Life Cycle Assessment Of Waste Management Research Articles

Development of a Municipal Solid Waste Management Life Cycle Assessment Tool for Banepa Municipality, Nepal

In this study, the life cycle assessment (LCA) method has been used to evaluate the environmental impacts of various municipal solid waste (MSW) management system scenarios in Banepa municipality, Nepal, in terms of global warming potential (GWP), acidification potential (AP), eutrophication potential (EP), human toxicity potential (HTP), abiotic depletion potential (ADP), and photochemical ozone creation potential (POCP). There are at least six possible scenarios of MSW management in Banepa: the current or baseline scenario (Scenario 1); composting with landfilling (Scenario 2); material recovery facility (MRF) recycling, composting, and landfilling (Scenario 3); MRF and anaerobic digestion (AD); composting, and landfilling (Scenario 4); MRF, composting, AD, and landfilling (Scenario 5); and, finally, incineration with landfilling (Scenario 6). Using both information from Ecoinvent 3.6 (2019) and published research articles, a spreadsheet tool based on the LCA approach was created. The impact of the recycling rate on each of the six abovementioned scenarios was evaluated using sensitivity analysis, which showed that the recycling rate can considerably decrease the life-cycle emissions from the MSW management system. Scenario 3 was found to have the least overall environmental impact with a GWP of 974.82 kg CO2 eq. per metric ton (t), EP of 0.04 kg PO4 eq./t, AP of 0.15 kg SO2 eq./t, HTP of 4.55 kg 1,4 DB eq./t, ADP of −0.03 kg Sb eq./t, and POCP of 0.06 kg C2H4 eq./t. By adoption of MRF and biological treatments such as composting and AD, environmental impact categories such as AP, EP, HTP, ADP, POCP, and GWP can be significantly reduced. The findings of this study can potentially serve as a reference for cities in the developing world in order to aid in both the planning and the operation of environmentally friendly MSW management systems.

Are LCA Studies on Bulk Mineral Waste Management Suitable for Decision Support? A Critical Review

Bulk mineral waste materials are one of the largest waste streams worldwide and their management systems can differ greatly depending on regional conditions. Due to this variation, the decision-making context is of particular importance when studying environmental impacts of mineral waste management systems with life cycle assessment (LCA). We follow the premise that LCA results—if applied in practice—are always used in an improvement (i.e., decision-making) context. But how suitable are existing LCA studies on bulk mineral waste management for decision support? To answer this question, we quantitatively and qualitatively assess 57 peer-reviewed bulk mineral waste management LCA studies against 47 criteria. The results show inadequacies regarding decision support along all LCA phases. Common shortcomings are insufficient attention to the specific decision-making context, lack of a consequential perspective, liberal use of allocation and limited justification thereof, missing justifications for excluded impact categories, inadequately discussed limitations, and incomplete documentation. We identified the following significant issues for bulk mineral waste management systems: transportation, the potential leaching of heavy metals, second-order substitution effects, and the choice to include or exclude avoided landfilling and embodied impacts. When applicable, we provide recommendations for improvement and point to best practice examples.

Are LCA Studies on Bulk Mineral Waste Management Suitable for Decision Support? A Critical Review

Bulk mineral waste materials are one of the largest waste streams worldwide and their management systems can differ greatly depending on regional conditions. Due to this variation, the decision-making context is of particular importance when studying environmental impacts of mineral waste management systems with life cycle assessment (LCA).We follow the premise that LCA results—if applied in practice—are always used in an improvement (i.e., decision-making) context. But how suitable are existing LCA studies on bulk mineral waste management for decision support? To answer this question, we quantitatively and qualitatively assess 57 peer-reviewed bulk mineral waste management LCA studies against 47 criteria. The results show inadequacies regarding decision support along all LCA phases. Common shortcomings are insufficient attention to the specific decision-making context, lack of a consequential perspective, liberal use of allocation and limited justification thereof, missing justifications for excluded impact categories, inadequately discussed limitations, and incomplete documentation. We identified the following significant issues for bulk mineral waste management systems: transportation, the potential leaching of heavy metals, second-order substitution effects, and the choice to include or exclude avoided landfilling and embodied impacts. When applicable, we provide recommendations for improvement and point to best practice examples.

Application of LCA modelling in integrated waste management

Life cycle assessment (LCA) has been used in waste management for the last two decades and hundreds of journal papers have been published. The use of LCA in waste management has provided a much-improved holistic view of waste management including waste flows and potential environmental impacts. Although much knowledge has been obtained from LCA studies, there is still a need to use LCA models in integrated waste management. This paper describes six areas where LCA is expected to play a role in waste management in the future: 1) understanding an existing waste management system; 2) improving existing waste management systems; 3) comparing alternative technologies/ technology performance; 4) technology development/prospective technologies; 5) policy development/strategic development; and 6) reporting. Illustrative examples are provided for each application area.

