Converting Waste Plastics into Fuel

Report on Waste Quantification and

Characterization for Bangkok Metropolitan

Administration

Prepared for

United Nations Environment Program

International Environmental Technology Centre (IETC)

Table of Contents

List of Tables i

List of Figures ii

Chapter 1 Introduction 1

1.1 Overview of Solid Waste Management for Bangkok

Metropolitan Administration (BMA)

1

1.2 Scope of Report 3

Chapter 2 Methodology for Data Collection 4

2.1 Secondary Data Collection 4

2.2 Qualification and quantification of residential waste 4

2.3 Recycling and Resource Recovery 5

2.4 Waste Analysis 5

2.4.1 Bulk density analysis 5

2.4.2 Moisture Content 6

2.4.3 Volatile Solids 7

2.4.4 Ash Content 7

2.4.5 Calorific Value 7

Chapter 3 Solid Waste Generation in BMA 8

3.1 Waste Generated by Different Generators 8

3.1.1 Municipal Solid Waste 8

3.1.2 Commercial Waste 16

3.1.3 Industrial Waste 17

3.1.4 Health Care Waste 18

3.1.5 Construction and Demolition Waste 20

3.2 Resource Recovery Pattern 21

3.3 Solid Waste Generated by Sources not Receiving

Collection Services

25

3.4 Wastes at Disposal Site 26

3.5 Other Analysis 30

3.5.1 Bulk Density 30

3.5.2 Moisture Content 31

3.5.3 Volatile Solids 32

3.5.4 Ash Content 33

3.5.5 Calorific Value 34

Chapter 4 Projection of Waste Generation 35

4.1 Municipal Solid Waste Generation 35

4.2 Waste Property Forecast 37

Chapter 5 Conclusion 39

Reference 40

List of Tables

Table 1 Physical Composition of Waste Discharged from Different

Income Levels

Table 2 Amount of Solid Waste Collected by Category

Table 3 Composition of waste from selected business sectors

Table 4 Distribution of Health Facility in the BMA

Table 5 Physical Composition of Medical Waste

Table 6 Comparison of wastes by utilization from three transfer stations

in fiscal year 2005

Table 7 Quantity of waste reduced after waste reduction campaigns and

estimation of costs saved

Table 8 Types and amount of treated and disposed solid waste in fiscal

year 2005

Table 9 Bulk Density of solid waste

Table 10 Moisture content of mixed waste at disposal site and at

collection trucks

Table 11 Average volatile solid contents of waste in BMA

Table 12 Ash content of solid waste

Table 13 Calorific values of solid waste

Table 14 Forecast of waste discharge growth rate

Table 15 Trend of waste composition in wet base (unit: %)

List of Figures

Figure 1 Relevant agencies with solid waste management in Bangkok.

Figure 2 Quantity of municipal solid waste generated

Figure 3 MSW generations in Bangkok in Relation to the population

growth and per capita generation rate

Figure 4 Physical component of municipal solid waste

Figure 5 Example of community solid waste composition collected. No

waste separation can be observed

Figure 6 Percentage of household hazardous waste delivered to three

transfer stations

Figure 7 Waste from local markets, unsorted

Figure 8 Waste from industrial process that sometime went untreated

Figure 9 Composition of infectious medical waste and general municipal

waste of medical institutions

Figure 10 Number of Office Building Construction Permits in Bangkok

Figure 11 Three types of recycling programs implemented in Thailand

Figure 12 Community Waste Bank

Figure 13 Compost productions from MSW

Figure 14 Composition of municipal solid wastes arrived at transfer

stations from 1994 to 2007

Figure 15 Forecast of municipal solid waste generation from year 2000 –

2016

Figure 16 Forecast of waste discharge and collection amount

Figure 17 Forecast of physical composition (wet base)

1

Chapter 1

Introduction

1.1 Overview of Solid Waste Management for Bangkok Metropolitan

Administration (BMA)

Bangkok, the capital city of Thailand is a mega-city located in the center of

the country on the low flat plain of Chao Phraya River which extended to the

Gulf of Thailand. It is surrounded by Samut Sakhon and Samut Prakan to the

south; Nakhon Pathim to the west; Nonthaburi, Pathumthani and Nakhon Nayok

to the north and Chachoengsao to the east. The elevation is ranging from 1.50-

2.3 m. Mean Sea Level. Bangkok has monsoon type of climate, which can be

classified into three main seasons; rainy, cool and hot. Within the area of

Bangkok, the city is divided into 50 districts and 154 sub-districts. Urbanized

area has speeded to cover almost half of the city area. Existing land use

consists of three main types; residential use (23 %), agricultural use (23.58 %),

and the rest for commercial, industrial and government use.

With an area of 1,568.737 sq. km., it ranks 68th in size out of the country’s

76 provinces but has the largest population and population density. The total

population in Bangkok as of 2003 was 5,844,607 (2,822,171 male and

3,022,436 female), which was approximately 10% of the total population of

Thailand.

The increasing quantity of solid wastes in Bangkok has caused serious

environmental problems, which in turn deteriorate quality of life of urban

populations. Rapid increase of wastes due to the trends of increasing

population, mass production and mass consumption has made it difficult for

authorities to manage solid waste properly.

