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Antimonite removal using marine algal species / K. Vijayaraghavan in Industrial & engineering chemistry research, Vol. 50 N° 17 (Septembre 2011) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 50 N° 17 (Septembre 2011) . - pp. 9864-9869 Titre : Antimonite removal using marine algal species Type de document : texte imprimé Auteurs : K. Vijayaraghavan, Auteur ; R. Balasubramanian, Auteur Année de publication : 2011 Article en page(s) : pp. 9864-9869 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Antimonite  Marine  algal Résumé : Three seaweed species (Turbinaria conoides, Sargassum sp., and Ulva sp.) were examined to assess their ability to sequester antimonite [Sb(III)] ions from aqueous solution. Among these species, both T. conoides and Sargassum sp. showed higher Sb(III) biosorption potential than Ulva sp. The pH-edge experimental results revealed the involvement of negatively charged groups in the biosorption of Sb(III). Biosorption isotherms obtained at pH 6 indicated that T. conoides provided higher uptake of Sb(III) (18.1 mg/g) than Sargassum sp. (14.9 mg/g) according to the Langmuir model. Kinetic studies indicated that the rates of Sb(III) removal by both brown seaweeds were high, with 95% of the process completed within 45 min. A pseudo-first-order model was found to describe the kinetic data satisfactorily with a high correlation coefficient and low percentage errors. Desorption experiments with 0.1 M HCl showed that it is possible to regenerate T. conoides for its continued use as a biosorbent for up to three sorption–desorption cycles without significant loss in sorption capacity. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie200776m [article] Antimonite removal using marine algal species [texte imprimé] / K. Vijayaraghavan, Auteur ; R. Balasubramanian, Auteur . - 2011 . - pp. 9864-9869. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 50 N° 17 (Septembre 2011) . - pp. 9864-9869 Mots-clés : Antimonite  Marine  algal Résumé : Three seaweed species (Turbinaria conoides, Sargassum sp., and Ulva sp.) were examined to assess their ability to sequester antimonite [Sb(III)] ions from aqueous solution. Among these species, both T. conoides and Sargassum sp. showed higher Sb(III) biosorption potential than Ulva sp. The pH-edge experimental results revealed the involvement of negatively charged groups in the biosorption of Sb(III). Biosorption isotherms obtained at pH 6 indicated that T. conoides provided higher uptake of Sb(III) (18.1 mg/g) than Sargassum sp. (14.9 mg/g) according to the Langmuir model. Kinetic studies indicated that the rates of Sb(III) removal by both brown seaweeds were high, with 95% of the process completed within 45 min. A pseudo-first-order model was found to describe the kinetic data satisfactorily with a high correlation coefficient and low percentage errors. Desorption experiments with 0.1 M HCl showed that it is possible to regenerate T. conoides for its continued use as a biosorbent for up to three sorption–desorption cycles without significant loss in sorption capacity. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie200776m

Biosorption of lanthanum, cerium, europium, and ytterbium by a brown marine alga, turbinaria conoides / K. Vijayaraghavan in Industrial & engineering chemistry research, Vol. 49 N° 9 (Mai 2010) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 49 N° 9 (Mai 2010) . - pp 4405–4411 Titre : Biosorption of lanthanum, cerium, europium, and ytterbium by a brown marine alga, turbinaria conoides Type de document : texte imprimé Auteurs : K. Vijayaraghavan, Auteur ; M. Sathishkumar, Auteur ; R. Balasubramanian, Auteur Année de publication : 2010 Article en page(s) : pp 4405–4411 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Biosorption Résumé : The ability of a brown marine alga, Turbinaria conoides, to remove four rare-earth elements (REEs; lanthanum, cerium, europium, and ytterbium) was evaluated. Results showed that T. conoides was an excellent biosorbent for all four REEs. The equilibrium pH was found to severely affect the biosorption performance; pH 4.9 ± 0.2 was found to be an optimum pH for favorable biosorption of REEs. The biosorption mechanism was found to proceed mainly by ion-exchange reactions between the lanthanide ions and the carboxyl groups present on the algal surface, confirmed by the pH edge, desorption, and scanning electron microscopy/energy-dispersive X-ray results. Biosorption isotherms were modeled using the Langmuir, Freundlich, and Toth isotherms, with the latter-described REE isotherms with very high correlation coefficients and lower error values. Maximum biosorption uptakes, according to the Langmuir model, were recorded as 154.7, 152.8, 138.2, and 121.2 mg/g for La, Ce, Eu, and Yb, respectively. Biosorption kinetics of REEs was found to be rapid, achieving 90% of total biosorption within 50 min. Desorption was successful with 0.05 M HCl, and the biomass was regenerated and reused for three sorption−desorption cycles without a significant loss in the biosorption capacity. