RESUMO
High performance liquid chromatography coupled to a diode array detector method was developed to detect disperse dyes in water samples over the range 0.50-35 ng, with detection limits of 0.09 ng, 0.84 ng and 0.08 ng, respectively, with good repeatability and accuracy. This study identifies the disperse azo dyes C.I. Disperse Blue 373, C.I. Disperse Orange 37 and Disperse Violet 93 as components of a commercial dye formulation assigned as Dispersol Black Dye (CVS) used in the textile industry for dyeing synthetic fibers that are contributing to the mutagenicity found in the Cristais River, São Paulo, Brazil. High performance liquid chromatography coupled to a diode array detector was applied to monitor the occurrence of these dyes in: (1) the treated industrial effluent, (2) raw river water, (3) treated river water, and (4) the sludge produced by a Drinking Water Treatment Plant (DWTP) which is located 6 km downstream from the textile industrial discharge, where dyes' concentrations changed from 1.65 ng L(-1) to 316 microL(-1).
Assuntos
Corantes/análise , Resíduos Industriais , Mutagênicos/análise , Indústria Têxtil , Poluentes Químicos da Água/análise , Cromatografia Líquida de Alta Pressão , Reprodutibilidade dos Testes , Espectrofotometria UltravioletaRESUMO
This work shows the chemical characterization of a dye processing plant effluent that was contributing to the mutagenicity previously detected in the Cristais river, São Paulo, Brazil, that had an impact on the quality of the related drinking water. The mutagenic dyes Disperse Blue 373, Disperse Orange 37 and Disperse Violet 93, components of a Black Dye Commercial Product (BDCP) frequently used by the facility, were detected by thin layer chromatography (TLC). The blue and orange dyes were quantified by high performance liquid chromatography (HPLC/DAD) in a raw and treated effluent samples and their contribution to the mutagenicity was calculated based on the potency of each dye for the Salmonella YG1041. In the presence of S9 the Disperse Blue 373 accounted for 2.3% of the mutagenic activity of the raw and 71.5% of the treated effluent. In the absence of S9 the Disperse Blue 373 accounted for 1.3% of the mutagenic activity of the raw and 1.5% of the treated effluent. For the Disperse Orange 37, in the presence of S9, it contributed for 0.5% of the mutagenicity of the raw and 6% of the treated effluent. In the absence of S9; 11.5% and 4.4% of the raw and treated effluent mutagenicity, respectively. The contribution of the Disperse Violet 93 was not evaluated because this compound could not be quantified by HPLC/DAD. Mutagenic and/or carcinogenic aromatic amines were also preliminary detected using gas chromatograph/mass spectrometry in both raw and treated and are probably accounting for part of the observed mutagenicity. The effluent treatment applied by the industry does not seem to remove completely the mutagenic compounds. The Salmonella/microsome assay coupled with TLC analysis seems to be an important tool to monitor the efficiency of azo dye processing plant effluent treatments.
Assuntos
Indústria Química , Corantes , Mutagênicos/análise , Biotransformação , Cromatografia Líquida de Alta Pressão , Cromatografia em Camada Fina , Testes de Mutagenicidade , Salmonella/genéticaRESUMO
The water produced by the Cristais River Drinking Water Treatment Plant (CR-DWTP) repeatedly produced mutagenic responses that could not be explained by the presence of disinfection byproducts (DBPs) generated by the reaction of humic acids and chlorine. In order to determine the possible role of chlorinated dye products in this mutagenic activity, solutions of a black dye commercial product (BDCP) composed of C.I. Disperse Blue 373, C.I. Disperse Orange 37, C.I. Disperse Violet 93, and chemically reduced BDCP (R-BDCP) were chlorinated in a manner similar to that used by the CR-DWTP. The resulting solutions were extracted with XAD-4 along with one drinking water sample collected from the CR-DWTP. All extracts showed mutagenic activity in the Salmonella/microsome assay. Dye components of the BDCP as well as its reduced chlorinated (CI-R-BDCP) derivative were detected in the drinking water sample by analysis with a high performance liquid chromatography/diode array detector (HPLC/DAD). The mutagenicity results of these products suggest that they are, at least in part, accounting for the mutagenic activity detected in the drinking water samples from the Cristais River. The data obtained in this study have environmental and health implications because the chlorination of the BDCP and the R-BDCP leads to the formation of mutagenic compounds (CI-BDCP and CI-R-BDCP), which are potentially important disinfection byproducts that can contaminate the drinking water as well as the environment.
Assuntos
Cloro/química , Corantes/farmacologia , Purificação da Água , Cloro/farmacologia , Cromatografia , Cromatografia Líquida de Alta Pressão , Meio Ambiente , Corantes de Alimentos , Modelos Químicos , Mutagênese , Testes de Mutagenicidade , Rios , Salmonella/metabolismo , Fatores de Tempo , Poluentes da Água , Abastecimento de ÁguaRESUMO
The oxidation of a reactive dye, Reactive Blue 4, RB4, (C.I. 61205), widely used in the textile industries to color natural fibers, was studied by electrochemical techniques. The oxidation on glassy carbon electrode and reticulated vitreous carbon electrode occurs in only one step at 2.0 < pH < 12 involving a two-electron transfer to the amine group leading to the imide derivative. Dye solution was not decolorized effectively in this electrolysis process. Nevertheless, the oxidation of this dye on Ti/SnO2/SbO(x) (3% mol)/RuO2 (1% mol) electrode showed 100% of decolorization and 60% of total organic carbon removal in Na2SO4 0.2 M at pH 2.2 and potential of +2.4V. Experiments on degradation photoelectrocatalytic were also carried out for RB4 degradation in Na2SO4 0.1 M, pH 12, using a Ti/TiO2 photoanode biased at +1.0 V and UV light. After 1h of electrolysis the results indicated total color removal and 37% of mineralization.