Aquatic Ecology and Water Quality Management Group, Department of Environmental Sciences, Wageningen University, P.O. Box 47, 6700 AA Wageningen, The Netherlands; Radboud University Nijmegen, Institute for Wetland and Water Research, Department of Environmental Science, P.O. Box 9010, 6500 GL Nijmegen, The Netherlands; Laboratory for Ecological Risk Assessment, National Institute for Public Health and the Environment (RIVM), P.O. Box 1, 3720 BA Bilthoven, The Netherlands.
Water Res. 2014 Jan 1;48:269-79. doi: 10.1016/j.watres.2013.09.036. Epub 2013 Sep 27.
Exposure modeling of engineered nanomaterials requires input parameters such as sedimentation rates and heteroaggregation rates. Here, we estimate these rates using quiescent settling experiments under environmentally relevant conditions. We investigated 4 different nanomaterials (C60, CeO2, SiO2-Ag and PVP-Ag) in 6 different water types ranging from a small stream to seawater. In the presence of natural colloids, sedimentation rates ranged from 0.0001 m d(-1) for SiO2-Ag to 0.14 m d(-1) for C60. The apparent rates of heteroaggregation between nanomaterials and natural colloids were estimated using a novel method that separates heteroaggregation from homoaggregation using a simplified Smoluchowski-based aggregation-settling equation applied to data from unfiltered and filtered waters. The heteroaggregation rates ranged between 0.007 and 0.6 L mg(-1) day(-1), with the highest values observed in seawater. We argue that such system specific parameters are key to the development of dedicated water quality models for ENMs.
工程纳米材料的暴露模型需要输入参数，如沉降速率和异质聚集速率。在这里，我们使用在环境相关条件下的静态沉降实验来估计这些速率。我们研究了 4 种不同的纳米材料（C60、CeO2、SiO2-Ag 和 PVP-Ag）在 6 种不同的水类型中，范围从小溪到海水。在天然胶体存在的情况下，沉降速率从 SiO2-Ag 的 0.0001 m d(-1)到 C60 的 0.14 m d(-1)。使用一种新的方法来估计纳米材料和天然胶体之间的异质聚集速率，该方法使用简化的基于 Smoluchowski 的聚集-沉降方程从未过滤和过滤的水中分离出异质聚集，从而估计异质聚集速率。异质聚集速率在 0.007 和 0.6 L mg(-1) day(-1)之间，在海水中观察到的速率最高。我们认为，这种特定于系统的参数是开发专门针对 ENM 的水质模型的关键。
