Cotransport of nanoplastics (NPs) with fullerene (C60) in saturated sand: Effect of NPs/C60 ratio and seawater salinity

Zhiqiang Dong; Wen Zhang; Yuping Qiu; Zhenglong Yang; Junliang Wang; Yidi Zhang

doi:10.1016/j.watres.2018.10.071

Cotransport of nanoplastics (NPs) with fullerene (C₆₀) in saturated sand: Effect of NPs/C₆₀ ratio and seawater salinity

Water Res. 2019 Jan 1:148:469-478. doi: 10.1016/j.watres.2018.10.071. Epub 2018 Oct 30.

Authors

Zhiqiang Dong¹, Wen Zhang¹, Yuping Qiu², Zhenglong Yang³, Junliang Wang⁴, Yidi Zhang⁵

Affiliations

¹ State Key Laboratory of Pollution Control and Resource Reuse, Ministry of Education Key Laboratory of Yangtze River Water Environment, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China; Shanghai Institute of Pollution Control and Ecological Security, International Joint Research Center for Sustainable Urban Water System, Shanghai, 200092, PR China.
² State Key Laboratory of Pollution Control and Resource Reuse, Ministry of Education Key Laboratory of Yangtze River Water Environment, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China; Shanghai Institute of Pollution Control and Ecological Security, International Joint Research Center for Sustainable Urban Water System, Shanghai, 200092, PR China. Electronic address: ypqiu@tongji.edu.cn.
³ School of Materials Science and Engineering, Jiading Campus, Tongji University, Shanghai, 201804, China.
⁴ School of the Environment, Zhejiang University of Technology, Hangzhou, 310014, China.
⁵ State Key Laboratory of Pollution Control and Resource Reuse, Ministry of Education Key Laboratory of Yangtze River Water Environment, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China.

PMID: 30408733
DOI: 10.1016/j.watres.2018.10.071

Abstract

Nanoplastics (NPs) have been identified as newly emerging particulate contaminants. In marine environments, the interaction between NPs and other engineered nanoparticles remains unknown. This study investigated the cotransport of NPs with fullerene (C₆₀) in seawater-saturated columns packed with natural sand as affected by the mass concentration ratio of NPs/C₆₀ and the hydrochemical characteristics. In seawater with 35 practical salinity units (PSU), NPs could remarkably enhance C₆₀ dispersion with a NPs/C₆₀ ratio of 1. NPs behaved as a vehicle to facilitate C₆₀ transport by decreasing colloidal ζ-potential and forming stable primary heteroaggregates. As the NPs/C₆₀ ratio decreased to 1/3, NPs mobility was progressively restrained because of the formation of large secondary aggregates. When the ratio continuously decreased to 1/10, the stability and transport of colloids were governed by C₆₀ rather than NPs. Under this condition, the transport trend of binary suspensions was similar to that of single C₆₀ suspension, which was characterized by a ripening phenomenon. Seawater salinity is another key factor affecting the stability and associated transport of NPs and C₆₀. In seawater with 3.5 PSU, NPs and C₆₀ (1:1) in binary suspension exhibited colloidal dispersion, which was driven by a high-energy barrier. Thus, the profiles of the cotransport and retention of NPs/C₆₀ resembled those of single NPs suspension. This work demonstrated that the cotransport of NPs/C₆₀ strongly depended on their mass concentration ratios and seawater salinity.

Keywords: Aggregation; Fullerene; Marine environment; Microplastics; Nanoplastics; Transport.

Publication types

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

MeSH terms

Colloids
Fullerenes*
Salinity
Seawater
Silicon Dioxide

Substances

Colloids
Fullerenes
Silicon Dioxide