Biofuel Produced from Solid-State Anaerobic Digestion of Dairy Cattle Manure in Coordination with Black Soldier Fly Larvae Decomposition

Abstract

This study was conducted to evaluate the feasibility of applying a two-step biological treatment process, solid-state anaerobic digestion (SSAD) and black soldier fly larvae (BSFL) composting, for the treatment of dairy cattle manure. Biogas from the SSAD of dairy cattle manure, and the digestate of SSAD was fed to BSFL. In turn, BSFL can be fed to animals as a protein supplement. Adjustment of the pH and 30% inoculation ratio (IR 30 ) during SSAD produced the highest theoretical methane yield, 626.1 ± 28.7 L CH 4 /kg VS des with an ultimate methane yield of 96.81 ± 2.0 L CH 4 /kg VS load . For BSFL composting, the groups with a feeding rate of 75 and 100 mg/day/larvae had the highest body weight change, which was 969.6 ± 28.4% and 984.1 ± 177.6%, respectively. The combination process of SSAD and BSFL composting increases the incentive for dairy cattle manure treatment instead of conventional composting and produced more valuable products. © 2019 by the authors.