P. D. Raut

Removal of Bi (III) with Adsorption Technique Using Coconut Shell Activated Carbon

Abstract In present study, we report the preparation of coconut shell activated carbon as adsorbent and its application for Bi (III) removal from aqueous solutions. The developed adsorbent was characterized with scanning electron microscope (SEM), Fourier Transform Infrared (FTIR), C, H, N, S analyzer, and BET surface area analyzer. The parameters examined include agitation time, initial concentration of Bi (III), adsorbent dose and temperature. The maximum adsorption of Bi (III) (98.72%) was observed at 250 mg·L−1 of Bi (III) and adsorbent dose of 0.7 g when agitation was at 160 r·min−1 for 240 min at (299±2) K. The thermodynamic parameters such as Gibbs free energy (ΔGθ), enthalpy (ΔHθ) and entropy (ΔSθ) were evaluated. For the isotherm models applied to adsorption study, the Langmuir isotherm model fits better than the Freundlich isotherm. The maximum adsorption capacity from the Langmuir isotherm was 54.35 mg·g−1 of Bi (III). The kinetic study of the adsorption shows that the pseudo second order model is more appropriate than the pseudo first order model. The result shows that, coconut shell activated carbon is an effective adsorbent to remove Bi (III) from aqueous solutions with good adsorption capacity.

A unified approach for high-throughput quantitative analysis of the residues of multi-class veterinary drugs and pesticides in bovine milk using LC-MS/MS and GC-MS/MS.

This paper reports a unified sample preparation approach for high-throughput multi-residue analysis of veterinary drugs and pesticides in a single sub-sample of bovine milk. The sample (5 g) was deproteinized with acetonitrile before an aliquot (I) was withdrawn, and the remainder was phase-separated using MgSO4 and NaCl. The acetonitrile layer (II) was recovered and the extracts combined, cleaned, and solvent-exchanged before the concentrations of veterinary drugs and pesticides were measured by ultra-fast liquid chromatography tandem mass spectrometry (UFLC-MS/MS). As a unique approach, extract II was analyzed simultaneously using gas chromatography tandem mass spectrometry (GC-MS/MS). Method performance for 78 drugs and 238 pesticides complied with CD 2002/657/EC and SANTE/11813/2017 guidelines, respectively, with significant savings in time and cost. Thus, it would be ideal for regulatory analysis of analytes ranging from non-polar organochlorine pesticides to polar drugs, including penicillins, quinolones, and tetracyclines.

Treatment of textile wastewater by Fenton's process as a Advanced Oxidation Process

Textile manufacturing is a major industry. These are then fabricated into cloth. There are many variable processes are available at spinning and fabric forming stages coupled with complexities of finishing and coloration processes to production of wide ranges of products. All the processes generate considerable volume of effluents and hence, forms major source of wastewater containing organic and inorganic substances. Thus, Fenton reagent is an oxidative decomposition and transformation of organic substrates by H2O2 / Fe 2+. Fenton reagent is a result of reaction between hydrogen peroxide (H2O2) and ferrous ion (Fe 2+ ) producing hydroxyl radical, and is a strong oxidant capable of oxidizing various organic compounds . This process evaluates oxidation and coagulation, for removal of color and Chemical Oxygen Demand (COD) from textile wastewater containing dyes. For effective removal efficiency pH value should be in the range of 2.5 to 4. Fentons reagent has been effective in treating various industrial wastewater and wide variety of dyes. Fenton process gives colour removal efficiency is 98% at pH 3 at FeSO4 of 0.2 gm/lit. and H2O2 of 0.1ml/lit. and COD removal efficiency is 85% at pH 3 at FeSO4 of 1.2 gm/lit. and dose of H2O2 of 0.6 ml/lit.