Behavior of Chromium in Soils: III. Oxidation

Bartlett, Richmond J.; James, Bruce R.

doi:10.2134/jeq1979.00472425000800010008x

Cited by 546 publications

(308 citation statements)

References 0 publications

Supporting

Mentioning

283

Contrasting

Unclassified

Order By: Relevance

“…As the solubility of organic matter increases with increasing pH, the dissociation of Cu-organic matter complexes can result in the leaching of Cu to groundwater. On the other hand, in the soil environments, Cr occurs in oxidation states Cr(III) and Cr(VI), which govern its mobility and toxicity (Bartlett and James, 1979). In Cr(III)-dominated systems, the prevalent species is CrOH at pH 2q 2-6, Cr(OH) at pH 6.5-11.5 and Cr(OH) at 0 y 3 4 pH)11.5 (Sass and Rai, 1987).…”

Section: Chemistry Of Cca Metals In Soilsmentioning

confidence: 99%

Metal contamination at a wood preservation site: characterisation and experimental studies on remediation

Bhattacharya

Mukherjee

Jacks

et al. 2002

The Science of The Total Environment

107

View full text Add to dashboard Cite

The aim of this investigation was to determine the occurrence of As, Cu, Cr and Zn in the soil at an abandoned wood preservation unit and to examine some possible extractants for the contaminants in the soil. The mean As content of the contaminated surface soils (0-10 cm) was 186 mg kg , where as the mean concentrations of Cu, Cr y1 and Zn in soils from the contaminated area were 26, 29 and 91 mg kg , respectively. The elevated As content in y1 the mineral soils is related to adsorption of inorganic As phases in the fine grained fractions, which are characterised by large surface area and high positive surface charge under the current acidic conditions. Cu and Cr were found to be rather mobile, which is reflected in their lower abundance in soils and significant accumulation in sediments in the drainage leaving the area. The fine fraction of the soil (-0.125 mm) has an average metal content increased by nearly 34% as compared to the -2-mm fraction conventionally used for the analysis and assessment of soil contamination. The -2-mm fraction constitutes approximately 65% of the total weight while the fine fraction (-0.125 mm) constitutes approximately 10%. These facts, taken together, are essential for the choice of remediation measures. Oxalate solutions have been tested as extractants for soil remediation. Dark acid oxalate extraction dissolves the amorphous Al-and Fe-oxides and hydroxides and mobilises the adsorbed inorganic As species. Oxalate also acts as a ligand for the cationic heavy metals, releasing them from exchangeable sites. With a three-step sequential leaching, up to 98-99% of the metals could be removed. At lower concentrations and higher pH, the leaching decreased to approximately 70%. ᮊ

show abstract

Section: Chemistry Of Cca Metals In Soilsmentioning

confidence: 99%

Metal contamination at a wood preservation site: characterisation and experimental studies on remediation

Bhattacharya

Mukherjee

Jacks

et al. 2002

The Science of The Total Environment

107

View full text Add to dashboard Cite

show abstract

“…The only known environmental oxidants of Cr(III) are Mn oxides (1). The role of Mn and its contribution to chromium cycling is complicated by the role of bacteria in the cycle, as well as by the potential utility of Mn oxides in the remediation of other environmental pollutants (e.g.…”

Section: Introductionmentioning

confidence: 99%

Cr(III) Is Indirectly Oxidized by the Mn(II)-Oxidizing Bacterium Bacillus sp. Strain SG-1

Murray

Tebo

2006

Environ. Sci. Technol.

View full text Add to dashboard Cite

Manganese oxides are the only known oxidants of Cr(III) in the environment, and predictions of the fate of Cr(III) have been based on Cr(III) oxidation rates with well-characterized Mn(III,IV) oxide minerals. Our research, however, indicates that the presence of Mn(II)-oxidizing bacteria, may accelerate these rates through the production of very reactive Mn oxides or intermediates formed in the oxidation process. Experiments with the Mn(II)-oxidizing Bacillus sp. strain SG-1 show that this bacterium can accelerate Cr(III) oxidation compared to both abiotic and biologically produced Mn oxides. Initial rates of Cr(III) oxidation by biogenic oxides were approximately 7 times faster than Cr(III) oxidation rates by equivalent amounts of synthetic δ-MnO 2 and 25 times faster by SG-1 spores with Mn(II). Cr(III) oxidation by SG-1 is not direct; Mn is required, but only in small amounts, indicating that it is recycled. Cr(III) oxidation is inhibited above 5 μM dissolved Mn(II), while Mn(II) oxidation is not, suggesting that the processes are controlled by different mechanisms. These results illustrate the need to consider bacterial activity and the concentration of Mn when predicting the potential for Cr(III) oxidation.

show abstract

“…Furthermore information is lacking on the influence of mycorrhiza on the uptake of other essential plant macro-and micronutrients in soils contaminated with Cr. It is known that Cr predominantly exists in two forms in soil: as a trivalent cation {( [21,22,23] Chromium (III) readily precipitates in soil, whereas greater environmental pollution problems occur with the more mobile and toxic Cr(VI). [24,25] Hence, this research was conducted to determine the effects of Glomus intraradices (Schenck and Smith) in the phytoremediation of Cr using sunflower seedlings (Helianthus annuus L.).…”

Section: Introductionmentioning

confidence: 99%

Mycorrhizal Fungi Increase Chromium Uptake by Sunflower Plants: Influence on Tissue Mineral Concentration, Growth, and Gas Exchange

Davies

Puryear

Newton

et al. 2002

Journal of Plant Nutrition

171

View full text Add to dashboard Cite

As a potential phytoremediation system for phytoextraction of chromium (Cr), we evaluated the influence of the arbuscular mycorrhizal fungus Glomus intraradices on leaf tissue elemental composition, growth and gas exchange of sunflower (Helianthus annuus L.). Sunflower seedlings were either inoculated with mycorrhizal fungi (AM) or non-inoculated (Non-AM) and then exposed to two Cr species: {12 mmol of trivalent cation (Cr þ3 ) [Cr(III)] or 0.1 mmol of divalent dichromate anion (Cr 2 O 7 À ) [Cr(VI)]}. Both Cr species depressed plant growth, decreased stomatal conductance (g s ) and net photosynthesis (A).

show abstract

Behavior of Chromium in Soils: III. Oxidation

Cited by 546 publications

References 0 publications

Metal contamination at a wood preservation site: characterisation and experimental studies on remediation

Metal contamination at a wood preservation site: characterisation and experimental studies on remediation

Cr(III) Is Indirectly Oxidized by the Mn(II)-Oxidizing Bacterium Bacillus sp. Strain SG-1

Mycorrhizal Fungi Increase Chromium Uptake by Sunflower Plants: Influence on Tissue Mineral Concentration, Growth, and Gas Exchange

Contact Info

Product

Resources

About