Municipal solid waste composition: sampling methodology, statistical analyses, and case study evaluation

Sound waste management and optimisation of resource recovery require reliable data on solid waste generation and composition. In the absence of standardised and commonly accepted waste characterisation methodologies, various approaches have been reported in literature. This limits both comparability and applicability of the results. In this study, a waste sampling and sorting methodology for efficient and statistically robust characterisation of solid waste was introduced. The methodology was applied to residual waste collected from 1442 households distributed among 10 individual sub-areas in three Danish municipalities (both single and multi-family house areas). In total 17 tonnes of waste were sorted into 10-50 waste fractions, organised according to a three-level (tiered approach) facilitating comparison of the waste data between individual sub-areas with different fractionation (waste from one municipality was sorted at "Level III", e.g. detailed, while the two others were sorted only at "Level I"). The results showed that residual household waste mainly contained food waste (42 ± 5%, mass per wet basis) and miscellaneous combustibles (18 ± 3%, mass per wet basis). The residual household waste generation rate in the study areas was 3-4 kg per person per week. Statistical analyses revealed that the waste composition was independent of variations in the waste generation rate. Both, waste composition and waste generation rates were statistically similar for each of the three municipalities. While the waste generation rates were similar for each of the two housing types (single-family and multi-family house areas), the individual percentage composition of food waste, paper, and glass was significantly different between the housing types. This indicates that housing type is a critical stratification parameter. Separating food leftovers from food packaging during manual sorting of the sampled waste did not have significant influence on the proportions of food waste and packaging materials, indicating that this step may not be required.

ISO 14001 adoption and industrial waste generation: the case of Swedish manufacturing firms

Adoption of environmental management systems (EMSs) based on ISO 14001 has constituted one of the most important developments in sustainable industry management in recent years. Previous research on the impact of EMSs has relied heavily on corporate representatives' subjective perception of benefits. Moreover, studies tend to focus on the systems' impact on firms' overall environmental performance, not distinguishing between the differences in different environmental aspects. This study aims to contribute knowledge about the influence of certified EMSs on industrial waste generation based on objective industrial waste data derived from mandatory annual environmental reports. The study focuses on changes in waste generation over a period of 12 years and includes both ISO 14001-certified firms (66 firms) and non-certified firms (50 firms). Consideration is given to the improvement efforts in the firms before EMS adoption. Analysis has been carried out using statistical methods for three different industrial waste parameters: hazardous waste, waste to landfill and the total amounts of waste. The results indicate that the certified EMSs have no statistically significant effect on any of the three waste parameters.

Removal performance of elemental mercury by low-cost adsorbents prepared through facile methods of carbonisation and activation of coconut husk

The preparation of chars and activated carbon as low-cost elemental mercury adsorbents was carried out through the carbonisation of coconut husk (pith and fibre) and the activation of chars with potassium hydroxide (KOH), respectively. The synthesised adsorbents were characterised by using scanning electron microscopy, Fourier transform infrared spectroscopy and nitrogen adsorption/desorption analysis. The elemental mercury removal performance was measured using a conventional flow type packed-bed adsorber. The physical and chemical properties of the adsorbents changed as a result of the carbonisation and activation process, hence affecting on the extent of elemental mercury adsorption. The highest elemental mercury (Hg°) adsorption capacity was obtained for the CP-CHAR (3142.57 µg g(-1)), which significantly outperformed the pristine and activated carbon adsorbents, as well as higher than some adsorbents reported in the literature.

Hazardous and toxic waste management in Botswana: practices and challenges

Hazardous and toxic waste is a complex waste category because of its inherent chemical and physical characteristics. It demands for environmentally sound technologies and know-how as well as clean technologies that simultaneously manage and dispose it in an environmentally friendly way. Nevertheless, Botswana lacks a system covering all the critical steps from importation to final disposal or processing of hazardous and toxic waste owing to limited follow-up of the sources and types of hazardous and toxic waste, lack of modern and specialised treatment/disposal facilities, technical know-how, technically skilled manpower, funds and capabilities of local institutions to take lead in waste management. Therefore, because of a lack of an integrated system, there are challenges such as lack of cooperation among all the stakeholders about the safe management of hazardous and toxic waste. Furthermore, Botswana does not have a systematic regulatory framework regarding monitoring and hazardous and toxic waste management. In addition to the absence of a systematic regulatory framework, inadequate public awareness and dissemination of information about hazardous and toxic waste management, slower progress to phase-out persistent and bio-accumulative waste, and lack of reliable and accurate information on hazardous and toxic waste generation, sources and composition have caused critical challenges to effective hazardous and toxic waste management. It is, therefore, important to examine the status of hazardous and toxic waste as a waste stream in Botswana. By default; this mini-review article presents an overview of the current status of hazardous and toxic waste management and introduces the main challenges in hazardous and toxic waste management. Moreover, the article proposes the best applicable strategies to achieve effective hazardous and toxic waste management in the future.

