The use of LCA in selecting the best MSW management system

This paper focuses on the study of eleven environmental impact categories produced by several municipal solid waste management systems (scenarios) operating on a provincial scale in Southern Italy. In particular, the analysis takes into account 12 management scenarios with 16 management phases for each one. The only difference among ten of the scenarios (separated kerbside collection of all recyclables, glass excepted, composting of putrescibles, RDF pressed bales production and incineration, final landfilling) is the percentage of separated collection varying in the range of 35–80%, while the other two scenarios, for 80% of separate collection, consider different alternatives in the disposal of treatment residues (dry residue sorting and final landfilling or direct disposal in landfill). The potential impacts induced on the environmental components were analysed using the life cycle assessment (LCA) procedure called “WISARD” (Waste Integrated System Assessment for Recovery and Disposal). Paper recycling was the phase with the greatest influence on avoided impacts, while the collection logistics of dry residue was the phase with the greatest influence on produced impacts. For six impact categories (renewable and total energy use, water, suspended solids and oxydable matters index, eutrophication and hazardous waste production), for high percentages of separate collection a management system based on recovery and recycling but without incineration would be preferable.     

Material and energy recovery in integrated waste management system--an Italian case study on the quality of MSW data

This paper analyses the way numerical data on Municipal Solid Waste (MSW) quantities are recorded, processed and then reported for six of the most meaningful Italian Districts and shows the difficulties found during the comparison of these Districts, starting from the lack of homogeneity and the fragmentation of the data indispensable to make this critical analysis. These aspects are often ignored, but data certainty are the basis for serious MSW planning. In particular, the paper focuses on overall Source Separation Level (SSL) definition and on the influence that Special Waste (SW) assimilated to MSW has on it. An investigation was then necessary to identify new parameters in place of overall SSL. Moreover, these parameters are not only important for a waste management system performance measure, but are fundamental in order to design and check management plan and to identify possible actions to improve it.     

Tools for evaluation of impact associated with MSW incineration: LCA and integrated environmental monitoring system

The identification of significant pollutants emitted from the contamination source is the first step in evaluating the impact associated with anthropic activity. Municipal solid waste (MSW) incinerators are still generally perceived as great pollutant sources, in particular due to their gaseous emissions from the stack, which constitute the major effluent from the plant. In this work a life cycle assessment and an integrated environmental monitoring system were applied together, in order to obtain complete information about the incineration process and its environmental impact. The former is a proven methodology, but its application to waste management systems constitutes a relatively new field of application with a great developmental potential. The contribution of the incineration process to the different environmental impact categories was investigated, finding many avoided impacts due to energy recovery. The latter is an innovative approach that allows a remarkable understanding of impact due to a contamination source; interesting correlations were found between heavy metals both in gas emissions and in natural matrices in the surroundings.     

Material and energy recovery in integrated waste management systems: an innovative approach for the characterization of the gaseous emissions from residual MSW bio-drying

In the sector of residual municipal solid waste management an increasing attention is put towards the role of biological treatments like bio-drying and bio-stabilization in order to decrease the need of landfilling volumes. The literature shows a lack of information concerning the emission factor of pollutants released from these processes. The available data are generally spot characterizations of concentration and air flow-rate that are used together in order to assess the emission factors. This approach caused significant differences among the available data as the release of pollutants is not steady. This paper belongs to a group of six papers concerning a research on material and energy recovery in integrated waste management systems, developed by a network of five universities. The contribution of the University of Trento, focuses on the bio-drying process with the following targets: (a) developing an innovative low cost method of sampling/measurement able to take into account the dynamics of release of pollutants; (b) checking the efficiency of a bio-filter; (c) verifying the variability of generation of some pollutants; (d) generating emission factors. The research was developed using a bio-drying pilot plant. As a treatment of the process air, the bio-reactor was coupled with a bio-filter. The emissions were characterized using an original approach based on the adoption of two measurement chambers suitable for hosting passive samplers. The passive samplers allowed the characterization of VOCs, N(2)O, NH(3) and H(2)S. A bio-chemical model, useful for energy and mass balances, supported the interpretation of the presented bio-drying run.     

LCA comparison of container systems in municipal solid waste management

The planning and design of integrated municipal solid waste management (MSWM) systems requires accurate environmental impact evaluation of the systems and their components. This research assessed, quantified and compared the environmental impact of the first stage of the most used MSW container systems. The comparison was based on factors such as the volume of the containers, from small bins of 60–80 l to containers of 2400 l, and on the manufactured materials, steel and high-density polyethylene (HDPE). Also, some parameters such as frequency of collections, waste generation, filling percentage and waste container contents, were established to obtain comparable systems. The methodological framework of the analysis was the life cycle assessment (LCA), and the impact assessment method was based on CML 2 baseline 2000. Results indicated that, for the same volume, the collection systems that use HDPE waste containers had more of an impact than those using steel waste containers, in terms of abiotic depletion, global warming, ozone layer depletion, acidification, eutrophication, photochemical oxidation, human toxicity and terrestrial ecotoxicity. Besides, the collection systems using small HDPE bins (60 l or 80 l) had most impact while systems using big steel containers (2400 l) had less impact. Subsequent sensitivity analysis about the parameters established demonstrated that they could change the ultimate environmental impact of each waste container collection system, but that the comparative relationship between systems was similar.     

