Abstract:In this study, an orthogonal test was used to investigate the effects of factors including the NaAc concentration, buffer concentration, applied voltage, and agitation speed on the removal efficiency of sodium acetate and gas production rate in a microbial electrolysis cell(MEC). The results of range analysis show that each factor was positively related to the removal efficiency of sodium acetate and the gas production rate. The results of variance analysis show that the factors are ranked in the following descending order according to their effects on the degradation of sodium acetate: the NaAc concentration, agitation speed, applied voltage, and buffer concentration; and according to their effects on the gas production rate, the factors are ranked in the following descending order: the applied voltage, buffer concentration, NaAc concentration, and agitation speed. The MEC had optimal performance with a sodium acetate removal efficiency of 98. 2% and a gas production rate of 0. 148 m3/(m3·d)under the optimal conditions of the NaAc concentration of 1. 5 g/L, the buffer concentration of 50 mmol/L, the applied voltage of 0. 9 V, and the agitation speed of 1000 r/min. This study shows that the operation conditions of the MEC could be optimized in terms of treatment efficiency or economical efficiency. For example, increasing the agitation speed, applied voltage, and buffer concentration could enhance the NaAc removal efficiency to some extent, and decreasing the agitation speed could result in a similar gas production rate with reduced energy consumption.