Analytical Hierarchy Process-Based Decision Making for Sustainable MSW Management Systems in Small and Medium Cities

Abstract

MSW management (MSWM) has become a crucial issue. To evaluate MSWM systems, several models have been developed and these models were mostly used for large cities only while a few were found for small and medium cities. There is no single optimal MSWM system that can be applied to both large and small cities since they have different characteristics. Evaluation of suitable MSWM systems for small and medium cities is very vital as decisions made at an early stage can have significant impacts at later phases as cities grow. In this study, MSWM systems evaluated by using the analytical hierarchy process (AHP) through pair-wise comparison matrices by 11 stakeholders from five groups, i.e., governmental, academic, technical, local authority, and NGOs. This study identified four main criteria (environmental, social, economic, and technical), and 12 sub-criteria (diversion from landfill, GHG emissions, environmental impacts, capital cost, O&M cost, revenue and benefit, public acceptance, creation of jobs, simplicity, maturity, and local equipment) to be simultaneously considered for selecting the most suitable MSWM systems among eight alternatives, i.e., mechanical biological treatment combined with composting (MBT-CP), mechanical biological treatment and recycling (MT-Re), landfill (LF), anaerobic digestion (AD), incineration (IC), gasification (GF), mechanical treatment combined with refuse-derived fuel (MT-RDF), and landfill gas (LFG). It was found that stakeholders prefer the environmental aspect as being the most important followed by social consideration, economic, and technical aspects and focus more on strong sustainability. Public acceptance is the most important sub-criteria preferred by stakeholders followed by environmental impacts and diversion from landfill. The most suitable MSWM system is the MBT-CP for medium city and MT-RDF for small city, while LF and LFG were identified as the worst options. This indicates that stakeholders prefer the waste-to-resource (WTR) scheme than waste-to-energy (WTE) to achieve sustainable MSW management in Thailand.