Electrochemical precipitation of chromium (Cr6+) from an electroplating wastewater

摘要: This research was conducted in the laboratory to investigate an alternative of Cr removal from electroplating wastewater using electrochemical precipitation (ECP) process. The ECP unit consisted electrolytic cell made two steel plates representing anode and cathode. DC power source applied had current (I) electrical potential (E) 3-6 A 30-75 V, respectively. Electroplating used experiments contained 6+ range 215-3860 mg/l, pH 1.5. parameters varied during were: E, hydraulic retention time (HRT), concentration, conductivity initial pH. optimum conditions found were potential, 75 V; current, 4.8 A; HRT, 50 min; pH, above 3.2. Under these conditions, concentrations remaining effluent less than 0.2 mg/l. Sludge produced a sludge volume index (SVI) 60-80, indication settleability. X-ray fluorescence analysis revealed formation Fe 2 O 3 FeCr 4 as main products. Power consumption be 14.7 - 20 kWh/m wastewater. economics process evaluated compared with some conventional treatment processes for removal.