02222nas a2200241   4500008004100000022001400041245007800055210006900133260007300202300001200275490000800287520134600295653002001641653001901661653002101680653004901701653002001750100002301770700002501793700002401818700002601842856011201868       2009                        eng d  a0011-916400aDefluoridation of drinking water using chemically modified bentonite clay0 aDefluoridation of drinking water using chemically modified bento  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcDEC  a687-6930 v2493 a<p>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.</p>10a10%La-bentonite10aDefluoridation10aKinetic modeling10aLangmuir and Freundlich adsorption isotherms10aWater treatment1 aKamble, Sanjay, P.1 aDixit, Priyadarshini1 aRayalu, Sadhana, S.1 aLabhsetwar, Nitin, K.  uhttps://library.ncl.res.in/content/defluoridation-drinking-water-using-chemically-modified-bentonite-clay-002246nas a2200277   4500008004100000022001400041245011100055210006900166260007300235300001000308490000800318520125700326653001501583653002101598653002501619653001301644653002101657100002301678700002401701700002401725700002001749700002601769700002401795700002601819856012301845       2010                        eng d  a0011-916400aAdsorption of fluoride from aqueous solution by alumina of alkoxide nature: batch and continuous operation0 aAdsorption of fluoride from aqueous solution by alumina of alkox  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcDEC  a15-230 v2643 a<p>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.</p>10aAdsorption10aAlkoxide alumina10aBreakthrough studies10aFluoride10aKinetic modeling1 aKamble, Sanjay, P.1 aDeshpande, Gunavant1 aBarve, Prashant, P.1 aRayalu, Sadhana1 aLabhsetwar, Nitin, K.1 aMalyshew, Alexander1 aKulkarni, Bhaskar, D.  uhttps://library.ncl.res.in/content/adsorption-fluoride-aqueous-solution-alumina-alkoxide-nature-batch-and-continuous-0