•First paper on the importance of incineration from a urban metabolism point of view.•Proves that incineration is necessary for sustainable waste management.•Historical and technical overview of ...100years development of MSW incineration.
Human activities inevitably result in wastes. The higher the material turnover, and the more complex and divers the materials produced, the more challenging it is for waste management to reach the goals of “protection of men and environment” and “resource conservation”. Waste incineration, introduced originally for volume reduction and hygienic reasons, went through a long and intense development. Together with prevention and recycling measures, waste to energy (WTE) facilities contribute significantly to reaching the goals of waste management. Sophisticated air pollution control (APC) devices ensure that emissions are environmentally safe. Incinerators are crucial and unique for the complete destruction of hazardous organic materials, to reduce risks due to pathogenic microorganisms and viruses, and for concentrating valuable as well as toxic metals in certain fractions. Bottom ash and APC residues have become new sources of secondary metals, hence incineration has become a materials recycling facility, too. WTE plants are supporting decisions about waste and environmental management: They can routinely and cost effectively supply information about chemical waste composition as well as about the ratio of biogenic to fossil carbon in MSW and off-gas.
This paper demonstrates the power of material flow analysis (MFA) for designing waste management (WM) systems and for supporting decisions with regards to given environmental and resource goals. ...Based on a comprehensive case study of a nationwide WM-system, advantages and drawbacks of a mass balance approach are discussed. Using the software STAN, a material flow system comprising all relevant inputs, stocks and outputs of wastes, products, residues, and emissions is established and quantified. Material balances on the level of goods and selected substances (C, Cd, Cr, Cu, Fe, Hg, N, Ni, P, Pb, Zn) are developed to characterize this WM-system. The MFA results serve well as a base for further assessments. Based on given goals, stakeholders engaged in this study selected the following seven criteria for evaluating their WM-system: (i) waste input into the system, (ii) export of waste (iii) gaseous emissions from waste treatment plants, (iv) long-term gaseous and liquid emissions from landfills, (v) waste being recycled, (vi) waste for energy recovery, (vii) total waste landfilled. By scenario analysis, strengths and weaknesses of different measures were identified. The results reveal the benefits of a mass balance approach due to redundancy, data consistency, and transparency for optimization, design, and decision making in WM.
Assessment methods are common tools to support decisions regarding waste management. The objective of this review article is to provide guidance for the selection of appropriate evaluation methods. ...For this purpose, frequently used assessment methods are reviewed, categorised, and summarised. In total, 151 studies have been considered in view of their goals, methodologies, systems investigated, and results regarding economic, environmental, and social issues. A goal shared by all studies is the support of stakeholders. Most studies are based on life cycle assessments, multi-criteria-decision-making, cost-benefit analysis, risk assessments, and benchmarking. Approximately 40% of the reviewed articles are life cycle assessment-based; and more than 50% apply scenario analysis to identify the best waste management options. Most studies focus on municipal solid waste and consider specific environmental loadings. Economic aspects are considered by approximately 50% of the studies, and only a small number evaluate social aspects. The choice of system elements and boundaries varies significantly among the studies; thus, assessment results are sometimes contradictory. Based on the results of this review, we recommend the following considerations when assessing waste management systems: (i) a mass balance approach based on a rigid input–output analysis of the entire system, (ii) a goal-oriented evaluation of the results of the mass balance, which takes into account the intended waste management objectives; and (iii) a transparent and reproducible presentation of the methodology, data, and results.
Summary
This article reviews, categorizes, and evaluates the objectives, means, and results of the application of material flow analysis (MFA) in waste management. It identifies those areas where MFA ...methodologies are most successful in supporting waste management decisions. The focus of this review is on the distinction between MFA on the level of goods and on the level of substances. Based on 83 reviewed studies, potentials, strengths, and weaknesses are investigated for the two levels of MFA when applied for analysis, evaluation, and improvement of waste management systems. The differences are discussed in view of effectiveness, applicability, and data availability. The results show that MFA on the level of goods are instrumental for understanding how waste management systems function, facilitating the connections of stakeholders, authorities, and waste management companies. The substance level is essential to assess qualitative aspects regarding resources and environment. Knowledge about the transformation, transport, and storage of valuable and hazardous substances forms the base for identifying both resource potentials and risks for human health and the environment. The results of this review encourage the application of MFA on both levels of goods and substances for decision making in waste management. Because of the mass balance principle, this combination has proven to be a powerful tool for comprehensively assessing if a chosen system reaches designated waste management goals.
In order to fulfill the objectives of environmental protection, today's focus on quantitative recycling rates must be amended by a more qualitative approach. Because modern products represent a mix ...of numerous and sometimes hazardous substances, ways must be explored to remove detrimental substances during recycling and to establish “clean cycles”. On the one hand, such a “clean cycle” strategy will result in better recycling qualities of secondary products and less dissipation of hazardous substances during further product use. On the other hand, the elimination of hazardous substances during recycling requires sinks for the disposal of the eliminated materials. These topics are presented in general as well as by case studies. In particular, the sink issue is addressed, differentiating between sinks and final sinks and discussing the challenge to supply appropriate final sinks for all materials that cannot be recycled.
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► Present recycling policies focus too much on maximizing recycling rates. ► Hazardous materials are kept in cycles instead of eliminating them from cycles. ► New priorities must be set to establish clean cycles. ► A clean cycle strategy results in residues that must be disposed of in sinks. ► Waste management must supply suitable sinks for substances eliminated from cycles.
The rationale for this article is that often, decision-makers in waste management (wm) tend to neglect goals and confuse them with means like circular economy or waste hierarchy. Because clear goals ...are crucial for developing effective wm strategies, the objectives of this mini review are (1) to clarify wm goals in a historical context by a literature review, (2) to investigate how (a) these goals have been observed in general scientific publishing and (b) specifically in Waste Management and Research (WM&R) and (3) to recommend measures for better consideration of wm goals by the publication sector. Based on general as well as specific bibliographic analyses of databases in Scopus and Google Scholar, the study confirms that little attention was given to wm goals in scientific publishing. For instance, during the first 40 years of WM&R, 63 publications and eight editorials were found containing terms related to wm goals, but only 14 respectively and eight explicitly discuss wm goals. We recommend focussing more on wm goals. Editors, authors, reviewers and professional associations in the field of wm should become aware of this challenge and react. If WM&R decides to become a strong platform for the issue wm goals, it will be in a unique selling proposition and more authors, articles and readers are likely to result. This article aims at setting a starting signal for such an endeavour.
This mini-review aims at proving that waste-to-energy (WtE) is an essential cornerstone for circular economy (CE). Based on literature, the history of thermal waste treatment over the last 150 years ...is investigated, from open burning to WtE with resource recovery and final sink function. The results show that in the past incineration solved the issues it was designed for but often created new and sometimes even worse problems: The introduction of incineration in the 19th century improved urban sanitation, decreased waste volume and prolonged operational life of landfills. But it also polluted the environment, triggering an unprecedented scientific and engineering effort of all stakeholders. Today, WtE is one of the best investigated and optimized technologies in waste management. It enables the recovery of energy as heat and electric power and facilitates the 'cleaning' of cycles by the destruction of hazardous organic substances. Recent developments in resource recovery from WtE residues allow to recycle metals and, in the case of sewage sludge, even phosphorus by thermal recycling. Combined with carbon capture and storage technology, WtE stands for a quantifiable contribution to greenhouse gas reduction. Today, WtE is indispensable to reach the goals of CE, namely recycling of energy and materials, supplying safe final sinks for persistent organic substances and minimizing the need for sinks for hazardous inorganic substances.
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