A step forward in quantifying the substitutability of secondary materials in waste management life cycle assessment studies

Life Cycle Assessment (LCA) is a widespread tool used to guide decision-makers towards optimal strategic choices for sustainable growth. A key aspect of LCA studies of waste management systems where recycling activities are present is to account for resource recovery and the related substitution effects. Although multiple scientific papers assume a 1:1 substitution ratio between similar materials/products, this is often incorrect as the actual ratio is likely to vary. The focus of this paper is on the calculation of the substitutability coefficient for secondary materials based on technical characteristics. A state of the art literature review showed that many different calculation procedures were applied, which led to a wide variety of substitutability coefficients (sometimes provided under different terminology). In this perspective, the objective of this paper is to provide guidelines on the procedure to be followed to calculate the substitutability coefficient for secondary materials, based on technical characteristics. These guidelines are then applied to two waste management case studies, one dealing with bottom ashes from incineration and the other with plastic waste. In total, sixteen technical substitutability coefficients are given for ten secondary materials, based on state of the art and presented case studies. The paper thus represents a step forward in quantifying the substitutability of secondary materials in waste management LCA studies. The guidelines presented may allow other case studies to enrich the list of coefficients, useful for all LCA practitioners in a harmonized way allowing a more correct evaluation of the environmental impacts associated with recycling activities.

Recycle, Bury, or Burn Wood Waste Biomass?: LCA Answer Depends on Carbon Accounting, Emissions Controls, Displaced Fuels, and Impact Costs

SummaryThis study extends existing life cycle assessment (LCA) literature by assessing seven environmental burdens and an overall monetized environmental score for eight recycle, bury, or burn options to manage clean wood wastes generated at construction and demolition activity sites. The study assesses direct environmental impacts along with substitution effects from displacing fossil fuels and managed forest wood sourcing activities. Follow‐on effects on forest carbon stocks, land use, and fuel markets are not assessed. Sensitivity analysis addresses landfill carbon storage and biodegradation rates, atmospheric emissions controls, displaced fuel types, and two alternative carbon accounting methods commonly used for waste management LCAs. Base‐case carbon accounting considers emissions and uptakes of all biogenic and fossil carbon compounds, including biogenic carbon dioxide. Base‐case results show that recycling options (recycling into reconstituted wood products or into wood pulp for papermaking) rank better than all burning or burying options for overall monetized score as well as for climate impacts, except that wood substitution for coal in industrial boilers is slightly better than recycling for the climate. Wood substitution for natural gas boiler fuel has the highest environmental impacts. Sensitivity analysis shows the overall monetized score rankings for recycling options to be robust except for the carbon accounting method, for which all options are highly sensitive. Under one of the alternative methods, wood substitution for coal boiler fuel and landfill options with high methane capture efficiency are the best for the overall score; recycling options are next to the worst. Under the other accounting alternative, wood substitution for coal and waste‐to‐energy are the best, followed by recycling options.

Comparative life cycle assessment of smartphone reuse: repurposing vs. refurbishment

Waste management for end-of-life (EoL) smartphones is a growing problem due to their high turnover rate and concentration of toxic chemicals. The versatility of modern smartphones presents an interesting alternative waste management strategy: repurposing. This paper investigates the environmental impact of smartphone repurposing as compared to traditional refurbishing using Life Cycle Assessment (LCA). A case study of repurposing was conducted by creating a smartphone “app” that replicates the functionality of an in-car parking meter. The environmental impacts of this prototype were quantified using waste management LCA methodology. Studied systems included three waste management options: traditional refurbishment, repurposing using battery power, and repurposing using a portable solar charger. The functional unit was defined as the EoL management of a used smartphone. Consequential system expansion was employed to account for secondary functions provided; avoided impacts from displaced primary products were included. Impacts were calculated in five impact categories. Break-even displacement rates were calculated and sensitivity to standby power consumption were assessed. LCA results showed that refurbishing creates the highest environmental impacts of the three reuse routes in every impact category except ODP. High break-even displacement rates suggest that this finding is robust within a reasonable range of primary cell phone displacement. The repurposed smartphone in-car parking meter had lower impacts than the primary production parking meter. Impacts for battery-powered devices were dominated by use-phase charging electricity, whereas solar-power impacts were concentrated in manufacturing. Repurposed phones using battery power had lower impacts than those using solar power, however, standby power sensitivity analysis revealed that solar power is preferred if the battery charger is left plugged-in more than 20 % of the use period. Our analysis concludes that repurposing represents an environmentally preferable EoL option to refurbishing for used smartphones. The results suggest two generalizable findings. First, primary product displacement is a major factor affecting whether any EoL strategy is environmentally beneficial. The benefit depends not only on what is displaced, but also on how much displacement occurs; in general, repurposing allows freedom to target reuse opportunities with high “displacement potential.” Second, the notion that solar power is preferable to batteries is not always correct; here, the rank-order is sensitive to assumptions about user behavior.

