A sensitive spectrophotometric method for the determination of trace amounts of chromium(VI) is described. Chromium(VI) forms chlorochromate anion in the presence of acid and chloride ion. The formed anion is extracted in toluene as ion-pair with a cationic dye rhodamine 6G. At 535 nlll absorption maximum molar absorptivity is 2x104 I mol-I em-I. The colour is stable for 4 h and the system obey...

The removal of the chromium (VI) ion from aqueous solutions with the Lewatit FO36 ion-exchange resin is described at different conditions. The effects of adsorbent dose, initial metal concentration, contact time and pH on the removal of chromium (VI) were investigated. The batch ion exchange process was relatively fast and it reached equilibrium after about 90 min of contact. The ion exchange p...

It is well known that soluble chromates, when added to blood in vitro or in vivo, hardly interact with the plasma components and easily penetrate the erythrocytes, and that reduction to the trivalent species follows.1-3) However, in vitro reduction of chromium(VI) in human4) and rat5) plasma has been observed. Some problems of the fate of chromium(VI) in blood, especially in vivo remain unsolve...

105 ABSTRACT: The isolated fungi species of different kinds from chromium contaminated soil sites located in Nagalkeni, Chennai were used for reducing chromium(VI) in a tannery industry wastewater of Nagalkeni, Chennai. The experiments were conducted to know biosorption potential of isolated fungi species for removing chromium(VI) in a tannery industry wastewater against the different pH, fungi...

Chromium is present in the environment in several different forms. The most common forms are chromium(0), chromium(III) (or trivalent chromium) and chromium(VI) (or hexavalent chromium). Chromium(III) occurs naturally in the environment and is an essential nutrient that helps the human body utilize sugar, protein and fat. Chromium(VI) and chromium(0) are generally produced by industrial process...

The in vivo binding of chromium to whole chromatin, polynucleosomes, DNA, and cytoplasmic RNA-protein fraction from liver and kidney was examined after treatment of rats with sodium dichromate and chromium(III) chloride. Significant amounts of chromium were bound to DNA and the nonhistone proteins of chromatin and to cytoplasmic RNA-protein fraction. The binding of chromium to the nuclear and c...

hydroponic experiments were performed to exam the dynamic change of endogenous proline in rice seedlings exposed to potassium chromate chromium (vi) or chromium nitrate chromium (iii). although accumulation of both chromium species in rice seedlings was obvious, more chromium was detected in plant tissues of rice seedlings exposed to chromium (iii) than those in chromium (vi), majority being in...

A critical appraisal of single-step extraction procedures of chromium species from soil was done in terms of their selectivity towards Cr(III) and Cr(VI) species. Samples of natural mineral and organic soil and samples of soil enriched with different chromium compounds of various solubility (in liquid or solid form) were used to simulate contamination of soil by liquid and solid wastes. The eff...

Bbstract Recent developments involving polymer-supported metal complexes as catalysts in oxidation reactions, using dioxygen, hydrogen peroxide, alkyl hydroperoxides, hypochlorite anion and iodosobenzene as oxidants are reviewed. binding of dioxygen, and in catalysis, along with the structurally closely related metallo-phthalocyanines, oxidative polymerization catalysed by polymer-supported cop...

BACKGROUND Kinetics, thermodynamics and equilibrium of the removal of chromium(VI) ions from aqueous solutions by using chemically activated leaves of Ficus nitida were investigated. Adsorption runs were performed as a function of pH, mass of biosorbent, contact time, initial concentration of chromium(VI) ions and temperature. RESULTS The optimum conditions for maximum removal of chromium(VI)...