Recycling of plastic packaging waste in Bandung City,Indonesia

Economic growth, changing consumption and production patterns are resulting in rapid increase in the generation of plastic wastes, including plastic packaging waste (PPW). A variety of PPW is identified in the municipal solid waste (MSW) stream. In this paper, quantity and composition of PPW at generators (residential and nonresidential sectors) and at the informal sector of waste recycling were measured, and accordingly the flow of PPW within Bandung City, Indonesia was analyzed. Though the generation rate per capita is not so high (25.1 g per day), total PPW generated by 2.3 million inhabitants in Bandung becomes 58.4 tonnes per day (3.76 % of total MSW generated). Due to lack of integrated MSW management, most of PPW is neither collected properly nor disposed of in appropriate manner by the municipality. Collection of valuable wastes including PPW is done predominantly by the informal sector without regard to health and safety. It is predicted that total PPW recycled by various informal waste recycling players like scavengers, junkmen, intermediates, and dealers is 27.5 tonnes per day (64.6 % of total PPW generated). Interviews regarding the existing handling methods and incentives preferred by generators to increase the recycling rate are also presented.     

State of municipal solid waste management in Delhi, the capital of India

Delhi is the most densely populated and urbanized city of India. The annual growth rate in population during the last decade (1991-2001) was 3.85%, almost double the national average. Delhi is also a commercial hub, providing employment opportunities and accelerating the pace of urbanization, resulting in a corresponding increase in municipal solid waste (MSW) generation. Presently the inhabitants of Delhi generate about 7000tonnes/day of MSW, which is projected to rise to 17,000-25,000tonnes/day by the year 2021. MSW management has remained one of the most neglected areas of the municipal system in Delhi. About 70-80% of generated MSW is collected and the rest remains unattended on streets or in small open dumps. Only 9% of the collected MSW is treated through composting, the only treatment option, and rest is disposed in uncontrolled open landfills at the outskirts of the city. The existing composting plants are unable to operate to their intended treatment capacity due to several operational problems. Therefore, along with residue from the composting process, the majority of MSW is disposed in landfills. In absence of leachate and landfill gas collection systems, these landfills are a major source of groundwater contamination and air pollution (including generation of greenhouse gases). This study describes and evaluates the present state of municipal solid waste management in Delhi. The paper also summarizes the proposed policies and initiatives of the Government of Delhi and the Municipal Corporation of Delhi to improve the existing MSW management system.     

Energy recovery and greenhouse gas reduction potential from food waste in Japan

Waste-to-energy is one effective waste management approach for a sustainable society. The purpose of this study was to clarify the potential for energy recovery and greenhouse gas (GHG) reduction that could be achieved by introducing anaerobic digestion (AD) facilities in the process of reconstructing aging incineration facilities in Japan. Using statistical data from 1068 incineration facilities, four future scenarios were considered and compared with the current situation. As results, compared with the current situation the amount of electricity generated could increase by 60 % in 2030, by combining AD facilities for food waste with new, high-efficiency incineration facilities for remaining municipal solid waste (MSW). From a life cycle perspective, net energy recovery in 2030 was approximately three times greater than in 2011, and GHG emission could be reduced by 27 %. The introduction of AD facilities is attractive for small authorities, which currently treat <100 t/day of MSW through incineration facilities without energy recovery. An AD facility is also beneficial for large authorities. On the contrary, in middle-scale authorities that treat 100–299 t/day of MSW, the reconstruction of incineration facilities to include electricity production capabilities requires careful consideration, because it will significantly influence energy recovery and GHG reduction effects.     

