Food Waste Co-Digestion with Microwave Pre-Treated Sewage Sludge to Enhance Biogas Production Through Anaerobic Digestion

Abstract

Malaysia has been experiencing rapid growth in population, massive development in industrialization and urbanization. It has resulted in the generation of a greater amount of wastes. Usually, the solid wastes are disposed at landfills, which are mostly saturated and overloaded with solid wastes, but, due to the scarcity of land and public complaints, making the building of new landfill almost impossible, hence the disposal of MSW is one of the major environmental issues faced by the country. Meanwhile, in the sewerage industry, sludge that is high in embedded energy is generated and it can be used to produce methane through anaerobic digestion especially in the modern mechanized sewage treatment plant (STP). However, the secondary thickened sludge (STS) is a poor substrate for anaerobic digestion. Studies have shown that the digestibility of STS can be improved my pre-treatment methods such as microwave pre-treatment prior to the anaerobic digestion. Besides that, co-digestion is an effective way to overcome the low biodegradability of STS which also promotes an environmentally and an ecologically friendly way to dispose of the food wastes. Also, it can be used to produce renewable energy which could reduce the dependency on fossil fuel for power generation. Moreover, it also can deliver beneficial synergies for the sewage industry and the MSW industry. This work elucidates the preliminary investigation of the potentials of co-digestion of microwave pre-treated STS and food waste and its effect on biodegradability and methane yield, which proposes a sustainable management of solid waste generated in urban areas while harnessing the resources to generate green electricity.