Property-close source separation of hazardous waste and waste electrical and electronic equipment--a Swedish case study

Through an agreement with EEE producers, Swedish municipalities are responsible for collection of hazardous waste and waste electrical and electronic equipment (WEEE). In most Swedish municipalities, collection of these waste fractions is concentrated to waste recycling centres where households can source-separate and deposit hazardous waste and WEEE free of charge. However, the centres are often located on the outskirts of city centres and cars are needed in order to use the facilities in most cases. A full-scale experiment was performed in a residential area in southern Sweden to evaluate effects of a system for property-close source separation of hazardous waste and WEEE. After the system was introduced, results show a clear reduction in the amount of hazardous waste and WEEE disposed of incorrectly amongst residual waste or dry recyclables. The systems resulted in a source separation ratio of 70 wt% for hazardous waste and 76 wt% in the case of WEEE. Results show that households in the study area were willing to increase source separation of hazardous waste and WEEE when accessibility was improved and that this and similar collection systems can play an important role in building up increasingly sustainable solid waste management systems.     

Solid waste management practices and review of recovery and recycling operations in Turkey

This paper provides a general overview of solid waste data and management practices employed in Turkey during the last decade. Municipal solid waste statistics and management practices including waste recovery and recycling initiatives have been evaluated. Detailed data on solid waste management practices including collection, recovery and disposal, together with the results of cost analyses, have been presented. Based on these evaluations basic cost estimations on collection and sorting of recyclable solid waste in Turkey have been provided. The results indicate that the household solid waste generation in Turkey, per capita, is around 0.6 kg/year, whereas municipal solid waste generation is close to 1 kg/year. The major constituents of municipal solid waste are organic in nature and approximately 1/4 of municipal solid waste is recyclable. Separate collection programmes for recyclable household waste by more than 60 municipalities, continuing in excess of 3 years, demonstrate solid evidence for public acceptance and continuing support from the citizens. Opinion polls indicate that more than 80% of the population in the project regions is ready and willing to participate in separate collection programmes. The analysis of output data of the Material Recovery Facilities shows that, although paper, including cardboard, is the main constituent, the composition of recyclable waste varies strongly by the source or the type of collection point.     

Proximate composition of household waste and applicability of waste management technologies by source separation in Hanoi,Vietnam

The organic fraction of municipal solid wastes in Southeast Asia, which has a high moisture content, accounts for a large proportion of total waste. Local governments need to pay adequate attention to the composition of wastes to determine alternative waste management technologies. This study proposed the use of a triangle diagram to describe changes in proximate composition and rates of successful source separation of municipal solid waste and to identify technical challenges about alternative waste management technologies such as incineration, composting, and refuse-derived fuel production based on physical and proximate composition analysis of household waste sampled in Hanoi, Vietnam, as a case study. The analysis indicated the effectiveness of different types of source separation as well as different levels of successful achievement of source separation as an adjustment mechanism for the proximate composition of waste. Proper categorization of wastes for source separation is necessary for the appropriate use of alternative waste management technologies. The results showed that, at a source separation rate of just greater than 0.52 in a three-way separation scheme, the waste separated as combustible waste would be suitable for incineration with energy recovery. Based on well-designed schemes of source separation, alternative waste management technologies can be applied.     

Comparison of old and new municipal solid waste management systems in Denizli, Turkey

Rapid economic growth, increasing population and change in living standards contribute to increasing the generation rate of municipal solid waste (MSW) in Denizli city, like other Turkish cities. The improper and poor MSW management system (old system) in Denizli caused environmental problems originating from the uncontrolled release of methane and leachate. In addition, the disposal of recyclable materials in unsanitary landfills is responsible for the consumption and destruction of natural sources. This paper presents a general overview of old and new MSW management practices in Denizli. Detailed data on MSW management practices including collection, transportation, disposal and recycling have been presented. The amount of solid waste generated in Denizli over the last decade has increased steadily over the years, from 108,500 tons in 1995 to 179,495 tons in 2006. The average MSW generation rate was found to be 1.23kg/day per capita. The major constituent of MSW in Denizli is food waste, but the percentage of recyclable waste has increased significantly recently. Except for metal wastes, the percentages of recyclable waste materials in Denizli are higher than in all neighborhood cities. The objective of this study is to compare the old and new MSW management systems in Denizli city. The MSW management system has been changed entirely last five years. A dumpsite was closed and a sanitary landfill with a composting facility was constructed. In addition, source separated collection has been carried out since 2002. The quantity of recyclable waste collected increased from 195 to 1549 tons. The amount of recyclable waste will continue to be increased by expanding the source separation collection system to all the districts of the city and preventing scavenging. Thus, revenue from recyclable waste ($7227 in 2006) is expected to increase. In addition, the capacity of the composting facility will be increased. Most importantly, information to increase public participation and awareness in municipal recovery programs has to be provided.     