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1000373 [article] Biosorption of lanthanum, cerium, europium, and ytterbium by a brown marine alga, turbinaria conoides [texte imprimé] / K. Vijayaraghavan, Auteur ; M. Sathishkumar, Auteur ; R. Balasubramanian, Auteur . - 2010 . - pp 4405–4411. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 9 (Mai 2010) . - pp 4405–4411 Mots-clés : Biosorption Résumé : The ability of a brown marine alga, Turbinaria conoides, to remove four rare-earth elements (REEs; lanthanum, cerium, europium, and ytterbium) was evaluated. Results showed that T. conoides was an excellent biosorbent for all four REEs. The equilibrium pH was found to severely affect the biosorption performance; pH 4.9 ± 0.2 was found to be an optimum pH for favorable biosorption of REEs. The biosorption mechanism was found to proceed mainly by ion-exchange reactions between the lanthanide ions and the carboxyl groups present on the algal surface, confirmed by the pH edge, desorption, and scanning electron microscopy/energy-dispersive X-ray results. Biosorption isotherms were modeled using the Langmuir, Freundlich, and Toth isotherms, with the latter-described REE isotherms with very high correlation coefficients and lower error values. Maximum biosorption uptakes, according to the Langmuir model, were recorded as 154.7, 152.8, 138.2, and 121.2 mg/g for La, Ce, Eu, and Yb, respectively. Biosorption kinetics of REEs was found to be rapid, achieving 90% of total biosorption within 50 min. Desorption was successful with 0.05 M HCl, and the biomass was regenerated and reused for three sorption−desorption cycles without a significant loss in the biosorption capacity. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1000373

Equilibrium isotherm studies for the multicomponent adsorption of lead, zinc, and cadmium onto Indonesian peat / R. Balasubramanian in Industrial & engineering chemistry research, Vol. 48 N°4 (Février 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N°4 (Février 2009) . - p. 2093–2099 Titre : Equilibrium isotherm studies for the multicomponent adsorption of lead, zinc, and cadmium onto Indonesian peat Type de document : texte imprimé Auteurs : R. Balasubramanian, Auteur ; S. V. Perumal, Auteur ; K. Vijayaraghavan, Auteur Année de publication : 2009 Article en page(s) : p. 2093–2099 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Indonesian  peat  Pb  Cadmium  Zinc  Langmuir  two-site  model Résumé : This study evaluates the potential of Indonesian peat to sequester Pb, Cd, and Zn in single-, double-, and triple-solute systems. The adsorption isotherms of Pb, Cd, and Zn onto peat in single-solute and multisolute systems were simulated using the Langmuir two-site model satisfactorily. The model and experimental data of binary and ternary systems demonstrated that the presence of the secondary metal ions in the system resulted in a decrease in the sorption capacity of the primary metal, mainly because of the competitive effects of metals for adsorption sites. The metal adsorption follows the order of sequence Pb > Cd > Zn for both single-solute and multisolute systems. A three-dimensional representation of the total metal uptake in binary systems showed a good agreement with the corresponding experimental data. In addition to ion exchange, a surface adsorption−complexation mechanism must be involved in the sorption mechanism of metal ions. Fourier transform IR results confirm that the carboxyl functional groups participated in metal binding. Desorption experiments revealed that greater than 90% of Pb, Cd, and Zn can be eluted from the peat. In addition, results suggested that the desorption efficiency decreased with an increase in the adsorbed metal concentration. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801022p [article] Equilibrium isotherm studies for the multicomponent adsorption of lead, zinc, and cadmium onto Indonesian peat [texte imprimé] / R. Balasubramanian, Auteur ; S. V. Perumal, Auteur ; K. Vijayaraghavan, Auteur . - 2009 . - p. 2093–2099. