Life Cycle Assessment Modelling of Greenhouse Gas Emissions from Existing and Proposed Municipal Solid Waste Management System of Lahore, Pakistan

Strategies for reducing greenhouse gas emissions from municipal solid waste management in Pakistan

The studies on municipal solid waste (MSW) management in Pakistan and its impacts on greenhouse gas (GHG) emissions are glaringly missing. Therefore, this study examines the effect of MSW management on GHG emissions in Pakistan and suggests the best suitable strategies for alleviating GHG emissions. The Intergovernmental Panel on Climate Change (IPCC) 2006 waste model (WM) was used to create inventory of GHG emissions from landfilling. The solid waste management GHG (SWM-GHG) calculator and strengths-weaknesses-opportunities-threat (SWOT) analyses were used as strategic planning tools to reduce GHG emissions by improving MSW management in Pakistan. The IPCC 2006 WM estimated 14,987,113 metric tonnes (Mt) carbon dioxide equivalents (CO₂-eq) of GHG emissions in 2016. The SWM-GHG calculator, on the other hand, estimated 23,319,370 Mt CO_2-eq of GHG emissions from management of 30,764,000 Mt of MSW in 2016, which included 8% recycling, 2% composting, and 90% disposal in open dumps. To reduce GHG emissions, two strategies including recycling-focused and incineration-focused were analysed. The recycling approach can reduce more GHG emissions than incineration, as it can reduce 36% of GHG emissions (as compared to GHG emission in 2016) by recycling 23% of MSW, anaerobically digesting 10% of MSW, and disposing of 67% of MSW in sanitary landfills (with energy recovery). Moreover, the SWOT analysis suggested integration of the informal sector, adoption of anaerobic digestion and formulation of explicit MSW regulations for improving the current management of MSW which will also result in lower GHG emissions.

Sustainable municipal waste management strategies through life cycle assessment method: A review

Increasing amounts of municipal solid waste (MSW) has gained widely concern on reduction, utilization and minimizing environmental impacts associated with waste management. Life cycle assessment (LCA) has been used to evaluate total environmental impact of municipal waste management (MSWM) options in strategy-planning and decision-making process. The exiting LCA studies have covered a large range of detailed focus from waste treatment technology to applied modelling methods in LCA of MSWM, yet an important concern for stakeholders, the relationship between practical management strategies and their LCA results, has not been comprehensively summarized. This paper reviews recent LCA studies focusing on MSWM system in 45 cases from both developing and developed regions to promote evolution of the MSWM system through modification of waste management strategies. Selected literatures conducted LCA with system boundary covering the whole MSWM system rather than single treatment process or specific type of waste. This review has explored distribution and evolution of LCA studies in waste management field and summarized critical parameters (system boundary, functional unit, assessment approach and data uncertainty) for conducting LCA of MSWM system. Comparison results from 45 worldwide cases indicated 33%-154% environmental benefit in Global warming potential (GWP) impact with implement of integrated solid waste management system to replace single landfill, incineration, or open dumping treatment. Key issues with upgrading of MSWM system have been highlighted to raise concern, i.e., the importance of targeted management strategy on organic and recyclable waste, the growing contribution of waste collection and transportation to the total environmental impact, as well as promoting multi-impacts assessment for MSWM system to achieve environmentally effective, economically affordable, and socially acceptable. Rather than focus on technical factors, results from this study indicated the key influences from understanding local limitation, environmental concern, management chain and comprehensive impact, providing useful strategies on improving MSWM with generalization results of LCA studies.

Testing the Role of Waste Management and Environmental Quality on Health Indicators Using Structural Equation Modeling in Pakistan

Improper management of municipal waste has become a growing concern globally due to its impact on the environment, health, and overall living conditions of households in cities. Waste production has increased because households do not adopt waste management practices that ensure sustainability. Previous studies on household waste management often considered socio-economic aspects and overlooked the environmental and behavioral factors influencing the disposal practices and health status. This study adopted four constructs, defensive attitude, environmental knowledge, environmental quality, and waste disposal, by employing a structural equation modeling approach to explore research objectives. Data from 849 households of the Islamabad-Rawalpindi metropolitan was collected by using a multi-stage sampling technique. The structural model results showed that the two constructs, environmental knowledge and defensive behavior, positively affect household health status. The most significant health-related considerations are waste disposal and environmental quality, both of which negatively impact health status and do not support our hypothesis. The results provide valuable perspectives to enable households to engage actively in waste management activities. The findings indicate that understanding the intentions of household health status drivers can assist policymakers and agencies in promoting an efficient and successful community programmes related to sustainable solid waste management by allowing them to foster how the desired behavior can be achieved.

