Sodium dichromate

About: Sodium dichromate is a research topic. Over the lifetime, 421 publications have been published within this topic receiving 6202 citations. The topic is also known as: Disodium salt & sodium bichromate.

Removal of chromium from cell liquor

Abstract: Soluble hexavalent chromium values are removed from aqueous chlorate solutions by employing a critical effective ratio of OH - :Cr 2 O 7 = ions of at least 3:1 in the aqueous chlorate solution and by employing a dithionite to reduce the hexavalent chromium to trivalent chromium, preferably in the mole ratio of S 2 O 4 = :Cr 2 O 7 = of at least 3:1. The trivalent chromium forms chromic hydroxide (Cr(OH) 3 ) with the hydroxyl ions and precipitates from the aqueous chlorate solution. The process is rapid and effective in quantitative removal of hexavalent chromium from the aqueous chlorate solutions and is especially useful for the removal of sodium dichromate from cell liquor which is intended to be employed in chlorine dioxide production and which is produced by diaphragmless electrolysis of sodium chloride.

Influence of metyrapone and phenobarbital on sodium dichromate nephrotoxicity in developing rats

Abstract: After the administration of equal doses of sodium dichromate, chromium concentrations in the kidney were lower in young than in adult rats. To test the age-dependent sensitivity to the nephrotoxicity of dichromate, young and adult rats were given doses to achieve identical chromium concentrations in the kidney. At equal renal concentrations, young rats had less functional and morphological damage than adult rats. As phenobarbital treatment in young rats enhanced the symptoms of nephrotoxicity and metyrapone treatment in adult rats decreased the symptoms of nephrotoxicity, age-dependent differences in chromate nephrotoxicity may be linked to an increase in the enzymatic reduction of Cr(VI) with age.

Variation of cell voltage with reaction time in electrochemical synthesis process of sodium dichromate

Abstract: To address the problems existing in the traditional production technique of sodium dichromate, a new green technology of producing sodium dichromate with an electrochemical synthesis method was studied. Using a self-made electrosynthesis reactor of pure titanium and stainless steel, with a multiple-unit metal oxides combination anode, a cathode of stainless steel, and a reinforcing combination cation exchange membrane with perfluorosulfonic and perfluorocarboxylic polymers, experiments were carried out on the direct electrochemical synthesis of sodium dichromate from sodium chromate. From the experimental results and electrochemical reaction principles, it was shown that the electrochemical synthesis reaction process of sodium dichromate may be quantitatively determined from the variation of the cell voltage measured macroscopically with reaction time. Cell voltages were experimentally measured at different initial sodium chromate concentrations in the anolyte, and the dependence of the cell voltage on reaction time was discussed. The mathematical model of the variation of cell voltage with reaction time and the change rate equation of cell voltage were established, and satisfactorily formulated the change law of cell voltage in the electrochemical synthesis process of sodium dichromate.

Treatment of carbon fibers

Abstract: Carbon fibers are surface oxidized by contacting the fiber with an aqueous solution comprising 5 - 20 weight percent sodium dichromate and 15 - 45 percent sulfuric acid for from one to sixty minutes at about the boiling point of the mixture. These fibers are useful in making resin-based composites by improving the adhesion between the fibers and the resin.