Assessment Of Waste Management Systems Research Articles

Quality degradation in glass recycling: substitutability model proposal

The sustainability assessment of waste management systems requires tools capable of evaluating material quality degradation during recycling. Existing research has predominantly focused on the development of substitutability models for plastics, leaving a gap in addressing other materials like glass. Glass is commonly regarded as endlessly recyclable, even though its actual recyclability depends on several crucial factors, such as colour and pollutant contamination. Many Life Cycle Assessment (LCA) studies in this field assume a one-to-one substitution coefficient, neglecting material deterioration and inaccurately representing real-world scenarios. This study proposes and assesses a substitutability model for glass, aiming to measure the replacement extent between virgin materials and recycled crushed glass (cullet). The methodology is based on two key factors: technical quality substitutability, considering impurities and colour contaminations in cullet, and market applicability, accounting for market demand. Once formulated, the model was applied to a European case study on glass waste treatment. Two scenarios were considered: one assuming complete substitution between cullet and raw materials, the other incorporating quality degradation. Findings indicate that, accounting for quality degradation, only 83% of cullet effectively replaces raw materials, resulting in a decrease of the benefit associated with recycling of 13–23% for the different examined impact categories, compared to complete replacement assumption. This underscores the importance of considering quality deterioration in glass recycling impact assessments.

A Review of Waste Management Decision Support Tools and Their Ability to Assess Circular Biowaste Management Systems

The circular economy concept offers a number of solutions to increasing amounts of biowaste and resource scarcity by valorising biowaste. However, it is necessary to consistently address the environmental benefits and impacts of circular biowaste management systems (CBWMS). Various decision support tools (DST) for environmental assessment of waste management systems (WMS) exist. This study provides a review of life cycle assessment based WMS-DSTs. Twenty-five WMS-DSTs were identified and analysed through a shortlisting procedure. Eight tools were shortlisted for the assessment of their applicability to deliver sustainability assessment of CBWMS. It was found that six tools model key properties that are necessary for assessing the environmental sustainability of CBWMSs, including waste-specific modelling of gaseous emissions, biogas generation or bioproduct composition. However, only two tools consider both waste-specific heavy metals content in bioproducts and the associated implications when applied on soil. Most of the shortlisted tools are flexible to simulate new technologies involved in CBWMS. Nevertheless, only two tools allow importing directly new background data, which is important when modelling substitution of new bioproducts developed in emerging biowaste refineries.

Linking energy scenarios and waste storylines for prospective environmental assessment of waste management systems

Multiple international and supranational organizations call upon changes in current waste management practices to play a key role in developing more sustainable economies. Life cycle assessment (LCA) is a popular method used to assess the sustainability of future waste management options. The uncertainties about future energy systems and waste compositions, however, may lead to ambiguous LCA results. One way to deal with this challenge is the development of joint energy and waste scenarios to investigate the robustness of waste management options. To date, joint energy and waste scenarios rely on the integration of large economic and engineering models. Complex models can hamper the transparency required for decision-makers to understand and implement LCA recommendations. Here we present the alternative of combining diverse energy scenarios and stakeholder-based waste storylines. This is a more qualitative approach than previous sustainable energy/waste evaluations and has a double aim: to address upfront the energy and waste composition sensitivity and enhance transparency by both relying on well-documented energy scenarios and involving stakeholders in the waste storyline formulation. We apply the approach to the Swiss municipal solid waste (MSW) management system in the context of the energy transition away from nuclear power. Three energy scenarios capture how radical the transition might be, while the storylines reflect societal developments and waste policies leading to low, high, and average MSW amounts. The approach delivers feasibility spaces of energy systems and waste compositions as input to the LCAs. It ensures a high level of transparency, which, in conjunction with the participation of decision-makers, has the potential to increase the chances of implementation of the recommendations based on LCA results.

Application of Factor Analysis in the Assessment of Solid Waste Management in Bolgatanga Municipality of Ghana

The issue of waste management has become a daunting challenge for many countries particularly for developing countries. The adverse effects of waste on human lives and the environment have reached scary levels that call for a thorough assessment of waste management systems across the globe and in particular developing countries. In Bolgatanga municipality of the Upper East Region of Ghana, the situation of waste disposal is appalling exposing residents to all kinds of health related risk. City authorities who have the responsibility of ensuring that the environment is clean and safe for habitation are confronted with the serious burden of managing waste disposal in the municipality. This study therefore sought to examine a set of 18 variables relevant to the topic under investigation and how they relate to influence solid waste management in the municipality from the perspective of residents of the Bolgatanga municipality through the application of Factor Analysis. The object of this approach is to identify a set of indicator variables that amalgamate to form common factors. The opinions of 400 subjects on Solid Waste Management in the municipality were successfully collected through the administration of questionnaires and analyzed. A preliminary analysis of the data showed that the correlation matrix was not an identity matrix and a KMO value of 0.797 described as “middling” was obtained. These provided the necessary and sufficient grounds for the application of Factor Analysis to the data. Further analysis of the data revealed five latent factors which are Institutional Dormancy, Financial Constraint, Infrastructural Lapses, Accessibility and Behavioral Canker as factors that need to be addressed in order to improve the status of Solid Waste Management in Bolgatanga municipality.

