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Environmental Engineering II (CE 3233)
Chapter: Solid Waste Management
Reference: 1. Water Supply and Sanitation by F. Ahmed and M.M MujiburRahman (ITN) – Part II Chapter 14
2. Environmental Engineering by Peavy, Rowe and Tchobanoglous
Lecture prepared by
Md Nuruzzaman
Lecturer, Department of Civil Engineering
Bangladesh Army University of Engineering and Technology (BAUET)
E-mail: [email protected], [email protected]
Phone: +8801719456829
Solid Wastes
Solid waste can be defined as useless, unwanted and discarded materials
coming from production and consumption.
Solid waste management
It encompasses all aspects concerning waste generation, onsite handling
and storage, collection, transportation, treatment, reuse/recycle and final
disposal.
Types of solid waste
1.Municipal waste
2. Industrial waste
3.Hazardous waste
Solid Waste Management
Municipal Waste
Solid wastes that are generated in residential and commercial
installation are termed as municipal waste. It primarily include food
waste, rubbish, ashes and residue, demolition and construction
wastes, street sweeping etc.
Industrial waste
Solid wastes that are derived as by-products from industrial operations
and manufacturing process, or discarded as useless.
Solid Waste Management
Hazardous waste
Waste that pose a substantial danger immediately or over a period of
time to human, plant, or animal life are classified as hazardous waste.
Waste is grouped as hazardous waste if it exhibits any of the following
characteristics:
1. Ignitability
2.Corrosivity
3.Reactivity
4.Toxicity
Solid Waste Management
Hazardous waste
Hazardous wastes are classified into 5 groups
1.Radioactive substances
2.Chemicals
3.Biological wastes
4.Flammable wastes
5.Explosives
Main source of hazardous biological waste are hospitals and
biological research facilities and industries.
Solid Waste Management
Definitions
Garbage/food waste
These are the putrescible wastes primarily resulting from food products.
•They include cooked and uncooked vegetables, fruits and other food
leftovers
•decompose quickly, resulting in unpleasant odors
•Need immediate attention for handling and disposal
Rubbish
It includes both combustible and non-combustible substances such as
paper, cans, broken glass, wood, cardboard, scrap metals etc.
Solid Waste Management
Definitions
Residential wastes
Waste generated in houses and apartments- may include paper,
cardboard, food cans, plastics, food waste, glass containers, garden
waste etc.
Commercial waste
Solid waste generated in commercial and service establishments such
as office buildings, hotels and restaurants, shops, market places etc.
Demolition and construction wastes
Waste produced from demolition and or construction of buildings roads
and other structures—include brick bat, concrete pieces , sand,
electrical wires glasses pipes etc.
Solid Waste Management
Definitions
Agricultural waste
Waste generated from agricultural activities such as growing plants
and raising animals – include plant stalks, leaves, husk and animal
manure.
Resource recovery
Extraction of economically useable materials and energy from wastes.
Re-use
Reclamation of material in its end-use form and its subsequent use in
the same form. Example—milk or soft drink bottles (i.e. glass) that
make several trips from the bottler to the consumers.
Solid Waste Management
Definitions
Recycling
Reprocessing of wastes to recover an original raw material. Example
– used news papers are recycled to make new paper.
Material conversion
Utilization of wastes in a different form of material such as compost
from newspaper or paving material from auto tires.
Energy recovery
Capturing the heat value from organic wastes, either by direct
conversion or by first converting it into an intermediate fuel products.
Solid Waste Management
Solid Waste Management
Effects of solid waste mismanagement
Specific problems associated with inadequate solid wastemanagement are:
1. foul odour near waste storage bins that are not emptied regularlyor not washed and disinfected periodically;
2. blocking of drainage systems resulting in wastewater overflowdue to indiscriminate dumping of solid wastes;
3. soiled streets due to inadequate street sweeping, uncontrolledlittering and dumping of domestic wastes.
4. Spreading of wastes by scavenging birds and animals nearuncollected garbage bins, other collection points and uncontrolleddumping sites;
Solid Waste Management
Effects of solid waste mismanagement
5. pollution of surface water bodies and groundwater) by leachatefrom solid wastes disposed of without proper planning anddesign;
6. land pollution from untreated and inadequately treated industrialwastes containing toxic substances and heavy metals;
7. indiscriminate disposal of hospital wastes that containpathogenic organisms which may lead to spread of infectiousdiseases;
8. transmission of vector-borne diseases;
9. health risks to solid waste workers and scavengers.
Solid Waste Management
Functional Elements of SWM
Solid Waste Management
Functional Elements of SWM
Waste generation
Involves those activities in which materials are identified as no longer
being of value and therefore are thrown away as useless or gathered
together for disposal.
