Photoassisted electrochemical treatment of azo and phtalocyanine reactive dyes in the presence of surfactants
An electrochemical treatment (EC) was applied at different intensities to degrade the chromophoric groups of dyes C.I. Reactive Black 5 (RB5) and C.I. Reactive Blue 7 (Rb7) until uncolored species were obtained. Decolorization rate constants of the azo dye RB5 were higher than the phtalocyanine Rb7...
| Authors: | , , |
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| Format: | article |
| Publication Date: | 2016 |
| Country: | España |
| Institution: | Universitat Politècnica de Catalunya (UPC) |
| Repository: | UPCommons. Portal del coneixement obert de la UPC |
| Language: | English |
| OAI Identifier: | oai:upcommons.upc.edu:2117/84798 |
| Online Access: | https://hdl.handle.net/2117/84798 https://dx.doi.org/10.3390/ma9030211 |
| Access Level: | Open access |
| Keyword: | Textile waste Coloring matter Electrochemistry Azo dyes Surface active agents Textile washing effluents Reactive dyes Phtalocyanine dyes Surfactants Decolorization Electrochemical treatment Photo-assisted electrochemical treatment Colorants azoics Colorants -- Tractament Electroquímica -- Aplicacions Aigües residuals -- Contaminació Agents tensioactius Àrees temàtiques de la UPC::Enginyeria química::Indústries químiques::Colorants, pintures i vernissos Àrees temàtiques de la UPC::Enginyeria tèxtil::Impacte ambiental |
| Summary: | An electrochemical treatment (EC) was applied at different intensities to degrade the chromophoric groups of dyes C.I. Reactive Black 5 (RB5) and C.I. Reactive Blue 7 (Rb7) until uncolored species were obtained. Decolorization rate constants of the azo dye RB5 were higher than the phtalocyanine Rb7 ones. In addition, the EC treatment was more efficient at higher intensities, but these conditions significantly increased the generation of undesirable by-products such as chloroform. The combination of EC with UV irradiation (UVEC) drastically minimized the generation of chloroform. The photo-assisted electrochemical treatment was also able to achieve decolorization values of 99%. Finally, mixtures of dyes and surfactants were treated by EC and UVEC. In the presence of surfactants, the decolorization kinetic of dyes was slowed due to the competitive reactions of surfactants degradation. Both methods achieved total decolorization and in both cases, the generation of haloforms was negligible. |
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