Values for the effective diffusivities decreased from 2.6 × 10-12 m2/s for the H-form to 2.0-2.3 × 10-12 m2/s for the modified forms. The sorption isotherms for o-xylene showed some unusual steps. 1.7 × 10-11 m2/s, irrespective of whether the H-form or the modified forms were investigated. The rate of sorption of p-xylene on all the samples investigated followed Fick's second law of diffusion, leading to an effective diffusivity of ca. mainly because of a decrease in micropore volume as determined by the t-plot method. The BET specific surface area decreased from 358 m2/g to 35-90 m2/g. The diffusivities of the samples were measured using a new flow gravimetric method involving the sorption of p- and o-xylenes. The sorption properties of samples of H-ZSM-5 zeolite and their forms modified with P, B and Mg were determined by the physical adsorption of nitrogen and evaluated by BET isotherm and t-plot methods. Scherrer crystallite size slightly improved in presence of Mg and Fe. It was observed that incorporation of these individual cations, the Mg and Ca did not show any improvement whereas the presence of Fe and Cu within the matrix of HBO has shown significant improvement in nitrate sorption potential of HBO and it was inferred that presence of Ca, Mg and Fe appear to be helpful in the formation of polymeric structures. HBO adsorbent mixed with cations, which has shown highest nitrate sorptive potential was characterized using XXRay diffraction pattern, Scanning electron micros copy and Fourier Transform Infrared spectroscopy analyses. Calcium and Magnesium were included for their wide availability and possible value addition towards the purpose. In an attempt of improving the potentials of HBO, incorporation of cations such as copper, iron and two transition metals each of which has vividly been used in the preparation of biimetallic adsorbents as well as polymeric ligand exchangers. Hydrous bismuth oxides based adsorbents are found to have nitrate sorptive properties along with their possible application in drinking water treatment. With the ultimate objective of developing an inorganic and sustainable sorptive media for nitrate abatement from drinking water, hydrous bismuth oxide (HBO) has been synthesized and studied as an adsorbent for aqueous medium in the present work. Nitrate contamination of drinking water has become a major health threat in many countries of the world including India and this issue needs to be resolved through developing advance technology to scale down the nitrate concentration and to make the water fit for drinking. Groundwater contamination by nonnmetallic inorganic contaminants has become a severe problem to the human kind and its healthy survival. Keywords: Hydrous Bismuth Oxides (HBOs), Nitrate removal, Cationic ligands, Characterization, Scherrer crystallite size. Scherrer crystallite size slightly improves in presence of Mg and Fe.
The Presence of Ca, Mg and Fe appear helpful in polymeric structure formation. It is observed that while incorporation of these individual cations, the Mg and Ca do not show any improvement while the presence of Fe and Cu with the matrix of HBO showed significant improvement in nitrate sorption potential.
Characterization of HBO, which indicated highest nitrate sorptive potential, along with the materials formed by incorporating these cationic ligands have been attempted using X-ray diffraction (XRD) pattern analyses, Scanning electron microscopy (SEM) and Fourier Transform Infrared (FTIR) spectroscopy determinations. Calcium and Magnesium are included for their wide availability and possible value addition towards the purpose.
In the attempt of improving useful properties of HBO, incorporation of copper, iron and two transition metals each of which has vividly been used in the preparation of bi-metallic adsorbents as well as polymeric ligand exchangers have been examined. Hydrous bismuth oxides (HBO) have been observed to give nitrate sorptive properties and their possible application in drinking water treatment has been explored. Nitrate abatement from drinking water, hydrous bismuth oxide has been used and studied as an adsorbent medium in the present work. With the ultimate objective of developing an inorganic and sustainable sorptive media for Nitrate contamination of drinking water becomes the health threat in many countries including India and this problematic issue needs to be addressed through advance technology to scale down the nitrate concentration and to make it fit for drinking.
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