Impact of Silver Nanoparticles on the Aqueous Environment: Analytical Method Development and Field Experiments

该项目的研究目标是调查消费品中的银纳米颗粒和潜在反应产物对水环境的影响。这项研究将包括制定一系列适当的分析方法，并将其应用于实验室和实地实验。目标是：1.废水和地表沃茨中溶解和纳米颗粒银检验的分析方法和取样策略的调整和优化。2.在实验室和现场实验中使用开发的方法来回答以下问题：-在废水处理过程中去除了多少银纳米颗粒和其他银物质？-污水处理厂排放的银纳米颗粒在地表水中的分布情况如何？- 银存在于哪些物种中？在水环境中会发生转化吗？在本项目的第1部分中，应开发多种分析方法，如同位素稀释分析、同位素分馏分析、单粒子ICP-MS和浊点萃取，用于识别和定量银物质，包括银离子Ag（I）和银纳米颗粒。所制定的方法应具有稳健性，足以分析湖水和沉积物等环境样品。在该项目的第2部分，银纳米粒子在污水处理厂的行为将通过平衡各自工厂的银输入和输出进行调查。流入物和流出物样品的形态将显示在污水处理过程中是否发生了物种转化。将评估银纳米颗粒对溶解、氧化、沉淀以及它们与有机物质（腐殖酸）的相互作用的行为。物种转化应通过第1部分中开发的一系列分析方法进行监测。为了评估银纳米颗粒对水环境的影响，将在加拿大安大略的实验湖区进行全湖添加研究。纳米粒子将被添加到一个实验湖作为点源。湖水将直接取样，并在湖水完全混合后取样。湖水和沉积物样品将采用项目第一部分中开发的方法进行分析。结果将提供有关湖中分布的信息以及物种信息。与实验室实验结果的比较，关于它们在溶解、沉淀、氧化等过程中的行为，将允许广泛评估银纳米颗粒对水环境的影响。

The research objective of the proposed project is the investigation of the impact of silver nanoparticles from consumer products and potential reaction products on the aqueous environment. The study will include the development of a range of adequate analytical methods and their application in laboratory and field experiments. The goals are:1. The adaption and optimization of analytical methods and sampling strategies for the examination of dissolved and nanoparticulate silver in wastewater and surface waters. 2. The employment of the developed methods in laboratory and field experiments to answer the following questions:- How much silver nanoparticles and other silver species are removed during wastewater treatment?- How does silver nanoparticles distribute in surface water after release from the sewage plant? - In which species is silver present? Do transformations take place in the aqueous environment?In part 1 of the project, diverse analytical methods such as isotope dilution analysis, isotope fractionation analysis, single particle ICP-MS, and cloud point extraction shall be developed for the identification and quantification of silver species, including silver ions Ag(I) and silver nanoparticles. The developed methods shall be robust and adequate for the analysis of environmental samples such as lake water and sediment. In part 2 of the project, the behaviour of silver nanoparticles in sewage treatment plants will be investigated by balancing of silver input and output of a respective plant. Speciation of influent and effluent samples will show if species transformation takes place during sewage treatment. The behaviour of the silver nanoparticles towards dissolution, oxidation, precipitation, as well as their interaction with organic matter (humic acids) will be assessed. Species transformation shall be monitored by a range of analytical methods developed in part 1. In order to assess the impact of silver nanoparticles on the aqueous environment, a whole lake addition study will be carried out in the Experimental Lake Area in Ontario, Canada. Nanoparticles will be added into an experimental lake as a point source. The lake will be sampled directly and after total mixing of the lake water. The lake water and the sediment samples will be analysed by means of the methods developed in part 1 of the project. The results will give information about distribution in the lake, as well as species information. A comparison with the results of the laboratory experiments regarding their behaviour during dissolution, precipitation, oxidation, etc. will allow an extensive assessment of the impact of silver nanoparticles on the aqueous environment.