Federal Institute for Geosciences and Natural Resources (BGR), Stilleweg 2 , Hannover 30655, Germany.
Environ Sci Technol. 2014 Nov 4;48(21):12628-35. doi: 10.1021/es5026189. Epub 2014 Oct 15.
The current study investigated the interaction of sterically stabilized OECD standard Ag ENP (AgNM-300k) and silver ions (Ag+) in 25 German arable soils with varying properties (organic carbon concentration of 0.4-25 mg g(-1) and clay content of <0.1-392 mg g(-1)) in 24 h batch retention experiments. A soil subset (n=8) was investigated to test the soil interactions with citrate-stabilized Ag ENP (AgCN30). The adsorption of Ag+ was consistent with the Freundlich model with high KF values (mean KF=2553 L kg(-1), n=25), which suggested a high retention of Ag+. The retention of AgNM-300k followed a linear partitioning model and generally exhibited a low retention for the majority of the investigated soils (group 1, mean Kr, linear=3.7 L kg(-1), n=19), and was correlated with the clay content (relation to log10(Kr, linear), r2=0.40, n=19). Soils showing a high retention of AgNM-300k (group 2, mean Kr, linear=1048 L kg(-1), n=6) either had a low (<5.1) or high pH (>7.0) and generally contained >200 mg g(-1) clay. For the sample subset tested, AgCN30 and AgNM-300k were retained in similar dimensions regarding the same soils. The results suggest that the highest risk of long-term ENP mobilization exists when Ag ENP are applied to agricultural soils with low clay contents (<130 mg g(-1)) and slightly acidic conditions.
本研究在 24 小时批式保留实验中，调查了具有不同性质（有机碳浓度为 0.4-25mg g(-1)，粘土含量<0.1-392mg g(-1)）的 25 种德国耕地土壤中，立体稳定的 OECD 标准 Ag ENP（AgNM-300k）与银离子（Ag+）的相互作用。对一个土壤子集（n=8）进行了调查，以测试与柠檬酸稳定的 Ag ENP（AgCN30）的土壤相互作用。Ag+的吸附与 Freundlich 模型一致，具有较高的 KF 值（平均值 KF=2553Lkg(-1)，n=25），表明 Ag+的保留率很高。AgNM-300k 的保留遵循线性分配模型，通常对大多数研究土壤（第 1 组，平均 Kr，线性=3.7Lkg(-1)，n=19）表现出低保留率，并且与粘土含量呈正相关（与 log10（Kr，线性）的关系，r2=0.40，n=19）。表现出高 AgNM-300k 保留率的土壤（第 2 组，平均 Kr，线性=1048Lkg(-1)，n=6）要么 pH 值低（<5.1），要么 pH 值高（>7.0），并且通常含有>200mg g(-1)的粘土。对于测试的样品子集，AgCN30 和 AgNM-300k 在相同的土壤中以相似的尺寸保留。结果表明，当 Ag ENP 施用于粘土含量低（<130mg g(-1)）和微酸性条件的农业土壤时，存在长期 ENP 迁移的最大风险。
