Lancaster Environment Centre, Lancaster University, Lancaster LA1 4YQ, United Kingdom.
Chemosphere. 2013 Jan;90(2):464-70. doi: 10.1016/j.chemosphere.2012.07.064. Epub 2012 Sep 11.
The two dimensional, small-scale, distribution of labile trace metals was investigated in a sandy loam soil historically treated with sewage sludge. After deployment of two DGT (diffusive gradients in thin-films) probes, their 1.8×15 cm windows were sliced into 5×5 mm and 5×8 mm rectangles to provide three vertical profiles with 5mm resolution. Both sets of profiles showed sharp maxima of Mn, Cd, Co, Cu, Ni and Zn, which varied systematically, both vertically and horizontally. The observed mobilisation of metals was highly localised, as each measurement corresponded to a volume of soil as little as 25-40 μL. Regression analysis indicated mobilisation of Cd, Co, Cu, Ni and Zn were strongly linked to mobilisation of Mn, while there was a strong linkage between Pb and Fe mobilisation. Localised reductive dissolution of Mn oxides or a localised lowering of pH were considered as possible mechanisms.
本研究调查了历史上施用污水污泥的砂壤土中易变痕量金属的二维、小尺度分布。部署了两个二维扩散梯度薄膜（DGT）探针后，将其 1.8×15 cm 的窗口切成 5×5 mm 和 5×8 mm 的矩形，以提供具有 5mm 分辨率的三个垂直剖面。两组剖面均显示 Mn、Cd、Co、Cu、Ni 和 Zn 的最大值明显增加，且无论是垂直还是水平方向均呈系统变化。观察到的金属迁移高度本地化，因为每个测量值对应于土壤体积小至 25-40 μL。回归分析表明 Cd、Co、Cu、Ni 和 Zn 的迁移与 Mn 的迁移密切相关，而 Pb 和 Fe 的迁移之间也存在很强的联系。局部还原溶解 Mn 氧化物或局部降低 pH 被认为是可能的机制。
