Basic chromium sulphate is the most versatile and common tanning agent in the leather industry. Under certain circumstances, the oxidation of the trivalent chromium salts into the hexavalent compounds, which are used in leather manufacture, is a crucial issue. In this study, different proportions of basic chromium sulphate were used in tanning and re-tanning processes according to a commonly us...

The ability of Bacillus sp. MRKV isolated from tannery effluent which shows resistant towards hexavalent chromium potassium dichromate (K2Cr2O7) was evaluated in this study. The bacterial strain was assayed for its reducing ability towards K2Cr2O7. The study revealed that the isolated strain has the ability to reduce the hexavalent chromium and the optimal conditions required for the chromium r...

Biotreatment of hexavalent chromium has attracted widespread interest due to its cost effective and environmental friendliness. However, the difficult separation of biomass from aqueous solution and the slow hexavalent chromium bioreduction rate are bottlenecks for biotechnology application. In this approach, a core-shell structured functional polymer coated magnetic nanocomposite was prepared ...

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...

Chromium is one of the 25 most widespread elements in the Earth’s crust and occurs as an indelible non-volatile trace element in raw materials used in cement clinker production (clay, limestone and iron additives in particular). Chromium in raw materials mentioned above is mainly in form of trivalent chromium. Naturally occurring chromium (III) is not initially harmful, since it is chemically s...

Workers of tanneries, welding industries, factories manufacturing chromate containing paints are exposed to hexavalent chromium that increases the risk of developing serious adverse health effects. This review elucidates the mode of action of hexavalent chromium on blood and its adverse effects. Both leukocyte and erythrocyte counts of blood sharply decreased in Swiss mice after two weeks of in...

The adsorption of hexavalent chromium on Kaolinite and Illite was studied in order to evaluate their potential for the reduction of hexavalent chromium mobility and their possible application for the treatment of polluted sediment. The influence of various parameters affecting the adsorption of hexavalent chromium, such as the pH of aqueous solution, the ionic strength and the initial metal ion...

The essentiality and carcinogenicity of chromium depend on its chemical form. Oxidation state and solubility are particularly important in determining the biological effects of chromium compounds. For this reason, total chromium measurements are of little value in assessing its nutritional benefits or its toxicological hazards. Aqueous sodium carbonate-sodium hydroxide solutions have been succe...

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...