The Effect of Light on Anaerobic Digestion Process of Household and Similar Waste under Mesophilic Regime

Anaerobic digestion is a promising technology that allows the production of biogas from different waste sources. Numerous studies have been conducted to optimize the production of methane-rich biogas, most of these studies have been carried out with anaerobic digestion systems operating under conditions of total darkness. Therefore, little is known about the effect of light on anaerobic digestion processes. The present work aims to study the photosynthesis-assisted anaerobic digestion of municipal solid waste with an average light intensity of 500 lux, provided by natural and artificial light continuously. The effect of light on biogas production and composition was studied. The results showed for the lighted digester, a low biogas production as well as a low methane content of about 0.11 l/d and 51 %, respectively, which represents a reduction of 40% in biogas and a 21.5 % in methane, compared to the unlighted digester.