@article { ISI:000230551600007, title = {General kinetic model framework for the interpretation of adiabatic calorimeter rate data}, journal = {Chemical Engineering Journal}, volume = {110}, number = {1-3}, year = {2005}, month = {JUN}, pages = {67-78}, publisher = {ELSEVIER SCIENCE SA}, type = {Article}, address = {PO BOX 564, 1001 LAUSANNE, SWITZERLAND}, abstract = {

Notwithstanding the variety and complexity of the reactions studied by adiabatic calorimeters like ARC, the data interpretation techniques are not general enough. Traditional thermokinetic analysis primarily lumps a complex multi-step reaction into a single overall reaction and ignores possible thermal effects in some of the possible side reactions. With detailed chromatographic/mass spectrometric analysis of the headspace gases and the condensed phase residues, the pressure profile becomes an additional source of identification of the mechanism and the kinetics of the overall reaction. Finally, in the context of new multiphase catalytic processes of greater efficiency and environment friendliness and with reference to the storage of potentially incompatible fluid mixtures in metallic containers, ARC studies of heterogeneous reaction systems are becoming part of the mandatory safety evaluations. With a few additional measurements a proper kinetic interpretation of the ARC data on such systems seems possible. The paper presents a general model that was shown to be easily adaptable to a number of published reactions of various complexities referred to above. Standard thermal hazard characteristics like the onset temperature, adiabatic temperature rise, self-heat rate, time-to-maximum rate, pressure-temperature profile, etc. could be accurately calculated by the model and these compared closely with the experimental data. It is hoped that the model would be useful as a general-purpose tool for the interpretation of adiabatic calorimetric data for the purpose of process hazard assessment. (c) 2005 Elsevier B.V. All rights reserved.

}, keywords = {accelerating rate calorimeters (ARC), Kinetic modeling, MOC (material of construction) incompatibility in storage, multi-step reactions, runaway reactions}, issn = {1385-8947}, doi = {10.1016/j.cej.2005.05.003}, author = {Bhattacharya, Arijit} } @article { ISI:000272015800038, title = {Defluoridation of drinking water using chemically modified bentonite clay}, journal = {Desalination}, volume = {249}, number = {2}, year = {2009}, month = {DEC}, pages = {687-693}, publisher = {ELSEVIER SCIENCE BV}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

Adsorption potential of metal oxide (lanthanum, magnesium and manganese) incorporated bentonite clay was investigated for defluoridation of drinking water using batch equilibrium experiments to gain insight of adsorption behavior, kinetics and mechanisms of adsorption of fluoride ion. The effect of various physicochemical parameters such as pH, adsorbent dose, initial fluoride concentration and the presence of interfering co-ions on adsorption of fluoride has been investigated. The 10\%La-bentonite shows higher fluoride uptake capacity for defluoridation of drinking water as compared to Mg-bentonite, Mn-bentonite and bare bentonite clay. The uptake of fluoride in acidic pH was higher as compared to alkaline pH. The equilibrium adsorption data fitted reasonably well in both Langmuir and Freundlich isotherm models. It was also observed that in the presence of certain co-existing ions can have positive effect on removal of fluoride, while carbonate and bicarbonate anions show deleterious effect. The rate of adsorption was reasonably rapid and maximum fluoride uptake was attained within 30 min. The modified adsorbent material shows better fluoride removal properties for actual field water, which could be due to the positive effect of other co-ions present in the field water. (C) 2009 Elsevier B.V. All rights reserved.

}, keywords = {10\%La-bentonite, Defluoridation, Kinetic modeling, Langmuir and Freundlich adsorption isotherms, Water treatment}, issn = {0011-9164}, doi = {10.1016/j.desal.2009.01.031}, author = {Kamble, Sanjay P. and Dixit, Priyadarshini and Rayalu, Sadhana S. and Labhsetwar, Nitin K.} } @article { ISI:000284342100003, title = {Adsorption of fluoride from aqueous solution by alumina of alkoxide nature: batch and continuous operation}, journal = {Desalination}, volume = {264}, number = {1-2}, year = {2010}, month = {DEC}, pages = {15-23}, publisher = {ELSEVIER SCIENCE BV}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

In this investigation, we report the adsorption potential of alkoxide origin alumina for defluoridation of drinking water using batch and continuous mode of operations. The effects of different operating parameters such as adsorbent dose, initial fluoride concentration, pH of the solution and interfering ions (usually present in groundwater) were studied with a view to understand the adsorption behavior of the material under various conditions. A thermodynamic study shows that the adsorption of fluoride by alkoxide origin alumina is an exothermic and spontaneous process. The kinetic results showed that the fluoride sorption follows pseudo-second-order kinetics. The applicability of adsorbent in the field is also tested through column breakthrough studies. It has been observed that with an increase in the flow rate and initial fluoride concentration, the breakthrough curve becomes sharper and the breakthrough time and adsorbed fluoride ion concentration decrease. The breakthrough curve also becomes steeper as the bed height increases. The alkoxide origin alumina based adsorbent media can be used directly for field applications since it is also commercially available in granular form. (C) 2010 Elsevier B.V. All rights reserved.

}, keywords = {Adsorption, Alkoxide alumina, Breakthrough studies, Fluoride, Kinetic modeling}, issn = {0011-9164}, doi = {10.1016/j.desal.2010.07.001}, author = {Kamble, Sanjay P. and Deshpande, Gunavant and Barve, Prashant P. and Rayalu, Sadhana and Labhsetwar, Nitin K. and Malyshew, Alexander and Kulkarni, Bhaskar D.} }