The evaluations of the potential carcinogenicity of metallic chromium and trivalent chromium by several international and national agencies [International Agency for Research on Cancer (IARC), 1990; Agency for Toxic Substances and Disease Registry (ATSDR), 1993; Canadian Environmental Protection Act (CEPA), 1994; United States Environmental Protection Agency (US EPA), 1998; United States Nation...

In the course of experimentation with various tissue fixations other than Os04 it was noticed that mixtures containing chromium compounds showed considerable promise. Therefore the fixation characteristics of three such compounds, CrC13, K2Cr~07 and Cr08 (the anhydride of H2Cr04), were systematically investigated. Although the action of all three was essentially similar, CrO~ proved to be the m...

Zinc chlorochromate nonahydrate is easily prepared from the aqueous solution of chromium trioxide and zinc chloride in quantitative yield. This oxidant, in methylene chloride and at room temperature, oxidizes thiols to their disulfides. Acetals and thioacetals are deprotected to their corresponding carbonyl compounds. Sulfides are selectively converted to ther sulfoxides or sulfones. Arylox...

The panel opened with a request to J. LaVelle (U.S. EPA) to enlarge upon his presentation of a bimodlal disposition for the plasma reduction of hexavalent chromium (and subsequent urine concentration) in an occupational group exposed to chromium. He replie(d that he did not know the size of the population that was exposed, but that the group consisted of workers at a dichromate plant, and the s...

Polychlorinated benzenes, dibenzo-p-dioxins (PCDD), and dibenzofurans (PCDF) may be formed below the combustion temperature in fly ash from municipal solid waste incinerators (MSWI). Copper catalyzes this formation, possibly by the Deacon reaction. Many other elements are also Deacon catalysts or promoters, and here we report results from a statistically designed experiment with 15 metal oxides...

Scientific interest on chromium removal from water and wastewater has escalated recently. Chromium compounds exist in the environment naturally but are mostly found due to anthropogenic activities (tanning, paint, cement industries, etc.). Hexavalent chromium [Cr(VI)] is of major environmental importance because it is one of the most stable chromium forms found in the environment. It is soluble...

This work aims at the reutilization of a Cr-loaded NaY zeolite obtained by biorecovery of chromium from water as catalyst in the oxidation of volatile organic compounds (VOC). Cr-NaY catalysts were obtained after biosorption of Cr(VI) using a bacterium, Arthrobacter viscosus, supported on the zeolite. The biosorption experiments were conducted at different pH values in the range 1-4. The cataly...

MOJ Food process Technol 2017, 4(3): 00096 The most stable oxidation states of chromium, e.g. Cr(III) and Cr(VI), exhibit significantly different biological and toxicological properties. Cr(III) is considered as an essential element for the proper functioning of living organisms, particularly in glucose metabolism, while Cr(VI) shows mutagenic effects. It is regarded as carcinogenic owing to it...

The treatment of the industrial wastewater can be particularly difficult in the presence of toxic compounds. Excessive concentration of Chromium in soluble form is toxic to a wide variety of living organisms. Biological removal of heavy metals using natural and genetically engineered microorganisms has aroused great interest because of its lower impact on the environment. Ralston metallidurans,...

Solvate-free sodium octahydrotriborate, NaB3H8, is prepared on a 20 gram scale from sodium amalgam and diborane in diethyl ether. This substance, which is chemically related to borohydride-based compounds being investigated as hydrogen storage materials, is also useful for the preparation of transition-metal complexes bearing B3H8 ligands. Treatment of CrCl3 with NaB3H8 affords a thermally unst...