Waste management Life Cycle Assessment: the case of a reciprocating air compressor in Brazil

Abstract Choose an environmentally End-of-Life (EoL) strategy is not an easy task. From a Life Cycle Assessment (LCA) point of view, depending on the processes and destinations applied after use, the entire life cycle is affected, even earlier steps, such as the acquisition of raw materials and manufacturing. This paper aimed to assess the environmental impacts of an air compressor in Brazil, from cradle to the grave, with focus on the comparison of three waste management alternatives. We defined a Remanufacturing, Recycling and Landfilling scenarios following European Directive on waste management hierarchy. LCA methodology was applied to evaluate the potentials impacts on Global Warming, Abiotic Resource Depletion, Total Cumulative Energy Demand and Land Occupation based on primary data collected by the Original Equipment Manufacturer (OEM). The case study indicates that the hotspot of this product system occurs in the use phase due the high demand of energy during its long life span. This predominance is such that it overcomes the differences among the three EoL scenarios. Removing this phase in LCA's result interpretation we found that for all categories Remanufacturing has the best environmental performance followed by Recycling and Landfilling. Remanufacturing was able to reduce the environmental impact by more than 40% compared to Landfilling through a reduced consumption of raw materials, manufacturing processes and environmental gains of avoided products.

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).

Review of LCA studies of solid waste management systems – Part II: Methodological guidance for a better practice

Life cycle assessment (LCA) is increasingly used in waste management to identify strategies that prevent or minimise negative impacts on ecosystems, human health or natural resources. However, the quality of the provided support to decision- and policy-makers is strongly dependent on a proper conduct of the LCA. How has LCA been applied until now? Are there any inconsistencies in the past practice? To answer these questions, we draw on a critical review of 222 published LCA studies of solid waste management systems. We analyse the past practice against the ISO standard requirements and the ILCD Handbook guidelines for each major step within the goal definition, scope definition, inventory analysis, impact assessment, and interpretation phases of the methodology. Results show that malpractices exist in several aspects of the LCA with large differences across studies. Examples are a frequent neglect of the goal definition, a frequent lack of transparency and precision in the definition of the scope of the study, e.g. an unclear delimitation of the system boundaries, a truncated impact coverage, difficulties in capturing influential local specificities such as representative waste compositions into the inventory, and a frequent lack of essential sensitivity and uncertainty analyses. Many of these aspects are important for the reliability of the results. For each of them, we therefore provide detailed recommendations to practitioners of waste management LCAs.

Participatory approach, acceptability and transparency of waste management LCAs: Case studies of Torino and Cuneo

The paper summarises the main results obtained from two extensive applications of Life Cycle Assessment (LCA) to the integrated municipal solid waste management systems of Torino and Cuneo Districts in northern Italy. Scenarios with substantial differences in terms of amount of waste, percentage of separate collection and options for the disposal of residual waste are used to discuss the credibility and acceptability of the LCA results, which are adversely affected by the large influence of methodological assumptions and the local socio-economic constraints. The use of site-specific data on full scale waste treatment facilities and the adoption of a participatory approach for the definition of the most sensible LCA assumptions are used to assist local public administrators and stakeholders showing them that LCA can be operational to waste management at local scale.

Environmental assessment and sustainable management options of leachate and landfill gas treatment in Estonian municipal waste landfills

PurposeThe purpose of this paper is to compare various landfill gas (LFG) and leachate treatment technologies in a life‐cycle perspective.Design/methodology/approachSince a landfill causes emissions for a very long‐time period, life‐cycle‐based environmental assessment was carried out to compare different technological options for sustainable leachate treatment and LFG collection and utilization. WAMPS, the life‐cycle assessment (LCA) model for waste management planning, was used for the environmental assessment of selected leachate and LFG treatment technologies.FindingsResults of both direct measurements in the studied landfills and LCA support the fact that leachate treatment with reverse osmosis has the best environmental performance compared to aerobic‐activated sludge treatment. Recently, the collection efficiency of LFG in the studied landfills is relatively low. In order to improve the overall environmental performance of LFG management the gas collection rate should be improved. LFG utilisation for energy recovery is an essential part of the system. The results of the study show that the avoided impacts of energy recovery can be even greater than direct impacts of greenhouse gas emissions from landfills. Therefore, measures which combine LFG collection with energy generation should be preferred to treatment in flare.Research limitations/implicationsIt should be noted that the results of this study do not express the total environmental impacts of the entire landfill system, but only the eutrophicating impacts and global warming related to the studied leachate and LFG management options. Therefore, it is recommended that further LCAs investigate also other relevant impact categories.Practical implicationsThe results of LCA modelling show that it is important to ensure the highest collection and treatment efficiency of leachate and LFG, since poor capture compromises the overall environmental performance of a landfill.Originality/valueThe paper provides a site‐specific data on sustainable leachate and LFG management in selected Estonian conventional municipal solid waste landfills. As such, the paper contributes to the development of the regional reference input data for LCA in waste management.