On-site handling and storage
Activities associated with the handling, storage and processing of solid
wastes at or near the point of generation.
Collection
Activities associated with the gathering of solid wastes and hauling of the
wastes after collection to a location where the collection vehicle is
emptied.
Solid Waste Management
Functional Elements of SWM
Transfer and transport
Activities associated with the transfer of wastes from the smaller
collection vehicle to larger transport equipment and subsequent
transport of the waste, usually over a long distance, to the disposal site.
Processing and recovery
Those techniques, equipment and facilities used both to improve the
efficiency of the other functional elements and to recover usable
materials, conversion products or energy from solid wastes.
Solid Waste Management
Functional Elements of SWM
Final disposal
Activities associated with ultimate disposal of solid wastes including
those wastes collected and transported directly to a landfill site
Solid Waste Management
Factors affecting the generation rate of solid wastes:
1. Geographic location
2. Season of the year
3. Collection frequency
4. Population characteristics
5. Public attitudes
6. Extent of salvage and recycling
7. Legislation
Solid Waste Management
Physical Composition of Solid Waste
Physical composition of solid waste involves the followings:
1. Identification of the individual components
2. Analysis of particle size
3. Moisture content
4. Density of solid waste
• Physical composition
1.Individual Components
Solid Waste Management
2.Particle size
The size of the component materials in solid wastes is of importance in
the recovery of materials, especially with mechanical means such as
trommel screens and magnetic separators.
3.Moisture Content
It is usually expressed as the mass of moisture per unit of wet or dry
material. The wet-mass moisture content is expressed as follows:
Moisture content(%)=(a-b)X100/a,
Where a= Initial mass of sample as delivered
b=Mass of sample after drying
Solid Waste Management
3.Moisture Content
Solid Waste Management
4. Density
Density of solid waste vary with
geographic location, season of
the year and length of storage.
Solid Waste Management
• Energy content
Chemical composition is important in evaluating alternative processing
and energy recovery option.
1.Proximate analysis
▪ Moisture(loss at 1050 C for 1 hr)
▪ Volatile matter(additional loss on ignition at 9500 C)
▪ Ash (residue after burning)
▪ Fixed carbon(remainder)
Solid Waste Management
• Energy content
2. Ultimate analysis– percentage of C, H, O, N, S, and ash
3. Ash analysis
▪ Flushing point of ash
▪ Ash residue
4. Energy Value
▪ As discarded basis
▪ Dry weight basis
▪ Ash-free dry basis
Solid Waste Management
On-site Storage
Factors that must be considered in the on-site storage of solid wastes
include:
(i) Type of container to be used,
(ii) The container location,
(iii) Public health and aesthetics, and
(iv) The collection methods to be used.
Solid Waste Management
Methods of solid waste collection
• Communal collection
• Block collection
• Curb-side collection
• House to House collection
Solid Waste Management
Classification of solid waste collection systems
• Hauled container system
• Stationary Container System
Solid Waste Management
Hauled container system
Collection system in which the containers used for the storage of wastes
are hauled to the processing, transfer, or disposal site, emptied, and
returned to either their original location or some other location are
defined as hauled container system.
Stationary Container System
Collection system in which the containers used for the storage of wastes
remain at the point of waste generation, except when moved for
collection are defined as stationary collection system.
Solid Waste Management
Solid Waste Transportation
Selection of vehicle should be made depending on the following
considerations;
1. Characteristics of waste
2. Method of collection
3. Types of roads to be served
4. Ease of maintenance and availability of spare parts
5. Cost of operation
Solid Waste Management
Processing of Solid Waste
Purposes of processing solid waste:
1. To improve the efficiency of solid waste management systems;
2. To recover usable materials
3. To recover conversion products and energy
Solid Waste Management
Techniques of processing solid waste management
1. Mechanical volume reduction (compaction)
2. Chemical volume reduction (incineration)
3. Component separation (manual and mechanical)
4. Mechanical size reduction (shredding)
5. Moisture content reduction (drying and dewatering)
Solid Waste Management
Source separation
Source separation may be defined as the setting aside of the recyclable
wastes at their point of generation for segregated collection and
transport.
The primary aim of source separation is to isolate valuable items from
mixed waste stream.
Solid Waste Management
Resource recovery
Resource recovery from mixed waste stream involves the centralized
processing of collected raw wastes to separate out recyclable materials
and to convert the remaining fraction into useful materials or energy
forms.
