Photocatalysis of 4-Chlorophenol Mediated by TiO sub(2) Fixed to Concrete Surfaces

Photocatalysis of 4-chlorophenol (4CP) mediated by TiO sub(2) fixed to concrete surfaces were assessed. The samples were analyzed using a Varian CP-3380 gas chromatograph with a Varian 8200 solid phase micro extraction (SPME) autosampler. Dark experiments 'No TiO sub(2)-No Sealer' were used to explore the possible 4CP degradation pathways of infiltration or absorption in the concrete substrate, and air-water partitioning. It was observed that the limiting factor for the photocatalytic oxidation of 4CP was not related to the surface kinetics, but to mass transfer of 4CP between bulk solution and catalyst. The lowest mean normalized 4CP concentrations were observed in the bulk solution of PVC batch reactors containing TiO sub(2) in the sealed concrete surface and exposed to continuous UV.