Quantity of general solid waste had increased from 3,260 tons per day in

1985 to that of 6,633 tons per day in 1995 and 9,472 tons per day in 2002. The

other type of waste is hazardous waste that consists of infectious waste from

2

hospitals, household hazardous waste, electronic waste and industrial

hazardous waste from manufacturing process.

The Environmental Department and 50 districts offices are responsible

for the collection of solid waste in Bangkok. BMA has applied both direct and

indirect methods for collecting solid waste. For direct collection method, the

waste is collected by vehicles or boats.

Indirect collection is a system in which BMA provides containers for

collecting waste at various sources such as markets, department stores, and

pedestrian walkways. The containers are classified according to food waste,

recyclable waste, and household hazardous waste. The collected waste is

transported to 3 transfer stations then transferred to 2 sanitary landfills at

Kumpaeng Saen district Nakhon Phathom province and Bang Plee district

SamutPrakarn province. Figure 1 shows the solid waste management scheme

of Bangkok.

3

Figure 1 Relevant agencies with solid waste management in Bangkok.

Source: Dept of Public Cleansing, BMA, 2002

1.2 Scope of Report

As there are many studies on solid waste management systems for BMA,

the data has been collected intensively with high accuracy. The report therefore

is done based on secondary data available. Site surveys and observations

were being conducted in order to verify the accuracy of available data. Data on

different type of wastes from different generation points were being discussed

separately.

Solid Waste

Disposal (96.52%)

Illegal Dumping Composted Naturally

On Site Recycling (3.48%)

Separated Not Separated

Recycled (1) by BMA (0.02%) Recycled (2) by Garbage Collectors (4.33%)

Collected

Transfer Stations

Recycled (3) by waste picker at sites (0.20%)

Evaporation of water Final Disposal

Total Recycled = 8.04%

4

Chapter 2

Methodology For Data Collection

2.1 Secondary Data Collection

Secondary data have been used to gain background information about

the formal solid waste management system as well as waste generation and

characterization in BMA. Most of the secondary data has been collected from

BMA reports, reports conducted by non-governmental organizations, published

research reports, articles, and books.

2.2 Qualification and Quantification of Residential Waste

The analysis of waste compositions was conducted in order to verify

accuracy of data acquired through literature search. Waste samples were

collected from waste collection trucks at different locations in Bangkok. Waste

was randomly loaded into a plastic bucket, which was then tapped on to the

ground few times. If this reduces waste volume in the bucket, additional waste

is added until the bucket is full. Balance was used to measure the weight of the

bucket and the weight of the filled basket. Waste is then sorted according to the

following items to determine waste composition:

• Paper (recyclable)

• Paper (non-recyclable)

• Textile

• Plastic and foam (recyclable)

• Yard waste

• Food waste

• Bone and shell

• Leather and rubber

• Metal

5

• Bottle and glass

• Ceramic and stone

• Unclassified

2.3 Recycling and Resource Recovery Patterns

Recycling has been an effective strategy used in Bangkok metropolis

area to reduce the quantity of waste generated. Data on recycling and resource

recovery patterns were collected via available data published and from

observation and informal interviews with sectors involved with recycling and

resource recovery.

2.4 Waste Analysis

There are many parameter related to waste characteristics that can help

waste manager to decide proper management scheme for waste in each

locality. In this report five parameters are discussed. The parameters are

density of waste, moisture content, volatile solid, ash content and calorific value.

2.4.1 Bulk Density Analysis

Waste bulk density is another important measure used to define the

number and capacity of waste storage and collection facilities required. Based

on waste density and the capacity of trucks, the amount of waste collected can

be measured in tons (weight). The high density measured reflects the less

effectiveness of compaction vehicles for waste transportation. However, waste

density provides rough information of the characteristics of solid waste

produced. The parameter is affected by many factors such as seasonal

variation and the way that waste is put into containers.

In this report, 20 samples of waste fractions were measured for bulk

density of solid waste in order to verify the accuracy of data available. Samples

were collected at random from waste collection trucks at different location in

6

Bangkok. Each sample was divided into two piles of waste; the number reported

here is an average from each sampling point. Waste was put into the weigh box

to overflowing. Weigh the filled box and calculate the bulk density to three

significant figures.

Calculation Bulk Density = (W- WT)/V

Where:

W = the weight of the box full,

WT = the weight of the box empty, and

V = the volume of the box determined

2.4.2 Moisture Content (MC)

Data on moisture content of mixed solid waste at the dumping site were

available. Therefore, the report has determined moisture content of residential

waste according to the standard procedures. Samples used for bulk density

analysis were used for MC analysis as well. Sample were divided into two piles;

the first pile for total moisture content while component of second pile will be

segregated for major components such as organic, paper, soft plastic, hard

plastic, and glass. Initial weight of each category was measure, after which the

samples were placed in electric oven at 90oC for 48 hours. Dried weights were

then record and calculation of moisture content was done with the following

formula;

Moisture Content (MC) = 100 x (W-D)/W

Where:

W = Wet weight of sample

D = Dried weight of sample

7

2.4.3 Volatile Solid

Volatile solids refer to the amount of matter that volatilizes when heated

to 550oC. After completion of the TS test, the crucible containing the total solids

mass is heated at 550oC until all volatile matter has been ignited and burned.

