Kinetics of Transition Metal Ion Catalyzed Oxidation of some Industrially Important Alcohols using Ammonium Meta Vanadate in Acidic Medium

Oxidation of alcohols has industrial importance as it yields several useful products.Toxic and costly metal ions like Os(VIII), Cr(VI), and Ru in different oxidation states are widely used for the oxidation of a variety of organic compounds. We are reporting herein the oxidation of the industrially useful primary alcohols, 2-Chloroethanol, 2-Butoxyethanol and 2-Phenoxyethanol using Ammonium metavanadate in acidic medium. Relatively less toxic and cheaper transition metal ions of the first series are effectively used as homogeneous catalysts for the oxidation of the alcohols to the corresponding aldehydes. 2- Chloroethanol is used as a precursor for ethylene oxide and is useful in the manufacture of crop protection chemicals, and pharmaceuticals.2-Butoxyethanol finds use in the making of paints, varnishes and industrial and household cleaners.

Arsenic Removal from Spent Liquor Generated during Processing of Vanadium Sludge

During production of ammonium meta-vanadate from vanadium sludge an arsenic containing (~2.2g/L) spent liquor is generated. Safe disposal of such liquor without arsenic contamination to the environment is essential. Therefore, various methods such as ion-exchange, adsorption, solvent extraction and precipitation were applied for recovery of arsenic from the spent liquor. Based on the Eh-pH diagram of As-H2O, the arsenic based species were delineated. For ion exchange Lewatit FO 36 and Amberlite IRA 400 Cl- resins were used to extract arsenic from the spent liquor. With Lewatit FO 36 a maximum of 20% arsenic was recovered at A/R ratio of 50. Amberlite IRA 400 Cl- on the other hand didnt extract arsenic at all. A two stage solvent extraction process using TBP as an extractant, with a recovery of 97% arsenic from the spent liquor was developed. From the loaded TBP almost complete stripping of arsenic was obtained with 0.1-0.5M NaOH solution. Precipitation of arsenic from the spent liquor as copper arsenate or iron arsenate was also examined. During the fixation of arsenic with iron, 70% arsenic was recovered in the precipitate. This process needs to be evaluated further with the aim of using the iron hydroxide containing arsenic for different applications.

Annealing Effect on Synthesis of VO2 (M) Nanopowders by a Novel Solution-Based Process

This paper describes a novel and simple method to preparing monoclinic VO2 (M) nanopowders via the reaction of ammonium meta-vanadate (NH4VO3) and oxalic acid dihydrate (C2H2O4•2H2O). The products were characterized by means of methods. XRD results show that well crystallized nanopowders of the monoclinic VO2 (M) were successfully synthesized, while the molar ratio between NH4VO3 and C2H2O4•2H2O was kept at 1:0.5~2.5, and the annealing temperature was 350~750 °C for 2~10 hour in nitrogen atmosphere. The spherical morphology of the samples is characterized by SEM. The crystallization temperature of the desired M/R-phase VO2 is lower than 387 °C in this work. And the phase transition temperature is determined by differential scanning calorimetry (DSC).

Spectrophotometric Determination of Malathion in Environmental Samples

A simple, rapid, sensitive, and precise spectrophotometric method for the determination of Malathion is described. The method is based on the decomposition of Malathion in the presence of alcoholic KOH. Dimethyldithiophosphate produced is made to react with Ammonium meta vanadate in Nitric acid with the formation of blue color. Acid degradation of too slow to be important under environmental reaction conditions. However, alkaline degradation is too fast to be a pathway in environmental condition. The products of alkaline degradation are temperature dependant. The absorbance maximum was observed at 760 nm. The Beers law is obeyed up to 11 ppm. Interference study was carried for other pesticides.

Separation of neptunium and plutonium from acidic medium using 3-phenyl-4-benzoyl-5-isoxazolone

SummaryThe extraction behaviour of plutonium (IV) and neptunium (IV) was studied from nitric as well as hydrochloric acid employing 3-phenyl-4-benzoyl-5-isoxazolone (PBI) in toluene as the extractant. The forward extraction in hydrochloric acid medium was carried out in presence of several holding oxidants out of which ammonium meta vanadate was found to give the best results. The stripping behaviour of Np and Pu was studied employing a variety of reagents out of which 0.1 M hydroquinione in 1:1 HCl was the most promising. The separation of Np from Pu under simulated conditions was attempted from hydrochloric acid medium giving a decontamination factor value of >10