A life cycle based multi-objective optimization model for the management of computer waste

The accelerating pace of waste generation from used electrical and electronic equipment is of growing global concern. Within this waste stream, computer hardware is quite significant in terms of both volume and risk to the environment because of the hazardous materials within it. The waste management hierarchy of prevention, reuse, recycle, treatment and disposal in landfill is accepted as a universal guideline for waste management. The contemporary concept of integrated solid waste management is very complex comprising of not only the environmental aspects or the technical aspects of the waste management hierarchy, but also incorporating economic, institutional, perceived risk and social issues in the context of complete life cycle of waste. Moreover, when to shift from one stage of hierarchy to another, is an involved decision warranting inclusion of several case specific issues. This paper presents a life cycle based multi-objective model that can help decision makers in integrated waste management. The proposed model has been applied to a case study of computer waste scenario in Delhi, India, which apart from having computer waste from its native population receives large quantities of imported second hand computers. The model has been used to evaluate management cost and reuse time span or life cycle of various streams of computer waste for different objectives of economy, perceived risk and environmental impact. The model results for different scenarios of waste generation have been analyzed to understand the tradeoffs between cost, perceived risk and environmental impact. The optimum life cycle of a computer desktop was observed to be shorter by 25% while optimizing cost than while optimizing impact to the environment or risk perceived by public. Proposed integrated approach can be useful for determining the optimum life cycle of computer waste, as well as optimum configuration of waste management facilities, for urban centers where computer waste related issues are of growing concern.     

Issues for small businesses with waste management

Participation by small and medium enterprise (SME) in corporate social responsibility issues has been found to be lacking. This is a critical issue, as individually SMEs may have little impact on the environment but their collective footprint is significant. The management style and ethical stance of the owner-manager affects business decision making and therefore has a direct impact on the environmental actions of the business. Although adoption of environmental practices to create competitive advantage has been advocated, many businesses see implementation as a cost which cannot be transferred to their customers. After a brief review of pertinent literature this paper reports on an exploratory investigation into the issue. Results show that whereas owner-managers of small enterprises express concern regarding the environment, this does not then translate into better waste management practices.     

生命周期评价在我国固体废物环境管理中的应用

生命周期评价是评价产品、工艺或活动（服务）整个生命周期阶段有关环境负荷,进而辨识和评价减少环境影响机会的一种非常有用的工具。将生命周期评价应用于固体废物环境管理,无疑对于我国建立科学化的固体废物环境管理模式具有十分重要的作用。本文对生命周期评价的定义、主要阶段、应用工具、特点进行了阐述,并对生命周期评价如何应用于我国固体废物环境管理进行了探讨。     

Understanding the total life cycle cost implications of reusing structural steel

Reuse of structural steel could be an environmentally superior alternative to the current practice, which is to recycle the majority (88%) of scrap steel. In spite of the potential benefits, and in a time when “sustainability” and “climate change” are critical societal issues, the question arises: why are greater rates of structural steel reuse not being observed? One of the major factors in the rate of structural steel reuse is how decision-makers understand the life cycle implications of their choice to recycle steel rather than reuse it. This paper contributes towards our understanding of these implications, particularly the cost implications, of reuse as an alternative to recycling by presenting a streamlined life cycle analysis and identifying the major contributors to each process. The results of a case study indicate that a significant reduction in some life cycle impact metrics (greenhouse gas emissions, water use) can result from reusing structural steel rather than recycling it. The largest contributors to the life cycle impact of recycling were the shredding, melting, and forming sub-processes. The largest contributor to reuse was the deconstruction sub-process. A total life cycle cost analysis is performed to understand the cost of damages to the environment and human health in combination with the cost of construction activities. Sensitivity and uncertainty analyses are also conducted to quantify variability in the results and determine economic conditions where the two processes have an equal cost.     