This amount is then figured as;

Volatile Solid (VS) = mcf –mcx / V

where:

mcf = crucible mass after drying at 103oC (mg)

mcx = crucible mass after drying at 550oC (mg)

V = sample volume (L)

A volatile solid is a useful approximation of the amount of organic matter

present in sample.

2.4.4 Ash Content

Ash content indicates the mass of incombustible material remaining after

burning a given waste sample as a percentage of the original mass of the waste

sample. Samples used for moisture content analysis were used for ash content

analysis. Weigh of samples were recorded, samples were then burned and

transferred to furnace operated at 600oC for two hours. The remaining ash was

allowed to cool down before the recording of ash weight. Calculation for

percentage of ash from residential wastes were done and compared with

acquired documents.

2.4.5 Calorific Value

The energy potential of waste depends on the mix of materials and their

moisture content. The higher the calorific value of the waste the more energy

can be extracted. In this report, calorific value presents is the number reported

by the BMA.

8

Chapter 3

Solid Waste Generation in BMA

3.1 Waste Generated by Different Generators

3.1.1 Municipal Solid Waste

The quantity of waste generated depends on many factors. The most

important are population growth, economic growth, and the efficiency of the

reuse and recycling system. Both the growth of population and economic

development have resulted in increasing municipal solid waste of Bangkok

Metropolitan Administration. Change in quantity of municipal solid waste

generated is shown in Figure 2.

Figure 2 Quantity of municipal solid waste generated

9

The municipal solid waste comprised of daily waste produced by

households, institutions and businesses is approximately 67% of the total waste

generation. The remaining 33% consists of hazardous and non-hazardous

industrial waste and hospital waste. Bangkok produces 8,500 ton/day of wastes

around 3.1 millions ton/year, equivalent to 24% of total wastes of the country.

During 1980-1997, the volume of waste increased by 10% but the figure

dropped to 1.52% during 2003-2007 due to BMA successful campaigns on

waste reduction and source separation (Figure 3).

Figure 3 MSW generations in Bangkok in Relation to the population growth and

per capita generation rate

10

(A) Waste Composition

Composition of waste generated in Bangkok is highly biodegradable,

mainly composed of an organic fraction with high moisture content. Food waste,

plastic/foam, paper, metal, and glass are the common component of waste (Fig.

4 - 5). The average moisture content of municipal solid waste in Bangkok is

around 50 % in wet mass basis.

Figure 4 Physical component of municipal solid waste

11

Figure 5 Example of community solid waste composition collected. No waste

separation can be observed.

When economic condition is taken into consideration, households from

different income levels generate slightly different waste composition. From the

study conducted by Japan Bank for International Cooperation – Special

Assistance for Project Formation (JBIC – SAPROF), households were

categorized into three income levels;

Class A Households: ≥ 30,000 Baht/month/household

Class B Households: 13,000 – 29,999 Baht/month/household

Class C Households: 1 – 12,999 Baht/month/household

Waste composition discharged from three categories was analyzed and

as reported in Table 1.

12

Table 1 Physical Composition of Waste Discharged from Different Income Levels

Class A Household Class B Household Class C Househo ld Item

% Weight (g) % Weight (g) % Weight (g)

On-Nuch Transfer

Station (%)

Food 55.9 273.8 57.6 253.4 58.3 233.2 51.4

Bone and Shell 1.6 8.1 0.6 2.7 1.5 6.1 2.1

Textile 1.2 6.0 1.7 7.3 1.0 3.9 2.9

Leather and Rubber 0.1 0.6 0.2 1.1 0.5 1.8 0.2

Wood and Leaves 6.9 34.0 3.6 15.9 1.8 7.1 2.6

Paper – recyclable 7.1 34.7 7.5 33.1 6.1 24.3 8.4

Paper – non-recyclable 3.6 17.6 2.3 10.1 3.4 13.7 5.0

Plastic and foam – recyclable 2.8 13.9 2.9 12.5 3.4 13.7 2.5

Plastic & foam – non-recyclable 12.2 59.8 15.8 69.7 15.3 61.4 19.2

Metal 1.7 8.4 1.4 6.3 1.5 6.1 1.8

Bottles & Glasses 6.0 29.5 5.5 24.3 6.6 26.2 3.2

Ceramic & Stones 0.0 0.0 0.3 1.2 0.1 0.4 0.4

Unclassified 0.0 0.1 0.1 0.4 0.1 0.2 0.1

Hazardous Waste 0.7 3.5 0.4 1.9 0.4 1.7 0.3

Total 100 490 100 440 100 400 100

Bulk Density (Kg/L) 0.14 0.14 0.15 0.19

13

(B) Waste Discharge Rate

Although waste composition did not vary much between households from

different income levels, however, the discharge ratio differed by income class.

The rate of waste discharge from class A and class B households were

noticeably higher than in class C household. Average discharge rate for each

income class is as follow;

Class A household: 490g/day

Class B household: 440g/day

Class C household: 400g/day

However, seasonal variation of discharge rate should also be taken into

consideration.

