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.     

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.     

Farm management indicators and farm typologies as a basis for assessments in a changing policy environment

This paper focuses on the assessment of farm management indicators and argues that typologies are a necessary tool for comprehensive environmental assessments. In the paper Andersen et al., [(2004a). Farming and the Environment in the European Community--using agricultural statistics to provide farm management indicators. Paper presented at OECD Expert meeting, March 2004, New Zealand. < http:webdomino1.oecd.org/comnet/agr/farmind.nsf/viewHtml/index/$FILE/Anderson_et_al.PDF> (1st of February 2006).] presented at the OECD expert meeting on farm management indicators in New Zealand in March 2004, a set of farm management indicators was presented in the framework of a typology of grazing livestock farming systems in the EU-15 (includes all Member States of the European Union before 2004). The present paper presents new results on farm management indicators within the framework of an extended typology for all farming sectors. It presents an environmentally oriented extension to the EU typology of farms currently used for assessing the situation of farming within the European Union. The extended typology is tested in relation to emerging policy issues such as environmental sustainability and rural viability by analysing some of the farm management indicators suggested in Andersen et al., [(2004a). Farming and the Environment in the European Community--using agricultural statistics to provide farm management indicators. Paper presented at OECD Expert meeting, March 2004, New Zealand. (1st of February 2006).]. Finally, recommendations in relation to the next generation EU farm typology are given.     

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.     

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。     

Trade and recycling of used tyres in Western and Eastern Europe

Truck tyres can cause significant environmental pressure through the life cycle. The main aim of this paper is investigate to what extent international policy measures on foreign trade, international recycling and harmonisation of legislation can contribute in effectively reducing environmental pressure caused in the truck tyre life cycle. A two-region simulation model, representing Western and Eastern Europe, is developed that integrates the complete life cycle, incorporates environmental impacts in its economic analysis, is technically dynamic by accounting for learning-by-doing effects, and allows for variations in trade of new and old truck tyres. In this study the economic, environmental and social effectiveness of harmonisation and trade measures in the European life cycle for truck tyre is tested. Several conclusions can be drawn from the model simulations. First, the environmental effects caused by the trade of used tyres from Western to Eastern Europe are of limited impact on the overall environmental damage caused by truck tyres. The consumption stage is by far the main contributor to environmental damage. Within the marginal analysis of trade, harmonisation of disposal fees illustrated to generate very limited positive results. The private and external costs in the solid waste management (SWM) stage are too limited to have a notable impact on the overall configuration of the European tyre life cycle. The introduction of strict laws on tread depth in Eastern Europe has a much stronger impact on material flows than the harmonisation scenario. This suggests that domestic policy measures should be the primarily focus on interventions in this stage of the life cycle, for instance, by improving the management of tyre pressure. Because trade of used tyres has little impact on the consumption stage, this issue should not get priority in European environmental programs.     

Transitions of municipal solid waste management. Part II: Hybrid life cycle assessment of Swiss glass-packaging disposal

In policy support of municipal solid waste (MSW) management, life cycle assessment (LCA) can serve to compare the environmental or economic impacts of two or more options for waste processing. The scope of waste management LCAs generally focuses less attention on future developments, e.g., where will recycling take place, and more on the environmental performance of prototypes, e.g., the incineration of all waste compared to recycling. To provide more robust support for Swiss waste glass-packaging disposal, scenarios of Swiss waste glass-packaging are assessed from a life cycle perspective. The scenarios consist in schemes for the disposal of the total amount of Swiss waste glass-packaging, i.e., different combinations of recycling and downcycling in Switzerland or abroad developed in Part I, Meylan et al. (2013). In this article (Part II), the disposal schemes are assessed with respect to eco-efficiency, an indicator that combines total environmental impacts and gross value added in Switzerland. Results show that no policy alternative guarantees environmental impact reductions and gross value added gains under all developments of exogenous constraints. Downcycling to foam glass in Switzerland is not only an environmentally sound disposal option, but it also buffers gross value added losses in case domestic recycling (and thus glass-packaging production in Switzerland) ceases in the future. The substitution of products based on raw materials other than Swiss cullet is the main responsible for change in environmental and economic impacts. Hence, an eco-efficiency maximizing policy should consider the products of disposal schemes. The combination of scenario analysis and eco-efficiency assessment as presented in this paper can be applied to other contexts (i.e., countries, waste fractions).     