Solid Waste Management
Options related to resource recovery
1. Re-use of useable items in household wastes, e.g. glass bottles,
metal containers, etc.;
2. Direct application of the wastes on land;
3. Recycling through material recovery processes;
4. Energy recovery through thermal combustion, incineration, etc.;
5. Composting and other chemical or biological processes;
Solid Waste Management
Incineration
Incineration is a process of reducing the combustible portion of the waste
to an inert residue by high temperature burning. The products of
combustion are ash, gases and heat energy. Incineration is used to
sterilize refuse.
Solid Waste Management
Recycling process in Bangladesh
Wastes in Bangladesh are salvaged basically in three steps:
(1) In the first stage, housewives separate refuse of higher market value
such as papers, bottles, fresh containers, old clothes, shoes, etc. and
sell them to street hawkers.
(2) Mostly, children of slum dwellers also known as Tokai carry out the
second stage of salvaging. They collect broken glass, cardboard,
waste papers, plastics, etc. from waste collection bins.
(3) Scavengers at the final disposal sites do the third stage of salvaging
when municipal trucks unload fresh refuse.
Solid Waste Management
Composting
Composting is the process of bacterial conversion of organic solid and
semisolid wastes into compost, which can be handled, stored and
transported without any adverse environmental effect, and can be used
as organic manure for improvement of soil quality and fertility.
Solid Waste Management
Favorable changes induced by Composting to soil
1. Increases organic content of the soil
2. Increases moisture retention capacity
3. Improves aeration at root zone
4. Improves soil texture
5. Increases soil fertility
6. Replenishes micro-nutrients in soils
Solid Waste Management
Factors affecting composting
1. The waste material subjected to composting must be biodegradable.
2. Suitable numbers and types of micro-organisms must be present.
3. The rate and efficiency of composting are dependent on the activity of
micro-organisms.
4. Environmental factors like pH, temperature and presence of oxygen
control the process.
5. The waste must be nutritionally balanced.
6. The presence of toxic substances has adverse effects on the
process.
Solid Waste Management
Basic Composting processOrganic Solid wastes
Salvaging/Packaging
Screening/Sorting
Shredding/pulverizing
Moisture adjustments
Aerobic composting
Maturing
Processing/Bagging
Saleable compost
Salvageable
Non compostable
Water additives
Air
𝐶𝑂2 , Excess air, 𝑁𝐻3
Figure: Flow diagram showing the basic process of aerobic composting
Solid Waste Management
Chemical Constituents Percent by weight
Organic matter 25-50
Carbon 8-50
Nitrogen (as N) 0.4-3.5
Phosphorus(as 𝑃2𝑂3) 0.3-3.5
Potassium as (𝐾2𝑂) 0.5-1.8
Ash 20-60
Calcium(as 𝐶𝑎O) 1.5-7.0
Solid Waste Management
Characteristic of Compost
Control parameters of effective aerobic composting
There are several important parameters which have to be in desirable
conditions for effective aerobic composting to occur at high
temperatures. Some of these parameters are discussed below:
1. Moisture Content
Moisture content should be in the range of 50-60% during the
composting process, the optimum being about 55%. When the
moisture contents drops much below 50%, the composting process
becomes slow.
Solid Waste Management
2. Carbon- nitrogen ratio
An optimum balance between carbon (C) and nitrogen (N) content in
necessary because the bacteria need a minimum supply of nutrients
to survive.
• Bacteria use carbon as an energy source and nitrogen for cell
building.
• The initial carbon –nitrogen ratio is a deciding factor in the speed
at which the decomposition takes place
• The ideal initial ratio is between 30:1 and 35:1 and if it exceeds
50, the time required increases considerably.
Solid Waste Management
2. Carbon- nitrogen ratio
• In solid waste the main source of nitrogen is the
vegetables/ putrescible matter which has a C/N ratio of
about 24:1 and the paper is the main source of carbon.
• Thus the higher the ratio of paper to vegetable/ putrescible
matter, the higher the C/N ratio.
Solid Waste Management
3. Oxygen requirements
• The availability of air is the key to the aerobic process of
composting. It is however very difficult to determine the exact
oxygen requirements because it depends many other factors
such as temperature, moisture content and availability of
nutrients
• A approximate method of monitoring the sufficient oxygen
supply is to check the compost for foul odours. Presence of
foul odours indicate the insufficient supply of oxygen.
Solid Waste Management
4. Temperature:
• Temperature is also the key factor affecting the biological activity.
• The broad range of optimum temperatures for the composting
process, 45-66 ºC helps a large variety of microorganisms to
precipitate in the process.
• Higher temperature for example 60-70 ºC for about 24 hours
should be maintained for pathogen destruction.
