Photochemical Treatment of Industrial Textile Effluent Containing Reactive Dyes

Abstract

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 TiO2 as semiconductor. The photocatalytic process was optimised according to the mass of the semiconductor (1.4 g l(-1)), flow of air (150 ml s(-1)), temperature (55 degrees C) 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.

Microbe-mediated remediation of dyes: Current status and future challenges

“…The only disadvantage is the short shelf life (20 min). Photochemical oxidation is the traditional technique used for industrial textile effluent treatment [62]. UV light activates the degradation of H 2 O 2 into hydroxyl radicals which may attack and release hydrogen atoms from organic molecules capable of the oxidizing organic compound.…”

A study of Reactive Red 198 adsorption on iron filings from aqueous solutions

“…[10] A significant portion of these dyes is used in various industries like cosmetics, textile, printing, wood and paper, tanning, food, plating and other industries. [11][12][13][14] Among these industries, textile industries are the largest consumers of dyes. [15] Therefore, dye is one of the most important materials polluting industrial sewage.…”

“…Three main methods of dye removal include physical, chemical and biological methods. [12][13][14]20] Different physicalchemical methods such as ultrafiltration, reverse osmosis, ion exchange and adsorption on materials such as activated carbon, coal, wood chips and silica gel have been used to remove dye and have enjoyed relative success. [21] In most studies, zero-valent iron is used as a sorption factor for reducing organic compounds, whereas in the recent years, zero-valent iron has been used as a reducing agent for removing compounds such as chlorinated solvents, polyhalogenated compounds (dichlorodiphenyltrichloroethane and polychlorinated biphenyls), volatile organic compounds and arsenic, in some studies.…”