An innovative photocatalytic technology in the treatment of river water containing humic substances.

This study addresses the application of a photoelectrocatalytic (PEC) system with separated hole and electron reactions to treat humic acid (HA) from river water. A TiO2 electrode, coated by the sol-gel method, is used for that purpose. The degradation of humic acid in the river water was followed with respect to time using parameters of UV254, color and total organic carbon (TOC). For comparison purposes the photocatalytic (PC) removal of HA was also studied on the same photoanode. The obtained results showed that the PEC system was much more effective than the PC method. The effect of other important reaction variables, such as external potential, oxygen and UV intensity on HA degradation were also investigated. For all the external applied potential conditions and UV intensity range over 90% removal of UV254 and color were obtained with the PEC system while TOC removal was between 58-80%.