Treatment of vegetable oil refinery wastewater by electrocoagulation

Abstract

The purpose of this work was to perform laboratory-scaled electrocoagulation experiments using iron electrodes to obtain discharge quality of the effluent from the vegetable oil refinery wastewater (VORW), which meets the regulation requirements without any pre- or additional treatment. The influences of initial pH, current density, distance between the electrodes and type of electrode connection (parallel or series) on the removal efficiency of COD, as well as specific energy consumption were evaluated. It has been shown that the removal efficiency of COD increased with increasing applied current density and distance between the electrodes, but decreased with increasing initial pH. The initial COD concentration of 25000 mgL(-1) was reduced to 167 mgL(-1) (corresponding to 99.3% removal), which complied with legal requirements with the running cost of 3.64 (sic)(kg COD)(remobed)(-1) after 1-h electrocoagulation at the conditions of 25 mAcm(-2) and pH 3.