Abstract
Effect of pretreatment by electrochemical oxidation on anaerobic digestion of waste milk and dairy manure was investigated in this study. Dairy farming discharges waste milk with dairy wastewater from a milking parlour. Anaerobic digestion is a major treatment method for manure and wastewater in livestock area. Milk fat is considered to be the main limiting component of the kinetics of dairy waste anaerobic digestion. It is known that the long-chain fatty acids (LCFAs) that are formed during the biodegradation of milk fat inhibit anaerobic bacteria. We discussed the effect of electrochemical oxidation as a pretreatment process on anaerobic digestion of waste milk. Concentrations of LCFAs in milk were decreased by electrochemical treatment using a DSA anode. The inhibition was observed on anaerobic digestion with 50 % inoculum, 35 % dairy manure and 15 % non-pretreated milk. The methane production was increased on anaerobic digestion by electrochemical treatment of milk using a DSA. The results suggested that anaerobic biodegradability for waste milk was improved by electrochemical oxidation using DSA.
