Chromium is a chemical element; it has symbol Cr and atomic number 24. It is the first element in group 6. It is a steely-grey, lustrous, hard, and brittle transition metal. [10] Chromium is valued for its high corrosion resistance and hardness.

2025年1月18日 · chromium (Cr), chemical element of Group 6 (VIb) of the periodic table, a hard steel-gray metal that takes a high polish and is used in alloys to increase strength and corrosion resistance. Chromium was discovered (1797) by the French chemist Nicolas-Louis Vauquelin and isolated as the metal a year later; it was named for its multicoloured ...

At pH between 0 and 4, trivalent chromium tends to form hexacoordinate complexes with complexing agents such as water, ammonia, sulfate, urea, and organic acids.

2000年3月1日 · This article includes a survey of chromium (Cr) occurrence in different environmental compartments, its pathways in the environment and the cross-sectional presentation of Cr speciation methods against the background of Cr chemistry.

Identifying and quantifying chromium in water are important for the protection of precious water resources from chromium pollution. Standard methods however are unable to easily distinguish toxic hexavalent chromium, Cr (VI), from innocuous trivalent chromium, Cr (III), are time-consuming, or require large sample quantity.

2023年12月21日 · Chromium has four stable isotopes, with chromium-52 being the most abundant comprising about 84%. Chromium-50 and chromium-53 have been used as stable isotope tracers. Synthetic chromium-51 is stylized experimentally as a radiotracer; the isotope decays via electron capture with associated loss of gamma rays, which can readily be detected.

The speciation of chromium is determined by the processes that control reduction/oxidation reactions in the environment. As can be seen by the adjacent simplified Pourbaix diagram of chromium species in water, species conversion can occur with …

2023年12月21日 · The chromium origin in the environment can be geogenic, anthropogenic, or both. The most common forms of chromium in soil and water are various species of Cr(III) or Cr(VI). Cr(III) has low solubility at most environmental conditions, …

Chromium is a naturally occurring element in rocks, animals, plants, soil, and volcanic dust and gases. (1) Chromium occurs in the environment predominantly in one of two valence states: trivalent chromium (Cr III), which occurs naturally and is an essential nutrient, and hexavalent chromium (Cr VI), which, along with

2024年9月5日 · High-resolution identification of chromium (Cr) species, especially various organic-Cr complexes, in a convenient and economically-feasible manner is the prerequisite for achieving the advanced treatment of chromium wastewater.