Electrocoagulation Treatment of Turbid Petrochemical Wastewater

Abstract

Electrocoagulation is an electrochemical process that has proven to be effective for wastewater treatment and water purification. Despite the high efficiency and environmental friendliness of the process, high capital and operating costs have made its application in industrial scale not encouraging. To make the process practicable in industrial wastewater treatment plants, solution needs to be found especially to energy consumption problem which contributes to high operating cost of the process. Therefore, this work investigates the factors that affect the energy consumption and efficiency of an electrocoagulation process used for removal of turbidity from petrochemical wastewater. The batch experiments were carried out by varying the values of current density, NaCl concentration and electrolysis time between 7.55 mA/cm 2 - 21.64 mA/cm 2 (0.4- 1.2A), 0.5 g/L - 2 g/L and 5 min-30 min respectively. The results showed that removal efficiency and energy consumption were largely affected by current density and electrolysis time. Moreover, the addition of supporting electrolyte decreased the energy consumption, but concentration beyond 1 g/L NaCl had no further effect on it. Under the operating conditions of 21.64 mA/cm 2 , 2 g/L NaCl and 30 min electrolysis the maximum turbidity removal efficiency was 97.43 %.