以大数据驱动固体废物管理创新的思考

2015年7月,国务院印发《关于积极推进"互联网+"行动的指导意见》,鼓励利用物联网、大数据开展信息采集、数据分析、流向监测,跟踪废物流向,创新再生资源回收模式。我国固体废物种类多、数量大,部分废物具有一定的综合利用价值。从环境风险角度来看,需要关注固体废物生产、转移、利用、处置等多个环节,一直是环境管理的难点。但以大数据和云计算为代表的新技术为推动固体废物有效利用、提升环境风险防控能力提供了可能。文章介绍了新加坡利用大数据关联模型分析技术开展共生产业园区规划和建设,以及江苏省利用大数据和物联网技术开展危险废物转移动态监管的案例,分析了大数据应用在固体废物管理方面的优势和存在的挑战,为固体废物管理大数据建设提出了初步设想。未来固体废物大数据的建设应围绕《土壤污染防治行动计划》,首先要服务社会,实现数据共享和信息公开;其次要服务于日常管理,固体废物管理部门可以通过大数据应用辅助决策,落实简政放权,实现智慧管理;再次要服务于环境应急,通过对固体废物全生命周期的数据实时采集和动态分析,整合应急资源,服务应急救援。     

Using LCA to evaluate impacts and resources conservation potential of composting: A case study of the Asti District in Italy

Separate collection of municipal solid waste has overcome the 50% threshold in the Asti District in northern Italy, nearly one-third being composed of household and green organic waste. In order to address present and future solutions, it becomes therefore fundamental to assess the environmental performances of the current management of organic waste from separate collection. A from-gate-to-cradle life cycle assessment (LCA) model has been developed by expanding system boundaries, in order to carry out the assessment in the context of the whole waste management streamline. The environmental performances of an existing aerobic plant were made available, based on field measured data, by paying attention to the role and contribution of waste management subsystems. The need for actual and reliable data on materials and energy input, as well as gross and net gains from materials recovery, including benefits arising from use of compost in farming activities, was probably the major drawback that had to be faced. The study integrated the findings of different investigations from the literature with field measured data in order to obtain a more comprehensive framework representative of the area under study. The results may help public administrators to better understand the suitability of using LCA tools when dealing with solid waste management strategies.     

Alternative scenarios to meet the demands of sustainable waste management

This paper analyses different alternatives for solid waste management that can be implemented to enable the targets required by the European Landfill and Packaging and Packaging Waste Directives to be achieved in the Valencian Community, on the east coast of Spain. The methodology applied to evaluate the environmental performance of each alternative is Life Cycle Assessment (LCA). The analysis has been performed at two levels; first, the emissions accounted for in the inventory stage have been arranged into impact categories to obtain an indicator for each category; and secondly, the weighting of environmental data to a single unit has been applied. Despite quantitative differences between the results obtained with four alternative impact assessment methods, the same preference ranking has been established: scenarios with energy recovery (1v and 2v) achieve major improvements compared to baseline, with scenario 1v being better than 2v for all impact assessment methods except for the EPS'00 method, which obtains better results for scenario 2v. Sensitivity analysis has been used to test some of the assumptions used in the initial life cycle inventory model but none have a significant effect on the overall results. As a result, the best alternative to the existing waste management system can be identified.     

采油作业“三废”控制技术研究与应用

针对采油作业产生的废酸、固废、废水处理成本高、技术不成熟等问题,研发改性废酸降压增注、深部调剖技术;高比重污泥悬浮研磨后的固废处理技术;低耗水打塞、原井液+CaCl2压井、原井液处理再利用技术,减少了"三废"的产生,解决了"三废"环保处理费高等问题,消除了环保隐患,实现了清洁生产,环境效益显著。     

Challenges facing the sustainable consumption and waste management agendas: perspectives on UK households

The management of municipal waste is one of the most emotive local environmental issues in the UK at present and represents a key sustainability “battleground” as local authorities seek to reduce waste arisings and encourage the reuse and recycling of materials among households. Within the literature on household waste management, a broad range of disciplinary perspectives and practical recommendations exist and it is the aim of this paper to step back and take stock of the role of households and communities in resource consumption and waste generation patterns across the UK within recent decades. By exploring the household in this context, trends in consumption and waste generation are outlined in addition to key influencing factors such as lifestyles and well-being, demographics and environment. Finally, key lessons learnt, challenges faced going forward and approaches for developing more sustainable practices at the household, community and national levels are discussed.     

