Print Email Facebook Twitter Combined effects of photoaging and natural organic matter on the colloidal stability of nanoplastics in aquatic environments Title Combined effects of photoaging and natural organic matter on the colloidal stability of nanoplastics in aquatic environments Author Xu, Yanghui (TU Delft Sanitary Engineering; Chinese Academy of Sciences) Ou, Q. (TU Delft Sanitary Engineering; Chinese Academy of Sciences) Li, Xiaoming (Chinese Academy of Sciences) Wang, Xintu (Chinese Academy of Sciences; Guilin University of Technology) van der Hoek, J.P. (TU Delft Sanitary Engineering; Waternet) Liu, Gang (Chinese Academy of Sciences) Date 2022 Abstract The transport and fate of nanoplastics (NPs) in aquatic environments are closely associated with their colloidal stability, which is affected by aging and natural organic matter (NOM) adsorption. This study systematically investigated the combined effects of photoaging and NOM (e.g. humic acids, HA; and a model protein, bovine serum albumin, BSA) on the aggregation kinetics of NPs (polystyrene, PS) in NaCl and CaCl2 solutions. Our results showed that photoaged NPs adsorbed less HA than pristine NPs due to weaker hydrophobic and π-π interactions. In return, HA showed weaker impacts on NPs’ stability after photoaging. Differently, photoaged NPs absorbed more BSA than pristine NPs due to stronger hydrogen bonding and electrostatic attraction. Thus, the inhibitory effects of BSA on the aggregation kinetics of NPs were enhanced after photoaging. Regarding the effects of NOM on the aging of NPs, our results showed that HA competed with NPs for photons and underwent photo-degradation. Subsequently, the destruction/reconstruction of adsorbed HA increased (in NaCl) or decreased (in CaCl2) the stability of NPs. Notably, light radiation-induced flocculation of BSA molecules, which wrapped and integrated NPs and lead to their destabilization. Overall, this study provided new insights into the aggregation behavior of NPs in aquatic systems, which have significant implications for predicting the transport and fate of NPs in complex real-world environments. Subject NanoplasticsColloidal stabilityNatural organic matterPhotoagingSteric repulsionPhoto-flocculation To reference this document use: http://resolver.tudelft.nl/uuid:bc68abb3-9345-40a6-8132-696ff076b5dd DOI https://doi.org/10.1016/j.watres.2022.119313 ISSN 0043-1354 Source Water Research, 226 Part of collection Institutional Repository Document type journal article Rights © 2022 Yanghui Xu, Q. Ou, Xiaoming Li, Xintu Wang, J.P. van der Hoek, Gang Liu Files PDF 2022_Nanoplastics_Photoag ... NOM_WR.pdf 6.58 MB Close viewer /islandora/object/uuid:bc68abb3-9345-40a6-8132-696ff076b5dd/datastream/OBJ/view