(C) Waste Collection Amount

BMA focuses on effective collection to minimize uncollected waste.

Collection trucks are rented to solve vehicle unavailability and problem on

vehicle maintenance. In fiscal year 2007, almost 65% of garbage trucks out of

are rented in service. Effective waste collection requires public cooperation on

proper time and places in dropping waste to reduce uncollected wastes.

Appropriate routing for collection trucks is required. The approaches employed

are:

1. Assigning of waste dropping and collection schedule

• Main streets, minor streets and market places:

1) 08.00 p.m. to 03.00 a.m.

2) Collection completed by 06.00 a.m.

• Collection is made daily for communities, small roads and lanes.

For areas inaccessible by collection trucks, volunteers collect waste at source

and put into a collection point.

2. Waste collection by types and increase collection frequency.

• General wastes • Daily or every other day based on location.

14

• Food wastes • Daily basis.

• Recyclable wastes • Every Sunday

• Hazardous wastes • 1st and 15th of the month

At present, most of municipal solid wastes were collected. BMA has

estimated that 99% of wastes generated were collected and transferred.

Quantity of waste collected is shown in Table 2. To further improve waste

collection, collection route map is re-arranged and information technology and

the Global Positioning System is introduced.

Table 2 Amount of Solid Waste Collected by Category.

Type 2002 2003 2004 2005 2006 2007

Amount of General

Garbage (ton/day)

9460.40 9,349.97 9,356.69 8,495.97 8,376.95 8,718.78

Volume of Hazardous

Waste (ton/day)

0.14 0.12 0.14 0.14 0.15 0.19

Volume of Infectious

Waste (ton/day)

14.285 15.367 15.245 16.197 17.356 18.820

(D) Household Hazardous Waste

A management system for most community generated hazardous waste

does not exist. While over half of the waste generated from community sources

such as households, gas stations, and dry cleaners is recycled, only one

percent of the remainder is treated. As a result, each year an estimated

140,000 tons of this waste is either co-disposed with municipal solid waste or

discharged to the sewer or directly to the environment. These practices

increase the risk of exposure to the general public, collection workers, and

scavengers, and can contribute to groundwater contamination.

In 2005, the Department of Environment predicted that the amount of

hazardous wastes contaminating with hazardous waste is 24.6 tons /day,

representing 0.29 percent of the total waste amount. The amount of household

hazardous waste collected and delivered to three waste transfer and treatment

15

centers is shown in Fig. 6. Only 0.5 percent could be collected and delivered by

BMA to the licensed company for disposal and proper handling of waste.

Figure 6 Percentage of household hazardous waste delivered to three transfer

stations

It should be noted that the pattern of hazardous waste delivered to

transfer stations is irregular. BMA therefore has developed and implemented

several plans to recover hazardous from household more effectively. For

example, BMA has cooperated with shopping malls, convenient stores and high

rise building to come up with the locations of containers accommodating

household hazardous waste and with collection for disposal.

16

3.1.2 Commercial Waste

Waste generated from commercial sources such as hotels, offices,

restaurants, and markets & department stores varies from household waste in

term of composition of each physical component. However, main components

are the same, which are biodegradable components such as food and yard

wastes, recyclable waste such as paper, plastic and metals. Study conducted

by Danish Cooperation for Environment and Development in 2000, indicated

the differences in waste composition of different business (Table 3). Note that

the availability of data in this aspect is limited. Available data may not be up to

date as well as may not be able to be used as representative for the whole BMA

however, it could provide overall picture of waste composition from different

commercial sectors. Figure 7 shows example of commercial waste generated.

Table 3 Composition of waste from selected business sectors.

Physical Composition (% by weight) Item

Hotel Office Restaurant

Paper 9.7 21.9 19.3

Cardboard 1.5 1.2 2.0

Aluminium 0.4 0.2 1.0

Other Metal 1.9 1.0 4.1

Glass Bottle 8.1 2.6 45.7

Other Glass 2.0 1.6 7.6

Plastic Bottle 1.0 0.7 2.0

Non-recyclable Plastic 9.6 22.6 5.1

Food Waste 49.9 17.8 5.1

Yard Waste 4.4 3.2 1.0

Hazardous Waste 0.9 1.1 0.0

Infectious Waste 0.0 0.0 0.0

Others 10.8 26.0 12.2

Total 100 100 100

17

Figure 7 Waste from local markets, unsorted.

3.1.3 Industrial Waste

Industrial waste in Thailand is divided into two groups; general waste and

hazardous waste. Most of general waste is treated by BMA, following normal

practice of solid waste management system. The other type of waste, which is

hazardous, is treated differently from factory to factory. Factories are supposed

to follow Hazardous Substance Act and other related laws and regulation. It is

required, by law, for factory to send its hazardous waste to licensed treatment

facilities. Only 24 percent of the hazardous waste produced in Bangkok and

vicinity is treated by licensed centralized treatment facilities and as a result only

a portion of the capacity of these facilities is being utilized. The remaining waste

is managed by a combination of cheaper cost and less regulated practices.

Other unlicensed treatment and disposal operators, waste buyers and private

recycling firms manage approximately 14 percent of the waste off-site through

disposal. In addition, 56 percent of hazardous waste is managed on the factory

site, which, due to the large numbers of factories, is difficult to regularly monitor

(Figure 8).

