PROCESSING OF GREEN WASTE FOR PRODUCTION OF COMPOST

Siti Nurbaidzuri Binti Reli @ Raily

TD 796.5 S623 2013 Master of Environmental Science

(Land Use and Water Resource Management) 2013

Pusat Khidmat MakJumat Akademik UNIVERSm MALIl.'I'SJA SARAWAK

P.KHIOMAT MAKLUMAT AKAOEMIK

111111111 Ili'ijjj 111111111 1000246934

PROCESSING OF GREEN WASTE FOR PRODUCTION OF COMPOST

SITI NURBAIDZURI BT RELI (11031869)

This thesis is submitted in partial fulfillment of the requirements for the Master of

Environmental Science (Land Use and Water Resource Management)

Faculty of Resource Science and Technology

Universiti Malaysia Sarawak

2013

-Student's Certification

I hereby certified that the present work is my own except for the paraphrases, quotations,

elaboration and summaries with each source quoted.

I also accord th~ copyright of the quotation to the Faculty of Resource Science of

Technology for publication if deemed fit.

Submission date Sitiit-uri bt Reli @ Raily

Supervisor's Endorsement

This graduation exercise entitled PROCESSING OF GREEN WASTE FOR

PRODUCTION OF COMPOST was prepared and submitted by SITI NURBAIDZURI

BINTI RELI @ RAlLY as a partial fulfillment of the requirement for the Master of

Environmental Science (Land Use and Water Resource Management).

Prof. Dr. K pli bin Bujang Supervisor, Faculty of Resource Science and Technology University Malaysia Sarawak

ACKNOWLEDGEMENf

I thank Allah, the Most Gracious and the Most Merciful for giving me strength,

patience and blessing to deal with my studies in completing my master project for the SLUSE

programme. For those without whom, there never would have been this written material. I

would like to express my appreciation to my parent whose help was invaluable in giving me

inspiration, love and motivation to succeed . Special thanks and appreciation to my project

supervisor Prof. Dr. Kopli bin Bujang for his sound and critical comments, opinions and

countless hours spent in helping and guiding with this project. My gratitude goes to my

lecturers for the knowledge given throughout my study at UNIMAS. Special thanks to Dewan

Bandaraya Kuching Utara (DBKU) for allowing me to conduct my project at their Compost

Centre, Sejingkat, Kuching. Finally, I wish to thank my friends, who have in many ways

encouraged and challenged me to perform my best.

Pusat Khidmat Maklumat Akademik e~IVERSm MALAYSIA SARAWAK

TABLE OFCONIENIS

Acknowledgement

Table of Contents II

List of Abbreviations v

List of Tables and Figures vi

Abstract ix

Abstrak x

1.0 INTRODUCTION 1

l.l Background of the study

1.2 Research problem 3

1.3 Problem statement 3

1.4 Objectives of the study 4

1.5 Scope of the field study 5

1.6 Significant of the study 5

2.0 LITERATURE REVIEWS 6

2.1 Composting 6

2.2 Parameters of composting 8

2.3 Municipal green waste management at DBKU 12

2.4 Documentation of green waste management 13

3.0 MATERIALS AND METHODS 14

3.1 Preliminary study 14

3.2 Materials 16

ii

163.2.1 Compost A

173.2.2 Compost B

173.3.3 Compost C

3.3 Methods 18

3.3.1 Preparation for box composting 18

3.3.2 Preparation of compost materials 20

3.4 Controls and the composting process 23

3.4.1 Aeration 23

3.4.2 Monitoring compost heap temperature 24

3.5 Analyses 25

3.5.1 Physical analysis 25

3.5.2 Maturity analysis 26

3.5.3 Physical characteristic of grind compost 31

3.5.4 C:N Ratio 32

4.0 RESULTS AND DISCUSSIONS 33

4.1 Temperature of compost piles 33

4.1.1 Compost A 33

4.1.2 Compost B 35

4.1.3 Compost C 36

4.2 Moisture Content 37

404.3 Carbon-to-nitrogen ratio (CIN)

424.4 Compost weight reduction

434.5 Water and dry matter loss

444.6 Germination analyses

iii

4.6.1 Compost A

4.6.2 Compost B

4.6.3 Compost C

4.6.4 Germination index

4.6.4.1 Compost A

4.6.4.2 Compost B

4.6.4.3 Compost C

5.0 CONCLUSION

6.0 REFERENCES

7.0 APPENDICES

44

49

53

56

57

58

59

62

64

68

iv

-

usr OF ABBREVIATIONS

DBKU Dewan Bandaraya Kuching Utara

°c Degree Celsius

GJ Germination Index

C/N Carbon to Nitrogen ratio

% Percentage

Kg Kilogram

nun Millimeter

em Centimeter

CO2 Carbon dioxide

m Meter

L Liter

v

usr OF TABlFS

No Title Page

Delivery of green wastes of fruit and vegetable from wholesalers to 13 DBKU compost centre, Sejingkat between February 2012 to

