The heteroaggregation and deposition behavior of nanoplastics on Al2O3 in aquatic environments

Jiayan Wu; Jieyu Liu; Pingxiao Wu; Leiye Sun; Meiqing Chen; Zhongbo Shang; Quanyun Ye; Nengwu Zhu

doi:10.1016/j.jhazmat.2022.128964

The heteroaggregation and deposition behavior of nanoplastics on Al₂O₃ in aquatic environments

J Hazard Mater. 2022 Aug 5:435:128964. doi: 10.1016/j.jhazmat.2022.128964. Epub 2022 Apr 28.

Authors

Jiayan Wu¹, Jieyu Liu¹, Pingxiao Wu², Leiye Sun¹, Meiqing Chen¹, Zhongbo Shang¹, Quanyun Ye¹, Nengwu Zhu¹

Affiliations

¹ School of Environment and Energy, South China University of Technology, Guangzhou Higher Education Mega Centre, Guangzhou 510006, PR China.
² School of Environment and Energy, South China University of Technology, Guangzhou Higher Education Mega Centre, Guangzhou 510006, PR China; The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, Guangzhou 510006, PR China; Guangdong Provincial Key Laboratory of Solid Wastes Pollution Control and Recycling, Guangzhou 510006, PR China; Guangdong Engineering and Technology Research Center for Environmental Nanomaterials, Guangzhou 510006, PR China. Electronic address: pppxwu@scut.edu.cn.

PMID: 35490632
DOI: 10.1016/j.jhazmat.2022.128964

Abstract

The ubiquitous Al₂O₃ is anticipated to interact with nanoplastics, affecting their fate and transport in aquatic environments. In this study, the heteroaggregation and deposition behaviors of polystyrene nanoplastics (PSNPs) on Al₂O₃ were systematically investigated under different conditions (ionic strength, pH, and natural organic matter). The results showed that significant heteroaggregation occurred between PSNPs and Al₂O₃ particles under acidic and neutral conditions. When the NaCl concentration was increased from 50 to 500 mM, the heteroaggregation ratio gradually increased. However, poly (acrylic acid) (PAA) inhibited the heteroaggregation of PSNPs-Al₂O₃ due to steric repulsion. The deposition of PSNPs on Al₂O₃ surfaces was inhibited as the NaCl concentration or pH values increased. Due to charge reversal and steric repulsion, humic acid (HA) and fulvic acid (FA) prevented the deposition of PSNPs onto Al₂O₃ surfaces, and the former was more effective in reducing the deposition rate. The interaction mechanism between PSNPs and Al₂O₃ was revealed by using various characterization techniques and density function theory (DFT) calculation. The results demonstrated that in addition to the dominant electrostatic interaction, there were also weak hydrogen bonds and van der Waals interactions. Our research is of great significance for predicting the migration and fate of PSNPs in aquatic environments.

Keywords: Al(2)O(3); DFT; Deposition; Heteroaggregation; Nanoplastics.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Humic Substances
Microplastics*
Osmolar Concentration
Polystyrenes / chemistry
Sodium Chloride*

Substances

Humic Substances
Microplastics
Polystyrenes
Sodium Chloride