18

Figure 8 Waste from industrial process that sometime went untreated.

3.1.4 Healthcare Waste

Infectious waste is managed much more effectively due to the ministerial

rules and regulations, which require health care premises to separate infectious

wastes for appropriate treatment to prevent any public heath threats.

The institutions that deal with technical matters of medical waste

management include the Pollution Control Department (PCD), the Department

of Health (DH) and the Bangkok Metropolitan Administration (BMA). Each

institution carries out its own functions rather independently. However, due to

the differences in the definition of medical waste used by each institution, there

are discrepancies in the basic data pertaining to hospital wastes, particularly

with respect to the types and generation rate of wastes. Due to the reasons

cited above, the waste generation rates issued by the BMA, DH and PCD are

0.11, 0.43 and 0.65 kg/bed/day respectively. In 1995 the DH commissioned a

study on the disposal of hospital wastes by incineration, which revealed that the

average waste-generation rate was 0.23 kg/bed/day.

In order to treat infectious waste appropriately, the BMA operates

incinerators for the disposal of medical wastes in the Bangkok area. Infectious

waste management practices are dependent upon the type of medical facility. In

Bangkok alone there are over 3,000 hospitals and clinics (Table 4). Table 5

shows physical characteristics of general and infectious medical waste. Figure

9 shows composition of medical waste and general solid wastes generated that

are kept for selling.

19

Table 4 Distribution of Health Facility in the BMA

Administrative Level Health Facility Number

Public Hospital • Medical school hospitals

• General Hospital

• Specialized hospital/institution

• Public health centers/branches

• 10-Beds hospital (BMA)

5

29

19

60/83

3

Private Hospital (With inpatient beds)

• No. of hospital

• No. of beds

117

16,001

Clinics (Without inpatient beds)

• Modern

• Traditional

2,821

260

Table 5 Physical Composition of Medical Waste

Components Composition (% dry weight basis)

Cotton/gross 67.15

Rubber glove 12.52

Plastic 13.48

Paper 2.71

Wood 3.23

Food 0.65

Leather 0.13

Metal 0.12

20

Figure 9 Composition of infectious medical waste and general municipal waste

of medical institutions.

3.1.5 Construction and Demolition Waste

The rapid urbanization of Thailand has generated and increased demand

for housing and infrastructure, which in turn creates large quantity of

construction and demolition waste. At present, increasing unregulated dumping

of construction waste and the limited space in landfill has become major waste

management problems.

21

Although some materials (i.e. wood, glass, and metal) presence in

municipal solid waste are perceived as building materials, it is unclear if these

materials wastes were generated from construction activity as they can also be

generated from other activities unrelated to construction.

The main components of construction waste are steel reinforcement,

wood, concrete, cement, bricks, and tiles. Nevertheless, quantity of each

component varies from site to site depending on size and design of construction

projects. Trend of construction and demolition waste has grown following

construction permits given by government authority.

3.2 Resource Recovery Pattern

From the information on composition of municipal solid waste in the

BMA, it can be seen that waste can be classified according to their utilization as

follow;

• Waste to be used in fertilizer fermentation,

• Waste to be used in recycled process, and

• Waste to be sent to landfill for final disposal.

At present BMA has initiate waste reduction program by the promotion of

compost production and waste separation for recycled materials. Table 6

compare waste arrived at three transfer stations by its utilization potential.

22

Table 6 Comparison of wastes by utilization from three transfer stations in fiscal

year 2005.

Transfer Station Type of Waste

Utilization On Nuch

(%)

Nong Khaem

(%)

Sai Mai

(%)

Average

(%)

Fertilizer Ferment Type

49.39 47.85 54.34 50.53

Food 44.25 41.36 47.35 44.32 Wood & Leaves 5.14 5.66 4.53 5.11 Others 0.0 0.83 2.46 1.10 Recycle Type 9.65 10.67 8.74 9.69 Paper (Recycled) 1.14 0.63 0.38 0.72 Plastic (Recycled) 4.12 1.91 1.62 2.55 Foam 0.52 1.31 1.76 1.20 Glass 1.54 5.02 2.94 3.16 Metal 2.33 1.80 2.04 2.06 Landfill type 40.96 41.48 36.92 39.78 Paper (non-recycled) 7.65 10.84 8.31 8.93 Plastic (non-recycled) 27.75 22.45 23.19 24.46 Leather & Rubber 0.68 1.41 0.39 0.83 Cloth & Textile 2.86 6.36 4.53 4.58 Stone & Ceramic 1.14 0.34 0.11 0.53 Bone & Shell 0.88 0.08 0.39 0.45

For BMA recycling practices are dominated by informal sector. Very low

portion of waste generated are being recycled. Most recycling efforts have

focused on encouraging community to establish garbage bank and composting

facilities. There are three basic type of recycling programs being implemented

in Thailand as shown in Figure 11.

23

Figure 11 Three types of recycling programs implemented in Thailand.

