Mesophilic anaerobic co-digestion of cheese whey with cow manure in batch reactor

Abstract

Anaerobic digestion is a biological process that takes place under very strict operating conditions, including a pH close to neutrality. This experimental work aims to study the effect of pH control on CH4 production in mesophilic anaerobic co-digestion of cheese whey with cow manure. Two experiments were conducted in batch reactor, the first without pH adjustment and the second with pH adjustment. The results of the first co-digestion revealed an inhibition of the methanization process by acidification of the medium and accumulation of volatile fatty acids; whereas during the second co-digestion with pH adjustment by sodium bicarbonates (1M), the process was improved with methane levels (> 50%) in the biogas. The accumulated biogas volume was two times higher for the same operating time in the digester.