Solid Waste Management
5. pH control
• The optimum pH range for most bacteria is between 6.0 and 7.5
• During the initial period (first 2 to 3 days) pH drops to 5.0 or less
and then begins to rise to about 8.5 for the remainder of the
aerobic process
• If the digestion is allowed to become anaerobic the pH will drop to
about 4.5
• To minimize the loss of nitrogen in the form of ammonia gas, pH
should not rise above 8.5
Solid Waste Management
Major considerations for composting of solid wastes in
Bangladesh
• Availability and sustainability of wastes
• Socio-economic conditions
• Technological access
• Marketing for compost
• Affordable prices for farmers
• Environmental legislation and enforcement
• Present disposal cost
• Institutional support
Solid Waste Management
Ultimate disposal methods of solid waste
➢ Sanitary landfilling
➢ Ocean Disposal
➢ Atmospheric disposal
➢ Land farming
➢ Deep-Well Injection
➢ Incineration
Solid Waste Management
Ultimate Disposal
Sanitary Landfill
Sanitary landfill may be defined as the operation in which wastes to be
disposed of are compacted in layers and covered with a layer of earth
at the end of each day’s operation. When the landsill site reaches its
ultimate capacity, a thick final layer of cover material is applied.
Solid Waste Management
Factors for selecting potential landfill sites for disposal of solid
wastes
1. Ensure that sufficient land area is available for disposal of
solid wastes for a reasonable period of time, preferably longer
than one year as for shorter periods the disposal operation is more
expensive
2. Haul distance, route location, local traffic patterns and access
condition must be considered.
3. Soil condition and topography of the site should be considered
so that the cover material is available at or near the landfill site.
Solid Waste Management
Factors for selecting potential landfill sites for disposal of solid
wastes
4. Climate conditions e.g., wind patterns and local surface water
hydrology of the area should be considered.
5. It is to be ensured that the movement of the leachate and the
gases from the landfill will not contaminate the groundwater
aquifer.
6. Extreme care is necessary in the operation of the landfill so
that it is environmentally acceptable with respect to noise,
odor, dust and vector control.
Solid Waste Management
Factors for selecting potential landfill sites for disposal of solid
wastes
7. The issue of the ultimate use of the completed landfill site is to be
considered prior to the layout and design of the proposed landfill.
Solid Waste Management
Figure: Typical sectional view of a sanitary landfill
Compacted solid waste
CellCell
Final cell
Cell
Daily cover
Final cover on slope face
3:1 typical slope
6 in. intermediate cover
Bench as required
Final cover system
Fin
al li
ftLi
ftLi
ftC
ell h
eig
ht
Lift
he
igh
t
Landfill liner system
Cell-width (variable)
Solid Waste Management
Methods of landfilling
1. Trench method
2. Area method
Trench method- It involves the excavation of a trench. The waste is
then placed into the trench, spread and compacted. The excavated soil
serves as cover material.
Area method- It does not involve excavation of trenches. Instead
wastes are spread and compacted on the surface of the ground. Cover
material is then spread and compacted over the layer of waste. This
area method is suitable on flat and gently sloping land
Solid Waste Management
Aspects for consideration in design and operation of sanitary
landfill
1. Landfill site selection
2. Landfilling methods and operation
3. Design of landfills
4. Gas and Leachate in landfills
5. Operation of landfills
6. Environmental factors
Solid Waste Management
Leachate
Leachate may be defined as liquid that has percolated throughsolid waste and has extracted dissolved or suspendedmaterials from it. In most landfills, the liquid portion of theleachate is composed of the liquid produced from thedecomposition of the wastes and liquid that has entered the landfillfrom external sources, such as surface drainage, rainfall,groundwater, and water from underground springs.
Solid Waste Management
Ocean Disposal of Solid Wastes
The idea of ocean disposal is that the ocean is a gigantic sink, inwhich an infinite amount of pollution of all types can be dumped, hasbeen discarded.
Landfarming
Landfarming is a waste-disposal method in which the biological,chemical, and physical processes that occur in the surface of the soilare used to treat biodegradable industrial wastes.
Solid Waste Management
Deep-Well Injection
Deep-well injection for the disposal of liquid wastes involvesinjecting the wastes deep in the ground into permeable rockformations (typically limestone or dolomite) or underground caverns.
Solid Waste Management
Environmental Engineering II (CE 3233)
Chapter: Food Sanitation
Reference: Principles of Food Sanitation by Norman G. Marriott Robert and B. Gravani
Lecture prepared by
Md Nuruzzaman
Lecturer, Department of Civil Engineering
Bangladesh Army University of Engineering and Technology (BAUET)
E-mail: [email protected], [email protected]
Phone: +8801719456829
Food Sanitation
Food Sanitation
Applied to the food industry, sanitation is the creation and
maintenance of hygienic and healthful conditions.
