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Nashik, India

Pethkar A.V.,Government Institute of Science | Bhagat A.P.,KTHM College
Materials Science Forum | Year: 2013

India is one of the largest producer and exporter of dyestuff among developing countries. Large amount of dyes is lost in industrial effluents during production and industrial use. Persistence of dyes in the environment, their non-biodegradability and toxicity necessitate urgent steps to develop environment-friendly approaches to remove them from wastewaters. The present work describes attempts to use iron-based catalytic nanoparticles (NPs) for removal and degradation of Acid Black 1, one of the notoriously toxic dyes. A rapid screening assay was developed in order to select NPs possessing reducing properties. Methylene blue (MB) dye (0.1mg/L, 250μl) was exposed to different preparations of NPs (7mg) for 30 minute in a 96-well microtiter plate and read at 630 nm using an ELISA reader. Iron sulphide nanoparticles (FeSNPs) stabilized by a plant biopolymer (BP) could remove >95% MB and were selected for further studies. The FeSNPs could remove Acid Black 1 efficiently (73.8%) with specific dye removal capacity of 19.7 mg/g NPs. FeSNPs were immobilized in alginate beads (average diameter 3.45 mm) and packed in polypropylene columns (22.5 cm long, 3 cm i.d.) having bed volume of 42 ml. Acid black 1 solution (20 mg/L) was passed through the columns at predetermined flow rates in up-flow mode using peristaltic pump. The mass transfer kinetics were favourable at a flow rate of 2.2 ml/min (mass transfer coefficient 9.38×10-5 L.mg-1.min-1), and 120 bed volumes of the solution could be treated with efficiency exceeding 90%. Analysis of column effluent by UV-visible and FTIR spectroscopy revealed that removal of dye from solution was due to reductive degradation. © (2013) Trans Tech Publications, Switzerland. Source

Gaikwad N.D.,KTHM College | Patil S.V.,P.A. College | Bobade V.D.,P.A. College
Journal of Heterocyclic Chemistry | Year: 2013

A series of new 1-[4-(2,3,4-substituted-phenyl) thiazol-2-yl]-3-(2,3,4- substituted-phenyl)-1H-pyrazole-4-carbaldehyde (4a-m), 4-[4-(4-substituted- phenyl) thiazol-2-yl]-3-(4-substituted-phenyl)-1-phenyl-1H-pyrazole (7a-i), 4-[4-(4-substituted phenyl)thiazol-2-yl]-1-phenyl-1H-pyrazol-3-amine (10a-g) have been synthesized by using Vilsmeier Haack formylation and Hantzsch reaction in high yield. All the synthesized compounds were tested qualitative (Zone of inhibition) and quantitative antimicrobial activities (MIC). Most of the synthesized compounds showed potent antimicrobial activity against gram positive and gram negative bacteria as well as fungi species. © 2013 HeteroCorporation. Source

Doke K.,University of Pune | Khan E.,University of Pune | Gaikwad V.,KTHM College | Gaikwad V.,University of Pune
Journal of Dispersion Science and Technology | Year: 2013

The present study investigates biosorption diffusion mechanism for the removal of toxic hexavalent chromium from aqueous solution using powdered cotton stalk an agricultural waste biomass. The effects of pH, temperature, adsorption isotherms, adsorption kinetics, and thermodynamic on chromium biosorption were investigated. The results showed that a maximum removal efficiency of 95% was achieved at pH 2. The pH at zero point charge (pHzpc) on biosorbent surface was 4.3. The adsorption kinetics showed that the pseudo-second order rate expression fitted well the biosrption process. The equilibrium isotherm was measured experimentally and results were analyzed by Langmuir, Freundlich, and Temkin isotherms using linearized correlation coefficients. The significant parameters for isotherms were determined. The Langmuir adsorption isotherm relative to two other isotherms was found to fit the equilibrium data best for chromium adsorption. Thermodynamic studies reveal that the biosorption of Cr(VI) on cotton stalk was endothermic, spontaneous and occurs with increase in disorder at solid-liquid interface. Adsorption diffusion kinetic was further analyzed and showed that biosorption mechanism was totally controlled by intraparticle diffusion mechanism. © 2013 Copyright Taylor and Francis Group, LLC. Source

Gaikwad N.D.,KTHM College | Patil S.V.,P.A. College | Bobade V.D.,P.A. College
Bioorganic and Medicinal Chemistry Letters | Year: 2012

A series of novel hybrid molecules 4a-y containing thiazole and benzotriazole templates were designed and synthesized. The structures of the synthesized compounds were elucidated by IR, 1H NMR, 13C NMR and mass spectral data. All the synthesized compounds were tested for their antimicrobial activity (zone of inhibition) against Gram-positive, Gram-negative strains of bacteria as well as fungal strains. After that minimum inhibitory concentrations (MICs), minimum bactericidal concentrations (MBCs) and minimum fungicidal concentrations (MFCs) of all the synthesized compounds were determined. The investigation of antimicrobial screening data revealed that most of the tested compounds showed moderate to good microbial inhibitions. © 2012 Elsevier Ltd. All rights reserved. Source

Bobade V.D.,P.A. College | Patil S.V.,P.A. College | Gaikwad N.D.,KTHM College
Journal of Chemical Research | Year: 2012

A series of new thiosubstituted 1,3,4-oxadiazole derivatives of coumarin were synthesised by reaction of 7-((5- mercapto-1,3,4-oxadiazol-2-yl)methoxy)-4- methyl-2H-chromen-2-one and α-haloketones by grinding, in solvent-free conditions at room temperature. The reaction was also carried out in ethanol in reflux conditions. Shorter reaction time and better yields were observed in solvent-free conditions. The structures of the compounds were characterised by IR, NMR, elemental analysis and mass spectral data. The synthesised compounds were evaluated for their in vitro antimicrobial screening on different strains of bacteria and fungi. Most of the compounds showed good to moderate activities. Source

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