The role of iron oxides on nickel fixation in soil

摘要：

Immobilisation of Ni exhibits pronounced slow reactions in soil and these fixation reactions might affect the natural attenuation of Ni contaminated soils. It is unclear which reactions occur but the speculation is made that diffusion into micro-porous iron oxides might contribute to Ni fixation. Two soil toposequences (Vietnam;Spain) with varying iron content/crystallography were sampied and amended with NiCl2 at 80 mg Ni/kg. Fixation of Ni was measured during 2 years as the loss of isotopically exchangeable Ni. Fixation increased with increasing contact time. In the Vietnamese toposequence (pH±4.0) Ni fixation (0-70％) was signif icantly positively correlated with the crystalline iron content (12-89 g(Fe)/kg). Soil pH explained Ni fixation more than iron oxides in the Spanish transect. Fixation of Ni was also measured in 4 different synthetic iron oxides and in organic matter. The data were used to model fixation in soil with an additive multi- surface model. Adsorption and fixation of Ni in soils was underestimated by the model, especially in low pH soils with a large iron content which suggests either a larger reactivity of natural iron oxides compared to synthetic oxides or that other soil constituents also fix Ni.

关键词： Iron oxides Ni fixation multi-surface model organic matter

作者: Jurgen Buekers Andre Maes Erik Smolders

作者单位: Division of Soil and Water Management, KULeuven, Kasteelpark Arenberg 20, 3001 Heverlee, Belgium tel: [phone], fax: [phone], Jurgen

会议类型: 国际会议

会议名称: 第九届痕量元素生物地球化学国际会议(9th International Conference on the Biogeochemistry of Trace Elements)

会议地点: 北京

会议语种:英文

页码: 590-591

在线出版日期: 2007-07-15（万方平台首次上网日期，不代表论文的发表时间）