December 2012

2 Moisture content and dry matter of the compost 38

3 Table of carbon an nitrogen content in compost 40

4 Reduction of weight 42

5 Water and dry matter loss of Compost A, Band C 43

6 Table of Germination Index after two days of incubation in the dark 56

usr OF FIGURES

No Title Page

Interview with Mr. Henable Henry Nessan 15

2 Processing of green wastes at compost centre 15

3 Compost A material 16

4 Compost B material 17

5 Compost C material 18

6 Compost boxes 19

7 19Compost boxes under canopy

8 20Preparation of compo sting materials for Compost A

vi

No Title Page

9 21Preparation of composting materials for compost B. (a) Size reduction of

materials and (b) mixing of the matrix in the composting box

10 22Preparation of composting materials for Compost C

II Mixing and turning of compost materials to control temperature, aeration 23 and enhance microbial degradation

content

analyses

12 Measurement of ambient temperature 24

13 Measurement of compost temperature 24

14 Weighing compost samples before and after drying to analyze moisture 25

15 Preparation of compost extract for Maturity and Germination Index 27

16 Preparation of samples for Maturity and Germination Index (GI) tests 28

17 Germinated green bean seeds 29

18 Germinated cabbage seeds 29

19 Measurement of root length 29

20 Physical characteristic of compost 31

21 Carbon and nitrogen analysis using CHN analyzer 32

22 Temperature profile of Compost A 34

23 Temperature profile of Compost B 35~

24 Temperature profile of Compost C 36

Moisture content of Compost A, Band C

26 Germination of green bean seeds on Compost A 45

25 38

vii

55

57

60

61

-"

No Title Page

46

28 Mean of root length for green bean seeds on Compost A 47

27 Germination of cabbage seeds on Compost A

48Mean of root length for cabbage seeds on Compost A

30 Germination of Green Bean Seeds on Compost B 49

A)

31 Germination of cabbage seeds on Compost B 50

32 Mean of root length for green bean seeds on Compost B 51

33 Mean root length of cabbage seeds on Compost B 52

34 Germination of Green Bean Seeds on Compost C 53

35 Germination of cabbage seeds on Compost C 54

36 Mean root length of green bean seeds on Compost B 55

37 Mean root length of cabbage seeds on Compost C

38 Green bean seeds germinated in 100% compost concentration (Compost

39 Germination Index (%) for green bean seeds

40 Germination Index (%) for cabbage seeds

29

VIII

-Processing of Green Waste for Production of Compost

Siti Nurbaidzuri binti Reli @ RaiJy

Master of Environmental Science Faculty of Resource Science and Technology

Universiti Malaysia Sarawak

ABSTRACf

The use of compost in plantation is very important as an amendment to the soil. This study was not only

significant in reducing the amount of waste in landfills but also helps the city to process their green wastes and to

produce their own compost for landscape activities. It is essential to encourage composting by transforming any

potential green wastes to become a usable and high quality end product. Aeration, temperature and moisture

content are three imponant principals which control the composting proces . A total of 365 kg of green waste

was used as materials for composting and towards the end of the process the weight was reduced by 160.4 kg.

This study foc uses on the process of green wastes to produce compost and explores the suitable type of material

used. The m thod used was box composting due to its simple operation, with manual turning once a week. Three

types of compost namely Compost A, Compost B and Compost C was produced from different types of green

wastes. Green wastes used for compost A were fruits, vegetables, green leaves, grasses and compost materials

from DBKU c mpost centre that has undergo decomposition for about two months. Hence. compost A was only

used as the baseline in this study. Compost B consisted of grasses, leaves, vegetables and fruits. Compost C was a

mixture of grasses and leaves from garden trimming. The initial weight of fresh Compost Band C was 87.9 kg

and 56.4 kg and the weight loss after 30 days of composting was 52.2 kg (59.4%) and 26.6 kg (52.5%),

respectively. The weight of the final marketable product from Compost B was 35.7 kg and Compost C at 26.8 kg.

From the re ult of this study, the best compost was compost C (C/N ratio 12:1, weight reduction of 52.5%)

which gave the highest Germination Index at 171 % (Green bean seeds test), germinated in 20% compost

concentration.