A critical review on plastic waste administration

The management of plastic waste through various methods such as landfilling, recycling, and incineration has several inherent shortcomings, such as a lack of resources, preparation, motivation, financial power, and expertise. Additionally, these methods are unable to handle the quantity and types of plastic waste, nor do they increase the public's interest in plastic waste management practices. According to research, environmental, economic, and social factors are the main drivers for reducing plastic waste. Experts from around the world have identified four significant areas of concern for which solutions have been proposed: methods of plastic waste reduction and management, the amount of plastic waste, the quality of waste/plastic, and awareness of plastic waste management/cost of plastic waste management. However, individual solutions proposed for these key areas of concern are facing several challenges, leading to delays in their adoption or less popularity globally. The review has identified the reasons for the less popularity of existing plastic waste management methods, which are less environmentally friendly and have a complex process, hence requiring serious reconsideration from technocrats and researchers to develop more sustainable and efficient procedures that do not produce more hazardous by-products. This study also found that financial incentives are one of the main drivers to ensure the mass participation of lower and working-class people.     

A disclosure of social and environmental results/economy resulting from the implementation of reverse logistics and final disposal of the post‐consumption product: The case of computer peripherals industry

This research was conducted with the objective of determining and evidencing the social and environmental/economic results from the implementation of a reverse logistics program providing for the recycling, reuse, and, when necessary, final, environmentally correct disposal of post‐consumption products and product wastes by a multinational manufacturer of computer peripherals with an operation based in the city of São Paulo, Brazil. The reverse logistics process (logisticareversa, or, in this paper, LR) was intended to meet the objectives and principles of the regulatory framework defined in the National Solid Waste Policy (PNRS) in Brazil. A single case study was carried out. The results showed that after the adoption of the solid waste management policy, the study company no longer disposed of 1,413,552 kilograms (kg) of materials classified as mixed iron, polystyrene, cardboard, toner powder, and plastic in landfills. The LR process made a profit in two companies: the company surveyed made, in Brazilian reais (R), R$ 9,188,185.51, and the company contracted to carry out the process made, R$ 411,325.97. This latter profit is called by us the “social profit.” The measurement of the environmental/economic, social, and financial results by internalizing the expenses of the LR program into the costs of production shows that reuse and recycling better meets the needs of society and the company than landfilling these post‐consumption materials. Furthermore, the use of cost accounting allows the verification of other goals not indicated in the current model, such as the generation of employment, income, mitigation of environmental problems, and the profit earned by the company contracted to implement the LR process. We also conclude that cost accounting makes it possible to obtain necessary information for decision makers, who are seeking to neutralize environmental impacts and promote sustainable development, thus harmonizing the economic, social, and environmental aspects, to understand the impacts of the LR process.     

Environmental evaluation of plastic waste management scenarios

The management of the plastic fraction is one of the most debated issues in the discussion on integrated municipal solid waste systems. Both material and energy recovery can be performed on such a waste stream, and different separate collection schemes can be implemented. The aim of the paper is to contribute to the debate, based on the analysis of different plastic waste recovery routes. Five scenarios were defined and modelled with a life cycle assessment approach using the EASEWASTE model. In the baseline scenario (P0) the plastic is treated as residual waste and routed partly to incineration with energy recovery and partly to mechanical biological treatment. A range of potential improvements in plastic management is introduced in the other four scenarios (P1–P4). P1 includes a source separation of clean plastic fractions for material recycling, whereas P2 a source separation of mixed plastic fraction for mechanical upgrading and separation into specific polymer types, with the residual plastic fraction being down-cycled and used for “wood items”. In P3 a mixed plastic fraction is source separated together with metals in a “dry bin”. In P4 plastic is mechanically separated from residual waste prior to incineration.A sensitivity analysis on the marginal energy was carried out. Scenarios were modelled as a first step assuming that marginal electricity and heat were based on coal and on a mix of fuels and then, in the sensitivity analysis, the marginal energy was based on natural gas.The study confirmed the difficulty to clearly identify an optimal strategy for plastic waste management. In fact none of the examined scenarios emerged univocally as the best option for all impact categories. When moving from the P0 treatment strategy to the other scenarios, substantial improvements can be obtained for “Global Warming”. For the other impact categories, results are affected by the assumption about the substituted marginal energy. Nevertheless, irrespective of the assumptions on marginal energy, scenario P4, which implies the highest quantities of specific polymer types sent to recycling, resulted the best option in most impact categories.     

Determinants of privatized solid waste management service provision in Lagos

The growing popularity of privatized solid waste management service in least developed countries warrants an exploration of factors that are likely to impact on its sustainability. This study takes integrated solid waste management approach by analyzing relevant issues on both market sides. We use a three step theme development sequence to analyze the data obtained on service providers through library research, observations and interviews. This was followed by an opinion survey on the demand side to elicit households’ support for service improvement. Findings show that source-separation issues, government enforcement, market segmentation, financial issues and waste disposal issues are key factors influencing improved service provision. Meanwhile, on the demand side, we found that households are willing to support proposed regulatory improvement in service provision. Thus, we suggest industrial stakeholders to consider the aforementioned supply side issues in designing future service improvements that will take advantage of existing demand side feasibility.     