Household hazardous waste quantification, characterization and management in China's cities: a case study of Suzhou

A four-stage systematic tracking survey of 240 households was conducted from the summer of 2011 to the spring of 2012 in a Chinese city of Suzhou to determine the characteristics of household hazardous waste (HHW) generated by the city. Factor analysis and a regression model were used to study the major driving forces of HHW generation. The results indicate that the rate of HHW generation was 6.16 (0.16-31.74, 95% CI) g/person/day, which accounted for 2.23% of the household solid waste stream. The major waste categories contributing to total HHW were home cleaning products (21.33%), medicines (17.67%) and personal care products (15.19%). Packaging and containers (one-way) and products (single-use) accounted for over 80% of total HHW generation, implying a considerable potential to mitigate HHW generation by changing the packaging design and materials used by manufacturing enterprises. Strong correlations were observed between HHW generation (g/person/day) and the driving forces group of "household structure" and "consumer preferences" (among which the educational level of the household financial manager has the greatest impact). Furthermore, the HHW generation stream in Suzhou suggested the influence of another set of variables, such as local customs and culture, consumption patterns, and urban residential life-style. This study emphasizes that HHW should be categorized at its source (residential households) as an important step toward controlling the HHW hazards of Chinese cities.

Impact of pedagogical method on Brazilian dental students' waste management practice

The purpose of this study was to conduct a qualitative analysis of waste management practices among a group of Brazilian dental students (n=64) before and after implementing two different pedagogical methods: 1) the students attended a two-hour lecture based on World Health Organization standards; and 2) the students applied the lessons learned in an organized group setting aimed toward raising their awareness about socioenvironmental issues related to waste. All eligible students participated, and the students' learning was evaluated through their answers to a series of essay questions, which were quantitatively measured. Afterwards, the impact of the pedagogical approaches was compared by means of qualitative categorization of wastes generated in clinical activities. Waste categorization was performed for a period of eight consecutive days, both before and thirty days after the pedagogical strategies. In the written evaluation, 80 to 90 percent of the students' answers were correct. The qualitative assessment revealed a high frequency of incorrect waste disposal with a significant increase of incorrect disposal inside general and infectious waste containers (p<0.05). Although the students' theoretical learning improved, it was not enough to change behaviors established by cultural values or to encourage the students to adequately segregate and package waste material.

Statistical analysis in MSW collection performance assessment

The increase of Municipal Solid Waste (MSW) generated over the last years forces waste managers pursuing more effective collection schemes, technically viable, environmentally effective and economically sustainable. The assessment of MSW services using performance indicators plays a crucial role for improving service quality. In this work, we focus on the relevance of regular system monitoring as a service assessment tool. In particular, we select and test a core-set of MSW collection performance indicators (effective collection distance, effective collection time and effective fuel consumption) that highlights collection system strengths and weaknesses and supports pro-active management decision-making and strategic planning. A statistical analysis was conducted with data collected in mixed collection system of Oporto Municipality, Portugal, during one year, a week per month. This analysis provides collection circuits' operational assessment and supports effective short-term municipality collection strategies at the level of, e.g., collection frequency and timetables, and type of containers.

Scientific basis of dissolved organic carbon limitation for landfilling of municipal treatment sludge--is it attainable and justifiable?

This study evaluated the scientific and technical basis of the dissolved organic carbon (DOC) limitation imposed on municipal sludge for landfilling, mainly for assessing the attainability of the implemented numerical level. For this purpose, related conceptual framework was analyzed, covering related sewage characteristics, soluble microbial products generation, and substrate solubilization and leakage due to hydrolysis. Soluble COD footprint was experimentally established for a selected treatment plant, including all the key steps in the sequence of wastewater treatment and sludge handling. Observed results were compared with reported DOCs in other treatment configurations. None of the leakage tests performed or considered in the study could even come close to the prescribed limitation. All observed results reflected 10-20 fold higher DOC levels than the numerical limit of 800 mg/kg (80 mg/L), providing conclusive evidence that the DOC limitation imposed on municipal treatment sludge for landfilling is not attainable, and therefore not justifiable on the basis of currently available technology.