In 2005, BMA initiated a policy to reduce waste by 10% per year. Intensive

campaigns launched at the public to reduce and separate wastes resulted in

continuing decrease of waste amount from 2005 to 2007. Costs saved are

averaged at Bahts 1,000/ton. Estimate cost saved during the implementation

years is shown in Table 7. Different efforts in resource recovery are shown in

Figure 12.

24

Figure 12 Community Waste Bank

Table 7 Quantity of waste reduced after waste reduction campaigns and

estimation of costs saved

Year

Quantity of

Waste Reduced

(Tons/day)

Estimate Cost

Saved

(Baht/day)

Total Cost Saved

(Million

Baht/year)

2005 860.42 860.420 314

2006 979.47 979,470 357

2007 637.91 637,910 232

Resource recovery system mentioned above is considered as formal

recycle strategy; however, in Thailand an informal sector of resource recovery

seems to be more active. Material recovery apart from that of BMA’s initiative

includes

(a) Material recovery by waste pickers and tricycle waste buyers in

towns.

In Thailand, recycling at generation source has long been

practiced. Households, shop houses and business sectors

normally separate their recyclable waste (mainly paper, glass and

metal) and store it until the amount is enough to sell to waste

buyer or recycling shops. Waste buyer purchases these materials

directly from waste generators. The study conducted by Pollution

25

Control Department estimated that each tricycle waste

picker/buyer can collect 158 kg/tricycle/day. The number of

tricycles waste picker/buyer working in Bangkok metropolis is

approximately 2100, therefore roughly, amount of recyclable

materials collected can be as high as 332 tons/day.

(b) Material recovery by BMA collection workers during their regular

waste collection work

BMA’s collection workers separate recyclable materials from

waste collected during regular waste collection and sell these

waste to waste traders located near transfer stations. It was

estimated that BMA’s collection trucks recycle a total of 413 ton of

waste per day.

(c) Material recovery by waste pickers at the transfer stations.

Waste pickers usually collect recyclables from waste temporally

piled at the transfer stations and sell these to waste traders or sell

directly to end-users.

3.3 Solid Waste Generated by Sources not Receiving Collection Services

Although the Department of Environment of BMA reported that collection

service could fully cover waste generated from different sources. There are

areas in Bangkok metropolis that may not receive the collection service. New

human settlement areas that expand with no planning have faced this problem

the most. Although BMA has claimed 100% waste collection, some of these

new settlement areas have very narrow roads, some areas may not be

accessible by car or collector trucks, therefore there are a huge quantity of solid

waste remain within such communities. On of the studies in Bangkok Noi district

indicated that quantity of waste uncollected can be as high as 23 % of waste

generated in community. Survey on new settlement areas is needed in order to

reroute the collection service and also to change method of collection wherever

possible to improve the efficiency of waste management system.

26

3.4 Wastes at Disposal Site

The composition of waste at disposal sites varies influencing by

economic conditions, social activities, culture and other factors. The Division of

Solid Waste Hazardous Waste and Nightsoil Management has monitored

closely the composition of waste entering transfer sites. Percentage of each

component is also changing from year to year. However, the main components

remain the same; food waste, plastic waste, and paper waste. Composition of

wastes arrived at transfer station from different years is shown in Figure 14.

The general conclusion of wastes arrived at transfer stations can be drawn as

followed;

1.) Wastes for composting represent the highest volume ranging from

49% to 61%. (Figure 13)

2.) Wastes to be disposed in landfills ranging from 33.15% to 40.13%

3.) Wastes for recycling ranging from 5.85% to 15.08%

Figure 13 Compost productions from MSW

27

Figure 14 Composition of municipal solid wastes arrived at transfer stations

from 1994 to 2007.

28

Apart from general municipal solid wastes, all three-transfer station also

collects infectious and household hazardous wastes. Quantity of each type of

waste in fiscal year 2005 is shown in Table 8. It can be seen that very low

quantity of infectious and household hazardous wastes can be collected, both

categories combined contribute less than one percent of total waste delivered.

29

Table 8 Types and amount of treated and disposed solid waste in fiscal year 2005.

General Waste Infectious Waste Household Hazardous Waste

Total (Ton/Month)

Treatment/Disposal Method Month

Sanitary Landfill (Ton)

Aerobic Fermentation

(Ton)

Total (Ton) Percent Total (Ton) Percent Total (Ton) Percent

Oct, 04 281,223.32 - 281,223.32 99.83 480.82 0.17 1.53 0.0005 281,224.85 Nov, 04 265,632.64 - 265,632.64 99.84 446.00 0.16 3.24 0.0012 265,635.88 Dec, 04 272,587.41 - 272,587.41 99.84 461.45 0.16 3.58 0.0013 272,590.99 Jan, 05 270,940.56 - 270,940.56 99.82 506.57 0.18 2.57 0.0009 270,943.13 Feb, 05 217,774.47 13,933.24 231,707.71 99.81 444.82 0.19 2.27 0.0009 232,154.80 Mar, 05 217,752.60 30,131.79 247,884.39 99.80 505.27 0.20 3.56 0.0014 248,393.22 Apr, 05 210,593.21 29,148.78 239,741.99 99.81 464.90 0.19 3.33 0.0013 240,210.22 May, 05 225,002.43 31,778.31 256,780.74 99.81 500.46 0.19 5.92 0.0023 257,287.12 Jun, 05 226,932.48 31,146.91 258,079.39 99.81 500.70 0.19 4.56 0.0017 258,584.65 Jul, 05 230,075.49 31,930.27 262,005.76 99.81 500.93 0.19 5.30 0.0020 262,511.99 Aug, 05 228,377.91 32,641.70 261,019.61 99.81 504.43 0.19 6.38 0.0024 261,530.42 Sep, 05 222,238.28 31,708.25 253,946.53 99.81 502.29 0.19 7.21 0.0028 254,456.03 Average 239,094.23 29,052.40 258,462.50 99.81 484.488 0.19 4.12 0.0015 258,915.51

