Evaluation of Efficiency of Electrochemical Process for COD and TSS Removal from Raisin Finishing Wastewater

In recent years,biological and chemical processes have been widely used in industrial and municipal wastewater treatment. Electrochemical process is a chemical process used for wastewater treatment. In recent years, this process has been increasingly employed for treatment of many wastewaters, especially for industrial wastewaters with high COD.
The wastewater from raisin-finishing units in Sahand Industrial Town in Malayer with the COD of 26850 mg/L and TSS of 2325 mg/L was collected. Electrolysis process consisted of a reactor with 9 L volume containing two different types of electrodes (Al and stainless steel). The process was conducted without any additives for wastewater treatment enhancing, in three different retention times (10-20 and 30 min) and applied voltages (10, 20 and 30 V). After each experiment, the output wastewater was investigated and the COD removal efficiency was calculated.
Results showed that in retention time of 30 min and applied voltage of 30V, removal efficiencies of COD and TSS using Al electrode were 88.28% and 95.05%, respectively. Moreover, the best removal efficiencies for COD and TSS were found to be 76.54% and 67.53%, which were obtained using stainless steel electrode in retention time of 30 min and applied voltage of 30V in 30 and 10 min respectively.
According to the results, electrochemical treatment along with other processes, such as adding electrolytes, can be used as a tool for reduction of industrial wastewater pollution.