Resumen
Malaysia was the second largest palm oil producer in the world after Indonesia. Palm oil offered a wide range of applications in different industries, particularly the food and consumer goods sectors. Processing of palm oil produced palm oil mill effluent (POME), a type of wastewater consisting a great amount of organic matter. It would affect the water quality when it was discharged into waterways due to its high chemical oxygen demand (COD) nature. The discharged POME failed to meet the requirements stipulated by Department of Environment and it caused adverse impact to the surrounding and environment, especially the aquatic ecosystem. Thus, this study investigated the alternative POME treatment method using electrocoagulation (EC). The main objective was to evaluate the efficiency of electrocoagulation, in particularly, reduction of chemical oxygen demand in POME. The effect of current density and stirring speed on electrocoagulation process were studied. The experiment was conducted in bench scale with reaction time of 30 min by using zinc plate electrode. POME sample of 140 mL was treated in batch mode. The current densities tested were 33.33, 50 and 66.67 mA/cm2 while the stirring speed examined were 100, 150 and 200 rpm. After the experiment was conducted, the results obtained showed that the COD removal efficiency improved with increasing current densities. However, it decreased with the increase of stirring speed. The optimum conditions obtained for electrocoagulation process were determined as 66.67 mA/cm2 and 100 rpm. The highest COD percentage reduction achieved was 96.78 %. Thus, this study proved that the proposed electrocoagulation method was effective in extracting the pollutants from POME and successfully reduced the COD level.