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Birbhum, India

Mukherjee K.,University of Burdwan | Ghosh D.,Krishna Chandra College | Saha B.,University of Burdwan
Desalination and Water Treatment | Year: 2015

Chromate, the invisible danger of environment is found to be degrading both animal and plant kingdom with its carcinogenic oxidizing ability by contaminating ground water. To prevent uncontrolled Cr(VI) contamination, various chemical methods for reduction of hazardous Cr(VI) to less toxic Cr(III) have been established of which aqueous reduction, ion exchange, liquid–liquid extraction, and electrocoagulation are found to be effective. Bioremediation, a greener approach is always of greater interest. The aim of the present study is to utilize mango leaves for the reduction of hexavalent chromium and to accelerate the reduction process by the use of surfactants. A 168 h study reveals that in absence of surfactants 58% of the total chromium(VI) is reduced, whereas removal percentage increases upto 75% in the presence of neutral surfactant TX-100 and upto 79% in the presence of anionic surfactant SDS. © 2015 Balaban Desalination Publications. All rights reserved. Source


Mukherjee K.,University of Burdwan | Ghosh D.,Krishna Chandra College | Saha B.,University of Burdwan
Tenside, Surfactants, Detergents | Year: 2014

Cr(VI) is introduced into environment as a byproduct of industries. It is highly toxic. Biosorption of hexavalent chromium by various types of sawdust appears as a very cost-effective alternative for decontamination of Cr(VI) bearing effluents. In this work water extract of siris sawdust is used for the bioremediation of hexavalent chromium. Cr(VI) ions were reduced to Cr(III) ions as a result of oxidation of organic components present in the water extract of siris sawdust. Formation of Cr(III) is proved by UV-VIS spectroscopy. Functional groups involved in the reduction of Cr(VI) are characterized by FTIR spectroscopy. Bioremediation rate is increased by the use of anionic surfactant sodium dodecylsulphate (SDS) and neutral surfactant Triton-X-100 (TX-100). Here they act as micellar catalyst. Formation of micelles which is responsible for the catalysis of the process is proved by SEM and optical images of the solution. In absence of surfactants 39% of the total chromium(VI) is reduced within 531 h whereas removal percentage increases upto 54% in presence of TX-100. Again in presence of SDS the reduction process is almost 99% complete within 531 h. © Carl Hanser Verlag GmbH & Co. KG. Source


Sar P.,University of Burdwan | Ghosh A.,University of Burdwan | Ghosh D.,Krishna Chandra College | Saha B.,University of Burdwan
Research on Chemical Intermediates | Year: 2015

The kinetics of oxidation of methanol by quinquivalent vanadium in aqueous sulfuric acid medium has been studied at 313 K under pseudo-first-order condition by UV-vis spectrophotometry. Nonfunctional sodium dodecyl sulfate (SDS) surfactant solution was used as a microheterogeneous micellar catalyst. The reaction rate and selectivity strongly depend on the chosen surfactant, and in some cases also on the surfactant concentration. The critical micelle concentration (CMC) values of the SDS surfactant in aqueous medium as well as in the presence of the substrate methanol were determined by the conductivity method, matching well with the kinetically determined CMC value. SDS was found to be an excellent catalyst for oxidation of methanol by vanadium(V) in aqueous sulfuric acid medium, leading to the corresponding oxidized product (formaldehyde), which was detected by 1H nuclear magnetic resonance (NMR). The micellar catalysis by SDS is due to strong binding of the cationic oxidant with the anionic surfactant. Formation of aggregates by the catalytic surfactant was studied using optical microscopy, and the change in shape and size of the aggregates in the reaction condition was studied by using scanning electron microscopy and the dynamic light scattering method. Mechanisms for this oxidation reaction in aqueous medium as well as with micellar catalyst are proposed, being completely supported by our experimental results. © 2014 Springer Science+Business Media. Source


Ghosh D.,Krishna Chandra College | Saha R.,Kg Engineering Institute | Saha R.,University of Burdwan | Ghosh A.,University of Burdwan | And 2 more authors.
Desalination and Water Treatment | Year: 2015

The presence of cadmium(II) in water possesses human health risks. Cadmium(II) has the harmful effects of high toxicity to the living organism in water. This review presents a compilation of biosorption of cadmium(II) by different biomaterials for the efficient removal of cadmium(II) from contaminated water. Kinetic models and adsorption isotherms have been discussed. The aim of this review is to present a broad view of adsorbents that have been identified and used for cadmium(II) removal from contaminated waters. The removal efficiency and adsorption of different biosorbents have been compared in this review. The influence of pH on removal of cadmium(II) efficiency has also been discussed. © 2013, © 2013 Balaban Desalination Publications. All rights reserved. Source

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