The separation of catalyst after photocatalytic reactions conducted in the presence of TiO2/FeCl3/UV

One of the problems connected with wastewater treatment by the photocatalytic method in the presence of TiO2 suspension is necessity of the later catalyst separation. The method proposed by us for this purpose, consists in the usage of coagulation of TiO2 suspension with the aid of FeCl3, particularly in the cases when addition of the salt is used in order to intensification of the photocatalytic process. The effects of the TiO2 separation were studied from the mixtures, after photocatalytic Acid Orange 7 degradation, with dosage of FeCl3 at different stages of the process. The coagulation was carried out at different pH values as well as different FeCl3 concentrations. It was stated that nearly 100% of separation and simultaneously, nearly 100% of decolouration of the examined Acid Orange 7 solutions after their illumination in the presence of TiO2/FeCl3 and coagulation which was produced only by increasing of pH of the obtained mixtures, were nearly possible. (c) 2004 Elsevier Ltd. All rights reserved.