Experimental and kinetic study on anaerobic digestion of food waste: The effect of total solids and pH

Abstract

This paper presents the results of laboratory experiments carried out on an anaerobic digestion of food waste with respect to the effect of solid concentration and pH. Total solid (TS) content ranging from 5.0% to 15.0% and pH value ranging from 5 to 9 were analyzed. Laboratory scale experiments using 2 l bioreactors were performed in batch mode operated at mesophilic temperature condition with a hydraulic retention time of 30 days. The cumulative volume of biogas produced was used to measure the reactor performance. The methane and carbon dioxide composition of the gas produced was measured using infra-red gas analyzers. The kinetics of biogas produced has been predicted using three different models (Gompertz model, modified Gompertz model, and Logistic model). The experimental results showed that the solid concentration 7.5% of TS and 7 pH produced a maximum biogas yield. The kinetic study showed that modified Gompertz model produced perfect goodness of fit and root mean square error when compared to other two models.