Key word: Green waste, compost, Germination Index

IX

Pemprosesan Sisa Hijau untuk Penghasilan Kompos

Siti Nurbaidzuri binti Reli @ Raily

Master of Environmental Science Faculty of Resource Science and Technology

Universiti Malaysia Sarawak

ABSTRAK

Kompos ada/ah penting untuk tanaman dan sebagai pel/yubur tallah. Kajian ini tidak hanya penting untuk

mengurangkan timbunan sampah di pusat pelupusan sampah tetapi juga membantu bandar ini ulltuk memproses

sisa hijau dall menghasilkan kompos untuk aktiviti pengurusan landskap. Adalah sangat penting untllk

menggalakkall kegiatall penghasilan kompos dengan menukar sisa hijau kepada produk yang berguna serta

berkualiti tinggi. Pengudaraan, suhu dan kelembapan adalah tiga prinsip penting yang mengawal penghasilall

kompos. Kajlall ini memberi fokus kepada proses penghasilan kompos menggllnakan sisa hijau serta mengkaji

jenis bahall YIlng sesuai digunakan. Kaedah yang digunakan adalah kotak kompos kerana pengendalianllya yang

mudah dan proses pembalikall ulltuk penglldaraan dilakukall seminggu sekali:Tiga kompos dalam kajiall ini iaitu

Kompos A, Kompos B dan Kompos C dihasilkan menggullakan sisa hijau yang berbeza. Jenis sisa hijau yang

digullakan untuk menghasilkan Kompos A adalah buah-buahan, sayur-sayuran, rumput, daun dan kompos yang

disediakan olell pihak pusal kompos Dewan Bandaraya Kuching Utara yang telah melallli proses pereputan

selama 2 bulall. Oleh itu, Kompos A hanya beifungsi sebagai tanda aras Ilntuk kajian illi. Kompos B pula terdiri

daripada, rumpul, daun-daun, sayur-sayuran dan buah-buahall. Kompos C adalah campuran rumput dan daun

daripada kerja pemangkasall taman. Berat awal Kompos A dan Kompos B adalah 87.9 kg dall 56.4 kg dan berat

kompos yang hilallg selepas 30 hari masing-masing adalah 52.2 kg (59.4%) dan 26.6 kg (52.5%.). Berat hasi!

akhir yang boleh dipasarkan untuk Kompos B adalah 35.7 kg dan Kompos C pada 26.8 kg. Hasil daripada kajian

ini mendapali kompos terbaik adalah Kompos C (nisbah karbon kepada nitrogen adalah 12:1, berat kompos

berkurangan sebllnyak 52.5%) dengan nilai index percambahan yang paling tinggi pada 17J% (ujian biji benih

kacang hijau), percambahan dalam kepekatan 20% larutan kompos.

Kala kunci: Sisa hijau, kompos, index percambahan

x

CHAPTERl

INTRODUCTION

1.1 BACKGROUND OF THE STUDY

Composting is a self-starting, self-heating and in certain circumstances, self­

limiting process (Finstein and Morris, 1975). Compost spread on soil surfaces as a

mulch to enrich and insulate the soil takes time before it actually enters the ground.

The mulch of soil can help in retaining soil moisture in dry conditions and help to

suppress weeds. Besides it can protect the soil from winds and heavy rain that may

cause damage to the soil. The compost started showing its importance and really works

when the organic matter gets into the soil. This is because soil structure depends

almost entirely on organic matter. Besides the compost is the favors habitat for worms

and other organisms.

The process of composting has been utilized as an agricultural practice for the

recycling of organic wastes by returning organic wastes of the society back to the land

in order to maintain soil fertility. The composting process return the nutrients to the

soil which could and did take place utilizing the crude raw wastes without recourse to a

specific or standard methodology in order to produce a 'composting' effect.

Composting is one of the options for solid waste management, treatment and

di posal options. Composting can be applied in many countries because it can be

adopted in a broad range of situation. The residue is more easily stored, transported

and disposed off than the starting material.

Basically, any organic materials can be composted with adequate amount of

materi al to form a heap of which the minimum critical volume is 1 m3, sufficient

available moisture and free air space between the interstices for oxygen diffusion

(Bujang, 1993).

Kuching city has a lot of landscape and good landscaping management that lead

to piling up of green waste produced every day. Therefore, to reduce the dumping of

green wastes at landfill, producing compost by using green wastes is a good initiative.

Composts used in agricultural areas can increase soil structure, water storage capacity,

and nutrient retention (Pandey and Shukla, 2006). Compost application reduces plant

diseases and subsequently reduces pesticide use (Keener et aI., 2001).

