Pre-treatment potential of electro-coagulation process using aluminum and titanium electrodes for instant coffee processing wastewater

Hoang Quang Huy Phan (Faculty of Environment - Natural Resources and Climate Change, Ho Chi Minh City University of Food Industry, Vietnam)
Nguyen Xuan Hoan (Faculty of Environment - Natural Resources and Climate Change, Ho Chi Minh City University of Food Industry, Vietnam)
Nhat Huy Nguyen (Faculty of Environment and Natural Resources, Ho Chi Minh City University of Technology, Vietnam)
Nguyen Duc Dat Duc (Faculty of Environment - Natural Resources and Climate Change, Ho Chi Minh City University of Food Industry, Vietnam)
Nguyen Thi Ngoc Anh (Faculty of Environment - Natural Resources and Climate Change, Ho Chi Minh City University of Food Industry, Vietnam)
Nguyen Thi Que (Faculty of Environment - Natural Resources and Climate Change, Ho Chi Minh City University of Food Industry, Vietnam)
Nguyen Thi Thuy (Faculty of Environment - Natural Resources and Climate Change, Ho Chi Minh City University of Food Industry, Vietnam)

Journal of Environment and Sustainability
Vol. 3 No. 3 (2019): pp. 127-212 (December 2019)

This study aimed at investigating the potential of electrocoagulation (EC) process using Al-Al and Al-Ti electrodes for the pre-treatment of instant coffee processing wastewater. Effects of various operating conditions, including cell voltage, time of treatment, inter-electrode distance, pH of solution, solution conductivity and agitation speed on the removals of chemical oxygen demand (COD) and color were considered. The maximum removal of COD and color was achieved at 87% and 99%, respectively, corresponding to COD and color in the effluents of 359-384 mg/L and 58-101 Pt-Co. Biodegradability of treated wastewater was significantly improved since BOD5/COD increased from initial value of 0.42 to 0.65 after treatment. Nether mixing nor adding of electrolyte was recommended. Moreover, the COD removal kinetics during EC process appeared to follow the first-order kinetic model. The operating costs were also determined as a reference for cost assessment of the treatment.