Improving ultraviolet light transmission in a packed-bed photoelectrocatalytic reactor for removal of oxalic acid from wastewater

A novel three-dimensional electrode–hollow quartz tube photoelectrocatalytic reactor was designed and characterized by the photocurrent enhancement and COD removal efficiency, and the packed-bed photoelectrocatalytic reactor was used to investigate the feasibility of synergetic photoelectrocatalytic degradation of oxalic acid. By comparison of the COD removal efficiencies of three processes, direct electrooxidation, photocatalysis, and photoelectrocatalysis, the results showed that not only a significant photoelectrochemical synergetic effect, but also good photocatalytic efficiency, were observed in the photoelectrocatalytic reactor. It was found that successful design of the photoelectrocatalytic reactor by introducing the hollow quartz tubes into the three-dimensional electrode-packed-bed photoelectrocatalytic reactor presented a good solution to the drawbacks for poorly treating the high concentration and low-transmittance wastewater by photocatalytic technology.