Alumina nanorods were prepared from chromium-containing alumina sludge, and the effects of doping elements, such as Cr, Fe, and Mg, were researched. The results show that the crystal transformation of alumina is restricted by the doped Cr and facilitated by the doped Fe and Mg, which is transformed from θ-Al2O3 to α-Al2O3 in the calcination process. Meanwhile, the crystal transformation of alum...

Treatment of CrCl3 with sodium octahydrotriborate, NaB3H8, affords a thermally unstable purple liquid thought to be a chromium(III) hydride of stoichiometry CrH(B3H8)2. This hydride converts rapidly at room temperature to the chromium(II) complex Cr(B3H8)2, which adopts a square-planar structure in which four hydrogen atoms form the coordination sphere of the chromium atom. This chromium(II) sp...

A. General Introduction Among the transition metal ions of the 3d series, Cr takes a particular position because of its variability in oxidation state, coordination numbers and molecular structure.1,2 The elucidation of these Cr species on inorganic oxidic surfaces is a complex task, which is of fundamental importance to understanding the behavior of Cr in the environment, colloids, and Cr-base...

This research involved the synthesizing of a reactive polymer, long alkyl quaternized poly(4-vinylpyridine) (PVP), and coating it on the surface of silica gel to produce a granular sorbent to remove Cr(VI) from water. Batch experiments were conducted to determine the kinetics, sorption isotherm, pH effects, and influence of other anions on the chromium adsorption onto the coated silica gel. The...

Chromium exists in many different oxidation states in the environment, Cr(VI) and Cr(III) being the most stable forms. Chromium has been known for over 100 years to be a human carcinogen. The greatest risk of cancer from chromium exposure is associated with Cr(VI). Cr(VI) enters cells via the sulfate anion transporter system and is reduced to intermediate oxidation states, such as Cr(V) and Cr(...

BACKGROUND Chromium picolinate (Cr(pic)3) is advocated as adjuvant therapy for impaired glycemic control, despite concerns for DNA damage. Potential toxicity of Cr(pic)3 should be greater for the kidney that accumulates chromium. Therefore, we tested the hypothesis that Cr(pic)3 treatment of obese Zucker rats (OZR) exacerbates renal abnormalities associated with dysglycemia. METHODS Male OZR ...

Absorptive characteristics of polyaniline synthesized in mixture of water and acetonitrile in 50/50 volume ratio was studied. Synthesized polyaniline in powder shape is used as an adsorbent to remove toxic hexavalent chromium from aqueous solutions. Experiments were conducted in batch mode with different variables such as agitation time, solution pH and initial concentration of hexavalent chrom...

Chromium exists in sediments in two oxidation states: Cr(III), which is relatively insoluble and nontoxic, and Cr(VI), which is much more soluble and toxic. Chromium(VI) is thermodynamically unstable in anoxic sediments, and acid-volatile sulfide (AVS) is formed only in anoxic sediments; therefore sediments with measurable AVS concentrations should not contain toxic Cr(VI). If this hypothesis h...

The goal of this experiment was to investigating of effects of different levels of nano chromium (N-Cr) in diet on egg quality and blood chromium content of japanese quail. Two hundred and forty laying japanese quail (45 day old) were randomly distributed to 20 experimental unit with 12 birds in cage pens of 40 × 80 cm. Experimental treatments include: 1) control national research council (NRC,...

Chromium is a highly toxic non-essential metal for microorganisms and plants. Due to its widespread industrial use, chromium (Cr) has become a serious pollutant in diverse environmental settings. The hexavalent form of the metal, Cr(VI), is considered a more toxic species than the relatively innocuous and less mobile Cr(III) form. The presence of Cr in the environment has selected microbial and...