Municipal solid waste management in China: a comparative analysis

This paper illustrates an overview of the past and present MSWM strategies in China. A comparison is made with MSWM in China, and other developed and developing countries to identify and analyze the problems of existing MSWM, and evaluate some effective suggestion to overcome the limitations. Rapid urbanization and economic growth are the main factors of increasing MSW generation in China. The generating MSW has 55.86 % food waste with high moisture contain due to unavailable source separation. Chinese MSWM is dominated by 60.16 % landfilling, whereas incineration, untreated discharge, and other treatments are 29.84, 8.21, and 1.79 %, respectively. In 2014, a total of 604 sanitary landfills, 188 incineration plants, and 26 other units were used for MSWM. With the magnitude of timing, the increasing rate of incineration unit and disposal capacity is higher than the landfill. In 2004–2014, the disposal capacity of landfill and incineration is increased from 68.89 to 107.44 and 4.49 to 53.3 million tons, respectively. However, the heating value in the majority of Chinese incineration plants is 3000–6700 kJ/kg and the inappropriate leachate treatment can be found in 47 % landfill sites. A proper taxation system for MSW disposal is not fully implemented in China, which has a negative impact on overall MSW recycling. From the comparative study of MSWM, it is revealed that the source separation MSW collection, high energy recovery from incineration plants, appropriate leachate treatment, effective landfill location and management, increase waste recycling and proper taxation system for MSW disposal are essential to improve MSWM in China.     

Leachate generation and biogas energy recovery in the Jebel Chakir municipal solid waste landfill,Tunisia

A survey was conducted between 2006 and 2008 in order to identify municipal solid waste (MSW) composition and its influence on leachate generation and to assess the amount of biogas yield from the Jebel Chakir landfill in Tunis City. The organic fraction was the predominant compound in the MSW, followed by paper, fine, plastic, leather, rubber, metal, textile, glass and ceramic. The average MSW moisture content varies from 60 % in the wet season to 80 % in the dry one. The recognised MSW composition is well representative if compared to that of cities in developing countries. A large leachate quantity is produced in the landfill of Jebel Chakir, despite the negative water balance of the site. Based on the annual MSW landfilled quantities and using the LandGEM model, the expected peak landfill gas (LFG) production is estimated to occur 1 year after the landfill closure with a rate of 3.53 × 10⁷ m³/year. The analysis of the potential conversion of LFG to electric energy shows it at a total LFG-to-electricity energy of around 257 GWh with a heating value of 4,475 kcal/m³ based on an LFG collection efficiency of 33 % and energy efficiency of 33 % giving an economic feasibility for a 10 MW power plant.     

Sustainability analysis of organic fraction of municipal solid waste conversion techniques for efficient resource recovery in India through case studies

Worldwide solid waste generation is nearly 1.3 billion tonnes/year, whereas in India 62 million tonnes of solid waste is generated per year by 377 million urban people. The increasing amount of solid waste in India, nearly 50% of which is organic matter, is the major concern for treatment and waste management. Several technologies are already in practice for the treatment of organic fraction of municipal solid waste (OFMSW) in India. It is important to assess the sustainability of these processes. In this study, the existing OFMSW technologies in India were examined. Case-study approach was taken for this purpose along with some published secondary reports. It was found that the selection of technology quite depends on the composition of the OFMSW. Food waste rich fractions are recommended for biomethanation, whereas the fractions rich in market waste and household waste are suitable for composting. Fractions rich in lignin and lignocellulosic materials are suitable for pyrolysis and gasification, whereas the rejects are to be sent for RDF preparation. Based on the findings, a sustainable framework has also been proposed, implementation of which may result in better waste management.     

Economic assessment and energy model scenarios of municipal solid waste incineration and gas turbine hybrid dual-fueled cycles in Thailand

Finding environmentally benign methods related to sound municipal solid waste (MSW) management is of highest priority in Southeast Asia. It is very important to study new approaches which can reduce waste generation and simultaneously enhance energy recovery. One concrete example of particular significance is the concept of hybrid dual-fuel power plants featuring MSW and another high-quality fuel like natural gas. The hybrid dual-fuel cycles provide significantly higher electrical efficiencies than a composite of separate single-fuel power plant (standalone gas turbine combined cycle and MSW incineration). Although hybrid versions are of great importance for energy conversion from MSW, an economic assessment of these systems must be addressed for a realistic appraisal of these technologies. This paper aims to further examine an economic assessment and energy model analysis of different conversion technologies. Energy models are developed to further refine the expected potential of MSW incineration with regards to energy recovery and environmental issues. Results show that MSW incineration can play role for greenhouse gas reduction, energy recovery and waste management. In Bangkok, the electric power production via conventional incineration and hybrid power plants can cover 2.5% and 8% of total electricity consumption, respectively. The hybrid power plants have a relative short payback period (5 years) and can further reduce the CO₂ levels by 3% in comparison with current thermal power plants.     

