Combined Photocatalytic and Electrochemical Treatment of Organic Matter and Heavy Metals

In the present study, simulated wastewater containing methylene blue, Zn2+ and Ni2+ was treated by two treatment methods: photocatalytic oxidation and electrochemical deposition. It is found that methylene blue could be degraded more efficiently by combined photocatalytic and electrochemical process than by photocatalytic oxidation or electrochemical deposition alone. The percentage removal of methylene blue in combined suspended photocatalytic and electrochemical process was 46.1% after 72 hours of treatment, while it was only 36.1% for a single suspended photocatalytic process and 23.5% for a single electrochemical process. On the other hand, no significant effect was observed for the percentage removal of Zn2+ and Ni2+ in combined suspended photocatalytic and electrochemical process. The influence of liquid flowrate, wavelength and pH to the removal of methylene blue, Zn2+ and Ni2+ was also investigated.