Effect of Different Electrodes on Humic Acid Removal by Electrocoagulation

The present study is about the reduction of humic acids (HA) by electrocoagulation (EC) method. Undesirable color, odor, taste, reacting with chlorine to produce toxic materials in water, and making a complex with heavy metal ions are some unfavorable environmental consequences of HA. Platinum and graphite as anode electrodes and platinum, titanium, and aluminum as cathode electrodes were used for this purpose. Also, solutions consisting of sodium sulfate (Na2SO4), as the electrolyte support, and humic acids at a concentration of 30 mg.l-1 were used in the reduction tests. We investigated the best condition for pollutant removal at pH values of 3, 5, and 7 and voltages of 5, 10, and 18. The samples were taken during the electrolysis and were analyzed by the pH meter and UV-visible spectrophotometer. Moreover, the oxidation phenomena on anodes surface were studied by cyclic voltammetry tests. The results confirm that the Gr/Al electrodes by coagulation phenomena shows the best performance in the elimination of HA at an electrolyte support concentration of 0.02 molar after approximately 23 min at a pH of 7 and a voltage equal to 10 V.