The new challenges of end-of-life tyres management systems: A Spanish case study

Directive 2008/98/EC released by the European Union represents a significant step forward in all relevant aspects of waste management. Under the already established, extended produced responsibility (EPR) principle, new policies have been enunciated to continuously achieve better overall environmental performance of key products throughout their life phases. This paper discusses how the directive is being articulated in Spain by the main integrated management system (IMS) for end-of-life (EOL) tyres since its creation in 2006. Focusing on the IMS technological, economic and legal aspects, the study provides a global perspective and evaluation of how the IMS is facing the current issues to resolve, the new challenges that have appeared and the management vision for the coming years.     

Report: integrated industrial waste management systems in China.

Various models of urban sustainable development have been introduced in recent years and some of these such as integrated waste management have been proved to be of particular value. Integrated industrial waste management systems include all the administrative, financial, legal, planning and engineering functions involved in solutions to the problems of industrial waste. Even though the pace of the improvement made to China's industrial waste management capacity is impressive, China has been unable to keep up with the increasing demand for waste management. This paper will evaluate the application of integrated industrial waste management systems in promoting urban sustainable development in the context of three case study cities in China (positive case, average case and negative case) by identifying and accessing the factors that affect the success or failure of integrated industrial waste management systems.     

Compostable cutlery and waste management: an LCA approach

The use of disposable cutlery in fast food restaurants and canteens in the current management scenario generates mixed heterogeneous waste (containing food waste and non-compostable plastic cutlery). The waste is not recyclable and is disposed of in landfills or incinerated with or without energy recovery. Using biodegradable and compostable (B&C) plastic cutlery, an alternative management scenario is possible. The resulting mixed homogeneous waste (containing food waste and compostable plastic cutlery) can be recycled through organic recovery, i.e., composting. This LCA study, whose functional unit is "serving 1000 meals", shows that remarkable improvements can be obtained by shifting from the current scenario to the alternative scenario (based on B&C cutlery and final organic recovery of the total waste). The non-renewable energy consumption changes from 1490 to 128MJ (an overall 10-fold energy savings) and the CO(2) equivalents emission changes from 64 to 22 CO(2) eq. (an overall 3-fold GHG savings).     

环保企业建立一体化管理体系初探

针对环保行业的特点，阐述了环保企业建立和实施质量、环境、职业安全健康一体化管理体系的必要性，并提出了建立一体化管理体系的主要方法和步骤。     

Material and energy recovery in integrated waste management systems: the potential for energy recovery

This article is part of a set of six coordinated papers reporting the main findings of a research project carried out by five Italian universities on "Material and energy recovery in Integrated Waste Management Systems (IWMS)". An overview of the project and a summary of the most relevant results can be found in the introductory article of the series. This paper describes the work related to the evaluation of mass and energy balances, which has consisted of three major efforts (i) development of a model for quantifying the energy content and the elemental compositions of the waste streams appearing in a IWMS; (ii) upgrade of an earlier model to predict the performances of Waste-to-Energy (WtE) plants; (iii) evaluation of mass and energy balances of all the scenarios and the recovery paths considered in the project. Results show that not only the amount of material available for energy recovery is significantly higher than the Unsorted Residual Waste (URW) left after Separate Collection (SC), because selection and recycling generate significant amounts of residues, but its heating value is higher than that of the original, gross waste. Therefore, the energy potential of what is left after recycling is always higher than the complement to 100% of the Source Separation Level (SSL). Also, increasing SSL has marginal effects on the potential for energy recovery: nearly doubling SSL (from 35% to 65%) reduces the energy potential only by one fourth. Consequently, even at high SSL energy recovery is a fundamental step of a sustainable waste management system. Variations of SSL do bring about variations of the composition, heating value and moisture content of the material fed to WtE plants, but these variations (i) are smaller than one can expect; (ii) have marginal effects on the performances of the WtE plant. These considerations suggest that the mere value of SSL is not a good indicator of the quality of the waste management system, nor of its energy and environmental outcome. Given the well-known dependence of the efficiency of steam power plants with their power output, the efficiency of energy recovery crucially depends on the size of the IWMS served by the WtE plant. A fivefold increase of the amount of gross waste handled in the IWMS (from 150,000 to 750,000 tons per year of gross waste) allows increasing the electric efficiencies of the WtE plant by about 6-7 percentage points (from 21-23% to 28.5% circa).     

