Phenol degradation was carried out in a photocatalytic pilot plant reactor equipped with a UV/vis mercury lamp. The total volume of treated water was equal to 1.35 m3. TiO2P25 was used as a photocatalyst and it was immobilized on two different supports: (i) a steel mesh and (ii) a fiberglass cloth. Moreover, the performance of commercially available Photospheres-40 was examined. In addition, an experiment in the absence of a photocatalyst was conducted. The commercially available Photospheres-40 were found to be inadequate for the presented application due to their fragility, which in connection with vigorous mixing and pumping led to their mechanical destruction and loss of floating abilities. The highest effectiveness of phenol decomposition and mineralization was observed in the presence of TiO2supported on the fiberglass cloth. After 15 h of the process, phenol and total organic carbon concentrations decreased by ca. 80% and 50%, respectively.