Adsorption effect of aqueous bichlorobiphenyls onto UV-illuminated titanium dioxide

Bichlorobiphenyls were adsorbed onto TiO(2) (Degussa P25) in batch equilibrium experiments. The results demonstrated that a triple-layer model (TLM) surface complex formation model described the adsorption of chlorobiphenyls onto the surface of the TiO(2) solid. The surface complex configuration and the adsorption reaction may have followed the equation derived from the TLM, involving the loss of a proton during the adsorption process. This dependence indicates that the oxidation reaction between surface-adsorbed substrates and photogenerated oxidants dominates. Both sorbed and dissolved components contribute to the observed degradation rate, that is, the 4,4'-CBP degradation rates might be stated as linear functions of the sorbed and dissolved concentrations. The contribution of the concentration of solution phase in degradation pathways is not negligible.