Adsorption of lead(II) onto PE microplastics as a function of particle size: Influencing factors and adsorption mechanism

Thanh-Binh Nguyen; Thi-Bao-Chau Ho; C P Huang; Chiu-Wen Chen; Wei-Hsin Chen; Shuchen Hsieh; Shu-Ling Hsieh; Cheng-Di Dong

doi:10.1016/j.chemosphere.2022.135276

Adsorption of lead(II) onto PE microplastics as a function of particle size: Influencing factors and adsorption mechanism

Chemosphere. 2022 Oct:304:135276. doi: 10.1016/j.chemosphere.2022.135276. Epub 2022 Jun 8.

Authors

Thanh-Binh Nguyen¹, Thi-Bao-Chau Ho¹, C P Huang², Chiu-Wen Chen³, Wei-Hsin Chen⁴, Shuchen Hsieh⁵, Shu-Ling Hsieh⁶, Cheng-Di Dong⁷

Affiliations

¹ Institute of Aquatic Science and Technology, National Kaohsiung University of Science and Technology, Kaohsiung City, 81157, Taiwan.
² Department of Civil and Environmental Engineering, University of Delaware, Newark, 19716, DE, USA.
³ Department of Marine Environmental Engineering, National Kaohsiung University of Science and Technology, Kaohsiung City, 81157, Taiwan. Electronic address: cwchen@nkust.edu.tw.
⁴ Department of Aeronautics and Astronautics, National Cheng Kung University, Tainan, 701, Taiwan; Research Center for Smart Sustainable Circular Economy, Tunghai University, Taichung 407, Taiwan; Department of Mechanical Engineering, National Chin-Yi University of Technology, Taichung 411, Taiwan.
⁵ Department of Chemistry, National Sun Yat-sen University, Kaohsiung City, 80424, Taiwan.
⁶ Department of Seafood Science, National Kaohsiung University of Science and Technology, Kaohsiung City, 81157, Taiwan.
⁷ Department of Marine Environmental Engineering, National Kaohsiung University of Science and Technology, Kaohsiung City, 81157, Taiwan. Electronic address: cddong@nkust.edu.tw.

PMID: 35690170
DOI: 10.1016/j.chemosphere.2022.135276

Abstract

The adsorption of Pb ions, on high-density polyethylene (PE) microplastics (MPs) with the diameter of 48-500 μm, was examined in this study. According to the Langmuir isotherm, MP of the smallest size, 48 μm, had the greatest adsorption capacity of 0.38 μmol g^-1. The mechanism of Pb ions adsorption onto PE MPs was chemical adsorption, in particular, hydrogen bonding and surface complexation. Pb adsorption onto PE particles was proceeded at a rapid rate, as predicted by the pseudo-second-order rate model (R² > 0.99). The PE 48 μm had the maximum adsorption capacity of 0.44 μmol g-1 (or 0.2 mol m^-2) at pH 5. While humic acid can operate as a bridging agent, boosting heavy metal adsorption on the surface of PE MPs, fulvic acid has the reverse effect. The findings indicated that PE particles may serve as a carrier of heavy metals in the aquatic environment, posing perceived risks to the environment and public health.

Keywords: Adsorption; Lead; Microplastic; Size effect; Surface complexation.

MeSH terms

Adsorption
Ions
Lead
Metals, Heavy*
Microplastics
Particle Size
Plastics
Polyethylene
Water Pollutants, Chemical* / analysis

Substances

Ions
Metals, Heavy
Microplastics
Plastics
Water Pollutants, Chemical
Lead
Polyethylene