Sorption of representative organic contaminants on microplastics: Effects of chemical physicochemical properties, particle size, and biofilm presence

Authors

Wenxuan Cui
Robert C. Hale, Virginia Institute of Marine ScienceFollow
Yichao Huang
et al.

Document Type

Article

Department/Program

Virginia Institute of Marine Science

Publication Date

2-2023

Journal

Ecotoxicology and Environmental Safety

Volume

251

Issue

114533

Abstract

Microplastic pollution has attracted mounting concerns worldwide. Microplastics may concentrate organic and metallic contaminants; thus, affecting their transport, fate and organismal exposure. To better understand organic contaminant-microplastic interactions, our study explored the sorption of selected polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), α-hexabromocyclododecane (α-HBCDD), and organophosphate flame retardants (OPFRs) on high-density polyethylene (HDPE) and polyvinylchloride (PVC) microplastics under saline conditions. Sorption isotherms determined varied between chemicals and between HDPE and PVC microplastics. Log Freundlich sorption coefficients (Log K_F) for the targeted chemicals ranged from 2.01 to 5.27 L kg^-1 for HDPE, but were significantly lower for PVC, i.e., ranging from Log K_F data (2.84 – 8.58 L kg^-1). Significant correlations between chemicals’ Log K_F and Log K_ow (octanol-water partition coefficient) indicate that chemical-dependent sorption was largely influenced by their hydrophobicity. Sorption was evaluated using three size classes (< 53, 53 – 300, and 300 – 1000 µm) of lab-fragmented microplastics. Particle size did not significantly affect sorption isotherms, but influenced the time to reach equilibrium and the predicted maximum sorption, likely related to microplastic surface areas. The presence of biofilms on HDPE particles significantly enhanced contaminant sorption capacity, indicating more complex sorption dynamics in the chemical-biofilm-microplastic system. Our findings offer new insights into the chemical-microplastic interactions in marine environment.

DOI

https://doi.org/10.1016/j.ecoenv.2023.114533

Creative Commons License

This work is licensed under a Creative Commons Attribution 4.0 International License.

Recommended Citation

Cui, Wenxuan; Hale, Robert C.; Huang, Yichao; and et al., Sorption of representative organic contaminants on microplastics: Effects of chemical physicochemical properties, particle size, and biofilm presence (2023). Ecotoxicology and Environmental Safety, 251(114533).

https://doi.org/10.1016/j.ecoenv.2023.114533