Journal
ENVIRONMENTAL POLLUTION
Volume 268, Issue -, Pages -Publisher
ELSEVIER SCI LTD
DOI: 10.1016/j.envpol.2020.114240
Keywords
Nanoplastics; Aggregation; Stability; Hydrochemical condition; Natural waters
Categories
Funding
- National Natural Science Foundation of China [41673131, 41925031]
Ask authors/readers for more resources
This study investigated the aggregation and stability of polystyrene (PS) nanoparticles under different hydrochemical conditions. The presence of natural organic matter (NOM) was found to be the most significant factor affecting NP aggregation in waters with high ionic strength and NOM content. PS NPs were highly suspended in all freshwaters and wastewater, while they aggregated rapidly and deposited in seawater.
Nanoplastics (NPs) are becoming emerging pollutants of global concern. Understanding the environmental behavior of NPs is crucial for their environmental and human risk assessment. In this study, the aggregation and stability of polystyrene (PS) NPs were investigated under different hydrochemical conditions such as pH, salt type (NaCl, CaCl2, Na2SO4), ionic strength (IS), and natural organic matter (NOM). The critical coagulation concentrations of PS NPs were determined to be 158.7 mM NaCl, 12.2 mM CaCl2, and 80.0 mM Na2SO4. Ca2+ was more effective in destabilizing PS NPs, compared to Na+, owing to its stronger charge screening effect. In the presence of monovalent ions, NOM reduced aggregation through steric repulsion, whereas in the case of divalent ions, NOM induced aggregation through cation bridging. Initial and long-term stability studies demonstrated that, in waters with high IS and NOM content, NOM was the most significant factor affecting NPs aggregation. PS NPs would be highly suspended in all freshwaters, and even in wastewater, whereas they would aggregate rapidly and deposit in seawater. Finally, a statistical model was established to evaluate the hydrodynamic diameter of NPs in different waters. The results indicated the stability of PS NPs in natural aquatic environments and their potential for long-term transport. (C) 2020 Elsevier Ltd. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available