Duester Lars, Prasse Carsten, Vogel Julia V, Vink Jos P M, Schaumann Gabriele E
Department of Environmental and Soil Chemistry, University of Koblenz-Landau, Institute for Environmental Sciences, Landau, Germany.
J Environ Monit. 2011 May;13(5):1204-11. doi: 10.1039/c1em10056d. Epub 2011 Mar 14.
The pore water transport of antimony and titanium, applied as nanoparticles (NPs), was studied by spiking stable suspensions of two different nanomaterials on the surface of an undisturbed floodplain soil. For preparation of stable dispersions, two different strategies were followed. (i) Comparable to those used in industrial applications: titanium dioxide nanoparticles, with an average diameter of 99 nm, were prepared by high-energy ball milling in water, whereas for (ii) antimony trioxide (Sb(2)O(3); average diameter 121 nm) a dispersing agent (sodium salt of poly[(naphthaleneformaldehyde)sulfonate] (pNFS) in water) was used. The upper 17 cm of a floodplain soil (river Rhine, Germany) was sampled using the minimally invasive sediment or fauna incubation experiment (SOFIE® two compartment cell; 3 l volume each), which preserved the pore system of the soil. The cells were equipped with 450 and 100 nm filter probes at different depths providing a non-invasive sampling of the pore water. The pore water was sampled at different times (T = 0, 24, 48, 96 and 196 h) and analysed by inductively coupled plasma quadrupole mass spectrometry (ICP-QMS). Sb and Ti were transported via the pore water of the floodplain soil to a depth of 14 cm, corresponding to the maximum cell depth. The highest Sb concentration in the pore water was detected after 24 h at a depth of 5.5-8 cm. Although the spiked concentration was higher for Ti than for Sb, the total Ti concentration in the pore water of the spiked cell was lower. This indicates a stronger agglomeration of TiO(2) NPs or a more intensive interaction of Ti with the solid matrix and a faster transport of Sb towards deeper soil layers. The results show that metal(loid)s from metal oxide NPs are transported in the soil pore water and, hence, have the potential to act as the source of contamination of deeper soil layers after soil surface contamination.
通过将两种不同纳米材料的稳定悬浮液添加到未扰动的河漫滩土壤表面，研究了作为纳米颗粒（NPs）的锑和钛的孔隙水传输情况。为制备稳定的分散体，采用了两种不同的策略。（i）与工业应用中使用的方法类似：通过在水中进行高能球磨制备平均直径为99 nm的二氧化钛纳米颗粒，而对于（ii）三氧化二锑（Sb₂O₃；平均直径121 nm），则使用了一种分散剂（聚[（萘甲醛磺酸盐）]（pNFS）的钠盐在水中）。使用微创沉积物或动物孵化实验（SOFIE®两室细胞；每个体积3升）对德国莱茵河河漫滩土壤上部17厘米进行采样，该实验保留了土壤的孔隙系统。细胞在不同深度配备了450和100 nm的过滤探头，用于对孔隙水进行非侵入性采样。在不同时间（T = 0、24、48、96和196小时）采集孔隙水，并通过电感耦合等离子体质谱仪（ICP-QMS）进行分析。锑和钛通过河漫滩土壤的孔隙水传输至14厘米深度，这与细胞的最大深度相对应。在24小时后，在5.5 - 8厘米深度处检测到孔隙水中最高的锑浓度。尽管添加的钛浓度高于锑，但添加细胞孔隙水中的总钛浓度较低。这表明TiO₂ NPs的团聚更强，或者钛与固体基质的相互作用更强烈，并且锑向更深土壤层的传输更快。结果表明，金属氧化物NPs中的金属（类金属）在土壤孔隙水中传输，因此，在土壤表面受到污染后，有可能成为更深土壤层污染的来源。