Sanitation applications refer to hygienic practices designed to
maintain a clean and wholesome environment for food production,
processing, preparation, and storage.
Foodborne Disease
A foodborne disease is considered to be any illness associated withor in which the causative agent is obtained by the ingestion of food.
Food Sanitation
Contamination Sources
1. Red Meat Products
Contamination of meat occurs from the external surface, such ashair, skin, and the gastrointestinal and respiratory tracts.
2. Poultry Products
The processing of poultry, especially defeathering and evisceration,permits an opportunity for the distribution of microorganisms.
3. Seafood Products
Seafoods are excellent substrates for microbial growth and arevulnerable to contamination during harvesting, processing,distribution, and marketing.
Food Sanitation
Contamination Sources
4. Adjuncts
Ingredients (especially spices) are potential vehicles of harmful orpotentially harmful microorganisms and toxins.
5. Equipment
Contamination of equipment occurs during production, as well aswhen the equipment is idle.
6. Employees
Of all the viable means of exposing microorganisms to food,employees are the largest contamination source
Food Sanitation
Contamination Sources
7. Air and Water
Contamination can result from airborne microorganisms in foodprocessing, packaging, storage, and preparation areas. Water canalso serve as a source of contamination.
8. Sewage
If raw sewage drains or flows into potable water lines, wells, rivers,lakes, and ocean bays, the water and living organisms such asseafood are contaminated.
Food Sanitation
Contamination Sources
9. Insects and Rodents
Flies and cockroaches are associated with living quarters, eatingestablishments, and food processing facilities, as well as with toilets,garbage, and other filth. These pests transfer filth from contaminatedareas to food through their waste products; mouth, feet, and otherbody parts; while the regurgitation of filth onto clean food duringconsumption.
Food Sanitation
Potential contamination of food by humans
Food Sanitation
Micro-organisms
A microorganism is a microscopic form of life found on all non-sterilized matter that can be decomposed. These organismsmetabolize in a manner similar to humans through nourishmentintake, discharge of waste products, and reproduction.
Food Sanitation
Types of Micro-organisms related to food sanitation
Three types of microorganisms occur in foods.
(1) Beneficial
Beneficial microorganisms include those that may produce newfoods or food ingredients through fermentation(s) (e.g., yeasts andlactic acid bacteria) and probiotics.
(2) Spoilage
Spoilage microorganisms, through their growth and ultimatelyenzymatic action, alter the taste of foods through flavor, texture, orcolor degradation.
(3) Pathogenic
Pathogenic microorganisms can cause human illness.
Food Sanitation
What causes microorganisms to grow?
1. Temperature
2. Oxygen Availability
3. Relative Humidity
4. Water Availability
5. pH
6. Oxidation-Reduction Potential
7. Nutrient Requirements
8. Inhibitory Substances
9. Interaction between Growth Factors
10.Role of Biofilms
Food Sanitation
Micro-organisms Common to Food
1. Molds (multicellular microorganisms, 30 to 100 μm in diameter)
2. Yeasts (generally unicellular, likely to grow on foods with lowerpH)
3. Bacteria (unicellular microorganisms, 1 μm in diameter)
4. Viruses (infective microorganisms with dimensions that rangefrom 20 to 300 nm)
Food Sanitation
HACCP
The Hazard Analysis Critical Control Point (HACCP) program is apreventive approach of consistent safe food production.
The program focuses on safety and not quality and should beconsidered separate from or a supplement to quality assurance.HACCP was incorporated to guarantee that food used in the U.S.space program would be 100% free of bacterial pathogens.
Food Sanitation
The HACCP concept is divided into two parts:
(1) Hazard analysis and (2) Determination of critical control points.
A hazard is the potential to cause harm to the consumer.
A critical control point (CCP) is an operation or step by whichpreventive or control measures can be exercised that will eliminate,prevent, or minimize a hazard (hazards) that has (have) occurredprior to this point.
Food Sanitation
Food safety and acceptability are most affected by:
(1) contaminated raw food or adjuncts.
(2) improper temperature control during processing and storage(time-temperature abuse).
(3) improper cooling through failure to cool to refrigeratedtemperature within 2 to 4 hours.
(4) improper handling after processing, cross-contamination(between products or between raw and processed foods).
(5) ineffective or improper cleaning of equipment.
(6) failure to separate raw and cooked products.