A hybrid procedure for MSW generation forecasting at multiple time scales in Xiamen City,China

Accurate forecasting of municipal solid waste (MSW) generation is crucial and fundamental for the planning, operation and optimization of any MSW management system. Comprehensive information on waste generation for month-scale, medium-term and long-term time scales is especially needed, considering the necessity of MSW management upgrade facing many developing countries. Several existing models are available but of little use in forecasting MSW generation at multiple time scales. The goal of this study is to propose a hybrid model that combines the seasonal autoregressive integrated moving average (SARIMA) model and grey system theory to forecast MSW generation at multiple time scales without needing to consider other variables such as demographics and socioeconomic factors. To demonstrate its applicability, a case study of Xiamen City, China was performed. Results show that the model is robust enough to fit and forecast seasonal and annual dynamics of MSW generation at month-scale, medium- and long-term time scales with the desired accuracy. In the month-scale, MSW generation in Xiamen City will peak at 132.2 thousand tonnes in July 2015 – 1.5 times the volume in July 2010. In the medium term, annual MSW generation will increase to 1518.1 thousand tonnes by 2015 at an average growth rate of 10%. In the long term, a large volume of MSW will be output annually and will increase to 2486.3 thousand tonnes by 2020 – 2.5 times the value for 2010. The hybrid model proposed in this paper can enable decision makers to develop integrated policies and measures for waste management over the long term.     

Analysis of potential RDF resources from solid waste and their energy values in the largest industrial city of Korea

The production potential of refuse derived fuel (RDF) in the largest industrial city of Korea is discussed. The purpose of this study is to evaluate the energy potential of the RDF obtained from utilizing combustible solid waste as a fuel resource. The total amount of generated solid waste in the industrial city was more than 3.3 million tonnes, which is equivalent to 3.0 tonnes per capita in a single year. The highest amount of solid waste was generated in the city district with the largest population and the biggest petrochemical industrial complex (IC) in Korea. Industrial waste accounted for 89% of the total amount of the solid waste in the city. Potential RDF resources based on combustible solid wastes including wastepaper, wood, rubber, plastic, synthetic resins and industrial sludge were identified. The amount of combustible solid waste that can be used to produce RDF was 635,552 tonnes/yr, consisting of three types of RDF: 116,083 tonnes/yr of RDF-MS (RDF from municipal solid waste); 146,621 tonnes/yr of RDF-IMC (RDF from industrial, municipal and construction wastes); and 372,848 tonnes/yr of RDF-IS (RDF from industrial sludge). The total obtainable energy value from the RDF resources in the industrial city was more than 2,240,000 × 10⁶ kcal/yr, with the following proportions: RDF-MS of 25.6%, RDF-IMC of 43.5%, and RDF-IS of 30.9%. If 50% or 100% of the RDF resources are utilized as fuel resources, the industrial city can save approximately 17.6% and 35.2%, respectively, of the current total disposal costs.     

Assessment of factors affecting household solid waste generation and its composition in Gulberg Town,Lahore, Pakistan