A cost evaluation method for transferring municipalities to solid waste source-separated system

Most of Israel’s waste is disposed in landfills, threatening scarce land resources and posing environmental and health risks. The aim of this study is to estimate the expected costs of transferring municipalities to solid waste source separation in Israel, aimed at reducing the amount of waste directed to landfills and increasing the efficiency and amount of recycled waste. Information on the expected costs of operating a solid waste source separation system was gathered from 47 municipalities and compiled onto a database, taking into consideration various factors such as costs of equipment, construction adjustments and waste collection and disposal. This database may serve as a model for estimating the costs of entering the waste source separation system for any municipality in Israel, while taking into consideration its specific characteristics, such as size and region. The model was used in Israel for determining municipalities’ eligibility to receive a governmental grant for entering an accelerated process of solid waste source separation. This study displays a user-friendly and simple operational tool for assessing municipalities’ costs of entering a process of waste source separation, providing policy makers a powerful tool for diverting funds effectively in promoting solid waste source separation.     

Selective collection as a pretreatment for indirect solid recovered fuel generation

Effective selective collection (SC) has been increasing in many countries of the European Union. As a consequence the composition of residual municipal solid waste (RMSW) is changing not only because of economic development, but also due to the collection system. The input of RMSW treatment plants is thus not homogeneous. This paper analyses two case studies involving a total of five SC scenarios and their impact on the generation of solid recovered fuel (SRF) with/without bio-drying, post-treatment and packaging take back programs (TBPs). These case studies are based on two types of SC: kerbside and drop-off. The latest regulation on SRF classification is taken into account: energy content, Cl and Hg concentrations are assessed and discussed. The role of the respirometric index (RI) is also analyzed. Results show that when SC is highly efficient RMSW can be classified directly as SRF, but only if the introduction of RI does not set stringent respirometric targets. The role of packaging TBPs is important as the residual waste remaining after the packaging has been processed, can be valorized increasing the lower heating value (LHV) of the residual RMSW and minimizing the streams that should be landfilled. The source separation of food waste has a significant impact on the suitability of bio-drying: when the SC of food waste is very efficient, its percentage in the RMSW may be too low for effective bio-drying.     

Using a contingent valuation approach for improved solid waste management facility: evidence from Kuala Lumpur, Malaysia

This study employed contingent valuation method to estimate the willingness to pay (WTP) of the households to improve the waste collection system in Kuala Lumpur, Malaysia. The objective of this study is to evaluate how household WTP changes when recycling and waste separation at source is made mandatory. The methodology consisted of asking people directly about their WTP for an additional waste collection service charge to cover the costs of a new waste management project. The new waste management project consisted of two versions: version A (recycling and waste separation is mandatory) and version B (recycling and waste separation is not mandatory). The households declined their WTP for version A when they were asked to separate the waste at source although all the facilities would be given to them for waste separation. The result of this study indicates that the households were not conscious about the benefits of recycling and waste separation. Concerted efforts should be taken to raise environmental consciousness of the households through education and more publicity regarding waste separation, reducing and recycling.     

Effect of informal recycling on waste collection and transportation: the case of Chiclayo city in Peru

This paper analyses the evolution of national solid waste policy in Peru and the increasing relevance of informal recycling. Despite this rise in relevance, source separation and incorporation of informal recyclers within municipal plans is still slow, and collection of mixed waste is being considered. Waste collection and transportation costs represent the main share in municipal budgets and this research calculates cost reductions as a result of informal recycling and waste picking. The city of Chiclayo in Peru is presented as a case study. The paper finds that so far, waste picking has resulted in a reduction of two collection rounds but not a reduction in the number of vehicles collecting waste. Looking to the future, recovery of the remaining materials will not have an effect on collection rounds and number of vehicles. The research concludes that synergy between municipal systems and informal recycling can be maximized if new operational conditions are implemented. It introduces the concepts of “critical work shift,” which is the time of the day when the system requires maximum quantity of resources (i.e. vehicle-hours), and “sensitivity to variations in waste amounts,” and proposes strategies to promote recycling based on these new operational concepts.     

A progress indicator-based assessment guide for integrated municipal solid-waste management systems

Managing municipal solid waste is a major concern for cities around the world. Particularly urban communities with developing economies are urged to improve their waste management practices, and set up appropriate waste management systems. Waste management is a city-specific topic; there is no ideal solution that can be operationalized everywhere. In developing cities, municipalities and decision makers need simple and effective indicators to assess the sustainability of their current waste management systems, and set a performance reference point. The current study investigates available literature and suggests a list of measurable sustainability indicators which are specific to solid-waste management. The list encompasses 27 indicators that cover the building blocks of an integrated solid-waste management system, i.e., collection and sorting, recycling, composting, energy recovery, and landfilling. An assessment tool is developed through a five-point Likert scale, evaluating these indicators. Case studies of Cairo and Brussels were analyzed. The outcomes of this analysis can be used as a benchmark on a local level in planning, clarifying policy objectives, and setting priorities.     

