vandana singh - Academia.edu (original) (raw)

Papers by vandana singh

Carbohydrate Polymers, 2005

Large rural populations in arid areas of Tanzania use polluted water from man-made water reservoi... more Large rural populations in arid areas of Tanzania use polluted water from man-made water reservoirs (charco dams) for drinking with minimal or without treatment. The ability of coagulant proteins purified from Parkinsonia aculeata seed to purify water from charco dam was studied. The P. aculeata coagulant proteins were purified from P. aculeata crude seed extract by simplified ion exchange chromatography (IEX). The Purified proteins are cationic in nature with molecular mass of about 6 kDa, very similar to that of Moringa oleifera proteins. Jar tests were used to investigate the coagulation performance of the purified proteins in comparison to that of a conventional chemical coagulant, which is aluminium sulphate (alum). Coagulation efficiencies of the purified proteins and alum varied slightly. The optimum coagulation dosages for the purified proteins and alum were 6 mg/L and 14 mg/L, which reduced turbidity from 880 NTU (initial raw water turbidity) to 3 and 13 NTU, respectively. The purified proteins reduced turbidity along with Fe 2+ , NO 3and PO 4 3in coagulated water samples to levels that complied with Tanzania Drinking Water Quality Standards, and, in some cases with WHO standards. Contrary to alum, PAP did not affect the pH and alkalinity of treated water hence; coagulant proteins do not need additives to regulate the pH. The IEX method used for seed protein purification is simple and easily scalable, and hence, it is recommended for production of potable water for poor communities.

Carbohydrate Polymers, 2009

Biomedical and Environmental Applications, 2011

Page 1. PART 3 MISCELLANEOUS BIOPOLYMERS Susheel Kalia and Luc Avérous (eds.) Biopolymers: Biomed... more Page 1. PART 3 MISCELLANEOUS BIOPOLYMERS Susheel Kalia and Luc Avérous (eds.) Biopolymers: Biomedical and Environmental Applications, (3-34) © Scrivener Publishing LLC Page 2. 10 Cassia Seed Gums: A Renewable Reservoir for Synthesizing High Performance ...

International Journal of Biological Macromolecules, 2015

Present communication reports on the synthesis and characterization of Hg(II) sorbing millimeter ... more Present communication reports on the synthesis and characterization of Hg(II) sorbing millimeter sized porous titania spheres (TSP). The synthesis utilizes guar gum-alginate hybrid beads as sacrificial template to polymerize titanium(IV) isopropoxide. The hybrid beads are crafted by pouring guar-alginate mixed solution to calcium bath. The mechanical strength of the beads depended on guar to alginate ratio in the mixed solution. The equal weight ratio of the two polysaccharides is appropriate for adequate mechanical strength beads. The unique performance of the templating beads is attributed to the synergistic interaction between guar gum and sodium alginate. FTIR, BET, SEM, TEM, XRD, TGA, and DTG analyses have been used for the characterization of the optimum performance TSP (TSPAG2). TSPAG2 is a mesoporous material that has higher surface area and narrower pore size distribution than pure alginate derived titania spheres (TSPA). TEM study demonstrated that TSPAG2 spheres are constituted of aggregated TiO2 nanoparticles of ∼ 10 nm size. TSPAG2 is able to capture >95% Hg(II) from synthetic Hg(II) solution in 10h at pH 5 as opposed to only 68% removal by TSPA.

Sanghi/Green, 2011

... Yves Chauvin (France), Robert Grubbs (USA), and Richard Schrock (USA) shared the prize for th... more ... Yves Chauvin (France), Robert Grubbs (USA), and Richard Schrock (USA) shared the prize for their contribution to the development of metathesis (meaning"change places"), an ener-getically favored and less hazardous method in organic synthesis, which has immense ...

Advances in Water Treatment and Pollution Prevention, 2012

Polysaccharides are the renewable natural reservoir which can be tailored to obtain a broad spect... more Polysaccharides are the renewable natural reservoir which can be tailored to obtain a broad spectrum of macromolecular materials. The multifunctional nature of polysaccharides offers wide flexibility of tailoring and modification. To suit adsorption applications, many water-soluble polysaccharides have been transformed to insoluble materials by chemical modification and cross-linking. These materials have also been utilized for coagulation–flocculation of industrial wastes. Depending upon the targeted application, which may be either adsorption or coagulation and flocculation, the solubility and characteristics of these materials are tailored. Present chapter focuses on the polysaccharides and polysaccharide-derived materials that are known to decolorize industrial waste and synthetic aqueous dye solutions through flocculation and adsorption.

