Department of Applied Chemistry, Faculty of Chemistry, Tabriz University, Tabriz, 51664, I.R. IRAN
Electrochemically generated iron can remove most contaminants present in water and wast water, by precipitation, adsorption, electrostatic interaction, and complex formation (generally called electrocoagulation-EC). In the present paper, pretreatment of brackish water having high total hardness (TH), alkalinity (A), and Cl¯ ions, is studied by application of a DC-electrical current ot the iron electrodes. Operating parameters such as electrical current density, volume flow, surface area of electrodes, distance between the two electrodes, water temperature, aerating flow, retention time, contact time of produced sludge before and after the process, addition of coagulant aid (bentonite) and the colloidal additive (clay particles) were optimized. Thie results of this study for a brakish sample with 11.8 TH, 5.6 (A), 12.4 , and 23.5 Cl¯ meq/lit indicate that the process is able to lower more than %94 the (TH), %92 (A), %50 and %43 Cl¯.