Decolouration of textile dyes in wastewaters by photocatalysis with TiO_2

摘要

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 commercial textile dyes. A photochemical reactor of parallel CPC reflectors with UV-transparent tubular receivers was used. The study of photodeg-radation 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 55 min operating time.