2010 Fiscal Year Final Research Report
Immobilization of heavy metals in rhizosphere soils : formulation of phytostabilization technology
| Project/Area Number |
21710077
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| Research Category |
Grant-in-Aid for Young Scientists (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
Environmental technology/Environmental materials
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| Research Institution | Mie University |
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Principal Investigator |
HASHIMOTO Yohey Mie University, 大学院・生物資源学研究科, 准教授 (80436899)
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| Project Period (FY) |
2009 – 2010
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| Keywords | 土壌汚染 / 不溶化 / 重金属 / 射撃場 |
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| Research Abstract |
To formulate successful phytostabilization strategies in a shooting range soil, understanding how heavy metals are immobilized at the molecular level in the rhizosphere soil is critical. The objectives of this study were to investigate i) how Pb speciation was modified in the rhizosphere soils of various plant species, and ii) solubility of Pb pellet in rhizosphere and subsequent impacts on soil ecosystems. Lead (Pb) speciation and solubility in rhizosphere soils of five different plant species were investigated using extended X-ray absorption fine structure (EXAFS) spectroscopy and chemical extraction. The EXAFS analysis indicated that Pb occurred as PbCO_3, Pb sorbed to organic matter, and Pb sorbed to pedogenic birnessite and/or ferrihydrite in the bulk soil. Comparison of the EXAFS spectra between bulk and rhizosphere soils demonstrated notable differences in fine structure, indicating that Pb species had been modified by rhizosphere processes. Denatured gradient gel electrophoresis demonstrated that Plant growth in the contaminated soil appeared to enrich bacterial populations since the general band profile exhibited in the rhizosphere soil was brighter than the control soil. Bacterial diversity was enhanced in the soil with the pH value of～7.
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