Treatment of Palm Oil Mill Effluent by Electrocoagulation Process

The purpose of current study was to examine the ability of electrocoagulation in decreasing chemical oxygen demand (COD) and total suspended solid (TSS) constituted in palm oil mill effluent. Bench-scale batch reactor containing two aluminum or steel plates (10 cm width x 30 cm height with 0.1 cm thickness) serving as electrodes with the interval distance of 3 cm was set up. The wastewater with COD concentration of 68,425 mg L-1 was treated in the reactor under the varied direct currents (0.3-1.3 A) and contact time (30-120 min). Sodium chloride was added to the wastewater to obtain the final concentration of 2 g L-1 (conductivity of 10 ms) prior to being fed into the reactor. The results showed that higher treatment efficiency when the aluminum was used as electrodes compared to the steel. COD removal efficiency was directly proportional to the contact time. The maximum COD and TSS removal observed at 1.3 A current input and 60 min contact time are 74.1 and 77.0%, respectively.