Reduction Kinetics of Hexavalent Chromium in Soils and Its Correlation with Soil Properties
- Wendan Xiaoa,
- Yibin Zhanga,
- Tingqiang Li *a,
- Bao Chena,
- Huan Wanga,
- Zhenli Heb and
- Xiaoe Yang *a
- a Ministry of Education Key Laboratory of Environmental Remediation and Ecological Health, College of Environmental and Resource Sciences, Zhejiang Univ., Hangzhou 310058, China
b Univ. of Florida, Institute of Food and Agricultural Sciences, Indian River Research and Education Center, Fort Pierce, FL 34945. Assigned to Associate Editor Tracy Punshon
The toxicity of chromium (Cr) to biota is related to its chemical forms and consequently to the redox conditions of soils. Hexavalent Cr[Cr(VI)] may undergo natural attenuation through reduction processes. In this study, the reduction kinetics of Cr(VI) in seven soils and its relationships with soil properties were investigated with laboratory incubation experiments. The results indicate that the reduction of Cr(VI) can be described by a first-order reaction. The reduction rates of Cr(VI) in the seven soils decreased in the order: Udic Ferrisols > Stagnic Anthrosols > Calcaric Regosols > Mollisol > Typic Haplustalf > Periudic Argosols > Ustic Cambosols. Simple correlation analysis revealed that the reduction of Cr(VI) in soils was positively related to organic matter content, dissolved organic matter content, Fe(II) content, clay fraction, and to the diversity index of the bacterial community but negatively correlated with easily reducible Mn content. Using stepwise regression, the reduction of Cr(VI) in soil could be quantitatively predicted by the measurement of dissolved organic matter content, Fe(II) content, pH, and soil particle size distribution, with a fitting level of 95.5%. The results indicated that the reduction of Cr(VI) in natural soils is not controlled by a single soil property but is the result of the combined effects of dissolved organic matter, Fe(II), pH, and soil particle size distribution.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
Copyright © 2012. . Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.