Quantitative assessments of municipal waste management systems: using different indicators to compare and rank programs in New York State

The primary objective of waste management technologies and policies in the United States is to reduce the harmful environmental impacts of waste, particularly those relating to energy consumption and climate change. Performance indicators are frequently used to evaluate the environmental quality of municipal waste systems, as well as to compare and rank programs relative to each other in terms of environmental performance. However, there currently is no consensus on the best indicator for performing these environmental evaluations. The purpose of this study is to examine the common performance indicators used to assess the environmental benefits of municipal waste systems to determine if there is agreement between them regarding which system performs best environmentally. Focus is placed on how indicator selection influences comparisons between municipal waste management programs and subsequent system rankings. The waste systems of ten municipalities in the state of New York, USA, were evaluated using each common performance indicator and Spearman correlations were calculated to see if there was a significant association between system rank orderings. Analyses showed that rank orders of waste systems differ substantially when different indicators are used. Therefore, comparative system assessments based on indicators should be considered carefully, especially those intended to gauge environmental quality. Insight was also gained into specific factors which may lead to one system achieving higher rankings than another. However, despite the insufficiencies of indicators for comparative quality assessments, they do provide important information for waste managers and they can assist in evaluating internal programmatic performance and progress. To enhance these types of assessments, a framework for scoring indicators based on criteria that evaluate their utility and value for system evaluations was developed. This framework was used to construct an improved model for waste system performance assessments.

Review of LCA studies of solid waste management systems--part II: methodological guidance for a better practice

Life cycle assessment (LCA) is increasingly used in waste management to identify strategies that prevent or minimise negative impacts on ecosystems, human health or natural resources. However, the quality of the provided support to decision- and policy-makers is strongly dependent on a proper conduct of the LCA. How has LCA been applied until now? Are there any inconsistencies in the past practice? To answer these questions, we draw on a critical review of 222 published LCA studies of solid waste management systems. We analyse the past practice against the ISO standard requirements and the ILCD Handbook guidelines for each major step within the goal definition, scope definition, inventory analysis, impact assessment, and interpretation phases of the methodology. Results show that malpractices exist in several aspects of the LCA with large differences across studies. Examples are a frequent neglect of the goal definition, a frequent lack of transparency and precision in the definition of the scope of the study, e.g. an unclear delimitation of the system boundaries, a truncated impact coverage, difficulties in capturing influential local specificities such as representative waste compositions into the inventory, and a frequent lack of essential sensitivity and uncertainty analyses. Many of these aspects are important for the reliability of the results. For each of them, we therefore provide detailed recommendations to practitioners of waste management LCAs.

Review of LCA studies of solid waste management systems--part I: lessons learned and perspectives

The continuously increasing solid waste generation worldwide calls for management strategies that integrate concerns for environmental sustainability. By quantifying environmental impacts of systems, life cycle assessment (LCA) is a tool, which can contribute to answer that call. But how, where and to which extent has it been applied to solid waste management systems (SWMSs) until now, and which lessons can be learnt from the findings of these LCA applications? To address these questions, we performed a critical review of 222 published LCA studies of SWMS. We first analysed the geographic distribution and found that the published studies have primarily been concentrated in Europe with little application in developing countries. In terms of technological coverage, they have largely overlooked application of LCA to waste prevention activities and to relevant waste types apart from household waste, e.g. construction and demolition waste. Waste management practitioners are thus encouraged to abridge these gaps in future applications of LCA. In addition to this contextual analysis, we also evaluated the findings of selected studies of good quality and found that there is little agreement in the conclusions among them. The strong dependence of each SWMS on local conditions, such as waste composition or energy system, prevents a meaningful generalisation of the LCA results as we find it in the waste hierarchy. We therefore recommend stakeholders in solid waste management to regard LCA as a tool, which, by its ability of capturing the local specific conditions in the modelling of environmental impacts and benefits of a SWMS, allows identifying critical problems and proposing improvement options adapted to the local specificities.

