Municipal Solid Waste Management Case Studies between Tokyo and Indonesia in Waste Sorting and Food Waste Processing Activities

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1 Municipal Solid Waste Management Case Studies between Tokyo and Indonesia in Waste Sorting and Food Waste Processing Activities Rina Riana SONDARI Institute of Technology, Bandung (ITB) Indonesia Jun ITABASHI Center for Int. Programs and Exchange The University of Electro-Communications Tokyo # Japan Masahisa Mabo SUZUKI Center for Int. Programs and Exchange The University of Electro-Communications Tokyo # Japan Abstract Municipal Solid waste management should be implemented in a better way due to waste contribution and environmental pollution. Indonesia s municipal waste management already has its concept and technical action which is can be improved. In this case is in waste sorting activity and food waste processing. Waste sorting is the first important activity in municipal solid waste management. Better sorting system and scavenging activity due to the next stage of recycling activity is necessary. Food waste as organic waste also has to be processed properly due to its effect to human health and environmental pollution. Tokyo, Japan is leading in municipal solid waste management with its high technology and applied comprehensively. By learning from Japan and considering many factors especially in technical approach of waste sorting activity and food waste processing, a better way in solid waste handling in Indonesia can be applied. Keywords: Municipal Solid Waste Management, Waste Sorting, Food Waste Treatment 1 Introduction In line with the growth of the population, the amount of the solid waste productions in a city is also increase. Large amount of solid waste should be handled properly in order to avoid the environmental pollution, bad impacts for human health, and also aesthetic problems that may come up with. Ecologically healthy and environmentally friendly ways should be applied to manage this solid waste. Waste sorting activity is the first important step of municipal solid waste management because there are different kinds of waste and it will be treated and processed based on the compositions and characteristics of the waste itself. For example is organic waste that should be separated from other kinds of waste because its special characteristic that is degradable. The degradable process will consist properly if there is no other irritant element in the organic waste pile. If this organic waste in this case is food waste is not managed well, this waste can just being stored. The storage of food waste contains volatile organic compounds (VOCs), nutrients (notably nitrogen) and also many trace elements that can be a suitable The the author is supported by JASSO Scholarship. growing place for bacteria, flies and also rats as the vectors of pathogens and disease. Besides those diseases, food waste also caused many environmental problems such as odorous, litter, and fires. In Tokyo, Japan waste sorting activity and food waste processing have a good implementation with wide range of technology. Sorting process started in every household with specific kinds of wastes such as burnable, unburnable, plastic, bottles, cans, and PET bottles. With this kind of waste sorting, the utility of the solid waste can be increased and easily turn into ne next recycling process. High technology in food waste processing activity in Tokyo also already implemented. For example in Tokyo Super Eco-Town, they turn the food waste into animal feed and also biogas generator in a large amount. Indonesia is still facing many problems in waste sorting and food waste processing activity. Generally there s no appropriate waste sorting activity is implemented in Indonesia. There s no separation of solid waste especially from household except the sorting by manual for reuse or recycling in the dumping site. This condition has relationship to the improper food waste processing activity in Indonesia because it mixed with other kinds of solid waste in the dumping site. This paper

2 is about case study between Tokyo and Indonesia in waste sorting activity and food waste process in the technical approach. By learning from the application in Tokyo and considering many factors such as waste compositions and characteristics, Indonesia may adopt some suitable way in waste sorting and food waste activity. 2 Waste Sorting Waste sorting is the first step in dealing with our solid waste treatments. After this step is done properly, next step will be much easier. Waste sorting activity is the first important step of municipal solid waste management because there are different kinds of waste and it will be treated and processed based on the compositions and characteristics of the waste itself. Waste sorting can be done in the source or in the end of the processing sites. Both have different approach. Waste sorting in the source In order to do efficient waste sorting, some factors are necessary to be considered: Can t be done manually can be done manually if only for garbage from the specific source The sorted organic waste heaped up in the disposal place can optimize the methane gasses production. There are some technologies applied for waste sorting activities in the dumping site area, for example in this Figure 1. The quantity of the solid waste 2. Economical factor 3. Able to be sorted Several advantages of waste sorting in the source: No contamination of different kinds of waste Facilitate the recycle of the waste Reduce the cost of next waste processing Long-lasting garbage disposal place Sorted waste should be kept in collection process, transportation process until the processing process. There are some wastes separating models: Model 1: process of sorting for one or more than one kind of inorganic waste in household scale or commercial place. Model 2: process of sorting for organic waste (composting) in household or commercial place Model 3: process of sorting for one or several organic and inorganic waste in household or commercial place Model 4: process of sorting for one or several inorganic waste in the temporary waste collection site Some consideration of process of waste sorting in the end of the waste disposal (dumping site) place: Huge quantity of waste Figure 1: Waste Sorting Technology 3 Food Waste Recycling Activities Food waste is a kind of organic waste that is generated from human needs activities both from food industries such as restaurant and also from household as the kitchen waste. The storage of food waste contains volatile organic compounds (VOCs), nutrients (notably nitrogen) and also many trace elements that can be a suitable growing place for bacteria, flies and also rats as the vectors of pathogens and disease. Besides those diseases, food waste also caused many environmental problems such as odorous, litter, and fires. That condition caused the organic waste such food waste should be undertaken appropriately. There are several ways in food waste processing to minimize the food waste are being transferred to the dumping site: 3.1 Composting Composting is a method to breaking down organic materials into an end product that is beneficial to soil and plants. When mixed with soil, compost increases the

