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 List of Figures i ii Chapter 1 Introduction 1 1.1 Overview of Solid Waste Management for Bangkok 1 Metropolitan Administration (BMA) 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 Table 2 Table 3 Table 4 Table 5 Table 6 Table 7 Table 8 Table 9 Table 10 Table 11 Table 12 Table 13 Table 14 Physical Composition of Waste Discharged from Different Income Levels Amount of Solid Waste Collected by Category Composition of waste from selected business sectors Distribution of Health Facility in the BMA Physical Composition of Medical Waste Comparison of wastes by utilization from three transfer stations in fiscal year 2005 Quantity of waste reduced after waste reduction campaigns and estimation of costs saved Types and amount of treated and disposed solid waste in fiscal year 2005 Bulk Density of solid waste Moisture content of mixed waste at disposal site and at collection trucks Average volatile solid contents of waste in BMA Ash content of solid waste Calorific values of solid waste Forecast of waste discharge growth rate Table 15 Trend of waste composition in wet base (unit: %)
List of Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 Figure 11 Figure 12 Figure 13 Figure 14 Relevant agencies with solid waste management in Bangkok. Quantity of municipal solid waste generated MSW generations in Bangkok in Relation to the population growth and per capita generation rate Physical component of municipal solid waste Example of community solid waste composition collected. No waste separation can be observed Percentage of household hazardous waste delivered to three transfer stations Waste from local markets, unsorted Waste from industrial process that sometime went untreated Composition of infectious medical waste and general municipal waste of medical institutions Number of Office Building Construction Permits in Bangkok Three types of recycling programs implemented in Thailand Community Waste Bank Compost productions from MSW 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 Figure 17 Forecast of waste discharge and collection amount Forecast of physical composition (wet base)
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 68 th 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 1
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. 2
Solid Waste Illegal Dumping Composted Naturally On Site Recycling (3.48%) Disposal (96.52%) Separated Not Separated Recycled (1) by BMA (0.02%) Recycled (2) by Garbage Collectors (4.33%) Collected Transfer Stations Evaporation of water Final Disposal Recycled (3) by waste picker at sites (0.20%) Total Recycled = 8.04% 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. 3
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 4
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 5
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- W T )/V Where: W = the weight of the box full, W T = 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 90 o C 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 D = Wet weight of sample = Dried weight of sample 6
2.4.3 Volatile Solid Volatile solids refer to the amount of matter that volatilizes when heated to 550 o C. After completion of the TS test, the crucible containing the total solids mass is heated at 550 o C until all volatile matter has been ignited and burned. This amount is then figured as; Volatile Solid (VS) = m cf m cx / V where: m cf m cx V = crucible mass after drying at 103 o C (mg) = crucible mass after drying at 550 o C (mg) = 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 600 o C 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. 7
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 8
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 9
(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 10
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: Class B Households: Class C Households: 30,000 Baht/month/household 13,000 29,999 Baht/month/household 1 12,999 Baht/month/household Waste composition discharged from three categories was analyzed and as reported in Table 1. 11
Table 1 Physical Composition of Waste Discharged from Different Income Levels Item Class A Household Class B Household Class C Household On-Nuch Transfer % Weight (g) % Weight (g) % Weight (g) 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 12
(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. 13
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 9460.40 9,349.97 9,356.69 8,495.97 8,376.95 8,718.78 Garbage (ton/day) Volume of Hazardous 0.14 0.12 0.14 0.14 0.15 0.19 Waste (ton/day) 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 14
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. 15
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. Item Physical Composition (% by weight) 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 16
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). 17
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. 18
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) Clinics (Without inpatient beds) No. of hospital No. of beds Modern Traditional 117 16,001 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 19
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. 20
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. 21
Table 6 Comparison of wastes by utilization from three transfer stations in fiscal year 2005. Type of Waste Utilization On Nuch (%) Transfer Station Nong Khaem (%) Sai Mai (%) Average Fertilizer Ferment 49.39 47.85 54.34 50.53 Type 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. 22
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. 23
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 24
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. 25
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 26
Figure 14 Composition of municipal solid wastes arrived at transfer stations from 1994 to 2007. 27
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. 28
Table 8 Types and amount of treated and disposed solid waste in fiscal year 2005. Month General Waste Infectious Waste Household Hazardous Waste Treatment/Disposal Total (Ton) Percent Total (Ton) Percent Total (Ton) Percent Method Sanitary Aerobic Landfill Fermentation (Ton) (Ton) Total (Ton/Month) 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 29
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. The resdata from Secondary Source Year Bulk Density (Kg/L) Data from Field Measurement During April May 2009 Sample Bulk Sample Bulk No. Density No. Density (Kg/L) (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 Average 0.36 Average 0.33 30
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. Data from Secondary Source Year Moisture Content (%) Data from Field Measurement During April May 2009 Sample Moisture Sample Moisture No. Content No. 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 Average 51.60 Average 49.92 31
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 Sample Volatile Sample Volatile Solid No. Solid No. Solid (%) (%) (%) 1994 33.95 1 31.23 13 43.27 Data from Secondary Source Data from Field Measurement During April May 2009 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 Average 37.60 Average 34.88 32
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 Sample Ash Sample Ash Content No. Content No. Content (%) (%) (%) Data from Secondary Source 1994 17.13 1 12.37 13 7.28 Data from Field Measurement During April May 2009 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 Average 12.92 Average 9.10 33
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 Data from Secondary Source 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 Average 1,426.80 34
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 35
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 36
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 37
Figure 17 Forecast of physical composition (wet base) 38
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. 39
Reference Bangkok Metropolitan Administration. Bangkok State of The Environment 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 2006-2007. Chiemchaisri, C., Juanga, J. P., and C. Visvanathan 2006. Municipal solid waste management in Thailand and disposal emission inventory. Environmental Monitoring and Assessment. Doi:10.1007/s10661-007- 9707-1. Kofoworola, O. F. and S.H. Gheewala. Estimation of construction waste generation and Management in Thailand. Waste Management, 29(2009)731-738. Luanratana, W. Cleaner Production Potential at Bangkok Metropolitan Administration. MS Thesis, Asian Institute of Technology. 2003. Luanratana, W, and Vivanathan, V. Sustainable waste management: A case study of Bangkok Metropolitan Authority, In Sustainable Development Policy and Administration. Edited by Mudakumura G.D., Mebratu, D., and Haque, M.S. 2006. Padungsirikul, P. Sustainable Solid Waste Landfill Management Research and Development in Thailand. World Bank. Thailand Environment Monitor 2003. 40