Urbanization as a determinant of health: a socioepidemiological perspective

Urbanization is a process that leads to the growth of cities due to industrialization and economic development and that leads to urban-specific changes. Urbanization is associated with profound changes in diet and exercise that in turn increase the prevalence of obesity with attendant increases in risk of type II diabetes and cardiovascular disease. The growing burden of disease among vulnerable populations and pervasive socioeconomic inequities within urban systems exaggerates the adverse impacts of urbanization on health. More than one half of children younger than age 5 of urban poor are stunted and/or underweight. More than one half of the child births occur at home, in slums, putting the life of the mother and newborn in serious risk. Inadequate reach of services due to illegality, social exclusion of slums, hidden slum pockets, and weak social fabric have resulted in a rapid proliferation of the unqualified private health sector, leading to high health expenditures and continuing a vicious cycle of poverty and ill health in urban slums.

Municipal solid waste management: identification and analysis of engineering indexes representing demand and costs generated in virtuous Italian communities

The definition and utilisation of engineering indexes in the field of Municipal Solid Waste Management (MSWM) is an issue of interest for technicians and scientists, which is widely discussed in literature. Specifically, the availability of consolidated engineering indexes is useful when new waste collection services are designed, along with when their performance is evaluated after a warm-up period. However, most published works in the field of MSWM complete their study with an analysis of isolated case studies. Conversely, decision makers require tools for information collection and exchange in order to trace the trends of these engineering indexes in large experiments. In this paper, common engineering indexes are presented and their values analysed in virtuous Italian communities, with the aim of contributing to the creation of a useful database whose data could be used during experiments, by indicating examples of MSWM demand profiles and the costs required to manage them.

Framework for integration of informal waste management sector with the formal sector in Pakistan

Historically, waste pickers around the globe have utilised urban solid waste as a principal source of livelihood. Formal waste management sectors usually perceive the informal waste collection/recycling networks as backward, unhygienic and generally incompatible with modern waste management systems. It is proposed here that through careful planning and administration, these seemingly troublesome informal networks can be integrated into formal waste management systems in developing countries, providing mutual benefits. A theoretical framework for integration based on a case study in Lahore, Pakistan, is presented. The proposed solution suggests that the municipal authority should draw up and agree on a formal work contract with the group of waste pickers already operating in the area. The proposed system is assessed using the integration radar framework to classify and analyse possible intervention points between the sectors. The integration of the informal waste workers with the formal waste management sector is not a one dimensional or single step process. An ideal solution might aim for a balanced focus on all four categories of intervention, although this may be influenced by local conditions. Not all the positive benefits will be immediately apparent, but it is expected that as the acceptance of such projects increases over time, the informal recycling economy will financially supplement the formal system in many ways.

Environmental-benefit analysis of two urban waste collection systems

Sustainable transportation infrastructure and travel policies aim to optimise the use of transportation systems to achieve economic and related social and environmental goals. To this end, a novel methodology based on life cycle assessment (LCA) has been developed in this study, with the aim of quantifying, in terms of CO2 emissions equivalent, the impact associated with different alternatives of waste collection systems in different urban typologies. This new approach is focussed on saving energy and raw materials and reducing the environmental impact associated with the waste collection system in urban areas, as well as allowing the design and planning of the best available technologies and most environment-friendly management. The methodology considers a large variety of variables from the point of view of sustainable urban transport such as the location and size of the urban area, the amount of solid waste generated, the level of social awareness on waste separation procedures, the distance between houses and waste collection points and the distance from the latter to the possible recovery plants and/or landfills, taking into account the material and energy recovery ratio within an integrated waste management system. As a case study, two different waste collection systems have been evaluated with this methodology in the ecocity Valdespartera located in Zaragoza, Spain, consisting of approximately 10,000 homes: (i) a system based on traditional truck transportation and manual collection, and (ii) a stationary vacuum waste collection system. Results show that, when operating at loads close to 100%, the stationary collection system has the best environmental performance in comparison with the conventional system. In contrast, when operating at load factors around 13% the environmental benefits in terms of net CO2-eq. emissions for the stationary collection system are around 60% lower in comparison with the conventional one.

