indicated high levels of pollution and most of the parameters
recorded very high concentrations beyond the international
standards for drinking water in both seasons; such as turbidity
(141.46 and 171.17FTU), TSS (125.2 and 159.61mg/l), TDS (1709.5
and 2043mg/l), BOD5 (52.2 and 76.17mg/l), conductivity (2518.2
and 2946.3 µs/cm), NH4+-N (2.8 and 6.20mg/l), PO43- (146-53 and
126.2mg/l), Cl- (284.34 and 536 mg/l), NO-2 (6.17 and 6.13mg/l),
NO-3 (74.03 and 87.83mg/l), Ca (22 1.86 and 364.23mg/l), heavy
metals; Fe (47.33 and 113.13mg/l), Mn (39.76 and 57.2mg/l), Cr
(1.63 and 7.63mg/l), Zn (17.33 and 34.5mg/l) and Pb (12.33 and
31.13mg/l); and low DO oxygen values (1.73 and 2.73mg/l). The
leachate sample recorded significant increase in Ca, Cl-, COD,
TSS, conductivity, turbidity, Fe, Cu, Cd, Zn, Pb and a significant
decrease in SO42- concentrations (284.37 to 144.97mg/l) during
the dry season (P<0.05).
The physico-chemical parameters analysed, for all the
borehole water and treated water samples agree with the
international standards for drinking water. Borehole one samples
recorded significant increase in salinity (0.22 to 0.65mg/l), NH+4-N
(2.8 to 6.2mg/l), Fe (0.08 to 0.33mg/l) and Mn (0.04 to 0.15mg/l).
BH2 recorded significant increase in Na (23.87 to 68.93mg/l),
NH4+-N (0.31 to 0.66mg/l), Fe (0.08 to 0.36mg/l) and Mn (0.02 to
0.13mg/l); BH3 recorded significant increase in salinity (0.19 to
0.59mg/l), Na (1.94 to 5.07mg/l), Fe (0.03 to 0.34mg/l), Mn (0.01 to
0.12mg/l) and a significant decrease in SO42- values (3.55 to
1.36mg/l). BH4 recorded significant increase in salinity (0.19 to
0.55mg/l), K (2.27 to 3.33mg/l) NH4+-N (0.38 to 0.65mg/l), Fe (0.04
CHAPTER FIVE SUMMARY AND CONCLUSION
151
to 0.35mg/l), Mn (0.02 to 0.11mg/l) and a significant decrease in
SO42- (3.04 to 0.36mg/l).
Most of the physico-chemical properties examined in the
stream water samples in both seasons agree with the
international standards, except for high, Fe (0.61 and 2.5mg/l) and
PO43- (4.21 and 5.96mg/l) in both seasons, and high Mn (2.37mg/l),
Cr (0.42mg/l), Cd (0.46mg/l) and Cu (3.95mg/l) during the dry
season only. The stream water sample recorded significant
increase in salinity (0.3 to 0.98mg/l), BOD5 (1.32 to 2.57mg/l), Na
(1.54 to 6.5mg/l) Cu (0.32 to 3.95mg/l), Mn (0.08 to 2.37mg/l), Cd
(0.005 to 0.46, Cr (0.004 to 0.42mg/l) and a significant decrease in
DO values (5.8 to 4.33mg/l).
The heavy metals results for soil samples from the
dumpsite, 10 and 20m outside the dumpsite and from the control
site agree with the international standards. Soil samples from the
dumpsite recorded significant increase in heavy metals contents
in both seasons at P<0.05; Fe (1813.0 and 1804mg/kg), Pb (9.90
and 11.82mg/kg); Zn (137.0 and 146.0mg/kg), Ni (12.56 and
11.82mg/kg), Cr (3.60 and 4.05mg/kg), Cd (9.05 and 12.2mg/kg)
and Mn (94.0 and 91.2mg/kg) compared with the results from the
control site; Fe (1791.56mg/kg) Pb (3.78mg/kg), Zn (50.90mg/kg),
Ni (2.19mg/kg), Cr (1.06mg/kg), Cd (1.09mg/kg) and Mn
(44.27mg/kg).
Thus these findings infer that;
1. The leachate samples from the dumpsite in both seasons
show high levels of pollution, with high physico- chemical
and heavy metal contents.
2. The effect of the leachate on the borehole water samples in
both season was not apparent.
3. The leachate from the dumpsite affected the qualities of the
surface and soil around the dumpsite.
152
4. There was a significant increase in COD, Fe, Mn, Cu, Zn and
Cd contents for leachate sample; Fe, Mn for the borehole
water samples and Fe , Mn and BOD5 for the stream water
samples at P<0.05 during the dry season.
