This study evaluated the toxicity of hexavalent and trivalent compounds of chromium to the pacu, Piaractus mesopotamicus, in acute exposures of 96 h through mortality and histopathological responses. Hexavalent potassium dichromate was more toxic than trivalent compounds of chromium chloride, chromium oxide and chromium carbochelate. Sufficient mortalities occurred only with potassium dichromat...

hen the first trivalent chromium electroplating process was commercially introduced in the mid-l970s, information on the corrosion properties of the deposits and other physical properties was unknown. To obtain a comprehensive understanding about the corrosion properties of trivalent chromium electrodeposits over a variety of nickel deposits, chromium deposits from trivalent chromium electrolyt...

I t has been reportedthat trivalent chromium plays an important role in insulin action. We have shown that, in the presence of trivalent chromium, insulin stimulated the glucose utilization of isolated rat lenses. This finding suggested the possibility that a variation in dietary chromium might be responsible for the repeated inconsistency in the insulin effect observed on the glucose utilizati...

Chromium exists primarily in two forms: trivalent and hexavalent. Trivalent chromium is present in the cationic form as Cr+3 and is an essential nutrient, but hexavalent chromium is toxic and exists as an anion, either as chromate (CrO4 -2) or dichromate (Cr2O7 -2). Therefore, the analysis of total chromium does not always provide a true indication of the effects of chromium present in a sample...

Hexavalent chromium (VI) compounds are widely used in industry, while trivalent chromium (III) is used as a nutritional supplement. CrVI is generally considered more toxic and carcinogenic than its trivalent form and the toxicity of this metal is associated with free radical processes generating reactive oxygen species (ROS). The detailed mechanism of ROS formation by chromium and its compounds...

the potential of citrobacter freundii, a gram negative bacteria for the remediation of hexavalentchromium (cr(vi)) and trivalent chromium (cr(iii)) from aqueous solutions was investigated. bioremediationof cr(vi) involved both biosorption and bioreduction processes, as compared to only biosorption processobserved with respect to cr(iii) bioremediation. in the case of cr(vi) bioremediation studi...

Corrosion is the degradation or deterioration of metal components due to a reaction with the environment. Chromate conversion coating is applied to passivate metallic surface to slow down (and prevent to some extent) corrosion process. Chromate conversion process uses chromium compounds including hexavalent chromium, which is toxic, carcinogenic and hazardous to human health and environment. He...

A trivalent chromium electroplating process has been io use commercially in North America since its introduction in 1975. Based upon years of laboratory and in-plant experience and testing, many process performance characteristics and physical properties of deposits have been determined. This paper compares the performance of trivalent chromium with hexavalent chromium processes. Factors such a...

The glucose tolerance factor is a dietary agent required in rats for maintenance of normal removal rates of glucose from the blood (2). Recently, we have identified trivalent chromium as the active ingredient (3). GTFl is present in natural diets, for instance table scraps or McCollum’s wheat-casein diet, whereas To&a yeast diets, casein-sucrose diets, and even commercial laboratory chows were ...

Author’s address: J.W.H. Mali, Javastraat 104, Nijmegen (The Netherlands) Last year some doubt arose about the real significance of the positive patch test for bichromate solutions, as positive patch tests and intra-cutaneous reactions for trivalent chromium compounds have been reported (Fregert et al.) and because trivalent chromium compounds, next to bichromate have often been found in the en...