Pollutant removal from tannery effluent by electrocoagulation

An electrocoagulation laboratory scale system was studied for the removal of organic and inorganic pollutants from a wastewater of leather finishing industrial process. In order to obtain optimal values of the system state variables, a fractional factorial 2(3) experimental design was applied. The electrocoagulation process response was evaluated on the basis of chemical oxygen demand (COD), turbidity, total suspended solid, total volatile solid, and elements concentration values. The interactions between initial pH and electrolysis time, as well as between initial pH and current density were significant only for the total chromium removal. The reactor working conditions close to natural effluent pH and electrolysis time in the range of 30-45 min were enough to achieve the cost-effective reduction of COD, turbidity and chromium concentrations. The electrocoagulation method has shown similar pollutant removal efficiencies when compared with the conventional one and can be used successfully for industrial applications. Based on its low operational cost, the electrocoagulation method could be recommended instead of the conventional one. (C) 2009 Elsevier B.V. All rights reserved.