Treatment Mechanisms and Operation Conditions of Arsenic Removal from Copper Smelting Effluent using Combined Process of Aeration Micro-electrolysis and Flocculation

An effective combined process of aeration micro-electrolysis and flocculation was utilized to treat arsenic that incoming contaminate level was 153 mg.L-1 from the metallurgical effluent. Treatment mechanisms and operation conditions were discussed which influenced the removal efficiency of arsenic. Under the optimal technological conditions, it was found that the removal efficiencies of COD and As were 92.5% and 99.7% respectively. The remain arsenic concentration in the treated wastewater was only 0.43mg.L-1 and met National Wastewater Discharge Standard(GB8978-1996) in China. Analysis by SEM and EDS revealed that using combined process, most of As(III) could be oxidized to As(V), which led to the high efficiency of arsenic removal. In the meantime, most of other heavy metals, such as Cu, Pb and Ni, had been removed. Therefore, the combined process is regarded as a promising technology in the treatment of arsenic from copper smelting effluent. It has bright future in application.