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Molecular Advances in Bioremediation of Hexavalent Chromium from Soil and Wastewater
Published in Maulin P. Shah, Removal of Refractory Pollutants from Wastewater Treatment Plants, 2021
Aditi Nag, Devendra Sharma, Sudipti Arora
The element chromium (Cr) is a heavy metal. It has an atomic number of 24. It is present as the first element in group number six and as the fourth transition metal on the periodic table. Cr is reported as the 17th most abundant element present in the Earth’s mantle, the most abundantly available heavy metal in the lithosphere, along with zinc, and stands 21st on the list of most abundant elements in the Earth’s crust ranging from 100–300 µg/g (Cervants et al., 2001). Thus, overall it is reported that Cr is the seventh most abundant element on Earth (Mohanty and Kumar Patra, 2013). Cr occurs naturally in rocks, soil, plants, animals, volcanic dust, and gases, among others It can be found as chromite (FeCr2O4) or as a complex with other metals like crocoite (PbCrO4), bentorite (Ca6[Cr,Al]2[SO4]3), tarapacaite (K2CrO4), and vauquelinite (CuPb2CrO4PO4OH). Cr is widely used in the textile, leather, and metal industries for making textile dyes and mordants, pigments, tanning of animal hides as plating, as an alloying agent, in the inhibition of water corrosion, in ceramic glazes and refractory bricks, etc. This wide range of applications has led to a high anthropogenic use of Cr, which has consequently led to environmental contamination. Thus, Cr presence in the environment has become an increasing concern in the last few years (Oliveira, 2012).
Vanadium and Chromium Groups
Published in Brian D. Fath, Sven E. Jørgensen, Megan Cole, Managing Global Resources and Universal Processes, 2020
Chromium (Cr) ranks 21st in abundance in the Earth’s crust and is found in a number of minerals with chromite (FeCr2O4) and crocoite (PbCrO4) as the principal ores of Cr. Molybdenum (Mo) ranks 54th in abundance in the Earth’s crust as it is found in a limited number of ores, including wulfenite (PbMoO4), molybdenite (MoS2), and powellite (CaMoO4). Molybdenum is also recovered as a by-product of copper and tungsten mining. Tungsten (W) ranks 58th in abundance and is found in a number of minerals including tungstite (WO3·H2O), wolframite [FeMn(WO4)2], and scheelite (CaWO4).[3,5,7,8] The world mining production and principal reservoirs of V, Nb, Ta, Cr, Mo, and W are given in Table 1.
Cr, 24]
Published in Alina Kabata-Pendias, Barbara Szteke, Trace Elements in Abiotic and Biotic Environments, 2015
Alina Kabata-Pendias, Barbara Szteke
Chromium occurs at several oxidation states, of which the most common are +3 and +6. It is precipitated from magma mainly in the Cr spinel mineral groups of the following formula: (Mg,Fe)O (Cr,Al,Fe)2 O4. Its relatively common minerals are chromite (FeCr2O4) and crocoite (PbCrO4). These minerals are likely to be associated with pyroxenes, amphibolites, and micas. The geochemical association of Cr with Fe and Mn resulted in its increased contents in Fe concretions of soils, and in ferromanganese nodules in sea bottom sediments.
Synergistic effect of PGPR and PSB for alleviation of chromium toxicity in Vigna radiata (L.) R. Wilczek seedlings
Published in International Journal of Phytoremediation, 2023
Monalisa Mohanty, Sikha Mohapatra
The leachability of different heavy metals was studied through different sorption kinetics of heavy metals (Chaturvedi et al.2006). Out of different toxic heavy metals, Chromium (Cr) is one which is released in huge quantities through opencast mining activities and various anthropogenic activities. It is the 17th most abundant element in the earth’s mantle (Mohanty and Patra 2020) which occurs naturally as chromite (FeCr2O4) in ultramafic and serpentine rocks or complexed with other metals like crocoite (PbCrO4), bentorite Ca6 (Cr, Al)2(SO4)3, tarapacaite (K2CrO4) and potassium dichromate (K2Cr2O7), (Avudainayagam et al.2003; Mohanty and Patra 2011a).
Lead contamination in Chinese surface soils: Source identification, spatial-temporal distribution and associated health risks
Published in Critical Reviews in Environmental Science and Technology, 2019
Yunhui Zhang, Deyi Hou, David O’Connor, Zhengtao Shen, Peili Shi, Yong Sik Ok, Daniel C. W. Tsang, Yang Wen, Mina Luo
Pb is a natural constituent of the Earth's crust, and may occur naturally and heterogeneously in soils by the natural weathering and erosion of crustal materials or via deposition of Pb emitted into the Earth’s atmosphere by volcanic activities, totally accounting for 80% of natural sources (Callender, 2003; Hou, O’Connor, et al., 2017). Forest fires and biogenic sources also contribute to soil Pb, accounting for 10% each. Pb from natural sources can be separated as atmospheric soil dust (allochthonous) or detritic source (autochthonous) (Bao, Shen, Wang, & Tserenpil, 2016). Naturally derived lead in soil is commonly in the form of gelena (PbS, logKsp = −27.5) and in smaller quantities in cerussite (PbCO3), anglesite (PbSO4), pyromorphite (Pb5(PO4)3Cl), crocoite (PbCrO4), litharge (PbO) and Massicot (PbO) (Ruby, Davis, & Nicholson, 1994; Mulligan, Yong, & Gibbs, 2001; Laperche, Traina, Gaddam, & Logan,1996). Pb usually coexists with copper, zinc and silver, and the metallic form of Pb in nature is rare (Cheng & Hu, 2010).
Toxic and carcinogenic effects of hexavalent chromium in mammalian cells in vivo and in vitro: a recent update
Published in Journal of Environmental Science and Health, Part C, 2022
Shehnaz Islam, Sreejata Kamila, Ansuman Chattopadhyay
Chromium (Cr) is the 21st most abundant element in the Earth’s mantle.1 It is a naturally occurring trace element present as chromite (FeCr2O4) in ultramafic and serpentine rocks or complexed with other metals like crocoite (PbCrO4), bentorite Ca6Cr2(SO4)3(OH)12 · 26H2O, tarapacaite (K2CrO4), and vauquelinite (CuPb2(CrO4)(PO4)(OH)), among others.2 This transition metal has seven oxidation states and the elemental [Cr (0)], trivalent [Cr (III)] and hexavalent [Cr (VI)] states are the most prevalent forms.3,4 Studies have shown that organic-Cr (III) species can be transformed into chromium (III) hydroxide [Cr (OH)3] nanocrystal with time. Chromium (III) oxide [Cr2O3] is transformed from Cr(OH)3 nanocrystals via dehydration, which is a more stable compound and helps in the mineralization and immobilization process of Cr.5 Environmental contamination of Cr (VI) occurs due to anthropogenic uses of various chromate compounds in industrial sectors like stainless steel and alloy production, welding, chrome electroplating, tanning of animal hides, textile pigments and dyes, reduction of water corrosion, ceramic glazes, refractory bricks etc. Anthropogenic sources contribute to almost 35% of all the Cr (VI) compounds.6 The widespread industrial applications have led to the rapid environmental accumulation of this metal to become a global public health concern in recent years (Table 1).7