Hybrid and combined electro-oxidation and peroxi-coagulation processes in effective treatment of textile reverse osmosis concentrate

Abstract

In this study, the treatment of reverse osmosis concentrate from a textile industry by hybrid and combined electrochemical processes was investigated. Firstly, the operating parameters of single electro-oxidation (EO) and peroxi-coagulation (PC) processes were optimized, and then the performances of hybrid EO-PC, PC-EO, and combined EO/PC processes were evaluated in pollutant removal under optimum conditions. Optimum conditions for processes were determined as pH: 5, 22.5 mA/cm2, inter-electrode distance: 3 cm, 120 min. Removal efficiency of chemical oxygen demand (COD) for the optimum conditions of EO, PC, EO-PC, PC-EO, and EO/PC were 78.5 %, 73.0 %, 73.8 %, 82.0 %, and 91.9 %, respectively. Specific energy consumption of EO, PC, EO-PC, PC-EO, and EO/PC processes were 61.9, 74.0, 64.0, 60.9, and 56.8 kWh/kg COD, respectively. The EO/PC process was the most effective and feasible one among applied single, hybrid, and combined processes. With the EO/PC, reverse osmosis concentrate met the receiving environment discharge criteria.