3 organic matter content, improves the physical properties of the soil, and supplies essential nutrients, enhancing the soil s ability to support plant growth. Compost can also be applied to the soil surface to conserve moisture, control weeds, reduce erosion, improve appearance, and keep the soil from gaining or losing heat too rapidly. Composting can be a solution to solve one of the solid wastes processing that is organic wastes such as leaves, foods, or any kind of biodegradable solid waste. In developing countries such as Indonesia, the compositions of municipal solid wastes are mostly organic or degradable waste. This kind of garbage can be harmful to the environment and human health. There should be a suitable method to minimize the impact of this garbage and composting can be the solution for this. Composting process will occur after all of the raw materials are mixed. This process can be divided into two phase, active phase and maturing phase. In the beginning, oxygen and easy degradable compound will be used by the mesophilic microbes. The temperature of the compost pile increase rapidly to C. This phase followed by the increase of ph. The temperature will be constantly high in a certain time. At this condition, thermophilic microbes will be in charge in decomposition process. The microbes use oxygen to fasten the organic matters become carbon dioxide CO 2, H 2 O and heat. After most of the materials are fastened, the temperature decreases periodically. After that advanced maturing phase will occur that is topsoil forming. During the composting process the volume and mass of the biomass of the materials will be reduced to 30-40% from the initial weight. Composting process can through aerobic or anaerobic process. in anaerobic process, decomposition occur without using oxygen. But in this process will rise odor from the compounds such as H 2 S, Ammonia, etc. Composting is about maintaining the activity of decomposer microbes. Many factors should be considered in order to keep the composting process is well done. Efficient decomposition occurs when aeration and moisture are adequate, when the particles of waste material are small and when the proper amounts of fertilizer and lime are added. 1. Aeration Microbes require oxygen to decompose organic wastes efficiently. Naturally, aeration occur when the temperature increase caused warm heat come out and colder air come into the compost pile. Aeration is depends on the porosity and humidity. If the aeration is obstructed, then anaerobic process will happened and caused odor. Aeration can be improved by doing some inversion or air circulation inside the compost pile. 2. Porosity Porosity is spaces between particles in the compost pile. Porosity can be calculated by measuring the cavity divided with the total volume. These cavities will be fulfilled by water and air. Air will supply oxygen for composting process. If these cavities are full of water then the oxygen supply will be disturbed and composting process also will be stop. 3. Moisture content Moisture hold an important role in the metabolism process of microbes and indirectly influenced the oxygen supply of the compost pile. Microbes use the organic matters if those organic matters are dissolved in water. Moisture 40-60% is the optimum rate for microbes metabolism. Moisture below 40 %will make the microbes activity decrease and it will be lower in the 15% rate of moisture. If the moisture is above 60%, nutrients will be diminished, air volume will decrease and microbes activity will also decrease, anaerobic process will occur and caused odor. 4. Temperature Heat produced from the microbes activity. There is a straight relationship between temperature raising and oxygen consumption. The higher temperature, the more oxygen consumption and the decomposition process will be faster. The rise of temperature occurs fast in the compost pile. Temperature about C shows faster composting activity. Temperature above 60 C will kill all the microbes except the thermo bacteria. High temperature also could kill the pathogens and weeds. 5. ph Optimum acidity range for composting process is about Composting itself will make changes in acidity (ph) of the material and organic matters. For instance, acid extrication temporarily could decrease the ph whereas ammonia production or any compound contained nitrogen could increase the ph at the beginning of composting process. Finished compost will have neutral ph. 6. Particle size The smaller the organic waste, the faster the compost will be ready to use. Smaller particles have much more surface area for a given volume and thus are more rapidly broken down by the microbes. 7. C/N Ratio Effective C/N ratio for composting process is about 30:1 to 40:1. Microbes rend the Carbon for energy source and use Nitrogen as protein synthesis. When the ratio of C/N is about 30% to 40%, the microbes got sufficient C for energy and N for protein synthesis. If the ratio is too high, microbes will be lack of nitrogen so it slows the composting process. This table is about the Nitrogen contents in compostable materials This table is about the Nitrogen contents in compostable materials

