PHOTOCATALYTIC DECOLOURATION OF TEXTILE DYES WASTEWATERS IN AN EXPERIMENTAL SOLAR PILOT PLANT

摘要

Chemicals dyes from the textile industry are a significant source of aquatic environmental pollution. Therefore, such industrial effluents must be treated before their release into the aqueous media. The photocatalytic removal of colour of a synthetic textile effluent, using TiO_2 suspensions under solar radiation, has been studied at pilot plant scale. A synthetic dye solution was prepared by a mix of six commercials textile dyes. A photochemical reactor of parallel CPC reflectors with UV-transparent tubular receivers was used. The study of photodegradation was carried out using the Taguchi's Parameter Design method. Following this methodology, the reaction was conducted under different flow conditions, pH and H_2O_2 concentrations. The results show that all dyes used in the experiences can be degraded successfully by photo-oxidation. The process shows a significant enhancement when it is carried out at high flows, alkaline media and high H_2O_2 concentration. Colour removal from the effluent was reached at 23 minutes operating time.