Mechanism of combination membrane and electro-winning process on treatment and remediation of Cu 2+ polluted water body

Abstract

Mechanism of treatment and remediation of synthetic Cu 2+ polluted water body by membrane and electro-winning combination process was investigated. The influences of electrolysis voltage, pH, and electrolysis time on the metal recovery efficiencies were studied. Relationship between trans-membrane pressure drop (Δ P), additions ratio, initial Cu 2+ concentration on operating efficiency, stability of membrane and the possibility of water reuse were also investigated. The morphology of membrane and electrodes were observed using scanning electron microscopy (SEM), the composition of surface deposits was ascertained using combined energy dispersive X-ray spectroscopy (EDX) and atomic absorption spectrophotometer. The results showed that using low pressure reverse osmosis (LPRO), Cu 2+ concentration could increase from 20 to 100 mg/L or even higher in concentrated solutions and permeate water conductivity could be less than 20 μS/cm. The addition of sodium dodecy/sulfate sodium dodecyl sulfate improved Cu 2+ removal efficiency, while EDTA had little side influence. In electro-reduction process, using plante electrode cell, Cu 2+ concentration could be further reduced to 5 mg/L, and the average current efficiency ranged from 9% to 40%. Using 3D electrolysis treatment, Cu 2+ concentration could be reduced to 0.5 mg/L with a current efficiency range 60%–70%.