Removal of Cr (VI) from contaminated waters by electrocoagulation process

The present study deals with the removal of Cr(VI) from solution by electrocoagulation (EC) process. The influence of operational parameters such as initial concentration, current density, initial pH and concentration of electrolyte on the electrocoagulation were investigated. The iron electrode was more effective than aluminum electrode. Because the electrochemical reduction of chromate ions by Fe2+ , produced from anod, is the important step in the removal of chromate. Our results revealed that, the removal efficiency was considered being affect by key factor of the current density. For a solution of 50 mg/l Cr(VI), almost 98% Cr(VI) were removed, when the pH was about 5, the time of electrolysis (tEC) was 25 min and the current density was 50A/m2. Also removal of Cr (VI) by EC in the presence of different supporting electrolytes such as NaCl, Na2SO4 and NaNO3 was studied. When NaCl was added as supportive electrolyte maximum removal efficiency was achiehved.