Study on Removal of Cadmium From Plating Baths Wastewater by Electrochemical Precipitation Method Publisher



Bazrafshan E¹ ; Kord Mostafapoor F^{2, 3} ; Zazouli MA⁴ ; Eskandari Z⁵ ; Jahed GHR⁶ Show Affiliations
Source: Pakistan Journal of Biological Sciences Published:2006

Abstract

The object of this study is evaluation of cadmium removal from industrial wastewater by electrochemical precipitation method. This study is a Laboratory experimental study which was done in pilot plant form. A glass tank in 1.45 L volume with four plate electrode was used to do experiments. The electrodes made of aluminum and zinc and connect to the positive and negative pole of DC power supply, respectively (monopolar mode). The tank was filled with synthetic wastewater that was containing cadmium ion in concentration 50 and 250 mg L -1 and then it was started up. The amount of cadmium ion removal was measured at pH 4,6 and 10 and in electric potential range of 10 to 25 volts. When the initial concentration of cadmium ion was 50 mg L-1, the highest amount of cadmium removal was 40 min after starting the process and when the initial concentration was 250 mg L-1, the highest amount of removal was obtained 70 min after starting at 10, 20 and 25 volts. Efficiency of this process was more than 99%. The results show that in pH range from 4 to 10, this process is applicable. In initial stages of the process, with initial pH of 4 to 6, pH has increased but in initial pH of 10, in both concentrations pH has decreased. In the initial concentration 50 and 250 mg L-1 of cadmium, SVI was 33.4-129.9 and 72.1-292.9 min. In electrochemical precipitation, the initial concentration was effective, so if the initial concentration increases, the time of process should increase too. In this process, the use of different electrical potentials can provide a wide range of pH for doing this process. © 2006 Asian Network for Scientific Information.