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Comparative analysis of conventional coagulation and electrocoagulation for polluted water treatment
1  Department of Sanitary and Environmental Engineering, Faculty of Engineering, Universidade do Estado do Rio de Janeiro/UERJ, Rio de Janeiro/ RJ 20550-013, Brazil
Academic Editor: Carmen Teodosiu

Abstract:

This work investigates the chemical coagulation (CC) and electrocoagulation (EC) processes for polluted water treatment. Polluted synthetic water was prepared (pH = 7, 365─357 mg Pt-Co L-1). Jar tests were conducted using aluminum sulfate as a coagulant (100 – 1600 mg Al2(SO4)3 L-1, pH = 4 – 9). The EC test was performed using a lab-scale device. The EC set-up was installed for the first time in the Sanitary and Environmental Engineering/ Uerj laboratory course. The students performed all the experiments. Aluminum electrode plates (15 x 3 x 2 cm) were connected in parallel, and a distance of 30 mm was maintained. The treatment performance was evaluated based on true color removals. Operating costs were calculated based on chemical utilization for CC (aluminum sulfate and sodium carbonate) and EC energy consumption under optimum conditions. Removal efficiencies of 94% and 88% were obtained in CC (pH = 7 and 800 mg Al2(SO4)3 L-1) and EC (pH = 7, 350 mA, and 40 min), respectively. The operating costs of CC and EC were estimated at 0.130 and 0.583 US$ m-3. As expected, the EC process had higher operating expenses than the CC process. However, EC may be attractive in remote settlements since modular and efficient systems are needed to guarantee drinking water production. No chemicals are required in this process; the treatment is automated, and less sludge is generated. The utilization of alternative energy sources can increase EC's cost-effectiveness. Future studies will focus on integrating EC and membrane-based treatments in modular set-ups. Decentralized water treatments can promote safe potable water, sanitation, and hygiene (WASH) in remote sites. Safe WASH is a prerequisite to health and the development of resilient communities.

Keywords: Costs; Drinking water; Polluted water; Treatment, WASH

 
 
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