4 Figure 2: Solid Waste Transformation in Aerobic and Anaerobic Composting Table 1: Optimum Condition for Hastening Composting Process 3.2 Biogas Generator Biogas is a mixture of mainly methane gas (CH 4 ) and carbon dioxide gas (CO 2 ). Biogas is produced in anaerobic decomposition process. Anaerobic decomposition process is biological process that occurs without the existing of oxygen. This process is done by the facultative microorganism and anaerobic obligate. The microorganisms change the organic compound into gas methane and carbon dioxide as the last result. There are two main pathways in anaerobic process: 1. Conversion of carbon dioxide and hydrogen into methane and water 2. Conversion formate and acetate into methane, carbon dioxide, and water. These pathway scan be seen in these following reaction: Table 2: Nitrogen contents in compostable material Based on the existing of oxygen, composting can be divided into 2 kinds: 1. Aerobic composting 2. Anaerobic composting Figure 3: Biogas Generation Pathways Based on the reactions above, the biochemical pathway in the organic compound decomposition process in anaerobic condition in order to form methane is using hydrogen and carbon dioxide, format, asetate, methanol, methylamin and carbon dioxide. There are four ingredients that are needed in biogas production: 1. Organic matter Table 3: Differences between Aerobic and Anaerobic Composting 2. Bacteria 3. Anaerobic conditions

5 4. Heat Organic matter is the food source for methane producing bacteria. The bacteria are necessary to convert the fats, carbohydrates and protein in the organic matter to the simple acids. The optimum condition for the bacteria is an anaerobic condition and the right temperature. Biogas contains moisture and hydrogen sulphide, before it is used in an engine the moisture must be condensed out, and the hydrogen sulphide removed to reduce maintenance problems. There are several factors that influenced the anaerobic decomposition process: 1. Acidity Anaerobic digestion will occur in a PH range of The lower PH rate the lower speed of fermentation will happen. Digestion will stop until the bacteria have absorbed the acids. A high PH will encourage the production of acidic carbon dioxide to neutralize the mixture. 2. C/N Ratio The bacteria in anaerobic process consume carbon roughly 30 times faster than nitrogen. Assuming all other conditions are suitable for biogas production, a carbon-nitrogen ratio of about 30:1 is ideal for the raw material fed into a biogas plant. A higher ratio will have the remaining of carbon after all of the nitrogen being consumed and it will make the bacteria starving and turn in to die, returning nitrogen to the mixture and slowing the process. Too much nitrogen will cause this to be left over at the end of digestion and reduce the quality of the biogas. 3. Temperature Anaerobic breakdown of waste occurs at the temperature between 0 69 C but the action of the digesting bacteria will decrease below 16 C. the fastest production of gas is between 29 and 41 C or between C. This is because of there are two different types of bacteria multiply best in these two ranges of temperature. The temperature of 32 Cand35 C has proven most efficient for stable and continuous production of methane. Basic design of Biogas Plant The digester is holding an important role in this anaerobic digestion process. The digester is an enclosed tank filled with the organic waste. Design differences mainly depend on the type of organic waste as the raw material, the temperature to be used in digestion and the materials available for construction. There are biogas systems designed for the specific organic materials like food waste particularly is vegetable waste. Since plant solid will not flow through pipes, this type of digester is best used as a single batch digester. Depend on the waste s material the batch digester will start producing biogas after 2-4 weeks. The biogas in anaerobic digester is collected in an inverted drum. A non-reversible valve is being used in order to prevent air being drawn to the digester, which would destroy the activity of the bacteria and provide a potentially explosive mixture inside the drum. Biogas can be used directly to produce thermal energy, used to be the power source of a gas or diesel engine to run the generator to produce electricity. 4 Present Situation of Municipal Solid Waste treatment in Waste Sorting and Food Waste Processing in Indonesia 4.1 Waste Sorting In fact, generally in Indonesia there is no separation of household waste except the sorting by manual for reuse or recycling at the dumping site. Some waste is sorted before the dumping. All types of waste should be collected in the same plastic bag. The plastic bag then restored in the unspecified dustbin, temporary waste collection points or only replaced in front of the house before he dump truck come. The other facts about the situation in solid wastes are uncontrolled disposals still common, many illegal refuses tip built up areas and dumps on riverbanks. Some people use plastic bags to store their waste but most of them put in the closest communal collection points. Figure 4: Temporary Waste Collection Point