The maturity of compost is very important to ensure the readiness of the

compost for soil amendment. Immature compost product have residual toxicity

compound that can induce high microbial activity and subsequent ntisappropriation of

oxygen (Beefa et aI. 1996). The gerntination index (GI) is the most sensitive parameter

used to evaluate toxicity of compost to seedlings and to test if the compost is matured

(Wong et al. , 2001). The maturity rate of the compost depends on the material used. GI

2

indicated increasing compost stability with processing time and gave significant

correlation with compost age (Gazi, 2007).

1.2 RESEARCH PROBLEMS

This scope of research problems intended to be revealed by this study are :

1.1 Current status of the composting activities performed by the local

municipali ties

1.2 Potentials of composting green wastes in reducing wastes chanelled to our

di minishing landfill sites

1.3 Possibility of marketing the compos ted green waste to the public, or for use as

a soil conditioner or mulching by the local councils

1.3 PROBLEM STATEMENT

Kuching is one of the cities in Malaysia that develops rapidly. Varieties of job

opportunities are prompting many people throughout the state to migrate and live in

this city. Increasing population in the city leads to improper disposal of wastes. Some

of the organic wastes and green wastes within the garbage heap actually can be

3

converted to compost. Composting of green and organic wastes can reduce the input of

wa tes in the landfill.

Dewan Bandaraya Kuching Utara (DBKU) compost centre which started

operating in 2002 focused on composting of green wastes. The effort done by DBKU

is very encouraging because they themselves produce a lot of green waste from their

landscaping activities. Besides, a lot of green wastes were sent to the compost centre

everyday by fruit and vegetable wholesalers. The multiplying heaps of green waste in

the compost centre required longer time to process. The study of suitable method

which could reduce the time required for composting process need to be conducted in

order to reduce the piling up of green wastes at the centre.

1.4 OBJECTIVES OF THE STUDY

The objectives of this study are, and not limited to the following, which are to:

1.4 study the composting effort done by Dewan Bandaraya Kuching Utara (DBKU)

1.5 identify the requirement for composting green waste

1.6 process the green wastes from municipal landscaping work and green waste

from dealer for the production of compost

4

Pusat Khidmat Maklumat Akademik J~lVtRSm MALAYSIA SARAWAK

1.5 SCOPE OF THE FIELD STUDY

The cope of the field study covered the processing of green wastes to produce

compost. This study was conducted at DBKU compost centre, Sejingkat, Kuching.

1.6 SIGNIFICANCE OF THE STUDY

The significance of this study are:

1.1 Academically, it is the best way to obtain hands-on knowledge from the

SLUSE programme.

1.2 Thi study can show the green waste production within areas under the custody

of Dewan Bandaraya Kuching Utara

1.3 Explanation of the method used to produce compost from green waste

1.4 The outcome of this study shows the composting activities that can help in

reducing landfill density and at the same time produce product that are useful to

both the environment and community.

5

CHAPTER 2

LITERATURE REVIEWS

2.1 COMPOSTING

The world's populations have multiplied rapidly and are expected to grow

continuou ly in the future. The waste generated raised as the population increased .

Landfil ls were occupied by the waste from many sources. Most of the waste produced

ended up and incinerated in the landfill although most of the waste could be

composted. Composting is the best way to reduce the needs to excavate peat which

will destroy natural habitat and also can spares the damage of environment that was

caused by waste's burning and burying activities. Organic matters that were sent to the

landfill will slowly decay but it will produce methane, the main contributor to global

warming.

Gardeners across the world spend millions of tons of growing media, mulching

material and oil conditioners. Composting of the green waste is an inexpensive way to

convert the unusable organic waste into useful compost that can be used as soil

amendment or organic fertilizer. Recycling of green wastes can be done by

compostin-g. which is a microbiological process in which a succession of mixed

6

microbial populations is decomposing heterogeneous organic matters (Beffa, 2002).

Compo ts used in agricultural areas can increase soil structure, water storage capacity,

and nutrient retention (Pandey and Shukla, 2006). In addition, compost application

reduce plant diseases and subsequently reduces pesticide use (Keener et at., 200 I).

The main prerequisites to composting are organic wastes, microorganisms,

water and oxygen. Plants need three important things from soil which are water,

nutrient and air. All those main key things can be provided by compost.

Materials used for composting have different chemical content, for example

grass mowing is nitrogen rich while wood contains carbon. The right ratio of waste

mixture is crucial for producing of good quality compost. Kitchen waste have lack

structural strength but it can decomposed faster. The decomposting process will cause

the waste to lose its structure and collapse into an airless smelly mess. This is why the

balance combination of materials needed for producing good compost. More fibre

material like leaves and hedge pruning can be added to stop the heap from collapsing

by considering the fact that the high fibre material will decomposed slowly than soft

material (Thompson, 2007).

