Treatment of Palm Oil Mill Effluent by Electrocoagulation with Aluminium Electrodes

Electrocoagulation is a treatment method that has the potential in removing various pollutants without generating secondary pollutants which only involves simple and compact equipment. In this study, the potential to treat palm oil mill effluent using an electrocoagulation process was studied. The objectives of the study are to determine the optimum current density, the optimum retention time, and the optimum initial pH of the sample for the electrocoagulation of palm oil mill effluent using aluminium in terms of removing chemical oxygen demand, suspended solids and colour of the palm oil mill effluent. The palm oil mill effluent samples were collected from Pertubuhan Peladang Negeri Johor palm oil mill. The range of current density, retention time and initial pH used to obtain the optimum value were 20-100 A/m 2 , 10-30 minutes, and 2-10, respectively. The distance between the electrodes and settling time were kept constant at 5 cm and 30 minutes, respectively. The sludge volume and the variability of pH changes throughout the electrocoagulation process were also studied. Results show that the optimum conditions for the electrocoagulation process using aluminium- aluminium electrode pair are current density of 80 A/m 2 , retention time of 15 minutes, and initial pH of 4. This optimum condition was able to reduce chemical oxygen demand, suspended solids, and colour up to 72.75%, 96.93%, and 92.79%, respectively. At the end of electrocoagulation, the sludge volume obtained was 27.27% and pH was increased from 4.00 to 4.38. It can be concluded that the electrocoagulation process has the potential to be utilized for effective removal of chemical oxygen demand, suspended solids and colour of the palm oil mill effluent.