Treatment of Electroplating Cr(VI) for Reduction Cr(VI) by Electrocoagulation in Continuous Operation
The performance of electrocoagulation, with aluminium sacrificial anode, in the treatment of metal ion Cr(VI) containing wastewater, has been investigated. Several working parameters, such as pH, current density and metal ion concentrations were studied in an attempt to achieve a higher removal capacity. Results obtained with synthetic wastewater revealed that the most effective removal capacities of studied metal could be achieved when the pH was kept between 4 and 8. In addition, the increase of current density, in the range 0.8 4.8Adm 2 enhanced the treatment rate without affecting the charge loading, required to reduce metal ion concentrations under the admissible legal levels. The process was successfully applied to the treatment of an electroplating wastewater where an effective reduction of Cr(VI) concentrations under legal limits was obtained, just after 20 min. The electrode and electricity consumptions were found to be 1 g l 1 and 32 A h l 1 respectively. The method was found to be highly efficient and relatively fast compared to conventional existing techniques