RESUMEN
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.
Asunto(s)
Compuestos Azo/química , Cloro/química , Colorantes/química , Mutágenos/química , Eliminación de Residuos Líquidos/métodos , Contaminantes Químicos del Agua/química , Compuestos Azo/efectos de la radiación , Compuestos Azo/toxicidad , Catálisis , Colorantes/efectos de la radiación , Colorantes/toxicidad , Electroquímica , Halogenación , Residuos Industriales , Mutágenos/efectos de la radiación , Mutágenos/toxicidad , Compuestos Organometálicos/química , Oxidantes/química , Procesos Fotoquímicos , Salmonella typhimurium/efectos de los fármacos , Salmonella typhimurium/genética , Industria Textil , Rayos Ultravioleta , Contaminantes Químicos del Agua/efectos de la radiación , Contaminantes Químicos del Agua/toxicidad , Purificación del Agua/métodosRESUMEN
Titanium (Ti) is currently the most widely used material for the manufacture of orthopedic and dental implants. Changes in the surface of commercial pure Ti (cp Ti) can determine the functional response of cells, and is therefore a critical factor for the success of the implant. However, the genotoxicity of titanium surfaces has been poorly studied. Thus, the purpose of this study was to evaluate the genotoxic potential of a new titanium surface developed by plasma treatment using argon-ion bombardment and compare it with an untreated titanium surface. Accordingly, comet assay, analysis of chromosomal aberrations (CAs), and Cytokinesis Block Micronucleus (CBMN) assay were carried out, using CHO-K1 (Chinese hamster ovary) cells grown on both titanium surfaces. Our results show that the untreated titanium surface caused a significant increase in % tail moment, in the number of cells with CAs, tetraploidy, micronucleus frequency, and other nuclear alterations when compared with the negative control and with the plasma-treated titanium surface. This difference may be attributed to increased surface roughness and changes in titanium oxide layer thickness.