(7) poor employee hygiene and sanitation practices
Food Sanitation
HACCP Development
1. Facilities: The facilities should be located, constructed, andmaintained according to sanitary design principles
2. Supplier control: Continuing supplier guarantee and supplierHACCP system verification.
3. Specifications: Written specifications for all ingredients,products, and packaging materials.
4. Production equipment: Constructed and installed according tosanitary design principles with preventive maintenance andcalibration schedules that are established and documented.
Food Sanitation
HACCP Development
5. Cleaning and sanitation: All procedures should be written andfollowed.
6. Personal hygiene: All personnel entering the manufacturing areashould follow the requirements for personal hygiene.
7. Training: All employees should receive training in personalhygiene, GMPs, cleaning and sanitation procedures, personalsafety, and their role in the HACCP program.
8. Chemical control: Documented procedures must be adopted toassure the segregation and proper use of nonfood chemicals (i.e.,cleaning compounds, fumigants, pesticides, and rodenticides) in theplant.
Food Sanitation
HACCP DEVELOPMENT
9. Receiving, storage, and shipping: Raw materials and productsshould be stored under sanitary conditions.
10. Traceability and recall: Raw materials and products should belot-coded and a recall system developed so that rapid and completetraces and recalls may be accomplished when necessary.
11. Pest control: An effective past control system should beimplemented.
Food Sanitation
Definitions related to Sanitizing Methods
A sterilant is an agent that destroys or eliminates all forms ofmicrobial life.
A disinfectant is an agent that kills infectious fungi and vegetativebacteria although not necessarily bacterial spores on inanimatesurfaces. Disinfection is a less lethal process than sterilization.
A sanitizer is a substance that reduces, but not necessarilyeliminates microbial contaminants on inanimate surfaces to levelsthat are considered to be safe from a public health standpoint. Asanitizer is effective in destroying vegetative cells
Food Sanitation
Sanitizing Methods
1. Thermal
2. Steam
3. Hot Water
4. Radiation
5. Vacuum/Steam/Vacuum
6. Chemical Sanitizing
Food Sanitation
Desired Sanitizer Properties
The ideal sanitizer should have the following properties:
1. Microbial destruction properties of uniform, broad-spectrumactivity against vegetative bacteria, yeasts, and molds to producerapid kill.
2. Environmental resistance (effective in the presence of organicmatter [soil load], detergent and soap residues, and waterhardness and pH variability)
3. Good cleaning properties
4. Nontoxic and nonirritating properties Water solubility in allproportions
Food Sanitation
Desired Sanitizer Properties
1. Acceptability of odor or no odor
2. Stability in concentrated and use dilution
3. Ease of use
4. Ready availability
5. Inexpensive
6. Ease of measurement in use solution
Environmental Engineering II (CE 3233)
Chapter: Air Pollution
Reference: Environmental Engineering by Peavy, Rowe and Tchobanoglous(Part 2 – Chapter 7: Air)
Lecture prepared by
Md Nuruzzaman
Lecturer, Department of Civil Engineering
Bangladesh Army University of Engineering and Technology (BAUET)
E-mail: [email protected], [email protected]
Phone: +8801719456829
Air Pollution
Definition
Air pollution may be defined as any atmospheric condition in whichsubstances are present at concentrations, above their normalambient levels, to produce measurable adverse effect on man,animal, vegetations or materials.
Air Pollution
Origin
1. Natural
All air contains natural contaminants such as pollen, fungi spores,salt spray and smoke and dust particles from forest fires and naturalvolcanic eruptions. It also contains naturally occurring CO,Hydrocarbon, H2S and CH4 from anaerobic decomposition oforganic matter
2. Anthropogenic (man-made activities)
Use of fossil fuel for heating and cooling, transportation, industry,incineration, etc.
Air Pollution
Types of sources:
1. Mobile Sources/Transportation such as motor vehicle, rail, ship,aircraft, etc
2. Stationary Sources: include utility, industrial and institutional andcommercial facilities. Examples are power plant, heating plant,paper and pulp industry, petroleum, refineries, municipal wastecombustion
3. Area sources: including many individual activities like gasolineservice station, small paint shops, open burning of solid waste,agricultural wastes, cooking, etc.
