ananya ghosh | National Institute of Technology, Durgapur (original) (raw)
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Papers by ananya ghosh
Well-dispersed single phasic flower-like zero valent iron nanoparticles have been synthesized und... more Well-dispersed single phasic flower-like zero valent iron nanoparticles have been synthesized under aer-obic conditions using a facile approach without the addition of any additives or templates. The role of hydroxyl groups of polyhydroxy alcohols in controlling surface morphology of nanoparticles has been thoroughly investigated. The obtained nanoparticles have been characterized by TEM, FE-SEM, XRD and BET surface area analyzer. Electron microscopy analyses reveal that the solvent plays a pivotal role in determining the morphology of the particles. With increase in viscosity of the solvent, formations of 'petal-like' structures, which are joined at the center are formed. The nitrate removal efficiency of the iron nanoparticles synthesized in different solvents has been studied and it is seen that the ''flower-like " iron nanoparticles were most active in the removal of nitrate. Experiments have been done by varying (i) nitrate concentrations, (ii) nanoparticle dose, and (iii) type of nanoparticles. The results conclude that highest removal efficiency ($100%) was achieved when the nanoparticle dose was 2.88 g/L, even for high nitrate concentrations up to 400 mg/L. The major highlight of this work is the fact that even though the nanoparticles synthesized in glycerol-water mixture have larger size in comparison to the other nanopar-ticles, still they remove the nitrates with highest efficiency. "
Desalination and Water Treatment, 2015
Synthesized nanoscale zero-valent iron (NZVI) particles were applied for the degradation of a rea... more Synthesized nanoscale zero-valent iron (NZVI) particles were applied for the degradation of a reactive dye Remazol Black B 133 and textile effluent. XRD and HR-TEM analysis of the synthesized particles showed body centered cubic crystal packing. The aggregates were spherical in shape and the size of the particles ranged from 5 to 15 nm. The reactive dye solution was substantially degraded by NZVI particles using ultrasonic irradiation under various experimental conditions created by varying NZVI dosages (0.15–0.30 g/L), initial dye concentration (25–200 mg/L), and pH (2–13). Experimental results suggest that NZVI particles work best within the pH range of 4–10. A unit gram of NZVI was found to degrade a maximum of 749.2 mg of RB B 133 dye and more than 80% of the dye was removed within 15 min of reaction time. During the degradation process, an oxidation– reduction potential change from 196 to −577 mV was detected, indicating reductive condition is necessary for effective dye removal. FT-IR analysis of the end products of the degradation process indicated the presence of an amino (–NH ) group resulting from the breakdown of the azo (–N=N–) group. Results suggest that the degradation followed pseudo-first-order kinetics with respect to dye concentration. The effluents of two textile industries were collected, characterized, and treated with NZVI particles, which led to the significant fall below the standard scale of American Dye Manufacturing Institute (ADMI). This lowering of ADMI value indicates that the overall color removal efficiency is irrespective of any specific dye present in the effluent. 2
Abstract—The effectiveness of Fenton’s reagent (H2O2/Fe+2) for chemical oxidation of the organic ... more Abstract—The effectiveness of Fenton’s reagent (H2O2/Fe+2)
for chemical oxidation of the organic content of wastewater
generated from a textile industry has been studied. The
oxidative agent generates reactive hydroxyl radical species
which degrades the reactive dye under study: Remazol brilliant
orange 3RID (RBO3RID). The experimental results indicate
that the oxidation process leads to a reduction in the chemical
oxygen demand (COD) concentration up to 97%. Response
surface methodology was used to optimize three different
process variables: COD to Hydrogen peroxide ratio, Hydrogen
peroxide-to-Fe (II) ratio and time. Analysis of variance
(ANOVA) showed a high coefficient of determination value. Effect of experimental parameters on the COD
removal efficiency of RBO3RID was established by the
response surface and contour plots. Results showed that COD
removal increases with increasing oxidation time and initial
Fe+2 concentration.
