Department of Environmental Science, Radboud University Nijmegen, Institute for Wetland and Water Research, PO Box 9010, 6500 GL Nijmegen, The Netherlands.
Chemosphere. 2010 Oct;81(6):711-5. doi: 10.1016/j.chemosphere.2010.07.062. Epub 2010 Aug 21.
The ecological risk assessment of chemicals including nanoparticles is based on the determination of adverse effects on organisms and on the environmental concentrations to which biota are exposed. The aim of this work was to better understand the behavior of nanoparticles in the environment, with the ultimate goal of predicting future exposure concentrations in water. We measured the concentrations and particle size distributions of CeO(2) nanoparticles in algae growth medium and deionized water in the presence of various concentrations and two types of natural organic matter (NOM). The presence of natural organic matter stabilizes the CeO(2) nanoparticles in suspension. In presence of NOM, up to 88% of the initially added CeO(2) nanoparticles remained suspended in deionized water and 41% in algae growth medium after 12d of settling. The adsorbed organic matter decreases the zeta potential from about -15 mV to -55 mV. This reduces aggregation by increased electrostatic repulsion. The particle diameter, pH, electric conductivity and NOM content shows significant correlation with the fraction of CeO(2) nanoparticles remaining in suspension.
包括纳米颗粒在内的化学物质的生态风险评估基于对生物机体产生的不良影响以及生物机体所暴露的环境浓度的确定。本工作的目的是更好地了解纳米颗粒在环境中的行为，最终目的是预测水中未来的暴露浓度。我们在不同浓度和两种类型的天然有机物（NOM）存在的情况下，测量了 CeO(2)纳米颗粒在藻类生长介质和去离子水中的浓度和颗粒尺寸分布。天然有机物的存在使 CeO(2)纳米颗粒在悬浮液中稳定。在 NOM 存在的情况下，在 12 天的沉降后，最初添加的 CeO(2)纳米颗粒中有高达 88%仍悬浮在去离子水中，有 41%悬浮在藻类生长介质中。吸附的有机物使 ζ 电位从约-15 mV 降低至-55 mV。这通过增加静电排斥作用减少了聚集。粒径、pH 值、电导率和 NOM 含量与悬浮在 CeO(2)纳米颗粒中的分数呈显著相关性。
