PHOTOCHEMICAL TREATMENT OF INDUSTRIAL TEXTILE EFFLUENT CONTAINING REACTIVE DYES

摘要

Textile effluents are a result of the use of reactive dyes which present a strong environmental impact. These are substances of concern when conventional treatment processes are to be considered. This work refers to the study of post-treatment (purification) of the textile effluent originating from the use of reactive dyes (after biological treatment for activated sludge) through photocatalysis using TiO_2 as semiconductor. The photocatalytic process was optimised according to the mass of the semiconductor (1.4 g 1~(-1)), flow of air (150 ml s~(-1)), temperature (55℃) and time of treatment (240 min). In the optimised conditions it was possible to verify high efficiency in the colour reduction (92%), COD (65%), BOD (40%) and TOC (29.3%). The study reached the conclusion that the photocatalytic process presents great potential as a method of post-treatment of effluents derived from the textile industry.