Source: Solid Waste Disposal Division

30

3.5 Other Analysis

3.5.1 Bulk Density

Bulk density of solid waste reported by BMA and from samples collected

seems to share same characteristic. The value ranges from 0.23 – 0.40 kg/L

with an average value of 0.33 Kg/L, slightly lower than that of BMA’s data. The

reason could be that samples collected in this study are taken from waste

collector trucks, while BMA’s samples were taken at transfer stations. The

density of MSW increases markedly as it is first generated in the household and

then finally disposed into landfill.

Table 9 Bulk Density of solid waste.

Year Bulk

Density

(Kg/L)

Sample

No.

Bulk

Density

(Kg/L)

Sample

No.

Bulk

Density

(Kg/L)

1994 0.35 1 0.29 13 0.32

1995 0.35 2 0.33 14 0.23

1996 0.35 3 0.35 15 0.30

1997 0.32 4 0.33 16 0.35

1998 0.42 5 0.28 17 0.36

1999 0.34 6 0.34 18 0.38

2000 0.38 7 0.26 19 0.36

2001 0.34 8 0.35 20 0.28

2002 0.39 9 0.36

2003 0.37 10 0.40

2004 0.39 11 0.39

2005 0.33 12 0.35

The

res

Dat

a fr

om S

econ

dary

Sou

rce

Average 0.36

Dat

a fr

om F

ield

Mea

sure

men

t Dur

ing

Apr

il –

May

200

9

Average 0.33

31

3.5.2 Moisture Content

The transfer of moisture takes place in garbage bins and collector trucks,

and thus the moisture contents of various components changes with time. The

moisture content becomes important when the refused is processed into fuel or

when it is burned.

Table 10 Moisture content of mixed waste at disposal site and at collection

trucks.

Year Moisture

Content

(%)

Sample

No.

Moisture

Content

(%)

Sample

No.

Moisture

Content (%)

1994 48.92 1 61.24 13 54.37

1995 49.71 2 46.78 14 57.08

1996 49.11 3 55.60 15 46.79

1997 55.12 4 48.12 16 51.00

1998 57.00 5 53.50 17 44.36

1999 52.76 6 49.89 18 50.15

2000 60.43 7 48.0 19 47.45

2001 55.62 8 62.31 20 55.63

2002 46.46 9 58.54

2003 44.16 10 53.43

2004 49.98 11 47.87

2005 49.94 12 62.11

Dat

a fr

om S

econ

dary

Sou

rce

Average 51.60

Dat

a fr

om F

ield

Mea

sure

men

t Dur

ing

Apr

il –

May

200

9

Average 49.92

32

3.5.3 Volatile Solids

Volatile solids content is often used as a measure of the biodegradability

of the organic fraction of solid waste, however, it can be misleading as some of

the organic constituents f MSW are highly volatile but low in biodegradability.

Table 11 Average volatile solid contents of waste in BMA.

Year Volatile

Solid

(%)

Sample

No.

Volatile

Solid

(%)

Sample

No.

Volatile

Solid

(%)

1994 33.95 1 31.23 13 43.27

1995 38.89 2 36.00 14 34.48

1996 39.26 3 40.67 15 29.57

1997 34.25 4 33.34 16 31.36

1998 32.57 5 37.58 17 33.28

1999 38.82 6 35.36 18 28.41

2000 33.16 7 35.95 19 32.67

2001 33.74 8 33.26 20 34.63

2002 - 9 31.47

2003 43.61 10 36.62

2004 41.50 11 38.41

2005 43.86 12 40.03

Dat

a fr

om S

econ

dary

Sou

rce

Average 37.60

Dat

a fr

om F

ield

Mea

sure

men

t Dur

ing

Apr

il –

May

200

9

Average 34.88

33

3.5.4 Ash Content

After combustion, the remaining part of solid waste is ash that is needed

to be disposed, thus affect design capacity of landfill. Ash from MSW

combustion also contain hazardous compounds such as metals

Table 12 Ash content of solid waste.

Year Ash

Content

(%)

Sample

No.

Ash

Content

(%)

Sample

No.

