Optimization of an Electrocatalytic Membrane Reactor for Phenolic Wastewater Treatment by Response Surface Methodology

Qiqi Guan, Hong Wang, Jianxin Li, Xianhui Li, Yang Yang, Tonghua Wang



A TiO2 loading carbon membrane called TiO2/carbon electrocatalytic membrane as anode and a stainless steel mesh as cathode constituted an electrocatalytic membrane reactor (ECMR) to treat phenolic wastewater. A synthetic phenol wastewater as the feed was prepared by mixing 10.0 mM phenol and electrolyte (Na2SO4) with the concentration of 15  g/L. A systematic experimental design based on the response surface methodology was used to optimize the operating conditions of ECMR. The effects of three-level-four-factors including current density, residence time, pH and temperature and their mutual interactions on the removal rate of COD were investigated. The results showed that two variables of residence time and current density have significant effect on the COD removal rate of phenolic wastewater. The removal rate of COD obtained by the model would be 82.23 % at the optimized conditions: current density of 0.33  mA/cm2, residence time of 4.77 min, pH of 5.56, temperature of 36.65 °C. The COD removal rate obtained by the experiment was 82.31 %. The experimental results were in good agreement on the predicted value obtained. The energy consumption of ECMR was 0.32 kWh/kg COD during the treatment of 10.0 mM phenolic wastewater at the optimal parameter conditions.

Keywords: Electrocatalytic membrane reactor; phenolic wastewater; response surface methodology; TiO2/carbon membrane; chemical oxygen demand (COD)