Transport and retention of polymeric and other engineered nanoparticles in porous media

Xiaoping Xin; Jonathan D Judy; Fengliang Zhao; Sofia L Goodrich; Brent S Sumerlin; Peter J Stoffella; Zhenli He

doi:10.1016/j.impact.2021.100361

Transport and retention of polymeric and other engineered nanoparticles in porous media

NanoImpact. 2021 Oct:24:100361. doi: 10.1016/j.impact.2021.100361. Epub 2021 Nov 1.

Authors

Xiaoping Xin¹, Jonathan D Judy², Fengliang Zhao³, Sofia L Goodrich⁴, Brent S Sumerlin⁴, Peter J Stoffella¹, Zhenli He⁵

Affiliations

¹ University of Florida, Institute of Food and Agricultural Sciences, Department of Soil and Water Science, Indian River Research and Education Center, Fort Pierce, FL 34945, USA.
² University of Florida-IFAS, Department of Soil and Water Sciences, Gainesville, FL 32611, USA.
³ University of Florida, Institute of Food and Agricultural Sciences, Department of Soil and Water Science, Indian River Research and Education Center, Fort Pierce, FL 34945, USA; Environment and Plant Protection Institute, Chinese Academy of Tropical Agriculture Science, Haikou 571101, China.
⁴ University of Florida, Department of Chemistry, Gainesville, FL 32611, USA.
⁵ University of Florida, Institute of Food and Agricultural Sciences, Department of Soil and Water Science, Indian River Research and Education Center, Fort Pierce, FL 34945, USA. Electronic address: zhe@ufl.edu.

PMID: 35559820
DOI: 10.1016/j.impact.2021.100361

Abstract

Increasing applications of nanoparticles (NPs) in agriculture have raised potential risks to soil and aquatic ecosystems. A comparative study examining the transport of commonly used NPs in porous media is of critical significance for their application and regulation in agroecosystems. In this study, laboratory column leaching experiments were conducted to investigate the transport and retention of polysuccinimide NPs (PSI-NPs) in two saturated porous media with different grain sizes, as compared with multi-walled carbon nanotubes (MWCNTs), nano-Ag and nano-TiO₂. Zeta potential of the NPs was negative at pH_6.3 and decreased in an order of PSI-NPs > nano-TiO₂ > MWCNTs > nano-Ag. The coarse and fine sands used in this study had negative charges with similar zeta potentials. The movement of NPs was affected by grain size, with larger sizes facilitating mobility while finer sizes favoring retention of NPs in the porous matrix. The retention profile significantly varied between the two sand columns, with more NPs transported to deeper layers in the coarse sand than the fine sand. The relative percentage of NPs detected in leachate was found to be positively correlated with the zeta potential of NPs (r = 0.931). Among the NPs, nano-Ag had the most negative zeta potential, and therefore was the most mobile, followed by MWCNTs and nano-TiO₂. Having the least negative zeta potential, PSI-NPs had the lowest mobility, as compared with other NPs regardless of matrix grain size. This work reveals grain size and zeta potential of NPs are major factors that influence transport of NPs along the vertical porous profile, as well as demonstrating the relative unimportance of NP composition, which could serve as important guideline in nanomaterials application, risk assessment, and waste management in agroecosystems.

Keywords: Engineered nanomaterials; Environmental fate; Grain size; Vertical transport; Zeta potential.

Publication types

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

MeSH terms

Ecosystem
Nanoparticles*
Nanotubes, Carbon*
Polymers
Porosity
Sand

Substances

Nanotubes, Carbon
Polymers
Sand