Digested Slurry Recirculation in Thermophilic Wet Anaerobic Digestion of Dairy Manure without Water Dilution

Abstract

Wet anaerobic digestion is functioned with substrate contains high moisture content. In the case of substrates from stanchion barn, the mixing of bedding with manure increases total solids content (TS). Thus, large amount of water is required to dilute the mixture before its use in wet anaerobic digestion. In this study, the use of digested slurry recirculation in a wet anaerobic digestion without water dilution was examined. Continuous wet anaerobic digestion of dairy manure at a temperature of 55°Cwas carried out. The TS of dairy manure was adjusted using filtrated digested slurry. The obtained results show that the use of digested slurry to replace water in wet anaerobic digestion of dairy manure was effective.