5.25.25.25.2 RecommendationsRecommendationsRecommendationsRecommendations
1. At present, groundwater is suitable for domestic
purposes.
2. The stream water flowing at the study area requires
requisite treatment for its intended use during the wet
and dry seasons.
3. At present, soil at dumpsite and outside the dumpsite is
suitable for agricultural activities since the heavy metal
concentrations in the soil were below the permissible
limit in both seasons.
4. Periodic monitoring of ground water, stream water and
soil around the dumpsite should be encouraged at both
government and individual levels to know the current
levels of the assessed parameters.
5. Seminars and campaign programs should be set up to
sensitize the populace on the dangers of solid waste to
the environment and human health.
6. The state and federal ministry of environment should
adopt a good waste management approach to the
indiscriminate disposal of waste to the environment. This
can be achieved by practicing resource recovery
methods like, reducing, reusing recycling and
restoration of damaged environment.
7. The chemical composition of waste to be disposed at the
dumpsite should be determined before they are finally
disposed or utilized for beneficial purposes.
153
8. A drainage system should be constructed around the
dumpsite to reduce water fluxes at the dumpsite and
leachate production. This will help to reduce the rate and
volume of leachate migration into the stream and low
land soils.
9. Based on the outcome of this research, steps needed to
be taken to review the efficiency of the refuse dumpsite,
including advancement in technology and location of
dumpsite at appreciably distance to our water bodies, as
well as replacing municipal dumpsites with proper
engineered landfills in Nigeria.
5.35.35.35.3 Contributions to knowledgeContributions to knowledgeContributions to knowledgeContributions to knowledge
Waste deposition at dumpsite may lead to the production of
a highly polluted liquid substance (leadchate) which may
contaminate the soil, surface water and groundwater samples if it
comes into direct contact with them.
Most of the physical, chemical and heavy metal content in
leachate, soil and water samples show mark variations in both
seasons.
5.45.45.45.4 Suggestion for further studiesSuggestion for further studiesSuggestion for further studiesSuggestion for further studies
This research work has not put an end to further research
on the topical issue around the examined dumpsite. Rather, it
should served as a “seed” from which similar findings may make
reference of . This work only determined the inorganic pollutants
known to impact on human health. Therefore, organic pollutants
in the soil and water around the dumpsite known to impact
negatively on human health should be assessed.
154
Also, air quality assessment around the dumpsite should be
carried out so as to determine the level of impact on the ambient
air around the dumpsite.
The wastes components at the dumpsite should be analysed
for their respective chemical parameters, as this will reveal the
chemical nature of the wastes disposed of.
Health implication of the solid waste disposal at the
examined dumpsite should be embarked upon by correlating sex
of workers, years of service and exposure factors with different
health related problems such as eye irritations, difficulty in
breathing, asthma, cough, pneumonia, malaria, typhoid,
dysentery and fatigue.
155
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165
Appendix I Independent P-values t-test for the physio-chemical parameters in ground water, surface stream, treated water and leachate
BH1 BH2 BH3 BH4 SW TW LEAC