The Potential for Using Life Cycle Inventory Analysis in Local Authority Waste Management Decision Making

A life cycle inventory model was applied to a range of waste management scenarios in the waste collection authorities of Gloucestershire. The life cycle model and the results of modelling different waste management options are described. Model results were submitted to waste managers in the six authorities and utilization of the information was analysed. Analysis suggests that a range of factors arising from both model implementation and the local policy context affects the form and extent of utilization. Increased levels of environmental knowledge and understanding will be required to make effective use of life cycle analysis in local authority decision making.     

Life cycle indicators for monitoring the environmental performance of European waste management

As widely recognised by EU legislation, Life Cycle Thinking (LCT) is a viable approach to support sound waste management choices. In this context, the Institute for Environment and Sustainability (IES) of the European Commission Joint Research Centre (JRC) has lead the development of macro-level, life cycle based waste management indicators to quantify and monitor the potential environmental impacts, benefits, and improvements associated with the management of a number of selected waste streams generated and treated in Europe.The waste management indicators developed make use of a combination of macro statistical waste management data combined with emissions/resource life cycle data for the different elements of the waste treatment chain. Indicators were initially calculated for the entire European Union (EU-27) and for Germany, covering several waste streams and a broad range of environmental impact categories.An indicator developed for a given waste stream captures the potential environmental impact associated with the generation and management of that waste stream. The entire waste management chain is considered, i.e. from generation to final treatment/disposal. Therefore, system boundaries for the selected waste streams include also the treatment or recycling of secondary waste (e.g. bottom ash from the incineration of household waste), and secondary products (e.g. recovered paper), as well as energy recovery.The experiences from the development of these life cycle based waste management indicators suggest that more detailed and quality-assured waste statistics are needed, especially covering the many different treatment operations and options. Also, it would be beneficial if waste statistics had a higher disaggregation level of waste categories, as well as more detailed information about waste composition. A further development of the indicators should include an increased number of waste streams, as well as calculation of the results for all Member States.     

Methodological aspects of life cycle assessment of integrated solid waste management systems

Environmental life cycle assessment (LCA) developed rapidly during the 1990s and has reached a certain level of harmonisation and standardisation. LCA has mainly been developed for analysing material products, but can also be applied to services, e.g. treatment of a particular amount of solid waste. This paper discusses some methodological issues which come into focus when LCAs are applied to solid waste management systems. The following five issues are discussed. (1) Upstream and downstream system boundaries: where is the ‘cradle’ and where is the ‘grave’ in the analysed system? (2) Open-loop recycling allocation: besides taking care of a certain amount of solid waste, many treatment processes also provide additional functions, e.g. energy or materials which are recycled into other products. Two important questions which arise are if an allocation between the different functions should be made (and if so how), or if system boundaries should be expanded to include several functions. (3) Multi-input allocation: in waste treatment processes, different materials and products are usually mixed. In many applications there is a need to allocate environmental interventions from the treatment processes to the different input materials. The question is how this should be done. (4) Time: emissions from landfills will continue for a long time. An important issue to resolve is the length of time emissions from the landfill should be considered. (5) Life cycle impact assessment: are there any aspects of solid waste systems (e.g. the time horizon) that may require specific attention for the impact assessment element of an LCA? Although the discussion centres around LCA it is expected that many of these issues are also relevant for other types of systems analyses.     

“十四五”时期危险废物污染防治思路探讨

"十三五"时期,我国环境质量改善和生态文明建设取得显著进展,"十四五"时期生态环境保护面临的形势和任务仍然严峻艰巨,亟须正确识别当前的环境形势以及未来的重大环境问题,制定针对性的规划。本文概述了"十三五"期间我国危险废物污染防治取得的进展和成效,并分析了当前危险废物环境风险防控面临的废物产生量大且持续增加、环境风险高、利用处置短板凸显、综合利用风险防控不足等突出问题,从制度优化、科学管理和技术支撑等重点任务、重大工程方面,提出"十四五"环境保护危险废物污染防治规划思路,为编制"十四五"危险废物污染防治规划提供参考。     

