Removal of phenols and COD from petroleum refinery wastewater using electrocoagulation method

Abstract

This study investigates the possibility of removing phenols and chemical oxygen demand (COD) from petroleum wastewater (refinery wastewater) using an electrocoagulation (EC) reactor supplied with aluminium electrodes. The influence of current density (CD) (4 to 12 mA/cm2), distance between electrodes (DBE) (20 to 40 mm), and treatment time (T) (up to 120 min) was investigated by carrying out several sets of batch flow experiments. The concentrations of COD and phenols were measured using the Hach-Lang spectrophotometer and standard cuvette tests (LCK 514, LCK 314, or APC 400 for COD, and LCK 346 or LCK 345 for phenols (according to the residual concentration). The results of the present study confirmed the ability of the electrocoagulation method to reduce the concentrations of both phenols and COD in petroleum wastewater within a relatively short treatment time. It has been found that the best removal efficiency of COD and phenols were 80% and 58%, respectively. The best removal efficiency was attended, after 100 min of electrolysing, at CD of 8 mA/cm2 and DBE of 20 mm.