This paper analyzes and compares the findings of the characterization study of collected solid waste from households of three different socioeconomic groups in Lahore, Pakistan, over the four seasons, i.e. Spring (March–April, 2008), Summer (May–June, 2008), Monsoon (August–September, 2008) and Winter (December 2008 and January 2009). The generation rate of waste was 0.96 kg/cap/day for high-income, 0.73 kg/cap/day for middle and 0.67 kg/cap/day for low-income group. The average of total household solid waste (HSW) generation is 0.79 kg/cap/day (including 0.75 kg/cap/day for spring, 0.77 kg/cap/day for summer, 0.86 kg/cap/day for monsoon and 0.76 kg/cap/day. The breakdown for the major physical components of the waste shows that organic waste accounts for the largest proportion (67.46 %). The relations between waste generation rates by physical category and subcategory, in addition to factors such as socioeconomic groups (population density levels, household income and household size), seasonal variation, and daily variation (difference of HSW generation among days of a week) were also analyzed. Statistical analysis shows that there was no significant difference in overall waste generation among days of a week. A significant difference between the seasons for food waste, cardboard, PET, HDPE, other hazardous waste, battery cells, and dust and stone (p < 0.001) was found. The generation rates were found to be higher when compared to other developing countries.     

An investigation on mechanical property of MSW-derived fuel pellet produced from hydrothermal treatment

This paper presents a study on the effect of hydrothermal treatment (HTT) on municipal solid waste (MSW) and mechanical property of fuel pellet. The lab-scale HTT was conducted at the condition of 180–240 °C and 30–90 min. Results showed that the HTT could improve fuel property of MSW including heating value, dewatering and drying performance. The fuel pellet was produced at three different diameters (4, 6, and 8 mm). Tests of mechanical property and water adsorption were performed. Results showed that the fuel pellet was able to withstand the axial load of 19–54 N and the radial load of 72–130 N. The 8-mm pellet exhibited lowest Young’s modulus (18.26 MPa) indicating flexibility and ductility. Durability of the fuel pellet was high (91–94%) while the Hardgrove Grindability Index (HGI) was (57–76) higher than that of the biomass pellet (18–22) and the subbituminous coal (46–49) indicating the ease of grinding. The equilibrium moisture content of the fuel pellet was 5–6%. The small fuel pellet reached adsorption equilibrium faster than the large one. In sum, the fuel pellet produced from HTT showed good fuel property as well as mechanical property for transportation and utilization.     

Research on solid waste management system: to improve existing situation in Corlu Town of Turkey

Over the past decades, uncontrolled population growth and rapid urbanization and industrialization have resulted in environmental problems in Corlu Town, Turkey. One of the most important problems is solid waste due to inadequate management practices. Nowadays, increasing public awareness of the environment compels local authorities to define and to adopt new solutions for waste management. This paper presents a general overview of current solid waste management practices in Corlu Town and principles of the recommended municipal solid waste (MSW) management system. In Corlu, 170 tonnes of municipal solid waste are generated each day, or 1.150 kg per capita per day. Approximately one-half of the municipal solid waste generated is organic material and 30% of the MSW consists of recyclable materials. The recommended system deals with maximizing recycling and minimizing landfilling of municipal solid waste, and consists of separation at source, collection, sorting, recycling, composting and sanitary landfilling. This study also analyzed the recommended system with respect to feasibility and economics. To evaluate whether the suggested system is cost effective or not, the operating cost of the recommended system and market prices of recyclable materials were compared, and the results show that the recommended system will reduce required landfill volume up to 27% of compared to the present situation. The profit of the recommended system is estimated to be about 80 million US dollars.     

A survey on municipal solid waste and residents’ awareness in Da Nang city, Vietnam

A survey on solid waste generation and residents’ awareness was conducted in Da Nang city, Vietnam in 2010. We took samples from residents, hotels, restaurants, and city markets. Data reveals that each resident generates on average 0.71 kg/capita/day (3 kg/household/day). Regarding the composition, organic waste (food, flowers, leaves, grass) accounts for about 70 % of residents’ waste followed by plastics. Likewise, about 14 % of residents’ waste can be recycled. Furthermore, we find that middle income households in the suburbs have the largest waste generation with 4.9 kg/household/day. We consider that this finding is explained by their dedication to agricultural activities, such as planting fruit trees and vegetables, and gardening. Finally, we find that only about 60 % of interviewees have knowledge of how to segregate waste, however more than 90 % of them are willing to cooperate with the introduction of a waste segregation program in the city.     