Ash

Content

(%)

1994 17.13 1 12.37 13 7.28

1995 11.40 2 8.73 14 8.72

1996 11.63 3 9.25 15 6.25

1997 10.63 4 10.27 16 8.25

1998 10.43 5 8.26 17 10.21

1999 8.42 6 7.15 18 9.22

2000 6.41 7 11.71 19 6.59

2001 10.64 8 10.92 20 8.26

2002 - 9 8.31

2003 12.23 10 9.48

2004 8.52 11 8.29

2005 6.20 12 12.59

Dat

a fr

om S

econ

dary

Sou

rce

Average 12.92

Dat

a fr

om F

ield

Mea

sure

men

t Dur

ing

Apr

il –

May

200

9

Average 9.10

34

3.5.5 Calorific Values

The heat value of various components of solid waste is quite different. In

this report the calorific value or heat value is described as Low Heat Value

(LVH) or net calorific energy which is realistic number as it has deducted the

latent heat of vaporization from the gross calorific energy.

Table 13 Calorific values of solid waste

Year Low Heat Value

(KCal/Kg)

1994 1,234.29

1995 1,451.79

1996 1,472.04

1997 1,210.79

1998 1,123.65

1999 1,430.34

2000 1,129.62

2001 1,184.58

2002 1,946.35

2003 1,697.49

2004 1,567.62

2005 1,674.06

Dat

a fr

om S

econ

dary

Sou

rce

Average 1,426.80

35

Chapter 4

Projection of Waste Generation

4.1 Municipal Solid Waste Generation

The amount of waste in Bangkok is likely to increase at an average of 10

percent annually until year 1997. However, the quantity of waste generated

tended to reduce afterward. As a result of waste minimization campaign in

Bangkok metropolis, quantity of waste collected in 2005 reduced 9.2 percent

from that of year 2004. The projection of municipal solid waste generation was

done up to the year 2016 (Figure 15).

Figure 15 Forecast of municipal solid waste generation from year 2000 – 2016.

As it can be seen that the projection of waste generation is different from

real situation the BMA has readjust the forecast to reflect future waste

generation.

The fluctuation in quantity of waste discharge is generally related to

number of population and income. The factors determine level of material

36

consumption and resulted in waste generation. Study conducted by Luanratana

and Visvanathan in Mudakumura ed. assumed that the amount of waste

generation in Bangkok would grow in accordance with the GDP. Forecast for

waste discharge growth rate is shown in Table 14. The waste discharge

amount forecast and waste collection amount are shown in Figure 16.

Table 14 Forecast of waste discharge growth rate.

2000 - 2010 2011 - 2020 After 2021

Per Capita GDP Growth 2.5% 3.4% 3.4%

Waste Discharge Grow Rate 2.25% 3.06% 3.06%

Source: Mudakumura, et al., 2006

Figure 16 Forecast of waste discharge and collection amount

37

4.2 Waste Property Forecast

Luanratana (2003) has predicted changes in waste composition in wet

based. Trend in physical composition of waste in wet based is shown in Table

15. Waste physical composition forecast until 2019 was done using existing

data together with statistical analysis. Figure 17 show the result of the forecast

of physical composition of waste.

Table 15 Trend of waste composition in wet base (unit: %)

Year Paper Textile Plastic Wood Food Bone

Shell Rubber Metal Glass

Stone

Ceramic

1996 11.3 7.3 19.1 3.0 46.6 0.4 2.4 2.8 6.7 0.5

1997 11.4 6.2 17.4 5.8 51.9 0 0.6 2.3 4.5 0

1998 11.6 3.7 19.8 14.5 43.4 0 0.8 2.0 4.2 0

1999 9.6 11 25.8 7.9 40.9 0 2.2 1.0 1.7 0

2000 13.4 2.9 21.7 2.6 51.8 2.1 0.2 1.8 3.2 0.4

Ave. 11.46 6.22 20.76 6.76 46.9 0.5 1.24 1.98 4.06 0.18

38

Figure 17 Forecast of physical composition (wet base)

39

Chapter 5

Conclusion

The report on quantification and characterization of solid waste in

Bangkok Metropolitan Administration was carried out based on available

secondary data. Various secondary sources were compiled and verified their

accuracy with each other. Primary data, especially in waste property and

composition were collected in order to verify the accuracy of existing data.

Result of waste analysis varies slightly from that of existing data. It could

be influenced by several factors such as seasonal change, economic conditions

and consumption behavior of population. However, the results of both primary

and secondary data do provide good insight of solid waste composition and

quantity of waste generated.

From the study, solid waste of BMA has high organic content and

appropriate for composting process. However, trend in waste composition show

increasing proportion of waste plastics that can be recycled.

Material recovery in Bangkok has increased due to waste reduction

campaign implemented by the BMA. However, the quantity of material

recovered is still low and there is a possibility of increasing such recovery.

Informal sector in material recovery should be promoted and organized. The

recycle activity done by waste collectors during their regular waste collection

should be control to increase efficiency of waste collection process.

The report was done base on current socio-economic situation.

Population growth and economic growth that normally influence waste

generation rate change over time, with economic recession in 2009, waste

generation forecast may not be applicable and readjustment of the forecast may

be necessary.

40

Reference

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2002.

Bangkok Metropolitan Administration. Statistical Profile of BMA 2003.

Bangkok Metropolitan Administration. Bangkok State of The Environment

2005.

Bangkok Metropolitan Administration. Bangkok State of The Environment

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Chiemchaisri, C., Juanga, J. P., and C. Visvanathan 2006. Municipal solid

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