Life Cycle Impact Assessment of Garbage-Classification Based Municipal Solid Waste Management Systems: A Comparative Case Study in China

Confronted with a series of problems caused by surging generation of municipal solid waste (MSW), the Chinese central and local governments have promulgated and implemented policies to deal with them, including promotions of the classification of MSW. However, to date, practical knowledge and understanding about benefits for garbage classification from its environmental performance perspective is still limited. The present study is purposed to comprehensively investigate the environmental effects of garbage classification on municipal solid waste management (MSWM) systems based on three proposed garbage classification scenarios in China, via a comparative life cycle impact assessment (LCIA). Taking advantage of Impact Assessment of Chemical Toxics (IMPACT) 2002+ method, this comparative LCIA study can quantitatively evaluate midpoint, endpoint, and single scored life cycle impacts for the studied MSWM systems. A Monte Carlo uncertainty analysis is carried out to test the effectiveness and reliabilities of the LCIA results. The LCIA and uncertainty analysis results show that MSWM systems based on various garbage classification scenarios have significant variations in the studied midpoint, endpoint, and single scored environmental impacts. Different garbage classification scenarios have their individual environmental-friendly superiority for specific impact categories. Overall, results of this study demonstrate that MSW treatment systems integrated with garbage classification are more environmentally friendly by comparison with non-classification; and that the more elaborate the level of MSW classification, the smaller its impacts on the environment.

Application of a life cycle assessment for assessing municipal solid waste management systems in Bolivia in an international cooperative framework

Using a life cycle assessment (LCA) to evaluate municipal solid waste management (MSWM) systems is strongly recommended and the approach has been used in high-income contexts. However, stakeholders in low to middle income countries are not aware of the potential of this approach, mainly due to a lack of financial resources and technical ability. The present work introduces a LCA of MSWM system scenarios into a developing city using an academic licence for the LCA software that is available for use exclusively by researchers. The MSWM system in place in 2018 in La Paz (Bolivia) was assessed according to seven scenarios. The novelty of the research is twofold: the use of LCA academic licensing in a low to middle income region where LCA is unknown as planning tool; and discussing the potential of the approach in conjunction with local and international stakeholders with a view to starting MSWM projects. The results of the analysis allow for the consideration of energy recovery and materials recycling as the main methods by which the environmental impact of MSW can be reduced, as has also been reported by other LCA studies conducted with full licensing of the relevant software. Moreover, the research is the basis for cooperative development projects that will adopt the LCA approach as the main assessment tool. The study discusses the importance of cooperation between universities and local governments for implementing new strategies for MSWM assessment and planning. The research is a contribution towards improving technical knowledge in developing countries for boosting sustainable development.

Solid Waste Management Policy Implications on Waste Process Choices and Systemwide Cost and Greenhouse Gas Performance

Solid waste management (SWM) is a key function of local government and is critical to protecting human health and the environment. Development of effective SWM strategies should consider comprehensive SWM process choices and policy implications on system-level cost and environmental performance. This analysis evaluated cost and select environmental implications of SWM policies for Wake County, North Carolina using a life-cycle approach. A county-specific data set and scenarios were developed to evaluate alternatives for residential municipal SWM, which included combinations of a mixed waste material recovery facility (MRF), anaerobic digestion, and waste-to-energy combustion in addition to existing SWM infrastructure (composting, landfilling, single stream recycling). Multiple landfill diversion and budget levels were considered for each scenario. At maximum diversion, the greenhouse gas (GHG) mitigation costs ranged from 30 to 900 $/MTCO₂e; the lower values were when a mixed waste MRF was used, and the higher values when anaerobic digestion was used. Utilization of the mixed waste MRF was sensitive to the efficiency of material separation and operating cost. Maintaining the current separate collection scheme limited the potential for cost and GHG reductions. Municipalities seeking to cost-effectively increase landfill diversion while reducing GHGs should consider waste-to-energy, mixed waste separation, and changes to collection.