Polyamide microplastics as better environmental vectors of Cr(VI) in comparison to polyethylene and polypropylene microplastics

Xuechun Shao; Qi Zhang; Weiyu Liang; Kailin Gong; Mengru Fu; Sadia Saif; Cheng Peng; Wei Zhang

doi:10.1016/j.marpolbul.2022.114492

Polyamide microplastics as better environmental vectors of Cr(VI) in comparison to polyethylene and polypropylene microplastics

Mar Pollut Bull. 2023 Jan:186:114492. doi: 10.1016/j.marpolbul.2022.114492. Epub 2022 Dec 18.

Authors

Xuechun Shao¹, Qi Zhang¹, Weiyu Liang¹, Kailin Gong¹, Mengru Fu¹, Sadia Saif², Cheng Peng³, Wei Zhang⁴

Affiliations

¹ State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, School of Resource and Environmental Engineering, East China University of Science and Technology, Shanghai 200237, China.
² Department of Environmental Sciences, Kinnaird College for Women, Lahore 54000, Pakistan.
³ State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, School of Resource and Environmental Engineering, East China University of Science and Technology, Shanghai 200237, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China. Electronic address: cpeng@ecust.edu.cn.
⁴ State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, School of Resource and Environmental Engineering, East China University of Science and Technology, Shanghai 200237, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China. Electronic address: wzhang@ecust.edu.cn.

PMID: 36535232
DOI: 10.1016/j.marpolbul.2022.114492

Abstract

The adsorption, desorption, and their influence factors of Cr(VI) by microplastics (MPs) in the solution was investigated in this study. The results demonstrated that UV aging promoted adsorption, while the increase of salinity and natural organic matter (NOM) inhibited adsorption. The particle size affected the total Cr(VI) active adsorption sites on MPs, while the pH changed the electrostatic force. The Cr(VI) adsorption by MPs conformed to the pseudo-first and pseudo-second order kinetic models, and was monolayer and inhomogeneous. SEM-EDS, XPS and ATR-FTIR analyses demonstrated that the physical adsorption dominated the adsorption process. Especially, the highest adsorption capacity of Cr(VI) by polyamide (PA) MPs was attributed to their hydrophilic amide groups. However, Cr(VI) was only released from PA MPs, of which desorption rate followed the sequence of seawater (79.5 %) > fresh water (66.6 %) > deionized water (34.8 %). Thus, PA MPs might be non-negligible environmental vectors for the transport of Cr(VI).

Keywords: Adsorption mechanisms; Aquatic environment; Chromium ions; Desorption behavior; Microplastics.

MeSH terms

Adsorption
Microplastics*
Nylons
Plastics
Polyethylene
Polypropylenes
Water Pollutants, Chemical* / analysis

Substances

Microplastics
chromium hexavalent ion
Polyethylene
Plastics
Nylons
Polypropylenes
Water Pollutants, Chemical