An integrated appraisal of energy recovery options in the United Kingdom using solid recovered fuel derived from municipal solid waste

This paper reports an integrated appraisal of options for utilising solid recovered fuels (SRF) (derived from municipal solid waste, MSW) in energy intensive industries within the United Kingdom (UK). Four potential co-combustion scenarios have been identified following discussions with industry stakeholders. These scenarios have been evaluated using (a) an existing energy and mass flow framework model, (b) a semi-quantitative risk analysis, (c) an environmental assessment and (d) a financial assessment. A summary of results from these evaluations for the four different scenarios is presented. For the given ranges of assumptions; SRF co-combustion with coal in cement kilns was found to be the optimal scenario followed by co-combustion of SRF in coal-fired power plants. The biogenic fraction in SRF (ca. 70%) reduces greenhouse gas (GHG) emissions significantly (～2500 g CO₂ eqvt./kg DS SRF in co-fired cement kilns and ～1500 g CO₂ eqvt./kg DS SRF in co-fired power plants). Potential reductions in electricity or heat production occurred through using a lower calorific value (CV) fuel. This could be compensated for by savings in fuel costs (from SRF having a gate fee) and grants aimed at reducing GHG emission to encourage the use of fuels with high biomass fractions. Total revenues generated from coal-fired power plants appear to be the highest (£95/t SRF) from the four scenarios. However overall, cement kilns appear to be the best option due to the low technological risks, environmental emissions and fuel cost. Additionally, cement kiln operators have good experience of handling waste derived fuels. The scenarios involving co-combustion of SRF with MSW and biomass were less favourable due to higher environmental risks and technical issues.     

Measuring bulky waste arisings in Hong Kong

All too often, waste authorities either assume that they know enough about their bulky waste stream or that it is too insignificant to deserve attention. In this paper, we use Hong Kong as an example to illustrate that official bulky waste figures can actually be very different from the reality and therefore important waste management decisions made based on such statistics may be wrong too. This study is also the first attempt in Hong Kong to outline the composition of bulky waste.It was found that about 342 tonnes/day of wood waste were omitted by official statistics owing to incomplete records on actual bulky waste flow. This is more than enough to provide all the feedstock needed for one regular-sized wood waste recycling facility in Hong Kong. In addition, the proportion of bulky waste in the municipal solid waste (MSW) streams in Hong Kong should be about 6.1% instead of the officially stated 1.43%. Admittedly, there are limitations with this study. Yet, present findings are suggestive of significant MSW data distortion in Hong Kong.     

Municipal solid waste management in Malaysia: Practices and challenges

Rapid economic development and population growth, inadequate infrastructure and expertise, and land scarcity make the management of municipal solid waste become one of Malaysia’s most critical environmental issues. The study is aimed at evaluating the generation, characteristics, and management of solid waste in Malaysia based on published information. In general, the per capita generation rate is about 0.5–0.8 kg/person/day in which domestic waste is the primary source. Currently, solid waste is managed by the Ministry of Housing and Local Government, with the participation of the private sector. A new institutional and legislation framework has been structured with the objectives to establish a holistic, integrated, and cost-effective solid waste management system, with an emphasis on environmental protection and public health. Therefore, the hierarchy of solid waste management has given the highest priority to source reduction through 3R, intermediate treatment and final disposal.     

Development of waste gasification and gas reforming system for municipal solid waste (MSW)

To achieve both high-efficiency power generation and high detoxification performance, advanced-type waste power generation plants such as pyrolysis and gas reforming plants are suggested. Further surveys on actual operational data of these plants are required in terms of reliability of the system when it is introduced to waste disposal sites. To verify the technical effectiveness of advanced-type waste power generation using the pyrolysis and gas reforming method, we evaluated 10?tons/day of municipal solid wastes (MSW) treated in a demonstration plant. A demonstration test was conducted over 100?days including 35?consecutive days of operation treating MSWs. The test results show high recycling performance and harmless nature of the plant which proves it to be an excellent waste recycling system. Major test results are as follows: (1) stabilization of waste treatment is possible with the wastes of various qualities, (2) clean gas is produced from the waste whose energy recovery ratio is approximately 40?%. (3) 99.3?% weight % of dried waste are recovered as valuable materials such as clean gas, char and metal, (4) total amount of dioxin emission to the outside of the plant is very small, down to 0.0051–0.018?μg?TEQ per ton waste.     

