Characterization of Landfills Solid Waste in Muscat and Estimation of their Energy Recovery

Abstract

Solid waste management is one of the most important issues faced by the Sultanate of Oman. Disposal of municipal solid waste (MSW) in engineered landfills without any pre-treatment or separation is the only option available. Engineered landfills themselves are still new and their waste properties have not been well studied. A reliable database of the solid waste compositions, properties, and estimated energy content is important and the first stage in an efficient waste management system. This is an essential requirement, notwithstanding the complexity of the investigations in this area and the associated logistical challenges. This study investigates the sort of the MSW from landfills in Muscat Governorate. Muscat MSW samples were gathered from Al Amerat and Barka landfills in 2020. MSW compositions were analyzed in terms of the materials ratios (food, plastics, papers… etc.), followed by investigating the ability of recycling that waste. MSW physiochemical properties of both landfills were studied. Therefore, eleven solid waste samples were collected in February from each landfill. Another eleven solid waste samples were collected from Barka landfill in March 2020. All solid waste samples preparation was done manually, and they were converted from solid into the liquid phase for laboratory analysis. The results demonstrated that about 50% of the weight of disposed waste at both landfills is a recyclable material. MSW biodegradable organic content was high observed. MSW moisture content was observed to be within the range from 21.5 to 43.3%. In addition, MSW volatility and loss of ignition both were on the high sides; between 47.0 and 82.0% and between 56 and 91%; respectively. Total oxides ratio in the MSW were within the range of 12.4 and 44.06%. Silica was the highly influential oxide followed by Calcium Oxide. Furthermore, Muscat MSW found more than 18000 kJ/kg which results in high energy content. Six chemical formulas of the MSW were derived from the waste categories elemental analysis with and without sulfur element. It has been noticed from this study that almost half of Muscat's municipal solid waste can be recyclable. Thus, the recycling industry should be adopted to utilize solid waste for the production of renewable material sources that can be an alternative to oil resources. Moreover, MSW biodegradable portion is high with a suitable degree of moisture content for the composting and biodegradation process. Waste-to-energy technologies are also feasible for Muscat MSW because of their high energy content associated with high volatility.