Air Pollution
Types of sources:
5. Household and commercial waste
6. Agriculture burning
7. Industrial and hazardous waste incineration
8. Miscellaneous
(a) Domestic fuel, wood burning
(b) Forest fire, volcanic eruption, Chemical and materials used indifferent process
Air Pollution
Classification
According to Origin
Primary Pollutants: those emitted directly to the atmosphere andfound there in the form in which they are emitted (Stable form),e.g.SOx, NOx, HC
Secondary Pollutants: derived from the primary pollutants bychemical or photochemical reaction or by hydrolysis or oxidation intothe atmosphere e.g. O3 and Peroxyacetyl Nitrate (PAN)
Air Pollution
Classification
According to Chemical Composition
Organic: HC: Benzene, Methane Hexane, etc
Inorganic: CO, CO2, SOX, NOX, H2S, NH3, etc
According to State of Matter
Gaseous: CO, CO2, NOx, SOx, CH4, etc
Particulate/Aerosole: dust, smoke, fumes, fly ash, etc (specificparticulate size)
Air Pollution
Effects of air pollution
1. Effect on atmospheric properties
Air pollution affect atmospheric properties in the following ways:
I. Visibility reduction
II. Fog formation and precipitation
III. Solar radiation reduction
IV. Temperature and wind direction alteration
V. Possible effect on global climate change
Air Pollution
Effects of air pollution
2. Effects on materials
Air pollutants can affect materials by soiling or chemicaldeterioration
3. Effects on vegetation
Gaseous pollutants enter plant through stomata in the course ofnormal respiration of plant. Once in the leaf, pollutants destroychlorophyll and disrupt photosynthesis.
Air Pollution
Effects of air pollution
4. Effects on human health
Extremely high concentrations of air pollutants (for several hrs/days)can result in serious Air Pollution Episodes, causing significantdeath or injuries.
Air Pollution
Particulates
Particulates are any dispersed matter, solid or liquid, in whichthe individual aggregates are larger than a single smallmolecule (about 0.002 µm in dia) but smaller than about 500µm .
Air Pollution
Mode of formation of Particulates
Dust: small solid particles created by breakdown of largemasses by crushing, grinding or blasting or processing andhandling of materials such as coal, cement or grains. Settleunder the influence of gravity. Size ranges from 1.0 to 10,000µm.
Fumes: solid particles that are formed by the vaporcondensation. Sizes ranges from 0.03 to 0.3 µm.
Air Pollution
Mode of formation of Particulates
Mist, fog: liquid particles or droplets formed by thecondensation of vapor. Mist are usually less than 10 µm indiameter. If the mist concentration is high enough to obscurevisibility, the mist is called a fog.
Smoke: fine, solid particles resulting from incompletecombustion such as coal, wood, tobacco, etc. Size rangesfrom 0.5 to 1.0µm.
Spray: liquid particles formed by atomization of parent liquidssuch as pesticides and herbicides. Size ranges from 10 to1000µm.
Air Pollution
Air quality index (AQI):
AQI is a tool that simplifies reporting air quality to the generalpublic. It has been adopted by USEPA and is used by manycities to report to the public an overall assessment of a givenday’s air quality.
• Color is key for communication
• Ranges from 0 to 500 (no units)
• Provides indicator of the quality of the air and its healtheffects
Air Pollution
AQI Value Air Quality Descriptor Color Code
0-100 Good Green
1001 -200 Unhealthy Orange
201-300 Very Unhealthy Violet
301-500 Extremely Unhealthy Red
Purpose of AQI:
1. To inform people about air quality conditions in a simple format
2. Promote public interest and action to reduce emissions
AQI categories in Bangladesh:
Environmental Engineering II (CE 3233)
Chapter: Noise Pollution
Reference: Environmental Noise by Pollution Enda Murphy Eoin A. King
Lecture prepared by
Md Nuruzzaman
Lecturer, Department of Civil Engineering
Bangladesh Army University of Engineering and Technology (BAUET)
E-mail: [email protected], [email protected]
Phone: +8801719456829
Noise Pollution
Definition
Environmental Noise is unwanted sound created by human activitiesthat is considered harmful or detrimental to human health andquality of life.
Sources of Noise Pollution
• Transportation systems are the main source of noise pollution in urban areas.
• Construction of buildings, highways, and streets cause a lot of noise, due to the usage of air compressors, bulldozers, loaders, dump trucks, and pavement breakers.
• Industrial noise also adds to the already unfavorable state of noise pollution.
• Loud speakers, plumbing, boilers, generators, air conditioners, fans, and vacuum cleaners add to the existing noise pollution.
