We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
Charge mediated interaction of polystyrene nanoplastic (PSNP) with minerals in aqueous phase
Summary
Researchers investigated how polystyrene nanoplastics interact with common soil and sediment minerals, finding that positively charged iron oxide minerals (goethite and magnetite) strongly adsorb nanoplastics via electrostatic attraction and hydrogen bonding, while negatively charged clay minerals do not — providing mechanistic insight into how nanoplastics may accumulate in iron-rich soils and sediments.
A large number of plastic products potentially become smaller particles, including nanoplastics, under multiple actions in the environment. The interactions between nanoplastic particles and constituents in the environment, such as minerals, would greatly affect the transport, fate and toxic effects of nanoplastics. In this study, the interactions of polystyrene nanoplastic (PSNP) with four typical minerals, including goethite, magnetite, kaolinite and montmorillonite, in aqueous phase were investigated. The stability of PSNP colloidal suspension decreased in the presence of the positively charged goethite or magnetite, while it was not affected by the negatively charged montmorillonite and kaolinite, suggesting that there was a strong electrostatic attraction between PSNP and the two iron oxides. Incubation of PSNP with other three metal oxides with different surface charges, MnO, AlO and SiO, confirmed the importance of electrostatic interaction in the stability of PSNP suspension. The transmission electron microscopy (TEM) analysis and batch adsorption experiments indicated that PSNP was effectively adsorbed on goethite or magnetite due to the strong electrostatic attraction between them. The Fourier transform infrared spectra (FTIR) and two-dimensional correlation spectroscopy (2D-COS) analyses indicated that there was strong hydrogen bonding between the -OH (γ-FeOOH) of goethite and PSNP, contributing to the higher adsorption of PSNP on goethite than magnetite. These findings shed light on the interactions of PSNP with mineral surfaces, and potential fate of PSNP under natural conditions in the water environment.