optimization of nitrate reduction by electrocoagulation using response surface methodology

conclusions the results of this study show that it is possible to remove nitrate, and its intermediates from waste water. regarding the desirability of the process, the field scale study is proposed. results the results showed that by applying electric current of 0.14 a for 120 minutes, the nitrate content would reduce down to 97%. the obtained r2 for the nitrate removal model was higher than 0.99. with regard to supporting electrolytes, more nitrate reduction is obtained with nacl. the oxidation reduction potential (orp) was changed from 220 to -375 mv and this range is suitable for denitrification and nitrate reduction. background the presence of nitrate and its intermediates are considered undesirable compounds in the environment. various methods have been proposed to remove nitrate from wastewater and water streams. objectives in this study, we investigated removal of nitrate from an aqueous solution by the process of electrocoagulation, using aluminum/graphite as the anode/cathode electrodes. materials and methods we applied response surface methodology (rsm) as the statistical method for modeling, and optimizing the applied variables. all experiments were performed according to the standard methods for the examination of water and wastewater. to prepare the optimum condition, we considered the following amount of compounds and conditions: nacl, 1 g/l; nitrate concentration range, 50-200 mg/l; applied electric current range, 0.05-0.2 a; anode, aluminum; cathode, graphite; and detention time: 120 minutes.