Assessment of the waste electrical and electronic equipment management systems profile and sustainability in developed and developing European Union countries

The assessment of waste management systems for electrical and electronic equipment (WEEE) from developed economies (Germany, Sweden and Italy) and developing countries (Romania and Bulgaria), is discussed covering the period 2007–2014. The WEEE management systems profiles are depicted by indicators correlated to WEEE life cycle stages: collection, transportation and treatment. The sustainability of national WEEE management systems in terms of greenhouse gas emissions is presented, together with the greenhouse gas efficiency indicator that underlines the efficiency of WEEE treatment options. In the countries comparisons, the key elements are: robust versus fragile economies, the overall waste management performance and the existence/development of suitable management practices on WEEE.Over the life cycle perspective, developed economies (Germany, Sweden and Italy) manage one order of magnitude higher quantities of WEEE compared to developing countries (Romania and Bulgaria). Although prevention and reduction measures are encouraged, all WEEE quantities were larger in 2013, than in 2007. In 2007–2014, developed economies exceed the annual European collection target of 4 kg WEEE/capita, while collection is still difficult in developing countries. If collection rates are estimated in relationship with products placed on market, than similar values are registered in Sweden and Bulgaria, followed by Germany and Italy and lastly Romania. WEEE transportation shows different patterns among countries, with Italy as the greatest exporter (in 2014), while Sweden treats the WEEE nationally. WEEE reuse is a common practice in Germany, Sweden (from 2009) and Bulgaria (from 2011). By 2014, recycling was the most preferred WEEE treatment option, with the same kind of rates performance, over 80%, irrespective of the country, with efforts in each of the countries in developing special collection points, recycling facilities and support instruments. The national total and the recycling carbon footprints of WEEE are lower in 2013 than in 2007 for each country, the order in reducing the environmental impacts being: Germany, Italy, Sweden, Bulgaria and Romania. The negative values indicate savings in greenhouse gas emissions. In 2013, the GHG efficiency shows no differences of the WEEE management in the developed and developing countries.

Sustainability assessment and comparison of waste management systems: The Cities of Sofia and Niš case studies

Sustainability assessment of a waste management system is a very complex problem for numerous reasons. Firstly, it is a problem of environmental assessment, economic viability and social acceptability, and also a choice of the most practical waste treatment technique, taking into account all the specific areas in which a waste management system is implemented. For these reasons, among others, it is very important to benchmark, cooperate and exchange experiences in areas with similar characteristics. In this study, a comparison of waste management scenarios in the Cities of Niš and Sofia was performed. Based on the amount and composition of municipal solid waste, and taking into account local specifics (economic conditions, social acceptance, etc.), different scenarios were developed: landfilling without energy recovery, landfilling with energy recovery, mechanical-biological treatment, anaerobic digestion with biogas utilization and incineration with energy recovery. Scenario ranking was done using multi-criteria analysis and 12 indicators were chosen as the criteria. The obtained results show that the most sustainable scenario in both case studies is the mechanical-biological treatment (recycling, composting and Refuse Derived Fuel production). Having in mind that this scenario is the current waste management system in Sofia, these results can help decision-makers in the City of Niš in choosing a successful and sustainable waste management system.

Energy–environment–economy assessment of waste management systems from a life cycle perspective: Model development and case study

How to choose an energy-efficient, environmentally friendly and economically affordable municipal solid waste (MSW) management system has been a major challenge to be taken up by decision makers. Although life cycle assessment (LCA) has been widely used for the evaluation of energy consumption and environmental burden, the economic factor is not considered yet in LCA procedures. Thus, in the present study life cycle 2E (energy and environment) assessment is extended to a 3E (energy, environment, and economy) model. To evaluate economic performance, life cycle cost (LCC) is adjusted in accordance with LCA. Afterwards, multi-criteria decision making (MCDM) method is improved to integrate 3E factors. Besides, a two-step weight factor analysis is added, not only to test the robustness of the model, but also to adopt different preferences proposed by different stakeholder groups. This novel 3E model is then applied for the comparison of different MSW treatment technologies: (1) landfill; (2) landfill with biogas conversion to electricity; (3) incineration with energy recovery. Results show that incineration scores 0.944/1 and performs best among all scenarios; landfill with biogas to electricity, with final score 0.722/1, ranks second; and landfill without energy recovery (score: 0/1) is the worst choice. Furthermore, the weight factor analysis also shows a highly credibility of the results: when changing each factor’s weight from 0 to 1, less than 30% of the cases exhibit the variation in ranking order; almost no change in ranking order occurs when considering the different perspectives from government, enterprise and residents.