Environmental effectiveness of swine sewage management: a multicriteria AHP-based model for a reliable quick assessment

Environmental issues related to swine production are still a major concern for the general public and represent a key challenge for the swine industry. The environmental impact of higher livestock concentration is particularly significant where it coincides with weaker policy standards and poor manure management. Effective tools for environmental monitoring of the swine sewage management process become essential for verifying the environmental compatibility of farming facilities and for defining suitable policies aimed at increasing swine production sustainability. This research aims at the development and application of a model for a quick assessment of the environmental effectiveness of the pig farming sewage management process. In order to define the model, multicriteria techniques, and in particular, Saaty's analytic hierarchy process, were used to develop an iterative process in which the various key factors influencing the process under investigation were analyzed. The model, named EASE (Environmental Assessment of Sewages management Effectiveness), was optimized and applied to the Lake Trasimeno basin (Umbria, Italy), an area of high natural, environmental and aesthetic value. In this context, inadequate disposal of pig sewage represents a potential source of very considerable pollution. The results have demonstrated how the multicriteria model can represent a very effective and adaptable tool also in those decision-making processes aimed at the sustainable management of livestock production.

Participatory research revealing the work and occupational health hazards of cooperative recyclers in Brazil

Although informal waste collectors are sometimes organized in cooperatives, their working conditions remain extremely precarious and unsafe. The paper discusses the findings of action oriented, participatory qualitative research with several recycling groups in the metropolitan region of São Paulo, Brazil. During workshops with the recyclers mapping, acting, and drawing methods helped reveal health hazards from collection, separation and transportation of recyclable materials. Major health problems relate to chemical and biological hazards, musculoskeletal damage, mechanical trauma and poor emotional wellbeing. The recent federal legislation on solid waste management opens new avenues for the inclusion of recycling cooperatives in selective waste collection. Nevertheless, we express the need to consider the distinctive characteristics and vulnerabilities of recycling groups, when developing safer work environments in these social businesses. We also suggest that the workspace be ergonomically organized and that public awareness campaigns about selective waste collection are conducted regularly to increase the quality of source separation. The introduction of electric hand pushed carts can further reduce health strains. This research has produced a better understanding of the work of the recyclers and related health risks. The interactive qualitative research methodology has allowed for the co-creation and mobilization of specific knowledge on health and safety in recycling cooperatives.

[Assessment system for watershed ecological health in the United States: development and application]

To meet the water quality goals of the Clean Water Act, the environmental agencies in the United States (U.S.) have developed a comprehensive ecological assessment system of watershed health in the last two decades. The system employs a watershed approach, and includes a large set of hydrological, chemical, and biological indices, having become an essential part of the watershed water quality management system in the U.S. and provided strong support for the protection of water environment and the restoration of aquatic system. In this paper, the development and application of the ecological assessment system of watershed health by the U.S. environmental regulators, especially the U.S. Environmental Protection Agency (US EPA), were overviewed from the aspects of related laws and regulations, ecosystem function analysis, ecological health indicators, comprehensive assessment system, and monitoring and data management systems, and the health assessment systems for the rivers, lakes, estuaries, coasts, and wetlands adopted by the National$t1-1-1 Aquatic Resource Surveys (NARS) were introduced. Some suggestions for the future development of the scientific ecological assessment system of watershed health in China were put forward based on the understanding of the protection and remediation practices of our water environment.

Improving waste segregation while reducing costs in a tertiary-care hospital in a lower-middle-income country in Central America

Healthcare waste (HCW) management and segregation are essential to ensure safety, environmental protection and cost control. Poor HCW management increase risks and costs for healthcare institutions. On-going surveillance and training are important to maintain good HCW practices. Our objectives were to evaluate and improve HCW practices at Hospital Bloom, San Salvador, El Salvador. We studied HCW disposal practices by observing waste containers, re-segregating waste placed in biohazardous waste bags, and administering a seven-itemsknowledge survey before and after training in waste management at Hospital Bloom. The training was based on national and international standards. We followed total biohazardous waste production before and after the training. The hospital staff was knowledgeable about waste segregation practices, but had poor compliance with national policies. Re-segregating waste in biohazardous waste bags showed that 61% of this waste was common waste, suggesting that the staff was possibly unaware of the cost of mis-segregating healthcare waste. After staff training in HCW management, the correct responses increased by 44% and biohazardous waste disposal at the hospital reduced by 48%. Better segregation of biohazardous waste and important savings can be obtained by HCW management education of hospital staff. Hospitals can benefit from maximising the use of available resources by sustaining best practices of HCW, especially those in hospitals in lower-middle-income countries.