title: Water chemistry controlled aggregation and photo-transformation of silver nanoparticles in environmental waters.
abstract: The inevitable release of engineered silver nanoparticles (AgNPs) into aquatic environments has drawn great concerns about its environmental toxicity and safety. Although aggregation and transformation play crucial roles in the transport and toxicity of AgNPs, how the water chemistry of environmental waters influences the aggregation and transformation of engineered AgNPs is still not well understood. In this study, the aggregation of polyvinylpyrrolidone (PVP) coated AgNPs was investigated in eight typical environmental water samples (with different ionic strengths, hardness, and dissolved organic matter (DOM) concentrations) by using UV-visible spectroscopy and dynamic light scattering. Raman spectroscopy was applied to probe the interaction of DOM with the surface of AgNPs. Further, the photo-transformation and morphology changes of AgNPs in environmental waters were studied by UV-visible spectroscopy, inductively coupled plasma mass spectrometry, and transmission electron microscopy. The results suggested that both electrolytes (especially Ca(2+) and Mg(2+)) and DOM in the surface waters are key parameters for AgNP aggregation, and sunlight could accelerate the morphology change, aggregation, and further sedimentation of AgNPs. This water chemistry controlled aggregation and photo-transformation should have significant environmental impacts on the transport and toxicity of AgNPs in the aquatic environments.
authors.affiliation: State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China. Electronic address: ygyin@rcees.ac.cn.
authors.forename: Yongguang
authors.initials: Y
authors.lastname: Yin
authors.affiliation: State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; School of the Environment, Jiangsu University, Zhenjiang 212013, China.
authors.forename: Xiaoya
authors.initials: X
authors.lastname: Yang
authors.affiliation: State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
authors.forename: Xiaoxia
authors.initials: X
authors.lastname: Zhou
authors.affiliation: State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
authors.forename: Weidong
authors.initials: W
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
authors.forename: Sujuan
authors.initials: S
authors.lastname: Yu
authors.affiliation: State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; Institute of Environment and Health, Jianghan University, Wuhan 430056, China. Electronic address: jfliu@rcees.ac.cn.
authors.forename: Jingfu
authors.initials: J
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
authors.forename: Guibin
authors.initials: G
authors.lastname: Jiang
mesh_terms: D005618:Fresh Water / Q000737:chemistry*; D006812:Humic Substances / Q000032:analysis; D007477:Ions / Q000032:analysis; D053768:Metal Nanoparticles / Q000737:chemistry*; D010782:Photolysis; D011205:Povidone / Q000032:analysis; D012834:Silver / Q000737:chemistry*; D013472:Sunlight; D013499:Surface Properties; D014874:Water Pollutants, Chemical / Q000737:chemistry*
chemical_list: D006812:Humic Substances; D007477:Ions; D014874:Water Pollutants, Chemical; D012834:Silver; D011205:Povidone
keywords: Aggregation; Silver nanoparticles (AgNPs); Sunlight; Transformation; Water chemistry