Advanced Materials Letters, 2010

Reactive and Functional Polymers, 2007

In view of easy availability of the plant and high demand of seed gums throughout the world, the ... more In view of easy availability of the plant and high demand of seed gums throughout the world, the present investigations have been carried out for possible exploitation of Ipomoea seeds as potential source of commercial gum. Graft co-polymerization with acrylamide was done to ...

Polymers for Advanced Technologies, 2007

Abstract In view of the known advantages of the microwave promoted reactions done in dry medium, ... more Abstract In view of the known advantages of the microwave promoted reactions done in dry medium, the seed gum sourced from Cassia marginata has been graft copolymerized with acrylonitrile in dry medium at neutral alumina support under microwave irradiation. ...

International Journal of Pharmacognosy, 1995

Roots of Ipomoea pestigrides are reported to be used as a purgative and for the treatment of boil... more Roots of Ipomoea pestigrides are reported to be used as a purgative and for the treatment of boils, carbuncles, and dog bites. These uses may be attributed to the presence of polysaccharides and oligosaccharides.

Pharmaceutical Biology, 1991

Abstract A water soluble biopolymer composed of D-galactose and D-mannose in molar ratio 1: 3 was... more Abstract A water soluble biopolymer composed of D-galactose and D-mannose in molar ratio 1: 3 was isolated from the seeds of C. surattensis. Hydrolysis of the methylated polysaccharide furnished three methylated sugars (i) 2, 3, di-O-methyl-D-mannose,(ii) 2, 3, ...

Pharmaceutical Biology, 2004

Ipomoea digitata plant is reported to be highly medicinal, and its seeds were found to contain a ... more Ipomoea digitata plant is reported to be highly medicinal, and its seeds were found to contain a substantial amount of seed gum. Owing to the high medicinal and industrial importance of the seed gums in general and the high medicinal value of the plant itself, ...

Journal of Sol-Gel Science and Technology, 2008

Journal of Hazardous Materials, 2009

Present study reports on peroxydisulfate/ascorbic acid initiated synthesis of Chitosan-graft-poly... more Present study reports on peroxydisulfate/ascorbic acid initiated synthesis of Chitosan-graft-poly(methylmethacrylate) (Ch-g-PMMA) and its characterization by FTIR, XRD and (13)C NMR. The copolymer remained water insoluble even under highly acidic conditions and was evaluated to be an efficient adsorbent for the three anionic azo dyes (Procion Yellow MX, Remazol Brilliant Violet and Reactive Blue H5G) over a wide pH range of 4-10 being most at pH 7. The adsorbent was also found efficient in decolorizing the textile industry wastewater and was much more efficient than the parent chitosan. Equilibrium sorption experiments were carried out at different pH and initial dye concentration values. The experimental equilibrium data for each adsorbent-dye system were successfully fitted to the Langmuir and Freundlich sorption isotherms. Based on Langmuir model Q(max) for yellow, violet and blue dyes was 250, 357 and 178, respectively. Thermodynamic parameters of the adsorption processes such as DeltaG degrees , DeltaH degrees , and DeltaS degrees were calculated. The negative values of free energy reflected the spontaneous nature of adsorption. The adsorption kinetic data of all the three dyes could be well represented by pseudo-second-order model with the correlation coefficients (R(2)) being 0.9922, 0.9997 and 0.9862, for direct yellow, reactive violet and blue dye, respectively with rate constants 0.91 x 10(-4), 1.82 x 10(-4) and 1.05 x 10(-4) g mg(-1)min(-1), respectively. At pH 7, parent chitosan also showed pseudo-second-order kinetics. The temperature dependence of dye uptake and the pseudo-second-order kinetics of the adsorption indicated that chemisorption is the rate-limiting step that controls the process.

Journal of Applied Polymer Science, 2007

Journal of Applied Polymer Science, 2008

Ceric ammonium sulfate/sodium disulfite redox system was evaluated for the poly(acrylamide) (PAM)... more Ceric ammonium sulfate/sodium disulfite redox system was evaluated for the poly(acrylamide) (PAM) grafting on to Cassia reticulata (CR) seed gum. Grafting conditions were optimized and the maximum %Grafting (%G) and %Efficiency (%E) achieved were 152 and 97.2%, respectively, using [disulfite] 0.005M; [ceric ammonium sulfate] 0.026M; [acrylamide] 0.11M; [gum] 0.125 g/25mL at 40 AE 0.28C. Representative CR-grafted gum (CRPAM) was characterized by Fourier transform infrared spectrometry (FTIR), X-ray diffraction (XRD), and thermogravimetric analysis (TGA). Under identical conditions, the redox initiator could result 142.6 %G and 91.2 %E on to guar gum (GG). Various physical properties of the CR gum/grafted CR gum, such as viscosity, water retention, and saline retention, were studied and compared with GG/grafted GG to find out the potential industrial use of CR gum and PAM-grafted-CR gum. V

