Optimization of copper and nickel removal by electrocoagulation through a recirculation flow bipolar reactor: statistical modeling.

Heavy metals have a detrimental effect on human health and environment if not managed efficiently. For this reason, industrial wastewaters are strictly regulated and have to be treated before being discharged. The efficiency of bipolar reactor with recirculation flow mode and aluminum electrode in removing copper and nickel from high concentrated solution by electrocoagulation was examined. The experimental design (Box-Behnken) was employed to investigate the effects of different operating conditions and their interactions on the removal: electrolysis time (t, min), current density (i, A/m²), pH, and initial concentration (Ci, mg/L). The results showed a high removal rate (97.42% for copper, and 100% for nickel), and also a good correlation between the values measured and those predicted by the Box-Behnken experimental design, for the removal of copper (R² = 0.94, P value = 0.0003) as well as of nickel (R² = 0.95, P value = 0.0001). [ABSTRACT FROM AUTHOR]