Photocatalytic reactors can play an increasing role in novel technologies for the purification of water polluted with organic chemicals. These organic pollutants may strongly adsorb on the TiO2-mesh system leading to an overall process influenced by the combined adsorption/reaction phenomena. In the present study, chlorinated aromatics frequently found as water contaminants (2chlorophenol and 2-4-dichlarophenol) are selected as model pollutants. It is demonstrated, developing experiments in a novel photocatalytic reactor (Photo-CREC unit) that addition of chlorine atoms to the phenol molecule has a significant impact on both adsorption and photoreaction. Due to catalyst deactivation and drop in lamp power, kinetic constants are corrected to conditions of new lamp and fresh catalyst. It is foreseen that using these corrected kinetic constants, high-energy efficiencies (PTEF) can be achieved in Photo-CREC.