Well-dispersed single phasic flower-like zero valent iron nanoparticles have been synthesized und... more Well-dispersed single phasic flower-like zero valent iron nanoparticles have been synthesized under aer-obic conditions using a facile approach without the addition of any additives or templates. The role of hydroxyl groups of polyhydroxy alcohols in controlling surface morphology of nanoparticles has been thoroughly investigated. The obtained nanoparticles have been characterized by TEM, FE-SEM, XRD and BET surface area analyzer. Electron microscopy analyses reveal that the solvent plays a pivotal role in determining the morphology of the particles. With increase in viscosity of the solvent, formations of 'petal-like' structures, which are joined at the center are formed. The nitrate removal efficiency of the iron nanoparticles synthesized in different solvents has been studied and it is seen that the ''flower-like " iron nanoparticles were most active in the removal of nitrate. Experiments have been done by varying (i) nitrate concentrations, (ii) nanoparticle dose, and (iii) type of nanoparticles. The results conclude that highest removal efficiency ($100%) was achieved when the nanoparticle dose was 2.88 g/L, even for high nitrate concentrations up to 400 mg/L. The major highlight of this work is the fact that even though the nanoparticles synthesized in glycerol-water mixture have larger size in comparison to the other nanopar-ticles, still they remove the nitrates with highest efficiency. "
Desalination and Water Treatment, 2015
Synthesized nanoscale zero-valent iron (NZVI) particles were applied for the degradation of a rea... more Synthesized nanoscale zero-valent iron (NZVI) particles were applied for the degradation of a reactive dye Remazol Black B 133 and textile effluent. XRD and HR-TEM analysis of the synthesized particles showed body centered cubic crystal packing. The aggregates were spherical in shape and the size of the particles ranged from 5 to 15 nm. The reactive dye solution was substantially degraded by NZVI particles using ultrasonic irradiation under various experimental conditions created by varying NZVI dosages (0.15–0.30 g/L), initial dye concentration (25–200 mg/L), and pH (2–13). Experimental results suggest that NZVI particles work best within the pH range of 4–10. A unit gram of NZVI was found to degrade a maximum of 749.2 mg of RB B 133 dye and more than 80% of the dye was removed within 15 min of reaction time. During the degradation process, an oxidation– reduction potential change from 196 to −577 mV was detected, indicating reductive condition is necessary for effective dye removal. FT-IR analysis of the end products of the degradation process indicated the presence of an amino (–NH ) group resulting from the breakdown of the azo (–N=N–) group. Results suggest that the degradation followed pseudo-first-order kinetics with respect to dye concentration. The effluents of two textile industries were collected, characterized, and treated with NZVI particles, which led to the significant fall below the standard scale of American Dye Manufacturing Institute (ADMI). This lowering of ADMI value indicates that the overall color removal efficiency is irrespective of any specific dye present in the effluent. 2
Abstract—The effectiveness of Fenton’s reagent (H2O2/Fe+2) for chemical oxidation of the organic ... more Abstract—The effectiveness of Fenton’s reagent (H2O2/Fe+2)
for chemical oxidation of the organic content of wastewater
generated from a textile industry has been studied. The
oxidative agent generates reactive hydroxyl radical species
which degrades the reactive dye under study: Remazol brilliant
orange 3RID (RBO3RID). The experimental results indicate
that the oxidation process leads to a reduction in the chemical
oxygen demand (COD) concentration up to 97%. Response
surface methodology was used to optimize three different
process variables: COD to Hydrogen peroxide ratio, Hydrogen
peroxide-to-Fe (II) ratio and time. Analysis of variance
(ANOVA) showed a high coefficient of determination value. Effect of experimental parameters on the COD
removal efficiency of RBO3RID was established by the
response surface and contour plots. Results showed that COD
removal increases with increasing oxidation time and initial
Fe+2 concentration.