Temperature 0.03 0.011 0.011 0.008 0.051 8E-04 0.036 pH 0.07 0.341 0.313 0.638 0.648 0.366 0.154 Turbidity 0.95 0.836 0.264 0.712 0.071 0.519 0.048 Salinity 0.02 0.008 0.002 0.006 0.004 0.189 0.006
Conductivity 0.68 0.142 0.47 0.093 0.109 0.189 0.001 Diss. Oxy 0.77 0.469 0.587 0.169 0.002 0.106 0.076 COD 0.23 0.442 0.613 0.338 0.148 1 0..017 BOD 0.21 0.5 0.278 0.07 0.002 0.064 0.073
R. Potential 0.16 0.766 0.441 0.871 0.713 0.505 0.251 T.Suspension 0.99 0.183 0.297 0.205 0.018 0.519 0.016 T.D. Solids 0.45 0.212 0.992 0.634 0.214 0.033 0.003 Ca 0.12 0.705 0.787 0.908 0.525 0.009 0.001
Mg 0.83 0.434 0.356 0.497 0.119 0.104 0.074 K 0.51 0.165 0.359 0.017 0.096 0.183 2E-04 Na 0.01 0.016 0.014 7E-04 0.006 0.087 0.078 HCo3 0.51 0.35 0.402 0.443 0.647 0.242 0.713 Nitrate 0.452 0.343 0.221 0.423 0.508 0.314 0.97
Ammonium 0.02 0.031 0.781 0.003 0.081 0.008 0.207 Phosphate 0.13 0.121 0.211 0.08 0.604 0.797 0.153 Sulphate 0. 01 0. 08 0. 029 0. 009 0. 581 0. 019 0. 647 Cl 0. 21 0. 104 0. 19 0. 298 0. 138 0. 217 0. 006
Fe 0. 02 0. 034 0. 007 0. 032 0. 057 3E-04 0. 007 Mn 0. 01 0. 006 0. 002 0. 003 0. 007 0. 002 0. 05
166
APPENDIXAPPENDIXAPPENDIXAPPENDIX IIIIIIII
WHO (2004) Standards for physico-chemical parameters in
portable water
Parameter Water
Temperature (oC) 12-25
Conductivity µs/cm 1400
pH 6.5-9.5
DO (Mg/l) 4.0
BOD5 (Mg/l) 0.5
Chloride (Mg/l) 250
Phosphate (Mg/l) 0.1
Sulphate (Mg/l) 500
Nitrate (Mg/l) 45
Nitrite (Mg/l) 0.1
Ammonium (Mg/L) 0.5
Turbidity (FTU) 25
Sodium (Mg/L) 200
Magnesium (Mg/L) 30.0
Potassium (Mg/L) 200
Calcium (Mg/L) 100
Iron (Mg/L) 0.3
Cadmium (Mg/L) 0.005
Chromium (Mg/L) 0.05
Lead (Mg/L) 0.05
Copper (Mg/L) 1.0
Zinc (Mg/L) 5.0
Manganese (Mg/L) 0.05
167
APPENDIXAPPENDIXAPPENDIXAPPENDIX IIIIIIIIIIII
World Health Organization (WHO 2004) standards for physico-
chemical parameters in soil.
Parameter Soil
Sodium (Mg/kg) 400-37000
Potassum (Mg/kg) 200-24000
Calcium (Mg/kg) 300-3100
Magnesium (Mg/kg) 1300-3500
Iron (Fe) (Mg/kg) 3000-250,000
Lead (Pb) (Mg/kg) 15-25
Zinc (Zn) (Mg/kg) 20-300
Nickle (Ni) (Mg/kg) 0-100
Managanese (Mg/kg) 200-9000
Chromium (Cr) (Mg/kg) 0-85
168
APPENDIX IV
Selected physical characteristics of soil sampled along wastes and non-wastes dumpsite Uyo-Akwa Ibom State
Field Code
Coordinates Distance from Central point
Particle size distribution (%)
Textural class
Silt/clay ratio
Bulk density (mgm-3)
Pore Space (%)
Moisture Content (%)
Sand Silt Clay
SS0 05o02’34”N 007o56’01”E
0.00 88.6 3.00 8.40 S 0.36 1.80 32 16.99
SSE1 05o02’31”N 007o56’04”E
10.0 74.66 10.98 14.36 Sl 0.76 1.70 36 19.09
SSE2 05o02’29”N 007o56’06”E
20.0 75.76 12.34 11.90 Sl 1.03 1.65 30 17.54
SSS1 05o02’35”N 007o56’03”E
10.0 76.66 10.98 12.36 Sl 0.89 1.50 43 11.36
SSS2 05o02’33”N 007o56’05”E
20.0 78.54 9.67 11.79 Sl 0.82 1.56 34 14.56
SSW1 05o02’30”N 007o56’03”E
10.0 76.66 10.22 13.12 Sl 0.78 1.60 40 18.56
SSW2 05o02’24”N 007o56’07”E
20.0 76.45 10.32 13.23 Sl 0.78 1.86 36 17.45
SSN1 05o02’23”N 007o55’53”E
10.0 70.66 4.98 24.34 Scl 0.20 1.40 47 18.76
SSN2 05o02’21”N 007o55’50”E
20.0 75.89 6.56 17.55 Scl 0.37 1.54 40 15.66
169
APPENDIX VAPPENDIX VAPPENDIX VAPPENDIX V
Selected chemical characteristics of soil sampled along wastes and non-wastes dumpsite Uyo-Akwa Ibom State
Field Code
Distance from central pt
PH EC (dsm-1)
Org C(%)
Total N(%)
Base Seat/ (%)
C.N ratio
SS0 0.0 6.45 0.130 1.52 0.06 81.89 25
SSE1 10.0 6.80 0.212 5.03 0.21 85.11 24
SSE2 20.0 5.60 0.201 4.45 0.24 75.65 19
SSS1 10.0 6.48 0.068 1.85 0.08 74.24 23
SSS2 20.0 6.10 0.124 2.28 0.06 82.45 38
SSW1 10.0 5.94 0.047 2.37 0.10 75.47 24
SSW2 20.0 5.54 0.025 1.45 0.09 78.45 16
SSN1 10.0 5.34 0.038 0.65 0.02 69.70 33
SSN2 20.0 6.50 0.026 1.68 0.05 75.45 34