7

2.2 PARAMETERS IN COMPOSTING

Aeration, moisture content, temperature, water and carbon to nitrogen ratio are

parameters which are important in the processing of green wastes for production of

compo t.

i. Aeration

Aeration is important in maintaining moisture content and uniform

temperature throughout the compost heap. Composting process is the biological

changes of chemical structure or organic matter by the help of oxygen. Air is

much more important than food in composting because composting is an

aerobic process where oxygen is needed along the process. Air requirements of

the microorganisms are dependent on the type of waste, process temperature,

stage of the process and process conditions. Anaerobic process will cause the

compost to take time to mature compare to composting with aerobic process

and the end product will contain ammonia and hydrogen sulphide that comes

with an unpleasant scent (Thompson, 2007). The average compost heap will

runs oot of air before it is running out of food. The compost heap must be

manually aerated, or mixed continually throughout the compo sting process

(Maynard, 2000). Turning of compost heap mixes the compost materials,

increase porosity, promotes drying through release of water vapor, and

expose the compost mass to high interior temperatures so that adequate

pathogen destruction occurs (Beffa, 2002).

8

II. Moisture content

Water is a better conductor of heat compared to air which cause the wet

compost heap will loses heat more quickly than dry heap. Moisture content has

consequences for aeration. The moisture content of the heap must be high

enough in order to allow composting to occur. However, high moisture content

will cause odour problems in composting facilities, unless a very high degree of

attention is paid to blending and mixing to ensure that a freely ventilating and

completely aerobic composting material structure is retained (Last, 2006). The

addi tional of water to the heap of the green waste depending on its moisture

content. If the moisture content of the heap is less than 75%, the water need to

be added reasonably (Lopez-Real, 1990; Bujang, 1993b).

iii. Temperature

All biological reaction takes faster reaction at higher temperatures

including composting process. The temperature reflects the current rate of

activity and prior microbial activity. The composting ecosystem tends to limit

itself due to inhibitory high temperatures resulting from excessive heat

accumulation (Beffa, 2002). The compost itself generates its own heat and a

fre h heap's of compost contain abundance of water, food and air. The bacteria

in the heap respire at a prodigious rate where this activity generates a lot of heat

and cause the temperature of the compost heat rises. At the temperature of

35°C, Phsycrophile bacteria play its role. As the temperature of the heap is

9

between 35-550C, the bacteria will be replaced by thermophiles and as the

temperature continue to arises until 85°C and above, the mesophilic bacteria

will take turn to live in the heap. High temperature is good because the compost

will mature faster and the heat is high enough to kill seeds and disease spores.

However the high temperature does not indicate the compost is success because

are often considered to reduce dramatically the functional microbial diversity.

A thermogenic phase with temperatures exceeding 60°C was even considered

as a "microbial suicide" (Beffa, 2002) and temperatures are high enough to kill

pathogens and weed seeds and to break down phytotoxic compounds

(Cooperband,2002).

iv. Water

Microorganism and soil animal needs water. The bacteria and microbes

that live in the compost heap especially worm very intolerant of drying out.

Therefore, the ideal compost heap needs to have water content with reasonable

rate. Too much water lead to water logging and cause the heap become smelly

and undergo anaerobic process. Oxygen will then quickly become limited, and

microbial activity will decrease, as reflected by the decreasing temperature

(Baldwin, 2(09).

10

v. Carbon to Nitrogen Ratio

In the making of compost, carbon to nitrogen (C :N) ratio is very

important. A mixture of carbon and nitrogen material must be placed in the

compost heap to ensure the good quality of the compost result. The nitrogen act

as the food supply for all microorganisms that help in compost production and

the correct mixture of compost initial materials in other hand will allow

efficient, fast compost production. Higher ratio complicated the pathway for

microbial degradation and lower ratio cause severe nitrogen losses through

ammonia volatilization.

Compost maturity and stability also can be measured by determining its

C:N ratio. The C:N ration should be between 25: 1 and 35: 1 for most compost

organi m to thrive and have a high degree of efficiency of N assimilation into

microbial biomass. When the C:N ratio is too low, N is lost through ammonia

volatilization (Maynard, 2000). A C:N ratio greater than 40: 1 promotes

immobilization of plant-available nitrogen and slows the decomposition

process because of limited N (Zibilzke, 2005). Green materials usually have

lower C:N ratios than woody materials or dead leaves (Cooperband, 2002). The

well-mature compost have C/N ratio of about 10, but it is difficult to achieve by

composting.

II