Division of Soil and Water Management, University of Leuven, Heverlee, Belgium.
Environ Toxicol Chem. 2013 Apr;32(5):1027-32. doi: 10.1002/etc.2159. Epub 2013 Mar 21.
The potential impact of diverse inputs of organic matter (hay, maize straw, and peat) on the mobility and bioavailability of Cd, Cu, Pb, and Zn was examined at laboratory scale for three soils with contrasting properties and for two moisture regimes: field capacity and saturated conditions. Soil solution was characterized for total soluble metals, dissolved soil organic carbon, and ultraviolet absorbance at 254 nm. Speciation analyses were performed with WHAM VI. For field capacity conditions, metal mobility increased (Pb>Cu>Zn>Cd) for all soils and treatments compared with controls and was significantly correlated (p<0.05) with dissolved organic matter (r=0.540). Solubilization of organic matter was mostly driven by Al mobilization (r=0.580, p<0.05) and variations in solution pH. The bioavailable pool of metals, estimated as free ion activities, decreased with the increasing occurrence of metal-organic matter complexes, which was accompanied by an increase in solution of highly aromatic organic matter. Soil saturation generally decreased metal mobility and the ratio of metal-organo matter complexes in solution. Consistently, such effects were accompanied by a decrease in the solubilization of organic matter and lower mobilization of Al, Fe, and Mn.
研究了在实验室规模下，三种具有不同特性的土壤和两种水分条件（田间持水量和饱和条件）下，不同有机物质（干草、玉米秸秆和泥炭）输入对 Cd、Cu、Pb 和 Zn 迁移性和生物有效性的潜在影响。土壤溶液中的总可溶性金属、溶解态土壤有机碳和 254nm 紫外吸光度进行了特征描述。采用 WHAM VI 进行了形态分析。对于田间持水量条件，与对照相比，所有土壤和处理的金属迁移性都增加（Pb>Cu>Zn>Cd），且与溶解态有机物（r=0.540）显著相关（p<0.05）。有机物的溶解主要是由 Al 的迁移（r=0.580，p<0.05）和溶液 pH 值的变化驱动的。金属的有效态，估计为自由离子活性，随着金属-有机物复合物的出现而减少，同时溶液中高芳香性有机物的含量增加。土壤饱和通常会降低金属的迁移性和金属-有机物复合物在溶液中的比例。同样，这些影响伴随着有机物的溶解减少和 Al、Fe 和 Mn 的迁移性降低。