LCA: A decision support tool for environmental assessment of MSW management systems

Life cycle assessment (LCA) can be successfully applied to municipal solid waste (MSW) management systems to identify the overall environmental burdens and to assess the potential environmental impacts. In this study, two methods used for current MSW management in Phuket, a province of Thailand, landfilling (without energy recovery) and incineration (with energy recovery), are compared from both energy consumption and greenhouse gas emission points of view. The comparisons are based on a direct activity consideration and also a life cycle perspective. In both cases as well as for both parameters considered, incineration was found to be superior to landfilling. However, the performance of incineration was much better when a life cycle perspective was used. Also, landfilling reversed to be superior to incineration when methane recovery and electricity production were introduced. This study reveals that a complete picture of the environmental performance of MSW management systems is provided by using a life cycle perspective.     

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.     

Identification and testing of potential key parameters in system analysis of municipal solid waste management

Life cycle assessment (LCA) and life cycle costing (LCC) are well-established methods used for many years in many countries for system analysis of waste management. According to standard LCA procedure the assessment should include improvement analysis, in many cases this is performed by simple sensitivity analyses. An obstacle to perform more thorough sensitivity analyses is that it is hard to distinguish input data important to the results, i.e. key parameters. This paper further elaborates sensitivity analyses performed in an environmental system analysis for a hypothetical Swedish municipality. In this paper, the method to identify and test input data that can be categorised as potential key parameters is described. The method and the results from computer simulations of the identified parameters are presented, and some conclusions are drawn regarding the robustness of the results for environmental impact from municipal solid waste management. The major conclusion is that the results are robust. Changes in results, when changing the preconditions, are often small and the changes observed do not lead to new conclusions; i.e., a change of ranking order between treatment options.     

Life-Cycle Impact Assessment of oil drilling mud system in Algerian arid area

The objective of this work is to assess the environmental impacts of the drilling mud system in Algeria's arid region. Water-based mud (WBM) and oil-based mud (OBM) are used during well drilling in Hassi Messaoud petroleum field, and have a considerable pollution potential particularly on the aquifer system which constitutes the single resource of drinking water in the Sahara. The Life-Cycle Assessment (LCA) approach is applied to evaluate the impacts of several drilling mud systems across all stages of their life cycle, e.g. use, treatment and disposal. Environmental impacts of five treatments scenarios corresponding to the drilling waste management applied in Hassi Messaoud are compared: reserve pit without treatment (burial option), secondary high centrifugation (vertical cuttings dryer), stabilisation/solidification online, stabilisation/solidification off line and thermal desorption. The impact assessment is carried on using the LCIA models of Impact 2002+ method in SIMAPRO7 software. This assessment identifies human toxicity and terrestrial eco-toxicity as the major impact categories in this specific arid context and quantifies the emissions contributions. The local environmental impact is the most important of the drilling mud life cycle and is mainly linked to emissions from reserve pits, treated cuttings, and drilling phase 16″ through the Turonian and Albian aquifer. The main contributing substances are aromatic hydrocarbons fraction and metals in particular barium, zinc, antimony, arsenic, and aluminium. Concerning the comparison of the treatment scenarios, it appears that stabilisation/solidification online is the best one; it has the lowest impact score in the two dominating categories because of the waste minimisation: mud storage avoided in the reserve pit. The second best scenario is the thermal desorption which obtains the lowest impact score in carcinogen effects due to hydrocarbons reduction (<1%) and avoided impacts of recovered oil. The toxic substances fate modeling will be improved by taking into account their site-specific impact.     

Environmental and economic analysis of management systems for biodegradable waste

The management system for solid and liquid organic waste affects the environment and surrounding technical systems in several ways. In order to decrease the environmental impact and resource use, biological waste treatment and alternative solutions for sewage treatment are often advocated. These alternatives include increased agricultural use of waste residuals. To analyse whether such proposed systems indicate improvements for the environment and its sustainability, systems analysis is a useful method. The changes in environmental impact and resource use is not only a result of changes in waste treatment methods, but also largely a result of changes in surrounding systems (energy and agriculture) caused by changes in waste management practices. In order to perform a systems analysis, a substance-flow simulation model, the organic waste research model (ORWARE), has been used. The results are evaluated by using methodology from life cycle assessment (LCA). An economic analysis was also performed on three of the studied scenarios. The management system for solid organic waste and sewage in the municipality of Uppsala, Sweden, was studied. Three scenarios for different treatments of solid waste were analysed: incineration with heat recovery, composting, and anaerobic digestion. These three scenarios included conventional sewage treatment. A fourth scenario reviewed was anaerobic digestion of solid waste, using urine-separating toilets and separate handling of the urine fraction. The results are only valid for the case study and under the assumptions made. In this case study anaerobic digestion result in the lowest environmental impact of all the solid waste management systems, but is costly. Economically, incineration with heat recovery is the cheapest way to treat solid waste. Composting gives environmental advantages compared to incineration methods, without significantly increased costs. Urine separation, which may be implemented together with any solid waste treatment, has great advantages, particularly in its low impact on the environment. However, there is a large increase in acidification.     