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N°4 (Février 2009) . - p. 2093–2099 Mots-clés : Indonesian  peat  Pb  Cadmium  Zinc  Langmuir  two-site  model Résumé : This study evaluates the potential of Indonesian peat to sequester Pb, Cd, and Zn in single-, double-, and triple-solute systems. The adsorption isotherms of Pb, Cd, and Zn onto peat in single-solute and multisolute systems were simulated using the Langmuir two-site model satisfactorily. The model and experimental data of binary and ternary systems demonstrated that the presence of the secondary metal ions in the system resulted in a decrease in the sorption capacity of the primary metal, mainly because of the competitive effects of metals for adsorption sites. The metal adsorption follows the order of sequence Pb > Cd > Zn for both single-solute and multisolute systems. A three-dimensional representation of the total metal uptake in binary systems showed a good agreement with the corresponding experimental data. In addition to ion exchange, a surface adsorption−complexation mechanism must be involved in the sorption mechanism of metal ions. Fourier transform IR results confirm that the carboxyl functional groups participated in metal binding. Desorption experiments revealed that greater than 90% of Pb, Cd, and Zn can be eluted from the peat. In addition, results suggested that the desorption efficiency decreased with an increase in the adsorbed metal concentration. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801022p

Removal of Cr(VI) ions by spent tea and coffee dusts / Syam K. Prabhakaran in Industrial & engineering chemistry research, Vol. 48 N°4 (Février 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N°4 (Février 2009) . - p. 2113–2117 Titre : Removal of Cr(VI) ions by spent tea and coffee dusts : reduction to Cr(III) and biosorption Type de document : texte imprimé Auteurs : Syam K. Prabhakaran, Auteur ; K. Vijayaraghavan, Auteur ; R. Balasubramanian, Auteur Année de publication : 2009 Article en page(s) : p. 2113–2117 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Spent  tea  Coffee  dusts  Cr(VI) Résumé : The potential use of spent tea and coffee dusts was investigated for the removal of Cr(VI) from aqueous solution. The removal mechanism was identified as the reduction reaction of Cr(VI) to Cr(III), followed by Cr(III) sorption to the biomass. The phenolic compounds in tea and coffee dusts serve as electron-donor groups for rapid reduction of Cr(VI). The pH edge experiments revealed that Cr(VI) reduction by both tea and coffee dusts was independent of pH whereas reduced Cr(III) adsorption onto biomass was strongly dependent on pH. Isotherm experiments revealed that tea and coffee dusts possess maximum chromium uptakes of 44.9 and 39.0 mg/g, respectively, at pH 4. Among the two isotherm models (Langmuir and Toth), the Toth model better described the chromium biosorption isotherms with high correlation coefficients and low percent error values. A kinetic model based on the redox reaction between Cr(VI) and biomass successfully described the kinetic data. A comparison of these kinetic data with those from Sargassum and Ulva sp., revealed that Cr(VI) reduction rate of coffee dust was 40 times faster than that of Ulva biomass and 144 times faster than that of Sargassum biomass. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801380h [article] Removal of Cr(VI) ions by spent tea and coffee dusts : reduction to Cr(III) and biosorption [texte imprimé] / Syam K. Prabhakaran, Auteur ; K. Vijayaraghavan, Auteur ; R. Balasubramanian, Auteur . - 2009 . - p. 2113–2117. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N°4 (Février 2009) . - p. 2113–2117 Mots-clés : Spent  tea  Coffee  dusts  Cr(VI) Résumé : The potential use of spent tea and coffee dusts was investigated for the removal of Cr(VI) from aqueous solution. The removal mechanism was identified as the reduction reaction of Cr(VI) to Cr(III), followed by Cr(III) sorption to the biomass. The phenolic compounds in tea and coffee dusts serve as electron-donor groups for rapid reduction of Cr(VI). The pH edge experiments revealed that Cr(VI) reduction by both tea and coffee dusts was independent of pH whereas reduced Cr(III) adsorption onto biomass was strongly dependent on pH. Isotherm experiments revealed that tea and coffee dusts possess maximum chromium uptakes of 44.9 and 39.0 mg/g, respectively, at pH 4. Among the two isotherm models (Langmuir and Toth), the Toth model better described the chromium biosorption isotherms with high correlation coefficients and low percent error values. A kinetic model based on the redox reaction between Cr(VI) and biomass successfully described the kinetic data. A comparison of these kinetic data with those from Sargassum and Ulva sp., revealed that Cr(VI) reduction rate of coffee dust was 40 times faster than that of Ulva biomass and 144 times faster than that of Sargassum biomass. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801380h