The determination of chromium(VI) at high concentrations can be performed spectrophotometrically with 1,5-diphenylcarbazite. The standard determination methods for chromium(VI) in leather like DIN53314 or IUC 18 have a detection limit of 3mg/kg leather. However the detection limit is not enough for lower concentrations. There is a need for lower detection limits because public awareness of hexa...

Chromium through natural processes and human activities enters the air, soil and water. Chromium-resistant bacteria are capable of reducing toxic Cr(VI) to less toxic Cr(III). In this work, batch studies were conducted to evaluate the effect of environmental factors on the rate of Cr(VI) reduction from synthetic wastewater of metal plating industry by Bacillus cereus under aerobic conditions. T...

In this work the possibility of simultaneous spectrophotometric determination of chromium (VI) and iron (III) in alloys with help of the mixed organic reagents (diphenylcarbazide and 1,10-phenanthroline, diphenylcarbazide and sulphosalicylic acid) is studied. We have applied curve fitting method to separate individual signals of chromium (VI) and iron (III) from overlapped absorption spectrum. ...

Concentration levels of hexavalent chromium in contaminated soil and in Zea mays plant parts were determined and Cr(VI) bioaccumulation and bioconcentration capacity of this plant were discussed. Zea mays seeds were sown in 40 mg Cr(VI)/kg dw polluted soil. After harvesting it was observed that hexavalent chromium concentrations in plant organs decreased in the following order: roots > stems > ...

chromium is one of the major causes of environmental pollution. to remove heavy metal ions from water, microorganisms can be used. in this study, dead fungal biomass of aspergillus niger is used. the biomass was boiled in 0.5 n naoh solutions to increase the metal removal capacity of a.niger and was applied when the ph of wash solution was in the normal range. the optimum adsorption ph value ob...

Several low cost biomaterials such as baggase, charred rice husk, activated charcoal and eucalyptus bark (EB) were tested for removal of chromium. All the experiments were carried out in batch process with laboratory prepared samples and wastewater obtained from metal finishing section of auto ancillary unit. The adsorbent, which had highest chromium(VI) removal was EB. Influences of chromium c...

Chromium is an important industrial metal, an environmental pollutant, and a human carcinogen. To investigate the mechanisms of chromium-induced carcinogenesis, activation of mitogen-activated protein (MAP) kinases ERK1 and ERK2 was examined in rat hepatoma cells following exposure to hexavalent chromium (Cr(VI)). Cr(VI) was found to activate both forms of MAP kinase in a dose- and time-depende...

Chromium reduction by Escherichia coli ATCC 33456 quantitatively transferred hexavalent chromium, Cr(VI), to trivalent chromium, Cr(III). The reduced chromium was predominantly present in the external medium. Supernatant fluids of cell extract, obtained by centrifugation at 12,000 and 150,000 x g, showed almost the same Cr(VI) reduction activity, indicating that Cr(VI) reduction by E. coli ATCC...

Chromium has been and is extensively used worldwide in multiple industrial processes and is routinely discharged to the environment from such processes. Therefore, this heavy metal is a potential threat to the environment and to public health, primarily because it is non-biodegradable and environmentally persistent. Chromium exists in several oxidation states, the most stable of which are triva...

Chromium exists usually in the (III) or (VI) oxidation states. In contrast to Cr(III), which is essential to mammalian systems, Cr(VI) is dangerous for humans due to its toxicity and carcinogenic properties. Cr(VI) compounds are highly soluble, mobile and bioavailable compared to Cr(III) species. Chromium is usually analyzed using instrumental methods such as AAS or ICP, which are accurate and ...