Clogging of finger drain systems in MSW landfills

A numerical model ‘BioClog’ is used to examine clogging of granular drainage material within finger drains at the base of landfills. The reduction in porosity of drainage material is evaluated as the accumulation of clog mass reduces the pore spaces of granular media. The leachate mounding within the landfills caused by the reduction in hydraulic conductivity of finger drain is modeled. The effect of overburden pressure on the engineering properties of waste material and consequent leachate mounding is considered. The calculated rates of leachate mound development for two landfills with finger drain leachate collection are shown to be in encouraging agreement with the observed data at the times when data were available. It is demonstrated that a significant leachate mound can be expected to develop over time when the leachate collection system is comprised of finger drains; however the rate of increase and the magnitude at a given time will depend on a number of factors including the grainsize, thickness and spacing of the finger drains, and the thickness of waste as well as the leachate generation rate.     

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.     

The city of San José's integrated waste management program: a case study for reaching high levels of diversion

The city of San José, California, USA, has a widely recognized integrated waste management program and is currently diverting close to 50% of its waste stream from landfill disposal. This paper describes the residential and commercial components of the city's waste management program. Information is presented on performance (e.g., types and quantities of materials that are collected, processed, and disposed of), customer service, and costs associated with the program. Received: October 4, 2000 / Accepted: February 15, 2001     

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.     

Public perception of odour and environmental pollution attributed to MSW treatment and disposal facilities: A case study

If residents’ perceptions, concerns and attitudes towards waste management facilities are either not well understood or underestimated, people can produce strong opposition that may include protest demonstrations and violent conflicts such as those experienced in the Campania Region of Italy. The aim of this study was to verify the effects of the closure of solid waste treatment and disposal facilities (two landfills and one RDF production plant) on public perception of odour and environmental pollution. The study took place in four villages in Southern Italy. Identical questionnaires were administered to residents during 2003 and after the closure of the facilities occurred in 2008. The residents’ perception of odour nuisance considerably diminished between 2003 and 2009 for the nearest villages, with odour perception showing an association with distance from the facilities. Post closure, residents had difficulty in identifying the type of smell due to the decrease in odour level. During both surveys, older residents reported most concern about the potentially adverse health impacts of long-term exposure to odours from MSW facilities. However, although awareness of MSW facilities and concern about potentially adverse health impacts varied according to the characteristics of residents in 2003, substantial media coverage produced an equalisation effect and increased knowledge about the type of facilities and how they operated. It is possible that residents of the village nearest to the facilities reported lower awareness of and concern about odour and environmental pollution because the municipality received economic compensation for their presence.     

Parametric study of MSW landfill settlement model

A newly developed and validated constitutive model that accounts for primary compression and time-dependent mechanical creep and biodegradation is used for parametric study to investigate the effects of model parameters on the predicted settlement of municipal solid waste (MSW) with time. The model enables the prediction of stress strain response and yield surfaces for three components of settlement: primary compression, mechanical creep, and biodegradation. The MSW parameters investigated include compression index, coefficient of earth pressure at-rest, overconsolidation ratio, and biodegradation parameters of MSW. A comparison of the predicted settlements for typical MSW landfill conditions showed significant differences in time-settlement response depending on the selected model input parameters. The effect of lift thickness of MSW on predicted settlement is also investigated. Overall, the study shows that the variation in the model parameters can lead to significantly different results; therefore, the model parameter values should be carefully selected to predict landfill settlements accurately. It is shown that the proposed model captures the time settlement response which is in general agreement with the results obtained from the other two reported models having similar features.     

Hospital waste management in Libya: A case study

In Libya, as in many developing countries, little information is available regarding generation, handling and disposal of hospital waste. This fact hinders the development and implementation of hospital waste management schemes. The specific objective of this study is to present an appraisal of the current situation regarding hospital waste management in Libya. Procedures, techniques, methods of handling, and disposal of waste are presented, as well as the amounts and compositions of hospital waste. This research was conducted in the form of a case study. Fourteen different healthcare facilities in three cities, Tripoli, Misurata, and Sirt, all located in the northwestern part of Libya, were selected for investigation. The investigation showed that the hospitals surveyed had neither guidelines for separated collection and classification, nor methods for storage and disposal of generated waste. This deficiency indicates the need for an adequate hospital waste management strategy to improve and control the existing situation. The average waste generation rate was found to be 1.3 kg/patient/day, comprised of 72% general healthcare waste (non-risk) and 28% hazardous waste. The average general waste composition was: 38% organic, 24% plastics, and 20% paper. Sharps and pathological elements comprised 26% of the hazardous waste component.