Degradation of Acid Blue 40 dye solution and dye house wastewater from textile industry by photo-assisted electrochemical process

In this paper, electrochemical and photo-assisted electrochemical processes are used for color, total organic carbon (TOC) and chemical oxygen demand (COD) degradation of one of the most abundant and strongly colored industrial wastewaters, which results from the dyeing of fibers and fabrics in the textile industry. The experiments were carried out in an 18L pilot-scale tubular low reactor with 70% TiO2/30% RuO2 DSA. A synthetic acid blue 40 solution and real dye house wastewater, containing the same dye, were used for the experiments. By using current density of 80 mA cm(-2) electrochemical process has the capability to remove 80% of color, 46% of TOC and 69% of COD. When used the photochemical process with 4.6 mW cm(-2) of 254nm UV-C radiation to assist the electrolysis, has been obtained 90% of color, 64% of TOC and 60% of COD removal in 90 minutes of processing; furthermore, 70% of initial color was degraded within the first 15 minutes. Experimental runs using dye house wastewater resulted in 78% of color, 26% of TOC and 49% of COD in electrolysis at 80 mA cm(-2) and 90 min; additionally, when photo-assisted, electrolysis resulted in removals of 85% of color, 42% of TOC and 58% of COD. For the operational conditions used in this study, color, TOC and COD showed pseudo-first-order decaying profiles. Apparent rate constants for degradation of TOC and COD were improved by one order of magnitude when the photo-electrochemical process was used.

Synthesis and characterization of Fe(III)-doped ceramic membranes of titanium dioxide and its application in photoelectrocatalysis of a textile dye

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Decolorization of textile dye by Candida albicans isolated from industrial effluents

The aim of the present work was to observe microbial decolorization and biodegradation of the Direct Violet 51 azo dye by Candida albicans isolated from industrial effluents and study the metabolites formed after degradation. C. albicans was used in the removal of the dye in order to further biosorption and biodegradation at different pH values in aqueous solutions. A comparative study of biodegradation analysis was carried out using UV-vis and FTIR spectroscopy, which revealed significant changes in peak positions when compared to the dye spectrum. Theses changes in dye structure appeared after 72 h at pH 2.50; after 240 h at pH 4.50; and after 280 h at pH 6.50, indicating the different by-products formed during the biodegradation process. Hence, the yeast C. albicans was able to remove the color substance, demonstrating a potential enzymatic capacity to modify the chemical structure of pigments found in industrial effluents.

Textile Dye Treated Photoelectrolytically and Monitored by Winogradsky Columns

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Electrolysis applied for simulated textile effluents degradation containing acid red 151 and acid blue 40

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Photoelectrocatalytic/photoelectro-Fenton coupling system using a nanostructured photoanode for the oxidation of a textile dye: kinetics study and oxidation pathway

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Electrochemical reduction of disperse orange 1 textile dye at a boron-doped diamond electrode

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Determination of the phthalocyanine textile dye, reactive turquoise blue, by electrochemical techniques

Turquoise blue 15 (AT15) is a reactive dye widely used in the textile industry to color natural fibers. The presence of these dyes in effluent and industrial wastewater is of considerable interest due ecotoxicological and environmental problems. The electrochemical reduction of this dye has been investigated in aqueous solution using cyclic voltammetry, controlled potential electrolysis and cathodic stripping voltammetry. Optimum conditions for dye discoloration by controlled potential electrolysis use an alkaline medium. Using cathodic stripping voltammetry a linear calibration graph was obtained from 5.00×10-8 mol L-1 to 1.00×10 -6 mol L-1 of AT15 at pH 4.0, using accumulation times of 180 and 240 s and an accumulation potential of 0.0 V. The proposed method was applied in direct determination of the dye in tap water and in textile industry effluent.

Impact of the Textile Dye Acid Blue 40 on the Periphyton of a Simulated Microecosystem

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Disperse Red 1 (textile dye) induces cytotoxic and genotoxic effects in mouse germ cells

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

A label-free impedimetric immunosensor for direct determination of the textile dye Disperse Orange 1

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Decolorization of textile indigo dye by ligninolytic fungi

The indigo dye is extensively used by textile industries and is considered a recalcitrant substance, which causes environmental concern. Chemical products used on textile processing, which affect the environment through effluents, can be voluminous, colored and varied. Vat textile dyes, like indigo, are often used and dye mainly cellulosic fibers of cotton. Decolorization of this dye in liquid medium was tested with ligninolytic basidiomycete fungi from Brazil. Decolorization started in a few hours and after 4 days the removal of dye by Phellinus gilvus culture was in 100%, by Pleurotus sajor-caju 94%, by Pycnoporus sanguineus 91% and by Phanerochaete chrysosporium 75%. No color decrease was observed in a sterile control. Thin layer chromatography of fungi culture extracts revealed only one unknown metabolite of Rf = 0.60, as a result of dye degradation. (C) 2001 Published by Elsevier B.V. B.V.

Electrochemical oxidation of an acid dye by active chlorine generated using Ti/Sn(1-x)Ir O-x(2) electrodes

The generation of active chlorine on Ti/Sn(1-x)Ir (x) O-2 anodes, with different compositions of Ir (x = 0.01, 0.05, 0.10 and 0.30 ), was investigated by controlled current density electrolysis. Using a low concentration of chloride ions (0.05 mol L-1) and a low current density (5 mA cm(-2)) it was possible to produce up to 60 mg L-1 of active chlorine on a Ti/Sn0.99Ir0.01O2 anode. The feasibility of the discoloration of a textile acid azo dye, acid red 29 dye (C.I. 16570), was also investigated with in situ electrogenerated active chlorine on Ti/Sn(1-x)Ir (x) O-2 anodes. The best conditions for 100% discoloration and maximum degradation (70% TOC reduction) were found to be: NaCl pH 4, 25 mA cm(-2) and 6 h of electrolysis. It is suggested that active chlorine generation and/or powerful oxidants such as chlorine radicals and hydroxyl radicals are responsible for promoting faster dye degradation. Rate constants calculated from color decay versus time reveal a zero order reaction at dye concentrations up to 1.0 x 10(-4) mol L-1. Effects of other electrolytes, dye concentration and applied density currents also have been investigated and are discussed.

Investigação da mutagenicidade do azocorante comercial BDCP (Black Dye Commercial Product), antes e após tratamento microbiano, utilizando o sistema teste de Allium cepa

Pós-graduação em Ciências Biológicas (Biologia Celular e Molecular) - IBRC