Carbohydrate Polymers, 2005

Large rural populations in arid areas of Tanzania use polluted water from man-made water reservoi... more Large rural populations in arid areas of Tanzania use polluted water from man-made water reservoirs (charco dams) for drinking with minimal or without treatment. The ability of coagulant proteins purified from Parkinsonia aculeata seed to purify water from charco dam was studied. The P. aculeata coagulant proteins were purified from P. aculeata crude seed extract by simplified ion exchange chromatography (IEX). The Purified proteins are cationic in nature with molecular mass of about 6 kDa, very similar to that of Moringa oleifera proteins. Jar tests were used to investigate the coagulation performance of the purified proteins in comparison to that of a conventional chemical coagulant, which is aluminium sulphate (alum). Coagulation efficiencies of the purified proteins and alum varied slightly. The optimum coagulation dosages for the purified proteins and alum were 6 mg/L and 14 mg/L, which reduced turbidity from 880 NTU (initial raw water turbidity) to 3 and 13 NTU, respectively. The purified proteins reduced turbidity along with Fe 2+ , NO 3and PO 4 3in coagulated water samples to levels that complied with Tanzania Drinking Water Quality Standards, and, in some cases with WHO standards. Contrary to alum, PAP did not affect the pH and alkalinity of treated water hence; coagulant proteins do not need additives to regulate the pH. The IEX method used for seed protein purification is simple and easily scalable, and hence, it is recommended for production of potable water for poor communities.

Carbohydrate Polymers, 2009

Biomedical and Environmental Applications, 2011

Page 1. PART 3 MISCELLANEOUS BIOPOLYMERS Susheel Kalia and Luc Avérous (eds.) Biopolymers: Biomed... more Page 1. PART 3 MISCELLANEOUS BIOPOLYMERS Susheel Kalia and Luc Avérous (eds.) Biopolymers: Biomedical and Environmental Applications, (3-34) © Scrivener Publishing LLC Page 2. 10 Cassia Seed Gums: A Renewable Reservoir for Synthesizing High Performance ...

International Journal of Biological Macromolecules, 2015

Present communication reports on the synthesis and characterization of Hg(II) sorbing millimeter ... more Present communication reports on the synthesis and characterization of Hg(II) sorbing millimeter sized porous titania spheres (TSP). The synthesis utilizes guar gum-alginate hybrid beads as sacrificial template to polymerize titanium(IV) isopropoxide. The hybrid beads are crafted by pouring guar-alginate mixed solution to calcium bath. The mechanical strength of the beads depended on guar to alginate ratio in the mixed solution. The equal weight ratio of the two polysaccharides is appropriate for adequate mechanical strength beads. The unique performance of the templating beads is attributed to the synergistic interaction between guar gum and sodium alginate. FTIR, BET, SEM, TEM, XRD, TGA, and DTG analyses have been used for the characterization of the optimum performance TSP (TSPAG2). TSPAG2 is a mesoporous material that has higher surface area and narrower pore size distribution than pure alginate derived titania spheres (TSPA). TEM study demonstrated that TSPAG2 spheres are constituted of aggregated TiO2 nanoparticles of ∼ 10 nm size. TSPAG2 is able to capture >95% Hg(II) from synthetic Hg(II) solution in 10h at pH 5 as opposed to only 68% removal by TSPA.

Sanghi/Green, 2011

... Yves Chauvin (France), Robert Grubbs (USA), and Richard Schrock (USA) shared the prize for th... more ... Yves Chauvin (France), Robert Grubbs (USA), and Richard Schrock (USA) shared the prize for their contribution to the development of metathesis (meaning"change places"), an ener-getically favored and less hazardous method in organic synthesis, which has immense ...

Advances in Water Treatment and Pollution Prevention, 2012

Polysaccharides are the renewable natural reservoir which can be tailored to obtain a broad spect... more Polysaccharides are the renewable natural reservoir which can be tailored to obtain a broad spectrum of macromolecular materials. The multifunctional nature of polysaccharides offers wide flexibility of tailoring and modification. To suit adsorption applications, many water-soluble polysaccharides have been transformed to insoluble materials by chemical modification and cross-linking. These materials have also been utilized for coagulation–flocculation of industrial wastes. Depending upon the targeted application, which may be either adsorption or coagulation and flocculation, the solubility and characteristics of these materials are tailored. Present chapter focuses on the polysaccharides and polysaccharide-derived materials that are known to decolorize industrial waste and synthetic aqueous dye solutions through flocculation and adsorption.

Advanced Materials Letters, 2010

Reactive and Functional Polymers, 2007

In view of easy availability of the plant and high demand of seed gums throughout the world, the ... more In view of easy availability of the plant and high demand of seed gums throughout the world, the present investigations have been carried out for possible exploitation of Ipomoea seeds as potential source of commercial gum. Graft co-polymerization with acrylamide was done to ...