6 Based on the table above, the majority of waste composition in Indonesia is kitchen waste in 58% percentage. Composting can be a solution in solid waste treatment in Indonesia. Composting in large scale does not exist yet, but there are some corporation between local government with local foundation to produce compost from their waste One of the examples is composting activity in Bali. Bali is the most important tourism destination in Indonesia with area= 5.632,86 km 2 and Population density = 588 people/ km 2. In Gianyar, Bali, They already applied composting to recycling their organic waste including food waste. Composting in Gianyar, Bali. Figure 5: Waste Sorting Activity Figure 7: A huge waste mountain towers in front of the recycling pilot building Figure 6: Scavenging Activity in Dumping Site 4.2 Food Waste Processing Table 4: Waste Composition in Indonesia Figure 8: Factory workers busy separating out biomass for composting

7 5 Present Situation of Municipal Solid Waste treatment in Waste Sorting and Food Waste Processing in Tokyo Figure 9: The biomass is aerated to ensure aerobic composting,resulting in the production of carbon dioxide and heat 5.1 Waste Sorting in Tokyo The waste sorting or separation system in Tokyo 23 wards divide the separation of waste based on the types of the waste such as: combustible waste, non combustible waste, bulky waste and recyclable waste. Separation of waste in Tokyo 23 wards: 1. Recyclable waste such as used paper, glass bottles, cans, PET bottles, etc. (collected once a week) 2. Combustible waste such as kitchen refuse, wood and grass, waste paper, etc (collected twice a week) 3. Non - combustible waste such as ceramics, plastics, etc (collected once a week) 4. Bulky waste such as furniture, futons, electronic waste( needs reservation and there is a charge) Figure 10: The quality of compost is inspected Figure 11: The compost is generated from biomass Plastics waste not suitable for recycling was classified as non combustible waste. In 2008, plastics have been classified as combustible waste and used for energy recovery at waste incineration plants. Those separations are done in the source such as in the household and collected regularly. The separated waste then being processed based on their characteristics. Based on the statistics, most of the wastes are combustible waste that is about This kind of waste is being transferred to the incinerations plants that are exist in the entire Tokyo. In the 23 wards area, 21 waste incineration facilities are located in residential and waterfront areas. Other kind of waste such as bulky waste including electronic and demolition waste are being transferred to a specific recycling plants that exist in Tokyo Super Eco Town. Tokyo Super Eco town has several facilities such as: 1. PCB Waste treatment 2. Waste fuel electric generation 3. Construction and Demolition waste recycling 4. Recycle Peer, having automated waste separation line 5. Used information and communication equipment recycling Figure 12: after the refurbishment 6. Future ecology, undertake the reuse and recycling of used personal computers and other electric, electronic and information related equipment

8 7. Animal feed from food waste 8. Biogas Power generation from food waste This waste sorting system is implemented well. It is need the comprehensive cooperation between the citizen, government and the industries. 5.2 Food Waste Processing in Tokyo Figure 14: Food Waste Figure 13: Food Waste Flow in Tokyo,source: TMG The Tokyo Metropolitan Government has been propelling the Super Eco-Town project to achieve more efficient disposal of industrial waste within Tokyo and encourage the development of environment-related industries. The government invited private business to establish waste treatment and recycling facilities in the city waterfront area. Two of the plants are related to the food waste processing. As we can see from the figure above that Super Eco Town in Tokyo handle about t/year of food waste from business related industry. Figure 15: The Food Waste Storage Animal Food Waste from Food Waste The food wastes are chopped and equalized first and then it is deep fried in a high temperature of oil until it almost has no water contamination. The dried food waste then moved into next treatment while the oil also experienced the recycling process. The food waste then being processed in order to separate the unwanted parts for example plastic. Wind is blown into the food waste and it makes the light particle will fly away. After they become powder, the food wastes are ready to be mixed with another material such as corn to be animal feed. Figure 16: The product (middle) 5.3 Biogas Generator Methane Fermentation Technology is converting biomasses with high rate of water such as food waste into methane (CH 4 ) and carbon dioxide (CO 2 ) from the organic compound by the action of anaerobic bacteria in the anaerobic condition. Energy can be raised

