Enhanced biogas production from penicillin bacterial residue by thermal-alkaline pretreatment

In this study, the orthogonal experimental design was used to determine the optimum conditions for the effect of thermal-alkaline pretreatment on the anaerobic digestion of penicillin bacterial residue. The biodegradability of the penicillin bacterial residue was evaluated by biochemical methane potential tests in laboratory. The optimum values of temperature, alkali concentration, pretreatment time and moisture content for the thermal-alkaline pretreatment were determined as 70 degrees C, 6% (w/v), 30 min, and 85%, respectively. Thermal-alkaline pretreatment could significantly enhance the soluble chemical oxygen demand solubilization, the suspended solid solubilization and the biodegradability. Biogas production was enhanced by the thermal-alkaline pretreatment, probably as a result of the breakdown of cell walls and membranes of micro-organisms, which may facilitate the contact between organic molecules and anaerobic microorganisms.