Polymers for Advanced Technologies, 2007

Abstract In view of the known advantages of the microwave promoted reactions done in dry medium, ... more Abstract In view of the known advantages of the microwave promoted reactions done in dry medium, the seed gum sourced from Cassia marginata has been graft copolymerized with acrylonitrile in dry medium at neutral alumina support under microwave irradiation. ...

International Journal of Pharmacognosy, 1995

Roots of Ipomoea pestigrides are reported to be used as a purgative and for the treatment of boil... more Roots of Ipomoea pestigrides are reported to be used as a purgative and for the treatment of boils, carbuncles, and dog bites. These uses may be attributed to the presence of polysaccharides and oligosaccharides.

Pharmaceutical Biology, 1991

Abstract A water soluble biopolymer composed of D-galactose and D-mannose in molar ratio 1: 3 was... more Abstract A water soluble biopolymer composed of D-galactose and D-mannose in molar ratio 1: 3 was isolated from the seeds of C. surattensis. Hydrolysis of the methylated polysaccharide furnished three methylated sugars (i) 2, 3, di-O-methyl-D-mannose,(ii) 2, 3, ...

Pharmaceutical Biology, 2004

Ipomoea digitata plant is reported to be highly medicinal, and its seeds were found to contain a ... more Ipomoea digitata plant is reported to be highly medicinal, and its seeds were found to contain a substantial amount of seed gum. Owing to the high medicinal and industrial importance of the seed gums in general and the high medicinal value of the plant itself, ...

Journal of Sol-Gel Science and Technology, 2008

Journal of Hazardous Materials, 2009

Present study reports on peroxydisulfate/ascorbic acid initiated synthesis of Chitosan-graft-poly... more Present study reports on peroxydisulfate/ascorbic acid initiated synthesis of Chitosan-graft-poly(methylmethacrylate) (Ch-g-PMMA) and its characterization by FTIR, XRD and (13)C NMR. The copolymer remained water insoluble even under highly acidic conditions and was evaluated to be an efficient adsorbent for the three anionic azo dyes (Procion Yellow MX, Remazol Brilliant Violet and Reactive Blue H5G) over a wide pH range of 4-10 being most at pH 7. The adsorbent was also found efficient in decolorizing the textile industry wastewater and was much more efficient than the parent chitosan. Equilibrium sorption experiments were carried out at different pH and initial dye concentration values. The experimental equilibrium data for each adsorbent-dye system were successfully fitted to the Langmuir and Freundlich sorption isotherms. Based on Langmuir model Q(max) for yellow, violet and blue dyes was 250, 357 and 178, respectively. Thermodynamic parameters of the adsorption processes such as DeltaG degrees , DeltaH degrees , and DeltaS degrees were calculated. The negative values of free energy reflected the spontaneous nature of adsorption. The adsorption kinetic data of all the three dyes could be well represented by pseudo-second-order model with the correlation coefficients (R(2)) being 0.9922, 0.9997 and 0.9862, for direct yellow, reactive violet and blue dye, respectively with rate constants 0.91 x 10(-4), 1.82 x 10(-4) and 1.05 x 10(-4) g mg(-1)min(-1), respectively. At pH 7, parent chitosan also showed pseudo-second-order kinetics. The temperature dependence of dye uptake and the pseudo-second-order kinetics of the adsorption indicated that chemisorption is the rate-limiting step that controls the process.

Journal of Applied Polymer Science, 2007

Journal of Applied Polymer Science, 2008

Ceric ammonium sulfate/sodium disulfite redox system was evaluated for the poly(acrylamide) (PAM)... more Ceric ammonium sulfate/sodium disulfite redox system was evaluated for the poly(acrylamide) (PAM) grafting on to Cassia reticulata (CR) seed gum. Grafting conditions were optimized and the maximum %Grafting (%G) and %Efficiency (%E) achieved were 152 and 97.2%, respectively, using [disulfite] 0.005M; [ceric ammonium sulfate] 0.026M; [acrylamide] 0.11M; [gum] 0.125 g/25mL at 40 AE 0.28C. Representative CR-grafted gum (CRPAM) was characterized by Fourier transform infrared spectrometry (FTIR), X-ray diffraction (XRD), and thermogravimetric analysis (TGA). Under identical conditions, the redox initiator could result 142.6 %G and 91.2 %E on to guar gum (GG). Various physical properties of the CR gum/grafted CR gum, such as viscosity, water retention, and saline retention, were studied and compared with GG/grafted GG to find out the potential industrial use of CR gum and PAM-grafted-CR gum. V