Documents disponibles écrits par cet auteur

An effective electrochemical Cr(VI) removal contained in electroplating industry wastewater and the chemical characterization of the sludge produced / Sarai Velazquez-Pena in Industrial & engineering chemistry research, Vol. 51 N° 17 (Mai 2012) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 51 N° 17 (Mai 2012) . - pp. 5905–5910 Titre : An effective electrochemical Cr(VI) removal contained in electroplating industry wastewater and the chemical characterization of the sludge produced Type de document : texte imprimé Auteurs : Sarai Velazquez-Pena, Auteur ; Carlos Barrera-Díaz, Auteur ; Ivonne Linares-Hernandez, Auteur Année de publication : 2012 Article en page(s) : pp. 5905–5910 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Electrochemical  Electroplating  wastewater Résumé : The goal of this work is to optimize the electrochemical reduction of hexavalent chromium in electroplating wastewater. The pH, electrolyte composition and concentration, and cathode metal were varied and the effect on reduction rate measured. Although all electrochemical systems studied reduced all Cr(VI) in the solutions, there were clear trends in the speed of the reactions. Because the reaction at pH 2 was faster than that at pH 4, acidity is favored. Higher electrolyte concentrations produced faster rates. Copper cathodes were faster than iron ones. Using the optimized conditions of pH 2 and a copper cathode, along with the high electrolyte concentration already present, actual electroplating wastewater was treated. The rate of Cr(VI) reduction was measured as a function of treatment time and was found to be even higher than that of the synthetic solutions. The 180 mg/L of Cr(VI) in the wastewater was completely reduced in about 15 min under optimal conditions. The sludge generated in the process was analyzed for morphology and elemental composition to provide insight into the mechanism of the reduction. The model electrochemical cell is as effective at reducing hexavalent chromium in actual electroplating wastewater as it is on synthetic solutions, so it can be effectively scaled up to industrial applications. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie200968s [article] An effective electrochemical Cr(VI) removal contained in electroplating industry wastewater and the chemical characterization of the sludge produced [texte imprimé] / Sarai Velazquez-Pena, Auteur ; Carlos Barrera-Díaz, Auteur ; Ivonne Linares-Hernandez, Auteur . - 2012 . - pp. 5905–5910. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 17 (Mai 2012) . - pp. 5905–5910 Mots-clés : Electrochemical  Electroplating  wastewater Résumé : The goal of this work is to optimize the electrochemical reduction of hexavalent chromium in electroplating wastewater. The pH, electrolyte composition and concentration, and cathode metal were varied and the effect on reduction rate measured. Although all electrochemical systems studied reduced all Cr(VI) in the solutions, there were clear trends in the speed of the reactions. Because the reaction at pH 2 was faster than that at pH 4, acidity is favored. Higher electrolyte concentrations produced faster rates. Copper cathodes were faster than iron ones. Using the optimized conditions of pH 2 and a copper cathode, along with the high electrolyte concentration already present, actual electroplating wastewater was treated. The rate of Cr(VI) reduction was measured as a function of treatment time and was found to be even higher than that of the synthetic solutions. The 180 mg/L of Cr(VI) in the wastewater was completely reduced in about 15 min under optimal conditions. The sludge generated in the process was analyzed for morphology and elemental composition to provide insight into the mechanism of the reduction. The model electrochemical cell is as effective at reducing hexavalent chromium in actual electroplating wastewater as it is on synthetic solutions, so it can be effectively scaled up to industrial applications. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie200968s

Removal of biorefractory compounds in industrial wastewater by chemical and electrochemical pretreatments / Carlos Barrera-Díaz in Industrial & engineering chemistry research, Vol. 48 N°3 (Février 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N°3 (Février 2009) . - p. 1253–1258 Titre : Removal of biorefractory compounds in industrial wastewater by chemical and electrochemical pretreatments Type de document : texte imprimé Auteurs : Carlos Barrera-Díaz, Auteur ; Ivonne Linares-Hernandez, Auteur ; Gabriela Roa-Morales, Auteur Année de publication : 2009 Article en page(s) : p. 1253–1258 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Industrial  wastewater  wastewater  --  Chemical  pretreatments  wastewater  --  Electrochemical  pretreatments  wastewater  --  Biological  treatment Résumé : The goal of this research was to investigate the effectiveness of chemical and electrochemical pretreatments in removing biorefractory compounds from a complex industrial wastewater. The presence of recalcitrant compounds in wastewater reduces the effectiveness of traditional biological treatments; in this case, the COD reduction was around 30%. Therefore, some pretreatments are required to eliminate the toxic substances and improve the biological efficiency. Chemical coagulation was evaluated using the standard jar testing technique with aluminum and iron sulfates and aluminum polyhydroxychloride (PAC). The best pollutant reduction was obtained when 4 mL dm−3 of PAC was added to the industrial wastewater. At the same time, a batch aluminum electrochemical reactor was used, and better COD and color reductions were obtained as compared to those obtained with the chemical method. After being subjected to the pretreatment, the wastewater was introduced into a laboratory-scale biological reactor in which the COD reduction was monitored, and a global reduction of 68% was obtained using the electrochemical + biological method. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800560n [article] Removal of biorefractory compounds in industrial wastewater by chemical and electrochemical pretreatments [texte imprimé] / Carlos Barrera-Díaz, Auteur ; Ivonne Linares-Hernandez, Auteur ; Gabriela Roa-Morales, Auteur . - 2009 . - p. 1253–1258. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N°3 (Février 2009) . - p. 1253–1258 Mots-clés : Industrial  wastewater  wastewater  --  Chemical  pretreatments  wastewater  --  Electrochemical  pretreatments  wastewater  --  Biological  treatment Résumé : The goal of this research was to investigate the effectiveness of chemical and electrochemical pretreatments in removing biorefractory compounds from a complex industrial wastewater. The presence of recalcitrant compounds in wastewater reduces the effectiveness of traditional biological treatments; in this case, the COD reduction was around 30%. Therefore, some pretreatments are required to eliminate the toxic substances and improve the biological efficiency. Chemical coagulation was evaluated using the standard jar testing technique with aluminum and iron sulfates and aluminum polyhydroxychloride (PAC). The best pollutant reduction was obtained when 4 mL dm−3 of PAC was added to the industrial wastewater. At the same time, a batch aluminum electrochemical reactor was used, and better COD and color reductions were obtained as compared to those obtained with the chemical method. After being subjected to the pretreatment, the wastewater was introduced into a laboratory-scale biological reactor in which the COD reduction was monitored, and a global reduction of 68% was obtained using the electrochemical + biological method. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800560n