9 from these methane generations into gas engines, fuel cells, boilers, etc. As the effect of the Food Recycling Law,etc. Nowadays energy generation from food waste is become often been applied. In Tokyo Super Eco-Town, a food recycling facility is being operated with the contribution to recycling society, safety, environmental performance, technological level, and so on. This food recycling facility has many features, such as: Methane fermentation and treatment facility with the capacity to the process 110 tons of food waste per day. More than any other facility in Japan The world s first plant in selling electric power generation from gas engines and fuel cells through methane fermentation. Table 5: Major Spesification of Food Recycling Facility Figure 17: The Appearance of Biogas Generation from Food Plant Table 6: Operation situation of food recycling facility (February 2007) 6 Discussion 6.1 Improvement in Indonesia s Waste Sorting Activity Figure 18: Food Waste Recycling Process Improvement of municipal solid waste will be started from the separation in the source by every household. This activity will significantly important for the next step in waste handling process. Since the biggest amount of Indonesia s solid waste composition is organic waste including food waste, it is necessary to sep-

10 arate them from other kinds of waste. If this organic waste can be processed properly, then it can reduce the large amount of the garbage pile in the dumping site. In the other hand, hazardous waste also has to be separated due to its special characteristic that is dangerous for human health and environment. Separating combustible and non-combustible waste based on Tokyo experience is not suitable to be implemented in Indonesia since Indonesia has not have a appropriate incineration plant. So it will make another problem to the environment. The better way to separate is degradable and not degradable waste. Again it is based on the major amount of waste composition that is organic waste. Other kind of wastes such as metal, glasses, cans, rubber, paper, etc can be categorized as recyclable waste. In the other hand, infectious waste in included to the hazardous waste which is needed special handling. 6.2 Improvement in Indonesia s Food Waste Processing Activity Composting is a suitable way to process food waste in Indonesia. High content of organic materials and high demand for compost make this method is more effective than other treatment. Indonesia is agricultural country so the demand for compost is high. Compost also important for improving tropical soils. In the other hand unwanted pollution caused by the dumping and burning organic material can be reduced. By learning by Tokyo s experience in animal feed from food waste, this method is difficult to be applied in Indonesia in this short time due to the high cost of construction fees (about yen) but low demand of animal food. Solid waste composition in Indonesia which is majority consists of organic waste from kitchen including food waste is suitable for biogas generator. In developing biogas generator in Indonesia, there are some threats to be considered. The first is the treatment and management of the municipal solid waste itself. Back to waste sorting activity, if the municipal solid waste in Indonesia has not being well sorted, then the food waste is still mixed with other kinds of waste that is can t be processed appropriately. The second is the citizens is having lack of knowledge and information about biogas,they don t realized that their wastes can be converted into energy. Appropriate waste sorting to be immediately implemented is the first step in to higher treatment of solid waste in this case is biogas generator from food waste. Waste composition in Indonesia makes organic waste including food waste processing have a big opportunity in being the best solution in municipal solid waste management technical approach. But due to the condition now, waste sorting is the most crucial first step to be taken. If the condition of municipal solid waste is still mixed, it s hard to get a good next processing such as biogas generator and large scale composting. In this case, corporation between citizens, government and industry also very important to realize the comprehensive municipal solid waste management in Indonesia. 8 Acknowledgements The author would like to thank the tutors team of JUSST, Mr. Kondo Keichi, Ms. Flora, Mr. Yu Itabashi and Mr. Kazuyoshi Shiohara, also to Mrs. Monica. Thank you for your guidance and helps in doing this study, Ms. Frilla Hafnesi as great partner and also best friend, and also UEC and JASSO scholarship for the opportunity to study in Japan. References [1] Thobanoglous, G, Theisen, Integrated Solid Waste Management, Mc. Graw-Hill International Edition, [2] international-projects/detail/mycproject/18.html, [3] [4] [5] english/pdf/waste.pdf, [6] e442/e pdf, [7] Tokyo Super Eco-Town, Japan. 7 Conclusion and Future Works