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Islam M.,Purushottam Institute of Engineering and Technology | Patel R.,National Institute of Technology Rourkela
Chemical Engineering Journal | Year: 2011

Adsorption characteristics of fluoride adsorption onto the thermally activated basic oxygen furnace (BOF) slag were identified as a function of pH and ion strengths in solution. In addition, adsorption mechanism was investigated by conducting batch tests on fluoride adsorption process of the thermally activated BOF slag, and making a comparative XRD analysis of fresh and exhausted adsorbent. SEM micrographs were obtained to study the effect of thermal activation on the morphology of the adsorbent. Batch experiments were performed to investigate effects of various experimental parameters such as contact time (5min to 8h), initial fluoride concentration (1-50mg/L), temperature (25, 35 and 45°C), pH (2-10) and the presence of competing anions on fluoride adsorption on thermally activated BOF slag. Kinetic data reveal that the uptake rate of fluoride was rapid at the beginning and equilibrium was achieved within 35min. The adsorption process was well described by pseudo-first-order kinetics model. The adsorption data better fitted Langmuir adsorption isotherm. The maximum adsorption capacity calculated from Langmuir isotherm model was up to 8.07mg/g. Thermodynamic study indicates an endothermic nature of adsorption and a spontaneous and favorable process. The optimum pH for fluoride removal was between 6 and 10. The fluoride adsorption was impeded by the presence of PO4 3-, followed by SO4 2- and NO3 -. © 2011 Elsevier B.V. Source


Giri A.K.,National Institute of Technology Rourkela | Patel R.K.,National Institute of Technology Rourkela | Mahapatra S.S.,National Institute of Technology Rourkela | Mishra P.C.,Purushottam Institute of Engineering and Technology
Environmental Science and Pollution Research | Year: 2013

In this work, removal of arsenic (III) from aqueous solution by living cells (Bacillus cereus), biosorption mechanism, and characterization studies have been reported. B. cereus cell surface was characterized using SEM-EDX and FTIR. Dependence of biosorption on pH of the solution, biosorbent dose, initial arsenic (III) concentration, contact time, and temperature had been studied to achieve optimum condition. The maximum biosorption capacity of living cells of B. cereus for arsenic (III) was found to be 32. 42 mg/g at pH 7. 5, at optimum conditions of contact time of 30 min, biomass dosage of 6 g/L, and temperature of 30 ± 2 °C. Biosorption data of arsenic (III) are fitted to linearly transformed Langmuir isotherm with R2 (correlation coefficient) > 0. 99. The pseudo-second-order model description of the kinetics of arsenic (III) is successfully applied to predict the rate constant of biosorption. Thermodynamic parameters reveal the endothermic, spontaneous, and feasible nature of sorption process of arsenic (III) onto B. cereus biomass. The arsenic (III) ions are desorbed from B. cereus using both 1 M HCl and 1 M HNO3. © 2012 Springer-Verlag Berlin Heidelberg. Source


Islam M.,Purushottam Institute of Engineering and Technology | Patel R.,National Institute of Technology Rourkela
Journal of Hazardous Materials | Year: 2011

The objective of the present research was to synthesize, characterize and to investigate adsorption of nitrate from synthetic nitrate solution by Ca-Al-Cl HTlc. In the present study Ca-Al-Cl HTlc was synthesized by co-precipitation method and was characterized using SEM, XRD, FTIR and TGA-DSC. To assess the practical usefulness, a detailed removal study of nitrate was carried out. The removal of nitrate was 84.6% under neutral condition using 0.35g of adsorbent in 100mL of nitrate solution having initial concentration of 10mg/L. Adsorption kinetic study revealed that the adsorption process followed first order kinetics. Adsorption data were fitted to linearly transformed Langmuir adsorption isotherm with R 2 (correlation coefficient)>0.99. Thermodynamic parameters were also calculated to study the effect of temperature on the removal process. In order to understand the adsorption type, equilibrium data were tested with Dubinin-Radushkevich isotherm. © 2011 Elsevier B.V. Source


Naushad M.,King Saud University | AL-Othman Z.A.,King Saud University | Islam M.,Purushottam Institute of Engineering and Technology
International Journal of Environmental Science and Technology | Year: 2013

A new organic-inorganic composite cation exchanger polyaniline Sn(IV) silicate has been synthesized. The physicochemical properties of this ion exchanger were determined using different analytical techniques including fourier transform infrared spectroscopy, simultaneous thermogravimetry-differential thermogravimetry analyses, X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy and elemental analysis studies. Ion exchange capacity and effect of heating temperature on ion exchange capacity were also carried out on this ion exchange material. Adsorption properties for different metal ions have been investigated and the results revealed that polyaniline Sn(IV) silicate had the highest adsorption capacity for Cd2+ ion. It's selectivity was tested by achieving some important binary separations. Dependence of adsorption on contact time, temperature, pH of the solution and exchanger dose had been studied to achieve the optimum conditions. Adsorption kinetic study showed that the adsorption process followed the first order kinetics. Adsorption data were fitted to linearly transformed Langmuir isotherm with R2 (correlation coefficient) >0. 99. The maximum removal of Cd2+ was found at pH 9. The adsorption was fast and the equilibrium established within 40 min. Thermodynamic parameters viz- entropy change, enthalpy change and Gibb's free energy change were also calculated. © 2013 Islamic Azad University (IAU). Source


Islam M.,Purushottam Institute of Engineering and Technology | Patel R.,National Institute of Technology Rourkela
Desalination | Year: 2010

Deleterious effects of nitrate on health are well known. A laboratory study was conducted to investigate the ability of Zn-Al-Cl layered double hydroxide for the removal of nitrate from synthetic nitrate solution. In the present study Zn-Al-Cl LDH was synthesized by co-precipitation method and was characterized using SEM, XRD, FTIR and TGA-DSC. To know the practical applicability, a detailed nitrate removal study was carried out. The removal of nitrate was 85.5% under neutral conditions, using 0.3g of LDH in 100mL of nitrate solution having initial concentration of 10mg/L. Adsorption kinetic study revealed that the adsorption process followed first order kinetics. Adsorption data were fitted to linearly transformed Langmuir isotherm with R 2 (correlation coefficient) >0.99. Thermodynamic parameters were also calculated to study the effect of temperature on the removal process. In order to understand the adsorption type, equilibrium data were tested with Dubinin-Radushkevich isotherm. The percentage removal was found to decrease gradually with increase in pH and the optimum pH was found to be 6. The presence of competitive anions reduced the nitrate adsorption in the order of carbonate>phosphate>chloride>sulphate. The Zn-Al-Cl LDH exhibited low desorption and poor regeneration. © 2010 Elsevier B.V. Source

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