Combustion characteristics of Malaysian municipal solid waste and predictions of air flow in a rotary kiln incinerator

Malaysia is in dire need of alternatives to landfilling for solid waste management. Recently, landfills have faced the problems of overfilling, overflowing of leachates leading to pollution of water resources, and uncontrolled dust emissions adversely affecting the local environment. With the rising cost of urbanization coupled with the high rate of waste generation, one possible method of waste treatment that is receiving particular attention by the government is incineration. Incineration of solid waste is rather new in Malaysia, with limited usage in handling small sources of waste generation such as the municipal solid waste (MSW) of resort islands; however, its potential in ameliorating the problems associated with solid waste treatment may make it an attractive alternative to landfill. This article presents the results of test runs conducted to investigate the performance of a locally designed and manufactured rotary kiln incinerator (RKI). The test runs were conducted using MSW collected from the Shah Alam municipality. The combustion efficiency was analyzed by looking at the temperature profiles and chemical species concentrations. To complement the combustion characteristics measurements, predictions of the air flow in the incinerator during the process were also investigated. The overall performance of the RKI suggests that it is suitable for treating MSW.     

Non-hazardous waste generation characteristics and recycling practices in Saskatchewan and Manitoba,Canada

The paper presents the results on the analysis of non-hazardous waste generation characteristics and recycling practices in Saskatchewan (SK) and Manitoba (MB) using the biennial waste reports published by Statistic Canada. The objectives are to examine the waste generation rates from both residential and non-residential sources from 1998 to 2010, and to evaluate the effectiveness of their recycling programs and regulations. In spite of the many similarities between the provinces, MB on average generated 17.5 % more residential waste than SK, and about 15 % less non-residential waste than SK during the study period. It appears that MB waste generation characteristics were very different from SK and the rest of Canada. The amount of MSW generation in MB was, to a certain degree, independent from the economic factors. Assuming status quos conditions, the linear models predicted that the per capita MSW generations in MB would be about 33 % lower than SK in 2020. Data from this study suggest that (1) curbside recycling programs and (2) pay-as-you-throw collection systems may be important factors for increasing diversion rate in SK. It is also found that the non-residential waste generation in Canada was substantially larger than the residential waste generation during the 13-year period.     

Current status of waste to power generation in Japan and resulting reduction of carbon dioxide emissions

We discuss the current status of waste to power generation (WPG) in Japan and various scenarios involving indirect reduction of carbon dioxide emissions by WPG. The number of WPG facilities domestically as of 2005 was 286. Power generation capacity attained 1,515 MW and power generation 7,050 GWh/year. This amount substitutes energy otherwise acquired from natural resources such as fossil fuels in thermal power plants. If the basic unit of carbon dioxide is 0.555 kg-CO₂/kWh, then the corresponding carbon dioxide emission reduction is calculated to be 3.9 million tons, equivalent to 26.7% of the 14.6 million tons emitted by municipal solid waste incinerators (MSWI) in 2005. Using various existing technological options, the power generation efficiency could reach more than 20% in MSWI facilities with capacity of 300 tons/day, although present efficiency is only 12.0%. If about 85% of MSW were incinerated in MSWI with power generation efficiency of 20% as a feasible assumption, the total power generation and the corresponding carbon dioxide reduction would be 16,540 GWh/year and 9.18 million tons, respectively, equivalent to 62.7% of the carbon dioxide emitted by MSWI. Also, the ratio of the additional reduction of carbon dioxide emissions by WPG to the total additional reduction (20,000 ktons/year) in Japan during the first commitment period would be 26.3%, suggesting that promotion of WPG in MSWI is an effective option for prevention of global warming.