纳米银在天然有机质作用下的化学转化机制及其效应研究

Silver nanomaterials (nano-Ag) have been the most widely used nanomaterials in commercial products, and they are inevitably released into aquatic environments through different pathways. As a result, there are growing concerns about the environmental impacts of released nano-Ag, particularly their unintended impacts on organisms and ecosystems. Chemical transformations, including oxidation, sulfidation, and chloridization, could be very important environmental processes of nano-Ag. Studying the processes and mechanisms of transformation of nano-Ag may lead us to understand more about their fate, bioavailability, and toxicity in the aquatic environments. Natural organic matter (NOM), including humic substances, extracellular polymeric substances (EPS) and proteins, inevitably interact with nano-Ag in aquatic environments, and affect their chemical transformations..In this research project, chemical transformation processes of nano-Ag in complex aqueous environments are investigated by using a combination of spectroscopy and electron microscope measurements. We aim to disclose the impacts of humic substances, EPS and proteins, individually or in combination on the pathways of oxidation, sulfidation, and chloridization of nano-Ag. In aqueous solutions, we also study the mechanisms of how the three transformation processes of nano-Ag affect their fate and bioavailability, and it also is of great significance to deeply assess the potential risk for ecological environments and human health.

纳米银材料的大量生产和广泛应用使其通过多种途径进入水环境，并且对水生生物产生毒性效应，最终将会对环境和人体健康带来危害。水环境中纳米银可发生氧化、硫化和氯化等化学转化，导致其团聚、迁移和赋存状态发生改变，并最终影响其生物有效性和毒性。天然有机质包括腐殖质、胞外聚合物和蛋白质等，在水环境中能够与纳米银发生相互作用，影响后者的化学转化过程。.本项目以不同形貌和包覆材料的纳米银为研究对象，拟采用批实验研究其在水环境中氧化、硫化和氯化等化学转化的反应动力学规律及相关机制。考察天然有机质（腐殖质、胞外聚合物和蛋白质等）的成分、化学结构、分子量等对纳米银化学转化行为的影响与机制，揭示纳米银的化学转化对其赋存状态以及改变其在水环境中生物有效性的内在机制，为深入科学地评价纳米银材料对生态环境和人类健康的安全性提供理论基础。

纳米银是一种大量生产和广泛应用的人工纳米材料。它通过多种途径进入水环境，并且对水生生物产生毒性效应，最终将会对环境和人体健康带来危害。水环境中纳米银可发生氧化溶解、硫化和氯化等化学转化，导致其团聚、迁移和赋存状态发生改变，并最终影响其生物有效性和毒性。天然有机质包括腐殖质、胞外聚合物和蛋白质等，在水环境中能够与纳米银发生相互作用，影响后者的化学转化过程。.本项目以不同形貌和包覆材料的纳米银为研究对象，采用批实验研究考察了不同种类天然有机质（包括腐殖酸、富里酸、蛋白质和胞外聚合物等）存在时，纳米银氧化溶解、硫化和氯化等化学转化的化学反应动力学和反应机理，以及天然有机质对纳米银最终赋存状态和化学转化过程的改变机制。通过多种光谱学分析技术，结合电子显微镜表征，通过化学结构形态和表面电位变化揭示了纳米银分别与腐殖酸、蛋白质和胞外聚合物的相互作用机制。阐明了纳米银在不同天然有机质环境中氧化溶解、硫化和氯化转化过程的关键影响机制。以胞外聚合物作为例，通过细胞毒性实验，研究了天然有机质对化学转化前后的纳米银的毒性效应的内在影响机制。将对深入科学地评价纳米材料对生态环境和人类健康的安全性提供理论基础和数据支持。