Environmental impacts and use of brominated flame retardants in electrical and electronic equipment

Management of waste electrical and electronic equipment (WEEE) or e-waste is becoming a major issue as around 20–50 million tons of such waste is generated worldwide and increasing at a higher rate than other solid waste streams. Electrical and electronic equipment (EEE) contains over 1,000 materials of which brominated flame retardants (BFRs) such as polybrominated biphenyls (PBBs) and polybrominated diphenyl ethers (PBDEs) have been the target of the regulators forcing manufacturers to adopt halogen-free flame retardants. As far as these alternatives are concerned, key consideration should be its performance during the whole life cycle through design, use and end-of-life management. The global halogen-free flame retardant movement has reached a point of no return. The most important issue as far as the environment is concerned, for which the transformation to halogen-free retardants was initially targeted, is to make sure that life span of the EEE using the alternatives to BFRs is not shortened thereby resulting in unforeseen increases in e-waste to deal with. The aim of this article is to investigate the environmental issues and current developments related to the use of BFRs in EEE manufacture. It describes the sources, toxicity and human exposure of BFRs, EOL management such as recycling and thermal treatments, exposure of BFRs from e-waste processing facilities and the environment around them and examines the developments and feasibility of the alternatives to BFR in EEE manufacture.     

ASSEMBLY OF MAP‐BASED STREAM NARRATIVES TO FACILITATE STAKEHOLDER INVOLVEMENT IN WATERSHED MANAGEMENT1

ABSTRACT: Watershed stewardship activities throughout North America have evolved into a process that requires more involvement in planning and decision making by community stakeholders. Active involvement of all stakeholders in the process of watershed stewardship is dependent on effective exchange of information among participants, and active involvement of a wide range of stakeholders from “communities of place” as well as those from “communities of interest.” We developed a map‐based stream narrative tool as a means to: (a) assemble a wealth of incompletely documented, “traditional” ecological or natural history observations for rivers or streams; and (b) promote a higher level of active involvement by community stakeholders in contributing to information‐based, watershed management. Creation of stream narratives is intended for use as a tool to actively engage local stakeholders in the development of a more comprehensive information system to improve management for multiple stewardship objectives in watersheds. Completion of map‐based stream narrative atlases provides a valuable supplement to other independent efforts to assemble observations and knowledge about land‐based natural resources covering entire watersheds. We are confident that completion of stream narrative projects will make a valuable addition to the information and decision making tools that are currently available to the public and resource agencies interested in advancing the cause of community‐based approaches to watershed and ecosystem management.     

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.     

USING STREAM BIOASSESSMENT PROTOCOLS TO MONITOR IMPACTS OF A CONFINED SWINE OPERATION1

ABSTRACT: The processing of waste from confined animal feeding operations (CAFOs) presents a major environmental challenge. Treatment of waste and subsequent land application is a common best management practice (BMP) for these operations in Kentucky, USA, but there are few data assessing the effect of runoff from such operations on aquatic communities. The authors sampled a stream bordering a CAFO with a land application program to determine if runoff from the fertilized fields was adversely affecting stream communities. Water chemistry, periphyton, and macroinvertebrate samples from riffle habitats downstream of the CAFO were compared to samples collected from an upstream site and a control stream in 1999 and 2000. Riffle communities downstream of the fertilized fields had higher chlorophyll a levels than other sites, but there were no significant differences in macroinvertebrate numbers or in biometrics such as taxa richness among the sites. The BMP in place at this site may be effective in reducing this CAFO's impact on the stream; however, similar assessments at other CAFO sites should be done to assess their impacts. Functional measures such as nutrient retention and litter decomposition of streams impacted by CAFOs should also be investigated to ensure that these operations are not adversely affecting stream communities.     