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.     

Environmental impact assessment of solid waste management in Beijing City, China

The environmental impacts of municipal solid waste management in Beijing City were evaluated using a life-cycle-based model, EASEWASTE, to take into account waste generation, collection, transportation, treatment/disposal technologies, and savings obtained by energy and material recovery. The current system, mainly involving the use of landfills, has manifested significant adverse environmental impacts caused by methane emissions from landfills and many other emissions from transfer stations. A short-term future scenario, where some of the landfills (which soon will reach their capacity because of rising amount of waste in Beijing City) are substituted by incinerators with energy recovery, would not result in significant environmental improvement. This is primarily because of the low calorific value of mixed waste, and it is likely that the incinerators would require significant amounts of auxiliary fuels to support combustion of wet waste. As for the long-term future scenario, efficient source separation of food waste could result in significant environmental improvements, primarily because of increase in calorific value of remaining waste incinerated with energy recovery. Sensitivity analysis emphasized the importance of efficient source separation of food waste, as well as the electricity recovery in incinerators, in order to obtain an environmentally friendly waste management system in Beijing City.     

Early detection and evaluation of waste through sensorized containers for a collection monitoring application

The present study describes a novel application for use in the monitoring of municipal solid waste, based on distributed sensor technology and geographical information systems. Original field testing and evaluation of the application were carried out in Pudong, Shanghai (PR China).The local waste management system in Pudong features particular requirements related to the rapidly increasing rate of waste production. In view of the fact that collected waste is currently deployed to landfills or to incineration plants within the context investigated, the key aspects to be taken into account in waste collection procedures include monitoring of the overall amount of waste produced, quantitative measurement of the waste present at each collection point and identification of classes of material present in the collected waste. The case study described herein focuses particularly on the above mentioned aspects, proposing the implementation of a network of sensorized waste containers linked to a data management system.Containers used were equipped with a set of sensors mounted onto standard waste bins. The design, implementation and validation procedures applied are subsequently described. The main aim to be achieved by data collection and evaluation was to provide for feasibility analysis of the final device. Data pertaining to the content of waste containers, sampled and processed by means of devices validated on two purpose-designed prototypes, were therefore uploaded to a central monitoring server using GPRS connection. The data monitoring and management modules are integrated into an existing application used by local municipal authorities.A field test campaign was performed in the Pudong area. The system was evaluated in terms of real data flow from the network nodes (containers) as well as in terms of optimization functions, such as collection vehicle routing and scheduling. The most important outcomes obtained were related to calculations of waste weight and volume. The latter data were subsequently used as parameters for the routing optimization of collection trucks and material density evaluation.     

Material and energy recovery in integrated waste management systems: a life-cycle costing approach

A critical assumption of studies assessing comparatively waste management options concerns the constant average cost for selective collection regardless the source separation level (SSL) reached, and the neglect of the mass constraint. The present study compares alternative waste management scenarios through the development of a desktop model that tries to remove the above assumption. Several alternative scenarios based on different combinations of energy and materials recovery are applied to two imaginary areas modelled in order to represent a typical Northern Italian setting. External costs and benefits implied by scenarios are also considered. Scenarios are compared on the base of the full cost for treating the total waste generated in the area. The model investigates the factors that influence the relative convenience of alternative scenarios.     

LCA of integrated MSW management systems: case study of the Bologna District

LCA as a decision-supporting tool in planning integrated municipal solid waste management is not, as yet, widely used in Italy. This paper presents a study concerning the application of the LCA methodology to support the development of the new waste management plan for the Bologna District. The main goal of the study was to show decision-makers at the political level the benefits obtainable with the use of LCA, in terms of the identification and quantification of the potential environmental impacts of different waste management strategies. The integrated waste management system of the Bologna District includes waste collection and transport, sorting, recycling, composting, incineration and landfilling. Three scenarios, referring to 2006 and assuming the presence of 950,000 inhabitants and the production of approximately 566,000 t of waste in the district, have been compared. A detailed model has been developed in order to capture effects related to the waste fraction from separated collection and to the different waste treatments. The discussion of the results has focussed in particular on the greenhouse effect and the acidification potential. On the basis of the results obtained, the analysis of an additional scenario characterised by a further increase in separated collection has been put forward.     

