(716f) Production of Biohydrogen and Valuable Bioproducts Via Anaerobic Fermentation with Engineered Biochars

Organic waste treatment through anaerobic fermentation (AF) is one of the promising options for managing organic waste and recovering bioenergy sources. Biochar (BC), the carbonaceous material (CM) made from thermal conversion of various biomass is proposed as cost-effective and sustainable additive to enhance AF performance because of its low-cost feedstock and physicochemical properties such as specific functional group, high porosity, and high conductivity. In this study, a novel engineered carbon material (calcium-modified BC, Ca-BC) was test for enhancement of AF system along with commercial BC and activated carbon (AC). To explore the effects of each CM on AF, we examined biochemical acid potential (BAP) test with 5g/L of each CM and compared to condition without any additives (Control) under mesophilic and thermophilic condition. Under mesophilic condition, substrate utilization efficiency (SUE) reached 100% in 2 days at BC, followed by 3 days at Control and Ca-BC while AC showed slowest SUE achieving 100% in 4 days. It was interesting to see different final products with various CMs. BC showed the highest H₂ production while Ca-BC showed the lowest H₂ production although all runs achieved 100% of SUE. Meanwhile, under thermophilic condition, Ca-BC only achieved 100% of SUE during the experiment period (8 days), possibly due to its high buffering capacity. Interestingly, Ca-BC showed the lowest H₂ production even though it was the only run to achieve 100% of SUE, which is a similar observation with results under mesophilic condition. These results suggest that the surface properties of CM are crucial factors to determine the major metabolic pathway of fermentative bacteria.