A Renewable Energy Application to the Electrochemical Reactor in the Treatment of Metal Cutting Wastewater: Double Criteria Optimization of Process

Electrochemical wastewater treatment methods are effectively used for all type of wastewaters and pollutants. One of the huge negative impact of these processes is the energy consumption of the process. Therefore, the goal of the study is to develop a minimal energy user Electrocoagulation (EC) option with an integration of a direct photovoltaic solar panel as a subsection of electrochemical processes for the degradation of low COD (Chemical Oxygen Demand) from metal cutting wastewater. To optimize the operating parameters of the EC process such as pH, current density (C.D.) and electrolysis time (E.T.) Box-Behnken Design by RSM was used with a double criterial optimization option. COD removal and energy consumption were evaluated as responses of the model and they were well-fitted with the quadratic model. Also, it was determined that all parameters are effective on EC process. Optimum conditions were found at a pH of 7.48, a C.D. of 30 A/m2, an E.T. of 65 min, an energy consumption of 3.9 kWh/m3 and a desirability of 0.954. At the optimum conditions, the energy consumption of the EC process was fulfilled from solar panel in a ratio of 71% and 1495% in overcast and sunny weather, respectively. Especially, the energy obtained by the solar panel in the sunny weather produces much more than the energy required of the process.