Noise Pollution
Noise Pollution
Effects of Noise Pollution
Solutions for Noise Pollution
1. Planting bushes and trees in and around sound generating sources is an effective solution for noise pollution.
2. Regular servicing and tuning of automobiles can effectively reduce the noise pollution.
3. Buildings can be designed with suitable noise absorbing material for the walls, windows, and ceilings.
4. Workers should be provided with equipment such as ear plugs and earmuffs for hearing protection.
Noise Pollution
Solutions for Noise Pollution
5. Similar to automobiles, lubrication of the machinery and servicing should be done to minimize noise generation.
6. Soundproof doors and windows can be installed to block unwanted noise from outside.
7. Regulations should be imposed to restrict the usage of play loudspeakers in crowded areas and public places.
8. Factories and industries should be located far from the residential areas.
Noise Pollution
Environmental Engineering II (CE 3233)
Chapter: Water Pollution
Reference: Environmental Engineering by Anil Kumar De and Amab Kumar De
Lecture prepared by
Md Nuruzzaman
Lecturer, Department of Civil Engineering
Bangladesh Army University of Engineering and Technology (BAUET)
E-mail: [email protected], [email protected]
Phone: +8801719456829
Water Pollution
The symptoms of water pollution of any water body/ground waterare:
• Bad taste of drinking water,
• Offensive smells from lakes, rivers and ocean beaches,
• Unchecked growth of aquatic weeds in water bodies(eutrophication),
• Dead fish floating on water surface in river, lake, etc.
• Oil and grease floating on water surface.
Water Pollution
Water Pollutants
The large number of water pollutants are broadly classified underthe categories:
1. Organic pollutants,
2. Inorganic pollutants,
3. Sediments,
4. Radioactive materials and
5. Thermal pollutants.
Water Pollution
Organic Pollutants
These include domestic sewage, pesticides, synthetic organiccompounds, plant nutrients (from agricultural run-off), oil, wastesfrom food processing plants, paper mills and tanneries, etc. Thesereduce dissolved oxygen (D.O.) in water.
Inorganic Pollutants
This group consists of inorganic salts, mineral acids, metals, traceelements, detergents, etc.
Water Pollution
Sediments
Soil erosion, as a matter of natural process, generates sediments inwater. Soil erosion is enhanced 5–10 times due to agricultural and100 times due to construction activities.
Radioactive Materials
Radioactive pollution is caused by mining and processing ofradioactive ores to produce radioactive substances, use ofradioactive materials in nuclear power plants, use of radioactiveisotopes in medical, industrial and research institutes and nucleartests.
Water Pollution
Thermal Pollutants
Coal-fired or nuclear fuel-fired thermal power plants are sources ofthermal pollution. The hot water from these plants is dumped aswaste into nearby lake or river where its temperature rises by about10°C.
Water Pollution
Eutrophication
Sewage and agricultural run-off provide plant nutrients in watergiving rise to the biological process known as eutrophication. Largeinput of fertiliser and nutrients from these sources leads toenormous growth of aquatic weeds which gradually cover the entirewaterbody (algal bloom). This disturbs the normal uses of water asthe water body loses its D.O. and ends up, in a deep pool of waterwhere fish cannot survive.
Environmental Engineering II (CE 3233)
Chapter: Sustainability of WSS and community management
Reference: Water Supply and Sanitation by M.F. Ahmed and M.M Rahman (ITN) – Part I: Chapter 1 and 2
Lecture prepared by
Md Nuruzzaman
Lecturer, Department of Civil Engineering
Bangladesh Army University of Engineering and Technology (BAUET)
E-mail: [email protected], [email protected]
Phone: +8801719456829
Sustainability of WSS
Sustainability
The success of sustainability of a project is achieved when it meets
its objectives and is maintained by its users over a significant period
of time.
Criterion of Sustainability of a water supply system
1. Provides an efficient and reliable services at a level which is
desired.
2. Can be financed or co-financed by the user with limited but
feasible external support and technical assistance.
3. Is being used in an efficient and effective way, without negatively
affecting the environment.
Dimensions of sustainability
1. the user community wanting an efficient and reliable service
2. The technology that has to provide it
3. The institutional environment
4. Efficient use of service
Sustainability of WSS
Reliable services over time for sustainability
1. Coverage
2. Continuity
3. Quantity
4. Quality
5. Cost
Sustainability of WSS
The user community
The user community is composed of different groups of people with
common but often also conflicting interest and ideas.
Community Management
Basic requirements for community management
1. Enabling environment which guarantees that user groups and
communities can legally establish water enterprise to manage
their water supply system.
2. A technology with operation and management requirements that
are within the capacity of the local level.
3. A level of service that responds to a realistic demand of the
community.
4. Partnership attitudes between agencies and communities or user
groups.
Community Management
Basic requirements for community management
5. Transparent decision making ensuring that informed choices can
be made.
6. Impartial institution that has power of authority.
7. Adequate monitoring to enable to learn from the process.
Community Management