A waste management planning based on substance flow analysis

The paper describes the results of a municipal solid waste management planning based on an extensive utilization of material and substance flow analysis, combined with the results of specific life cycle assessment studies. The mass flow rates of wastes and their main chemical elements were quantified with a view to providing scientific support to the decision-making process and to ensure that the technical inputs to this process are transparent and rigorous. The role of each waste management option (recycling chains, biological and thermal treatments), as well as that of different levels of household source separation and collection (SSC), was quantitatively determined. The plant requirements were consequently evaluated, by assessing the benefits afforded by the application of high quality SSC, biological treatment of the wet organic fraction, and thermal treatment of unsorted residual waste. Landfill volumes and greenhouse gas emissions are minimized, toxic organic materials are mineralized, heavy metals are concentrated in a small fraction of the total former solid waste volume, and the accumulation of atmophilic metals in the air pollution control residues allows new recycling schemes to be designed for metals. The results also highlight that the sustainability of very high levels of SSC is reduced by the large quantities of sorting and recycling residues, amounts of toxic substances in the recycled products, as well as logistic and economic difficulties of obtaining very high interception levels. The combination of material and substance flow analysis with an environmental assessment method such as life cycle assessment appears an attractive tool-box for comparing alternative waste management technologies and scenarios, and then to support waste management decisions on both strategic and operating levels.     

Impacts of a nutrient trading plan on stream water quality in Sugar Creek,Ohio

In the early 2000s, a phosphorus nutrient trading plan (NTP) requiring best management practices (BMPs) to be installed as pollution abatement strategies to offset phosphorus waste from the Alpine Cheese Company was implemented in four subwatersheds of Sugar Creek in northeast Ohio. To assess the impacts of the Alpine NTP, 49 sites were sampled approximately biweekly from 2010 to 2018 for phosphate, total phosphorus, nitrate, ammonia, and total nitrogen. In addition, the Ohio Environmental Protection Agency conducted stream health surveys at 21 sites before and after the BMPs were implemented. This study evaluated the potential impact of 68 BMPs implemented under the NTP on the observed changes in nutrient concentrations and stream health indicators. Most nutrient concentrations observed during high discharge conditions showed significant declines from 2010 to 2018 for all subwatersheds, which was most likely due to BMPs that reduced erosion and surface runoff. However, there were fewer significant declines and some significant increases in nutrient levels during low discharge conditions, suggesting a possible contribution from legacy nutrient sources. Most sites reported increases in stream health indicators, but many streams are still below recommended levels. Collectively, the installation of BMPs and decreases in nutrient concentrations observed during high discharge conditions can be attributed to the NTP and likely contributed to improved stream health.     

Multi-criteria evaluation technique for SFI site identification of NORMS and oil industry waste disposal – Possibilities in Kuwait

Waste generation and accumulating quantities of oil field waste are a matter of environmental concern. This study proposes the Slurry Fracture Injection (SFI) technique as an alternative waste disposal method. The slurried solids injection waste disposal method is environmentally secure and permanent, leaving no future liabilities that must be risk-evaluated or priced. An entire waste stream comprising ground solids and waste water can be injected into deep and hydraulically secure target strata with no contamination of potable water-bearing formations or formations outside the target zone that may contain resources (gas and oil). The slurry injection method can be used to clean and reclaim landfills, oil pits and granular waste dumps. This article proposes a two-tier screening method for evaluating the feasibility of this technique and the identification of suitable target zones. A stringent environmental and process control monitoring program should complement the planning and operational period to ensure environmental protection, waste containment, and regulatory HSE compliance.     

Characterizing a Major Urban Stream Restoration Project: Nine Mile Run (Pittsburgh,Pennsylvania, USA)

Urban stream restoration continues to be used as an ecological management tool, despite uncertainty about the long‐term sustainability and resilience of restored systems. Evaluations of restoration success often focus on specific instream indicators, with limited attention to the wider basin or parallel hydrologic and geomorphic process. A comprehensive understanding of urban stream restoration progress is particularly important for comparisons with nonurban sites as urban streams can provide substantial secondary benefits to urban residents. Here, we utilize a wide range of indicators to retrospectively examine the restoration of Nine Mile Run, a multi‐million dollar stream restoration project in eastern Pittsburgh (Pennsylvania, USA). Examination of available continuous hydrological data illustrates the high cost of failures to incorporate the data into planning and adaptive management. For example, persistent extreme flows drive geomorphic degradation threatening to reverse hydrologic connections created by the restoration and impact the improved instream biotic communities. In addition, human activities associated with restoration efforts suggest a positive feedback as the stream restoration has focused effort on the basin beyond the reach. Ultimately, urban stream restoration remains a potentially useful management tool, but continued improvements in post‐project assessment should include examination of a wider range of indicators.