Sustainable recycling of municipal solid waste in developing countries

This research focuses on recycling in developing countries as one form of sustainable municipal solid waste management (MSWM). Twenty-three case studies provided municipal solid waste (MSW) generation and recovery rates and composition for compilation and assessment. The average MSW generation rate was 0.77 kg/person/day, with recovery rates from 5-40%. The waste streams of 19 of these case studies consisted of 0-70% recyclables and 17-80% organics. Qualitative analysis of all 23 case studies identified barriers or incentives to recycling, which resulted in the development of factors influencing recycling of MSW in developing countries. The factors are government policy, government finances, waste characterization, waste collection and segregation, household education, household economics, MSWM (municipal solid waste management) administration, MSWM personnel education, MSWM plan, local recycled-material market, technological and human resources, and land availability. Necessary and beneficial relationships drawn among these factors revealed the collaborative nature of sustainable MSWM. The functionality of the factor relationships greatly influenced the success of sustainable MSWM. A correlation existed between stakeholder involvement and the three dimensions of sustainability: environment, society, and economy. The only factors driven by all three dimensions (waste collection and segregation, MSWM plan, and local recycled-material market) were those requiring the greatest collaboration with other factors.     

Source separation of household waste: a case study in China

A pilot program concerning source separation of household waste was launched in Hangzhou, capital city of Zhejiang province, China. Detailed investigations on the composition and properties of household waste in the experimental communities revealed that high water content and high percentage of food waste are the main limiting factors in the recovery of recyclables, especially paper from household waste, and the main contributors to the high cost and low efficiency of waste disposal. On the basis of the investigation, a novel source separation method, according to which household waste was classified as food waste, dry waste and harmful waste, was proposed and performed in four selected communities. In addition, a corresponding household waste management system that involves all stakeholders, a recovery system and a mechanical dehydration system for food waste were constituted to promote source separation activity. Performances and the questionnaire survey results showed that the active support and investment of a real estate company and a community residential committee play important roles in enhancing public participation and awareness of the importance of waste source separation. In comparison with the conventional mixed collection and transportation system of household waste, the established source separation and management system is cost-effective. It could be extended to the entire city and used by other cities in China as a source of reference.     

CO₂ emission factors for waste incineration: Influence from source separation of recyclable materials

CO₂-loads from combustible waste are important inputs for national CO₂ inventories and life-cycle assessments (LCA). CO₂ emissions from waste incinerators are often expressed by emission factors in kg fossil CO₂ emitted per GJ energy content of the waste. Various studies have shown considerable variations between emission factors for different incinerators, but the background for these variations has not been thoroughly examined. One important reason may be variations in collection of recyclable materials as source separation alters the composition of the residual waste incinerated. The objective of this study was to quantify the importance of source separation for determination of emission factors for incineration of residual household waste. This was done by mimicking various source separation scenarios and based on waste composition data calculating resulting emission factors for residual waste routed to incineration. Emission factors ranged from 27 to 40 kg CO₂/GJ. The results appeared most sensitive towards variations in waste composition and water content. Recycling rates and lower heating values could not be used as simple indicators of the resulting emission factors for residual household waste; however the fossil carbon ratio of the waste after source separation was found to be appropriately correlated with the emission factor. Based on the results, it is recommended to carefully evaluate the source separation and collection systems behind reported literature values when comparing different studies and when using the values for environmental assessment purposes.     

Economies of size and density in municipal solid waste recycling in Portugal

The recycling of municipal solid waste has a remarkable importance in the preservation of the environment and the welfare of the society. However, it is also important that this service can be provided with efficient costs. This paper aims to search for economies of output density and economies of size in the selective collection and recycling activities in Portugal and to identify the size the utilities should have to become more cost efficient. The sample comprises all Portuguese recycling utilities operating in the wholesale segment in the period 2006–2010. The results show that the Portuguese recycling utilities should increase the quantities of municipal solid waste for recycling (especially glass and paper) and also become larger to dimensions corresponding to a supply of 400–550 thousand inhabitants. With the increasing amount of glass collected, utilities are simultaneously struggling to fulfill the targets established by the European legislation and explore the existing economies of output density. The results also show that the management of these services carried out by private companies and the use of incineration (by utilities) seem to reduce the costs of utilities while the regulation of these services and the composting of waste held by utilities tend to increase costs.     

Estimating the public preferences for solid waste management programmes using choice experiments in Macao.

This paper reports on the potential to apply the choice experiment method to understand the public's preferences for solid waste management programmes in Macao. A random sample survey of 260 respondents in Macao was conducted during the summer in 2004. The survey data was analysed using conditional multinomial logit models. The study results indicate that Macao residents prefer: (1) waste segregation and recycling at source; (2) noise reduction during waste collection and transportation and (3) lower garbage fees. The study concludes that choice experiment is a reliable tool in the analysis of respondents' preferences for developing a suitable solid waste management programme in Macao.