Integrated electrocoagulation-tight ultrafiltration for river water decontamination: The influence of electrode configuration and operating pressure

Abstract

Most rivers have been contaminated by household and industrial wastes that are harmful to human health. In this research, electrocoagulation (EC) and tight ultrafiltration (tight UF) processes were integrated and used to treat the contaminated river water. The EC reactor was designed and equipped with an agitator system. The EC system was operated in continuous mode at a constant flow rate of 500 mL.min−1. Meanwhile, the tight UF membrane was polysulfone-based, which had a tight structure in the surface layer. The influence of applied current in two configurations of electrodes and the operating pressure of the membrane system was investigated. It was found that a high effluent quality was achieved when 4 anodes and 2 cathodes were used in the EC reactor at a current density of 7.4 mA.cm−2 and operating pressure of 15 psig in the tight UF membrane. The removal efficiency of the integrated EC-tight UF in reducing TDS, turbidity, BOD, and COD was 72.20%, 99.11%, 94.35%, and 81.55%, respectively. Operating cost of 0.83 US$.m−3 was achieved when the water production capacity of the EC-UF plant was designed for 150 m3.d−1, a current density in EC system of 7.4 mA.cm−2, and permeate flux in the tight UF membrane system was 50 L.m−2.h−1. The operating cost was decreased to 0.49 US$.m−3 when the production capacity was increased to 600 m3.d−1.

Keywords

• Clean technology
• Contaminated water treatment
• Electrocoagulation
• Hybrid system
• Tight-ultrafiltration