Frameworks for reducing greenhouse gas (GHG) emissions from municipal solid waste in Oman
Authors: Umar Tariq 
Published: May 2020

PurposeThe Gulf Cooperation Council member countries not only generate the highest quantity of municipal solid waste (MSW) per capita when compared globally, but also in most of these countries, such waste is just dumped at different landfill stations. In Oman, the total quantity of MSW stood at 2.0 million tons per year. The emission from this waste is estimated at 2,181,034 tons/year (carbon dioxide equivalent). This article attempts to develop frameworks that considered landfilling, composting and recycling of MSW.Design/methodology/approachTo know the composition of the municipal solid waste in Oman, a quantitative research method was employed. The greenhouse gas (GHG) emissions from MSWM in this study focus on three major gases, CO2, CH4 and N2O. The Intergovernmental Panel on Climate Change (IPCC) 2006 model is used to calculate GHG emissions from landfills and composting (IPCC, 2006). Four frameworks – baseline F0, framework F1, framework F2 and framework F3 – are outlined in this paper. The F0 represents the current situation of the MSW in which most of the waste goes to landfills and dumpsites. In F1, improved MSW collection service and landfilling are incorporated and open burning is restricted. The F2 considered landfilling and composting, while F3 is based on landfilling, composting and recycling.FindingsThe framework F2, which proposes the composting process for the organic waste which normally goes to landfills, results in the reduction of emissions by 40% as compared to landfill practice. Similarly, the samples of MSW collected in Oman show a good amount of recycling waste. The framework F3, which considers the landfill, composting and recycling, reduced the total GHG emissions from 2,181,034 tons/year to 1,427,998 tons/year (carbon dioxide equivalent), representing a total reduction of 35% in emissions.Research limitations/implicationsDifferent values such as CH4 correction factor, the fraction of degradable organic carbon and the fraction of DOC used to determine the GHG emissions from MSW considering landfilling, composting and recycling based on the IPPC model and existing literature review. The actual determination of these values based on the Oman conditions may result in more accurate emissions from MSW in Oman.Practical implicationsDifferent frameworks suggested in this research have different practical implications; however, the final framework F3, which produces fewer emissions, required a material recovery facility to recycle the MSW in Oman. For framework F3, it is important that the residents in Oman have enough knowledge and willingness to do the waste segregation at the household level. Apparently, such knowledge and willingness need to be determined through a separate study.Originality/valueThe frameworks F2 and F3 are considered to be more suitable solutions compared to the current practices for Oman and other gulf countries to reduce its per capita emissions from MSW and protect its local environment. There is a potential for further work that needs to explore the possible solutions to implement the suggested frameworks.