ارزيابي محيط زيستي چرخه حيات سامانه مديريت پسماند شهري (مطالعه موردي: شهر مشهد)

Environmental Life Cycle Assessment of Municipal Solid Waste Management System (Case study: Mashad City)

Solid Waste is one of the unavoidable products of every society that necessitates the establishment of municipal solid waste management (MSWM) system. Because of variability in quantity and composition of municipal solid wastes, the management methods are varied in terms of costs and environmental effects. Choice of the appropriate methods is largely facilitated through a decision support tool (DST). Life Cycle Assessment (LCA) with cradle to grave approach is one such tool that has been introduced in the last decade. In this study, we used this method to study the municipal solid waste management system of Mashad city. We developed three scenarios consisting of direct transport, composting and establishment of transfer stations. Inventory data for life cycle assessment were gathered from relevant literature, completed projects and through questionnaires and field works. The life cycle inventory (LCI) was accomplished using IWM-1 model and the results of the model were allocated to five categories consisting of energy consumption, greenhouse gases, acid gases, photochemical gases and toxic emissions. In every category, the ecological index as a quantitative measure to compare scenarios was calculated. From an environmental view, the results of this study showed that the composting alternative for managing wastes in Mashad city has lower environmental loads. Also, in the case that landfills and processing facilities are far apart, establishment of transfer stations may have important role in decreasing the energy consumption and environmental emissions.