NOPR Collection:

Quantitative thin layer chromatographic study of Al³⁺ in geological samples

2014-04-02T18:22:06Z

Title: Quantitative thin layer chromatographic study of Al³⁺ in geological samples Authors: Najar, P A Mohamed; Gondane, S R; Bhukte, P G; Nimje, M T; Puttewar, S P Abstract: A facile and sensitive quantitative visual analytical method has been developed for the determination of Al³⁺ in geological samples. The alumina (Al₂O₃) content in gibbsitic bauxite and related samples of geological origin is extracted in triple acidic medium. The sample solutions are purified and then subjected to quantitative thin layer chromatography (TLC) analysis. Combination of plain silica gel H and dilute aqueous solution of aluminon (0.005-0.50%) has been identified as the best chromatographic systems for the selective detection of Al³⁺. The important chromatographic parameters such as sample composition, pH effect, nature of adsorbent and mobile phase composition as well as detection limit are optimized in terms of spot size, colour stability and resolution of Al³⁺. The TLC chromatograms of Al³⁺ are quantitatively assessed by scanning densitometry and digital image analysis. Analytical potential of the optical quantitative methods have been verified for the quantitative TLC assessment of Al³⁺ in bauxite, soil, rock and aluminium spent potlining (SPL) samples with respect to the analogous wet analysis. Repeatability and reproducibility of the method are also evaluated under the optimized experimental conditions such as sample concentration, components and pH, slurry volume and layer thickness. Page(s): 146-154

Inhibitory action of xylenol orange on aluminum corrosion in hydrochloric acid solution

2014-04-03T18:21:38Z

Title: Inhibitory action of xylenol orange on aluminum corrosion in hydrochloric acid solution Authors: Desai, P S; Kapopara, S M Abstract: The inhibition effect of xylenol orange on the corrosion of aluminum (2S Grade) in 0.4-0.6 M HCL over the temperature range 313-333K has been studied. Both thermodynamic parameters and kinetic parameters with the inhibition effect have been correlated. The inhibition efficiencies of xylenol orange are investigated by weight loss and potentiodynamic polarization methods. The corrosion rate of aluminum decreases with increasing inhibitor concentrations and the efficiency of inhibition increases with increasing concentration of inhibitor up to almost 87% in 0.4M HCL and up to 84% in 0.6M HCL. The concentrations of inhibitor have been kept in the range 2-8 mM. It is also observed that the inhibition efficiency decreases with increasing HCl concentration and temperature. The adsorption of inhibitor on the aluminum surface obeys the Langmuir adsorption isotherm equation. The inhibition effect is satisfactorily explained by both thermodynamic and kinetic parameters. The experimental data have been successfully related with adsorption theory and kinetic equations. Polarization curves show that xylenol orange is a mixed-type inhibitor in hydrochloric acid. Page(s): 139-145

Water filter-based MBR unit in laundry effluent treatment

2014-04-04T18:21:54Z

Title: Water filter-based MBR unit in laundry effluent treatment Authors: Islam, M A; Muhtad, S M; Anwar, A; Islam, M M; Amin, M R; Islam, M Ar; Haque, A K M A Abstract: An aerobic membrane bioreactor (MBR) system has been equipped with low cost water filter units available in local market and tested as a bench-scale unit in a medium size laundry. The purpose of the study is to verify their potentiality for application in MBR systems as an alternative to polymer membrane modules. The performance of the system is evaluated in terms of flux recovery and COD level of the treated water. Cleaning operation is performed by mechanical rubbing/brushing and backflushing. In each operational cycle, the flux is found to deteriorate gradually due to fouling. Mechanical rubbing/brushing results in partial elimination of the fouling and thus partial recovery of the flux, while backflushing to remove the fouling causes internal damage to the filters. Fouling leads to an improvement in the COD removal. It is concluded that the filter units, if modified, could be used in MBR systems, and success of low cost filter-based MBR system would inspire countries with cheap labor to build wastewater treatment plants with their own capacities. Page(s): 134-138

Electroless and electrolytic deposition of nickel from deep eutectic solvents based on choline chloride^a

2014-04-02T18:21:53Z

Title: Electroless and electrolytic deposition of nickel from deep eutectic solvents based on choline chloride^a Authors: Ali, M Rostom; Rahman, Md Ziaur; Saha, S Sankar Abstract: The electroless and electrolytic deposition of nickel from a solution containing nickel chloride in either an ethylene glycol (EG)-choline chloride based or a urea-choline chloride based ionic liquids has been carried out onto copper and steel cathodes under different conditions. It is found that electroless nickel deposits of up to several microns has been obtained by dip coating from only EG based ionic liquids at temperature above 70°C without the use of catalysts. The influences of various experimental conditions on electrodeposition and the morphology of the deposited layers have been investigated by scanning electron microscopy and X-ray diffraction. It is shown that very smooth, shiny and dense with good adherence and bright metallic coloured nickel coatings can be obtained from both EG and urea-based ionic liquids at applied deposition potential of up to -0.50 V and applied deposition current density of up to -5.0 A m^-2 between 50°C and 100°C. The cathodic current efficiency for the deposition of Ni is about 97%. Page(s): 127-133

NOPR Collection:

Quantitative thin layer chromatographic study of Al3+ in geological samples

Inhibitory action of xylenol orange on aluminum corrosion in hydrochloric acid solution

Water filter-based MBR unit in laundry effluent treatment

Electroless and electrolytic deposition of nickel from deep eutectic solvents based on choline chloridea

Quantitative thin layer chromatographic study of Al³⁺ in geological samples

Electroless and electrolytic deposition of nickel from deep eutectic solvents based on choline chloride^a