Efficiency of energy recovery from municipal solid waste and the resultant effect on the greenhouse gas balance

Global warming is a focus of political interest and life-cycle assessment of waste management systems reveals that energy recovery from municipal solid waste is a key issue. This paper demonstrates how the greenhouse gas effects of waste treatment processes can be described in a simplified manner by considering energy efficiency indicators. For evaluation to be consistent, it is necessary to use reasonable system boundaries and to take the generation of electricity and the use of heat into account. The new European R1 efficiency criterion will lead to the development and implementation of optimized processes/systems with increased energy efficiency which, in turn, will exert an influence on the greenhouse gas effects of waste management in Europe. Promising technologies are: the increase of steam parameters, reduction of in-plant energy consumption, and the combined use of heat and power. Plants in Brescia and Amsterdam are current examples of good performance with highly efficient electricity generation. Other examples of particularly high heat recovery rates are the energy-from-waste (EfW) plants in Malmö and Gothenburg. To achieve the full potential of greenhouse gas reduction in waste management, it is necessary to avoid landfilling combustible wastes, for example, by means of landfill taxes and by putting incentives in place for increasing the efficiency of EfW systems.

Life Cycle Assessment of waste management systems in Italian industrial areas: Case study of 1st Macrolotto of Prato

Life Cycle Assessment (LCA) is not widely used as a decision-supporting tool in Italy, despite recent European Commission policies fostering its adoption to achieve an energy- and resource-efficient economy. In this paper, an LCA of waste management system of the 1st Macrolotto industrial area is presented. The aims of the study were to identify the environmental critical points of the system and to evaluate opportunities and problems in applying this methodology at industrial area level. After a description of the waste management system of the 1st Macrolotto industrial area, the main assumptions of the study and some elements of the system modelling are presented. Results confirmed that door-to-door separated collection and packaging recycling are successful strategies for reducing the use of natural resources. The cooperation of the waste management company, which was part of the area management structure, was strategic for the completion of the analysis. Country-specific databases and models should be developed for a widespread application of the LCA methodology to waste management in Italian industrial areas.

LCA-IWM: A decision support tool for sustainability assessment of waste management systems

The paper outlines the most significant result of the project ‘The use of life cycle assessment tools for the development of integrated waste management strategies for cities and regions with rapid growing economies’, which was the development of two decision-support tools: a municipal waste prognostic tool and a waste management system assessment tool. The article focuses on the assessment tool, which supports the adequate decision making in the planning of urban waste management systems by allowing the creation and comparison of different scenarios, considering three basic subsystems: (i) temporary storage; (ii) collection and transport and (iii) treatment, disposal and recycling. The design and analysis options, as well as the assumptions made for each subsystem, are shortly introduced, providing an overview of the applied methodologies and technologies. The sustainability assessment methodology used in the project to support the selection of the most adequate scenario is presented with a brief explanation of the procedures, criteria and indicators applied on the evaluation of each of the three sustainability pillars.

Allocation and ‘what-if’ scenarios in life cycle assessment of waste management systems

Many modern waste treatment processes and waste management systems are able to treat many different types of waste at the same time, and deliver a number of useful outputs (secondary materials, energy) as well. These systems are thus increasingly multi-functional. As such, in life cycle assessment studies, they create problems related to multi-functionality and allocation. Especially in LCAs of waste management systems, the solution in the form of system expansion or avoided burdens approach dominates the practice, and the partitioning approach plays a minor role. In this paper, we analyse the logic and problems of these two approaches. It appears that for the avoided burdens approach, the number of ‘what-if’ assumptions is so large that LCAs on the same topic lead to quite diverging results. Since ‘what-if’ questions cannot be answered in an unambiguous way, such questions should preferably be left outside of a primarily scientific tool. The partitioning approach is not free from arbitrary choices as well, but, in contrast to the ‘what-if’ approaches, it does not claim to predict what happens or what would have happened.

Integrated approach to the assessment of waste management systems within the SEA framework

This paper addresses the problem of evaluating the environmental performances of Urban Waste Systems. Specifically, the paper refers to the crucial problem of environmentally analysing the Urban Waste System Management Process. The application of the Dashboard of Sustainability has been deliberately suggested. The method has been selected because of its intrinsic simplicity and because it can provide the simultaneous evaluation of indicators which refer to different fields, such as the Environment, Economics and Quality in Institutional Services. The method has been applied to the city of Palermo. The results obtained have been compared to a couple of ideal scenarios.