In combination of all experiments, the optimum operating conditions were achieved as iron electrodes, current intensity of 3A, electrolysis time of 40 min, the raw pH with iron electrodes, resulting the maximum COD removal efficiencies of %. As a result, the electrocoagulation can be applied to leachate pre-treatment. | Vietnam Journal of Science and Technology 55 (5) (2017) 540-547 DOI: EFFECT OF SOME EFFECTIVE PARAMETERS ON COD REMOVAL FROM NAM SON LANDFILL LEACHATE BY ELECTROCOAGULATION Le Thanh Son1, *, Le Cao Khai2, Doan Tuan Linh1, Doan Thi Anh1 1 Institute of Environmental Technology, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet Road, Cau Giay District, Ha Noi, Viet Nam 2 Faculty of Chemistry, Hanoi Pedagogical University No2, Nguyen Van Linh Street, Xuan Hoa Ward, Phuc Yen, Vinh Phuc, Viet Nam * Email: Received: 15 February 2017; Accepted for publication: 28 July 2017 ABSTRACT Leachate becomes ahead of wastewaters as being the most difficult to treat due to its complex and widely variable composition. In this research, the leachate treatment performance by electrocoagulation (EC) was studied. The samples of leachate were taken from Nam Son landfill in Hanoi. The effects of factors namely current intensity, electrolysis time, initial pH and anode materials on the EC performance were investigated via chemical oxygen demand (COD) removal efficiencies. The input leachate properties were obtained as COD, NH4+ and pH in the range of around 6247 ± 295, 1270 ± 38 mg/l and 8 ± , respectively. Mono-polar electrocoagulation unit was set up in a batch system for leachate treatment with iron electrodes and approximately litter of leachate. Firstly, with the increase in current (1 to 4A), the COD removal efficiencies increased from to % (pH = 8 and operating time = 40 min). Secondly, by the increase in operating time, the treatment performance also went up significantly in first 40 min, then nearly level-off at above 73 % (pH = 8, current intensity = 3A). In addition, the effect of pH in range of 5 to 10 on the electrocoagulation process was studied and it showed the highest treatment efficiencies in neutral and mild alkaline medium, especially between 6 < pH < 8. Finally, the electrode .
