Optimization of trace elements using response surface methodology (RSM) for biogas production in dry anaerobic digestion

he effect of trace elements (Fe、Co and Ni) on mesophilic dry anaerobic digestion was investigated in this study. Response surface methodology (RSM), based on a three-level Box-Behnken Design with the Design-Expert Software, was employed in order to obtain the optimal concentrations of trace elements. The experiment results demonstrated that the optimized concentrations of trace elements were 15.0 mg FeoL-1, 1.0 mg CooL-1, 1.2 mg NioL-1, respectively. Under the optimized condition, the maximum accumulated biogas reached 7895.28 mL in mesophilic dry anaerobic digestion, which was consistent with the predicted value by the second-order polynomial model.