Electrochemical oxidation using Ti/RuO2 anode for COD and PAHs removal from aqueous solution

This study presents the surface morphology of Ti/RuO2 anodes prepared by coating solutions of RuCl3xH2O with three different concentrations i.e. low (0.4 M), medium (0.8 M) and high (1.2 M). Efficiencies of these anodes were determined in terms of COD removal at 3.33, 6.66 and 10 mA/cm2 current densities. The most effective anode was further employed for degradation of 16 priority polycyclic aromatic hydrocarbons (PAHs) in aqueous solution. The surface morphology and characteristics of electrodes were determined by FESEM and XRDxr0= XRD and quantification of PAHs by GC–MS. Anode coated with medium concentration (0.8 M) of Ru offered good results for COD removal and PAHs degradation. About 61% of COD removal was found by anode coated with medium concentration of Ru without using electrolyte at 10 mA/cm2. Similarly, 74.82, 68.94 and 75.68% of total ΣPAHs removal were obtained without using electrolyte at pH 3, 6 and 9. The NaCl as an electrolyte promoted the electro-generated oxidants, like chlorine and hypochlorite, which consequently increased the efficiency of electrolytic treatment. The current results will be supportive in applicability of this method as a treatment process for the petrochemical industry and wastewater containing PAHs.