Waste Management in Guangdong Cities: The Waste Management Literacy and Waste Reduction Preferences of Domestic Waste Generators

A questionnaire survey was conducted in 2002 on 1365 households in two prefectural-level cities in the Pearl River Delta, Jiangmen and Zhongshan. Three groups of issues are covered in this paper: 1) waste management literacy, concerns, and public participation; 2) waste recycling practices and the potential for waste avoidance; and 3) public environmental literacy. This study confirms findings from previous surveys and provides new information on important issues such as imposing monetary charges on waste and environmental activities, littering, source separation programs (SSPs), and public participation and expectations in local waste management. Saving up recyclable materials for redemption in waste depots is commonly practiced in mainland China regardless of the level of development of a city, although at the household level, high-income families tend to place less value on the revenues to be gained from redemption than lower income groups do. Data from the previous and the present studies indicate that such voluntary but largely economically driven waste recovery behavior diverts at least 10% of the household waste from the waste stream. Although uncompensated SSP is less appealing in the two cities than compensated SSP, it was found that when the median per capita income of a city reaches RMB2000 per month, a high participation rate for uncompensated waste recovery is more likely to occur. Education and income levels are the chief factors affecting littering behavior and the potential for waste avoidance. Contrary to general belief, the local Chinese community is active in microwaste management. The concern, however, is over the inability of the grassroots bureaucracy to deal with rising expectations for waste collection services and neighborhood cleanliness.     

Material savings through structural steel reuse: A case study in Genoa

One of the most challenging issues in the field of sustainable design is that of limiting the environmental impact of structural systems, as they contribute significantly to raw material consumption, global carbon emissions and solid waste production. This paper addresses the approach of the reuse of steel structure without melting which allows for savings in steel mass and the reduction of waste amounts offering moreover an opportunity to avoid environmental burdens related to the recycling process. Recent studies have stressed the technical feasibility of this strategy, which appears particularly effective in those countries in which a building's life is rather short, such as in Japan and US, though its application encounters more difficulties in most European countries, owing to longer building use. Besides stressing the architectural and structural feasibility of the above-mentioned strategy, this research work aims to quantify the mass savings that are achievable in this manner by presenting a real case study set in Italy. It consists in a railway station, which has been designed keeping in mind the partial employment of structural elements recovered from an old industrial building that is no longer in use. To estimate the amount of steel saved, two different structural models for the designed building have been carried out and compared. In the first one, the structure has been designed on the assumption of the reusing of recovered structural elements; in the second one, the same structure has been designed considering the use of new elements only. The final result of the analysis shows that steel reuse allowed for savings of up to 30% of steel.     

An energetic life cycle assessment of C&D waste and container glass recycling in Cape Town,South Africa

This study presents the results of a comparative life cycle assessment (LCA) on the energy requirements and greenhouse gas (GHG) emission implications of recycling construction and demolition (C&D) rubble and container glass in Cape Town, South Africa. Cape Town is a medium sized city in a developing country with a growing population and a rising middle class, two factors that are resulting in increased generation of solid waste. The City is constrained in terms of landfill space and competing demands for municipal resources.The LCA assessment was based on locally gathered data, supplemented with ecoinvent life cycle inventory data modified to the local context. The results indicated that recycling container glass instead of landfilling can achieve an energy savings of 27% and a GHG emissions savings of 37%, with a net savings still being achieved even if collection practices are varied. The C&D waste results, however, showed net savings only for certain recycling strategies. Recycling C&D waste can avoid up to 90% of the energy and GHG emissions of landfilling when processed and reused onsite but, due to great dependence on haulage distances, a net reduction of energy use and GHG emissions could not be confidently discerned for offsite recycling. It was also found that recycling glass achieves significantly greater savings of energy and emissions than recycling an equivalent mass of C&D waste.The study demonstrated that LCA provides an important tool to inform decisions on supporting recycling activities where resources are limited. It also confirmed other researchers’ observations that strict adherence to the waste management hierarchy will not always result in the best environmental outcome, and that more nuanced analysis is required. The study found that the desirability of recycling from an energy and climate perspective cannot be predicted on the basis of whether such recycling conserves a non-renewable material. However, recycling that replaces a virgin product from an energy-intensive production process appears to be more robustly beneficial than recycling that replaces a product with little embodied energy. Particular caution is needed when applying the waste management hierarchy to the latter situations.