Efficiency of Electro/Fe2+/Persulfate Process in Industrial Wastewater Treatment

Background and In Electro/Fe2+/persulfate process, persulfate radicals are produced as powerful oxidizing agents which increase the efficiency of this process. The aim of this study was to investigate the efficiency removal of COD, TSS and dye from industrial effluent in Buali industrial area in Hamedan. In this study, the batch experiment was performed using a reactor equipped with four iron electrodes. We studied the effects of some operating parameters including pH (3-11), divalent iron ion dose (0.1 to 0.5 g/L), concentration of persulfate anion (0.5-2 g/L) and direct current electric rate (1-5 A) in removal of COD, TSS and dye from wastewater. The COD, TSS and dye measurement was done according to the standard methods. The results showed that under optimum conditions (pH: 3, Fe+2 dosage: 0.1 g/L and density: 5A) the removal efficiencies of process in COD, TSS and dye were 91.6, 73.5 and 93.1%, respectively. By making changes in the parameters, the efficiency of process also changed. The removal efficiency of single application of electrooxidation was 58.2%, 52.2% and 68% for COD, TSS and dye, respectively. The electro/Fe2+/persulfate process showed acceptable performance in removal of COD, TSS and dye. Therefore, this process could be used as a pretreatment unit to reduce the load of raw wastewater pollution before entering the conventional treatment units. Furthermore, the assessment of synergistic effects of persulfate revealed that single application of electrochemical degradation in optimum conditions had a much lower efficiency compared to electro/Fe+2/persulfate process.