Modelling the release, dispersion and fate of nanoparticulate titanium dioxide from sunscreen products in recreational lakes

模拟休闲湖泊防晒产品中纳米颗粒二氧化钛的释放、分散和归宿

• 批准号: 519380927
• 负责人: Professor Dr. Andreas Lorke
• 金额: --
• 依托单位: Bundesanstalt für Gewässerkunde (BfG)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/519380927?language=en
• 关键词: Modelling; release; dispersion; fate; nanoparticulate

Titanium dioxide nanoparticles (n-TiO2) represent an increasing threat for aquatic ecosystems due to their persistence and the direct release from sunscreens in recreational waters during the bathing season. However, their impact is still difficult to evaluate because, on one side, analytical methods for monitoring their concentration in environmental media have been developed only recently. On the other side, their fate in aquatic systems is still insufficiently understood. In particular, the distribution between the surface microlayer (SML), bulk water, sediments, plants, and plankton depends on various mechanisms that were investigated individually in laboratory experiments, but were rarely assessed under environmental conditions. Furthermore, the role of wind in the dispersion of nanoparticles present in the SML has not been investigated so far, although it is expected to contribute significantly to the spatial dispersion of hydrophobic n-TiO2. In this project, we propose to investigate the distribution of n-TiO2 in a typical recreational lake and, based on detailed empirical data, assess a reactive transport model describing their fate. We will quantify and characterize the input of sunscreens using surveys and samples among bathers and determine the wash-off rate of sunscreen from the skin under field conditions using dedicated experiments. The amount of n-TiO2 in the water phase, in the surficial water (hydrophobic films), and in aquatic organisms will be determined using a newly developed method relying on trace elements to correct for the natural TiO2-background. A sampling campaign at a high measurement frequency will be conducted to obtain empirical data on the dispersion rate due to convection and wind drift on the SML. The accumulation of anthropogenic n-TiO2 in the sediment will be determined by monitoring the concentration before and after the bathing season. The obtained data will be used to develop, test, and optimize fate distribution models taking into account spatial dispersion due to convection and wind together with the nanoparticles’ properties and the water chemistry. Functional assays will be carried out for determining the parameters required for the fate model. Attachment efficiencies will be determined using n-TiO2 extracted from sunscreen and coated naturally in lake water. Surrogate for natural colloids will be selected based on a detailed investigation of the colloids in the study lake and used as heteroaggregation partners in the functional assays. To parametrize the effect of wind on the SML, flume mesocosm experiments will be conducted to produce and test the stability of sunscreen SML under controlled aero- and hydrodynamic conditions. The results will enable us to determine the most relevant processes involved in the fate of n-TiO2 from sunscreens in recreational waters and, thereafter, open the door to more accurate ecological risk assessment of inorganic UV-filter in sunscreens.

二氧化钛纳米颗粒 (n-TiO2) 对水生生态系统的威胁越来越大，因为它们的持久性以及在沐浴季节从娱乐水域中的防晒霜中直接释放。然而，它们的影响仍然难以评估，因为一方面，监测它们在环境介质中浓度的分析方法最近才被开发出来。另一方面，人们对它们在水生系统中的命运仍知之甚少。特别是，表面微层（SML）、大量水、沉积物、植物和浮游生物之间的分布取决于在实验室实验中单独研究的各种机制，但很少在环境条件下进行评估。此外，尽管预计风对疏水性 n-TiO2 的空间分散有显着贡献，但迄今为止，尚未研究风在 SML 中存在的纳米粒子分散中的作用。在这个项目中，我们建议研究典型休闲湖中 n-TiO2 的分布，并根据详细的经验数据，评估描述其命运的反应传输模型。我们将通过对沐浴者的调查和样本来量化和表征防晒霜的输入，并使用专门的实验确定在现场条件下防晒霜从皮肤上的洗掉率。水相、地表水（疏水膜）和水生生物中 n-TiO2 的含量将使用新开发的方法测定，该方法依靠微量元素来校正天然 TiO2 背景。将进行高测量频率的采样活动，以获得有关 SML 上对流和风漂移引起的扩散率的经验数据。沉积物中人为n-TiO2的积累量将通过监测沐浴季节前后的浓度来确定。获得的数据将用于开发、测试和优化命运分布模型，同时考虑对流和风引起的空间分散以及纳米颗粒的特性和水化学。将进行功能测定以确定命运模型所需的参数。附着效率将使用从防晒霜中提取并自然涂覆在湖水中的 n-TiO2 来确定。将根据对研究湖中胶体的详细调查来选择天然胶体的替代物，并将其用作功能测定中的异聚集伙伴。为了参数化风对 SML 的影响，将进行水槽中生态实验，以在受控空气和流体动力条件下生产和测试防晒霜 SML 的稳定性。这些结果将使我们能够确定与休闲水域中防晒霜中 n-TiO2 的归宿最相关的过程，从而为更准确地评估防晒霜中无机紫外线过滤剂的生态风险打开大门。