TY - JOUR
T1 - Colloidal stability of Fe3O4 magnetic nanoparticles differentially impacted by dissolved organic matter and cations in synthetic and naturally-occurred environmental waters
AU - Wang, Hao
AU - Zhao, Xiaoli
AU - Han, Xuejiao
AU - Tang, Zhi
AU - Song, Fanhao
AU - Zhang, Shaoyang
AU - Zhu, Yuanrong
AU - Guo, Wenjing
AU - He, Zhongqi
AU - Guo, Qingwei
AU - Wu, Fengchang
AU - Meng, Xiaoguang
AU - Giesy, John P.
N1 - Publisher Copyright:
© 2018 Elsevier Ltd
PY - 2018/10
Y1 - 2018/10
N2 - Better understanding of the colloidal behaviors of nanomaterials impacted by aquatic chemistry parameters is needed for appropriate evaluation of the environmental risks posed by nanomaterials in natural waters. In the study, the colloidal stability of Fe3O4 magnetic nanoparticles (Fe-MNPs) was evaluated over a range of chemistry characteristics [e.g., pH, dissolved organic matter (DOM), salt types, cationic strength] in six synthetic water samples. The findings from the synthetic water samples were further examined with eight “real world” environmental water samples. Our results demonstrated that DOM fraction, humic acid (HA), promoted suspension of Fe-MNPs more by hydrophobic interactions in addition to ligand exchange and electrostatic effects compared with fulvic acid (FA). Capability of cations to increase aggregation of Fe-MNPs were in the order of Ca2+ > Mg2+ >> Na+ because of their different degrees of bridging complexation with DOM molecules on particle surfaces. As a key parameter for indicating Fe-MNPs colloidal stability, Zeta (ζ) potentials of Fe-MNPs in these waters samples were well correlated to (R2 = 0.880, P < 0.001) the contents, types and adsorption forms of DOM and cations. However, several other factors could also affect the hydrodynamic diameter (HDD) of Fe-MNPs in the “real world” environmental waters. It assumed that ampholytic-DOM molecules such as amino acid- and protein-like molecules caused great aggregation of Fe-MNPs. These findings would be helpful for better understanding and evaluating the colloidal behaviors of nanomaterials when they released into natural water environment, thus could shed light on developing relevant pollution control strategies. The colloid stability of Fe-MNPs in environmental waters was affected by bridging complexation of cations with DOM molecules as well as adsorptions of amino acid- and protein-like molecules on the particle surface.
AB - Better understanding of the colloidal behaviors of nanomaterials impacted by aquatic chemistry parameters is needed for appropriate evaluation of the environmental risks posed by nanomaterials in natural waters. In the study, the colloidal stability of Fe3O4 magnetic nanoparticles (Fe-MNPs) was evaluated over a range of chemistry characteristics [e.g., pH, dissolved organic matter (DOM), salt types, cationic strength] in six synthetic water samples. The findings from the synthetic water samples were further examined with eight “real world” environmental water samples. Our results demonstrated that DOM fraction, humic acid (HA), promoted suspension of Fe-MNPs more by hydrophobic interactions in addition to ligand exchange and electrostatic effects compared with fulvic acid (FA). Capability of cations to increase aggregation of Fe-MNPs were in the order of Ca2+ > Mg2+ >> Na+ because of their different degrees of bridging complexation with DOM molecules on particle surfaces. As a key parameter for indicating Fe-MNPs colloidal stability, Zeta (ζ) potentials of Fe-MNPs in these waters samples were well correlated to (R2 = 0.880, P < 0.001) the contents, types and adsorption forms of DOM and cations. However, several other factors could also affect the hydrodynamic diameter (HDD) of Fe-MNPs in the “real world” environmental waters. It assumed that ampholytic-DOM molecules such as amino acid- and protein-like molecules caused great aggregation of Fe-MNPs. These findings would be helpful for better understanding and evaluating the colloidal behaviors of nanomaterials when they released into natural water environment, thus could shed light on developing relevant pollution control strategies. The colloid stability of Fe-MNPs in environmental waters was affected by bridging complexation of cations with DOM molecules as well as adsorptions of amino acid- and protein-like molecules on the particle surface.
KW - Environmental waters
KW - Fulvic acid
KW - Humic acid
KW - Magnetic nanoparticles
KW - Metal cations
KW - Suspension and aggregation
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UR - http://www.scopus.com/inward/citedby.url?scp=85049309640&partnerID=8YFLogxK
U2 - 10.1016/j.envpol.2018.06.029
DO - 10.1016/j.envpol.2018.06.029
M3 - Article
C2 - 29920469
AN - SCOPUS:85049309640
SN - 0269-7491
VL - 241
SP - 912
EP - 921
JO - Environmental Pollution
JF - Environmental Pollution
ER -