DECISION SUPPORT MODELS FOR SOLID WASTE MANAGEMENT - AN OVERVIEW

The purpose of this paper is to analyze some models currently used in the area of solid waste management, identified in literature as decision support models and developed for establishing a decision support system (DSS). They are usually designed to help decision makers to build up integrated programs for applying solid waste management alternatives such as recycling, treatment, incineration, disposal. These decision support models are based on cost benefit analysis, multicriteria analysis or life cycle assessment (LCA) respectively. The structure, types, advantages and limitation of these models were analyzed, the work being focused on the methodology of LCA in waste management. Types of LCA models and application in the solid waste management area and possible combinations of LCA with other methods used in literature such as cost-benefit analysis and multicriteria decision making are approached, discussed and compared.

International expert group on life cycle assessment for integrated waste management

Managing waste sustainably requires an assessment of the environmental costs and benefits of alternative waste management practices on a more sound and objective basis. The International Expert Group on life cycle assessment for integrated waste management (IEG) is a leading group of environmental experts with an interest in using Life Cycle techniques to inform waste management decision-making. Life Cycle Assessment (LCA) is a technique that can be used to provide information about the likely polluting emissions and predicted environmental impacts of alternative designs for products or services. LCA for waste management specifically focuses on the environmental consequences of discarding waste materials and consumer products, identifying the costs of waste collection, treatment and any potential benefit of utilising the discarded material. Through iterative examination of various treatment alternatives for wastes, LCA can help identify optimal environmental solutions for managing wastes, without risking that the choice of decisions will result in a worsening of the overall impact. The IEG holds biannual workshop-style meetings to share international knowledge in the research area and to progress research activities. The meetings consist of presentations on life cycle modeling, LCA case studies for municipalities and specific waste streams, as well as pioneering research on decision-making and interpretation. Technical matters and issues of consistency of approach are also addressed during meetings through the knowledge and research activities of members and through the invitation of guest experts to meetings. This article provides an introduction to the work of the IEG and a summary of discussions from the 11th meeting of the group.

International expert group on life cycle assessment for integrated waste management

Abstract Managing waste sustainably requires an assessment of the environmental costs and benefits of alternative waste management practices on a more sound and objective basis. The International Expert Group on life cycle assessment for integrated waste management (IEG) is a leading group of environmental experts with an interest in using Life Cycle techniques to inform waste management decision-making. Life Cycle Assessment (LCA) is a technique that can be used to provide information about the likely polluting emissions and predicted environmental impacts of alternative designs for products or services. LCA for waste management specifically focuses on the environmental consequences of discarding waste materials and consumer products, identifying the costs of waste collection, treatment and any potential benefit of utilising the discarded material. Through iterative examination of various treatment alternatives for wastes, LCA can help identify optimal environmental solutions for managing wastes, without risking that the choice of decisions will result in a worsening of the overall impact. The IEG holds biannual workshop-style meetings to share international knowledge in the research area and to progress research activities. The meetings consist of presentations on life cycle modeling, LCA case studies for municipalities and specific waste streams, as well as pioneering research on decision-making and interpretation. Technical matters and issues of consistency of approach are also addressed during meetings through the knowledge and research activities of members and through the invitation of guest experts to meetings. This article provides an introduction to the work of the IEG and a summary of discussions from the 11th meeting of the group.

Input‐Output Analysis of Waste Management

SummaryA new scheme of hybrid life‐cycle assessment (LCA) termed the waste input‐output (WIO) model is presented that ex‐plicitly takes into account the interdependence between the flow of goods and waste. The WIO model has two distin‐guishing features. First, it expands the Leontief environmental input‐output (EIO) model with respect to waste flows. It turns out that the EIO model is a special case of the WIO model in which there is a strict one‐to‐one correspondence between waste types and treatment methods. By relaxing this condition, the WIO model provides a general framework for LCA of waste management. Second, the WIO model takes into account the “dynamics of waste treatment”, which refers to the fact that the input‐output relationships of waste treatment are significantly affected by the level and composition of waste feedstock, by incorporating an engineering process model of waste treatment. Because waste treatment is expected to accept whatever waste is generated by industry and households, a proper consideration of this feature is vital for LCA of waste management. We estimated a WIO table for Japan and applied it to evaluating effects of alternative waste management poli‐cies with regard to regional concentration of incineration and the sorting of waste with regard to flammability. We found that concentrating treatment in a small number of large incin‐erators combined with an increased degree of sorting could decrease both landfill consumption and the emission of carbon dioxide.