RESUMO
Providing clean and safe drinking water by point of use (POU) disinfection methods has become a critical issue, especially in crises and epidemics. In this study, antimony-and nickel-doped tin oxide electrode (Ni-Sb-SnO2) was employed as an electrode for electro-catalytic disinfection of surface water. The synthetized electrodes were characterized using scanning electron microscope, linear sweep voltammetry and X-Ray diffraction techniques. The results revealed that the highest electrochemical disinfection efficiency was achieved by the Ni-Sb-SnO2 electrode under weak acidic conditions and its performance decreased with increasing pH towards alkaline environment. Based on the results, total coliform (TC) and fecal coliform (FC) were completely removed at current density of 0.67 mA cm-2. Moreover, the electrochemical disinfection of microorganisms showed that the process efficiency was directly proportional to increasing time and at 0.6 C cm-2 of charge passed, 3-log removal of the both indicators occurred after 15 min. The highest removal efficiency of TC and FC was also achieved at 8 mmol of NaCl concentration at <10 min of detention time. The results of this study depicted that the Ti/Ni-Sb-SnO2 electrode provides higher disinfection efficiency for the removal of TC and FC compared with Ti and SS/PbO2 electrodes. Moreover, the proposed system was able to completely eliminate heterotrophic, Streptococcus faecalis and Pseudomonas aerogenes indicators under optimal conditions. Therefore, it can be concluded that the proposed electrochemical system can be efficiency applied as a POU disinfection system for disinfection of water contaminated with microbial indicators, especially for crises and epidemics.
