Scenario analysis of the benefit of municipal organic-waste composting over landfill, Cambodia

Abstract

This paper presents insight into the benefits of organic waste recycling through composting over landfill, in terms of landfill life extension, compost product, and mitigation of greenhouse gases (GHGs). Future waste generation from 2003 to 2020 was forecast, and five scenarios of organic waste recycling in the municipality of Phnom Penh (MPP), Cambodia, were carried out. Organic waste-specifically food and garden waste-was used for composting, and the remaining waste was landfilled. The recycling scenarios were set based on organic waste generated from difference sources: households, restaurants, shops, markets, schools, hotels, offices, and street sweeping. Through the five scenarios, the minimum volume reductions of waste disposal were about 56, 123, and 219 m(3) d(-1) in 2003, 2012, and 2020, respectively, whereas the maximum volume reductions in these years were about 325, 643, and 1025 m(3) d(-1). These volume reductions reflect a landfill life extension of a minimum of half a year and a maximum of about four years. Compost product could be produced at a minimum of 14, 30, and 54 tons d(-1) in 2003, 2012, and 2020, respectively, and at a maximum in those years of about 80, 158, and 252 tons d(-1). At the same time benefit is gained in compost product, GHG emissions could be reduced by a minimum of 12.8% and a maximum of 65.0% from 2003 to 2020. This means about 3.23 (minimum) and 5.79 million tons CO(2)eq (maximum) contributed to GHG mitigation. In this regard, it is strongly recommended that MPP should try to initiate an organic-waste recycling strategy in a best fit scenario.