Sustainability evaluation framework for food waste composting

Abstract

The high rate of population growth and industrial development have led to a significant increase in the production of municipal solid waste (MSW) worldwide. The authorities have been facing significant challenges to materialise a sustainable framework of solid waste management, especially for food waste (FW). This study aims to develop a sustainability evaluation framework for FW composting. A case study of an existing FW composting plant in Minhang District, Shanghai, China was used as the basis for the framework development and evaluation of its potential impacts from environmental and economic perspectives. The environmental impact focuses on the greenhouse gas (GHG) emissions that were analysed through life-cycle inventory methodology in terms of carbon dioxide equivalent (CO2 -eq.) while the economic feasibility (EF) is evaluated using cost-benefit analysis (CBA). The sensitivity analysis for composting was also conducted to determine the critical economic factors that will impact the EF of the composting process. Based on the evaluated framework, the results showed that the FW management contributed to 32,988 kg CO2 -eq. of GHG emissions from the overall composting operation. The composting operation also provided -7,962 kg CO2 -eq. of GHG reduction from compost application on farmland, although insufficient to offset the overall GHG emissions. The CBA showed that the plant is financially viable, with net present worth of, in Chinese yuan, CNY 362,204,575 due to optimum compost selling price to generate profit. The sensitivity analysis revealed that the compost selling price significantly affected economic performance among other economic factors, such as labour, fuel price, and subsidy. The sustainability evaluation framework for FW composting was proposed to show how it can be considered as a guideline for the policymakers and local government to improve FW management via composting in the developing countries, especially Malaysia.