Assessment of by-products of chlorination and photoelectrocatalytic chlorination of an azo dye.
The present work describes a more efficient methodology for the chlorination of water containing disperse dyes, where the chlorinated byproducts identified by mass spectra are compared. For this investigation, we tested the degradation of CI Disperse Blue 291 dye, 2-[(2-Bromo-4,6-dinitrophenyl)azo]-5-(diethylamino)-4-methoxyacetanilide) a commercial azo dye with mutagenic properties. The present work evaluates the photoelectrocatalytic efficiency of removing the CI Disperse Blue 291 dye from a wastewater of the textile industry. We employed NaCl as a supporting electrolyte. It should be noted that photoelectrocatalytic techniques are non-conventional method of generating chlorine radicals. The by-products formed in this process were analyzed using spectrophotometry, liquid chromatography, dissolved organic carbon, mass spectral analysis and mutagenicity assays. The process efficiency was compared with the conventional chlorination process adopted during sewage and effluents treatment processes. This conventional chlorination process is less efficient in removing color, total organic carbon than the photoelectrochemistry technique. Furthermore, we shall demonstrate that the mutagenicity of the generated by-products obtained using photoelectrocatalysis is completely different from that obtained by the conventional oxidation of chloride ions in the drinking water treatment process.
Electroanalytical Chemistry Laboratory, Department of Analytical Chemistry, UNESP, University of São Paulo State, Brazil.
Rafael Leite
RL
de Oliveira
Marc A
MA
Anderson
Gisela de Aragão
Gde A
Umbuzeiro
Guilherme Julião
GJ
Zocolo
Maria Valnice Boldrin
MV
Zanoni
D001391:Azo Compounds / Q000737:chemistry* / Q000528:radiation effects / Q000633:toxicity; D002384:Catalysis; D002713:Chlorine / Q000737:chemistry*; D004396:Coloring Agents / Q000737:chemistry* / Q000528:radiation effects / Q000633:toxicity; D004563:Electrochemistry; D054879:Halogenation; D007220:Industrial Waste; D009153:Mutagens / Q000737:chemistry* / Q000528:radiation effects / Q000633:toxicity; D009942:Organometallic Compounds / Q000737:chemistry; D016877:Oxidants / Q000737:chemistry; D055668:Photochemical Processes; D012486:Salmonella typhimurium / Q000187:drug effects / Q000235:genetics; D013783:Textile Industry; D014466:Ultraviolet Rays; D014865:Waste Disposal, Fluid / Q000379:methods*; D014874:Water Pollutants, Chemical / Q000737:chemistry* / Q000528:radiation effects / Q000633:toxicity; D018508:Water Purification / Q000379:methods
D001391:Azo Compounds; D004396:Coloring Agents; D007220:Industrial Waste; D009153:Mutagens; D009942:Organometallic Compounds; D016877:Oxidants; D014874:Water Pollutants, Chemical; D002713:Chlorine; C102815:titanium isopropoxide