Can aged microplastics be transport vectors for organic micropollutants? - Sorption and phytotoxicity tests

• Type: Article in International Scientific Journal
• Date: 2022

Authors

Mariana N. Miranda (Author) FEUP; Ana R. Lado Ribeiro (Author) FEUP; Adrián M. T. Silva (Author) FEUP; Manuel Fernando R. Pereira (Author) FEUP

Journal

Title: Science of the Total Environment

Vol. 850

Pages: 1-10

ISSN: 0048-9697

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 0 Citations

Scopus - 0 Citations

Associated Projects

LA LSRE-LCM - Financiamento Plurianual 2020-2023 para a Unidade LA LSRE-LCM Laboratório de Processos de Separação e Reacção - Laboratório de Catálise e Materiais

Other information

Authenticus ID: P-00X-2RB

DOI: 10.1016/j.scitotenv.2022.158073

Abstract (EN): Microplastics have been investigated over the last decade as potential transport vectors for other pollutants. However, the specific role of plastic aging, in which plastics change their characteristics over time when exposed to environmental agents, has been overlooked. Therefore, sorption experiments were herein conducted using virgin and aged (by ozone treatment or rooftop weathering) microplastic particles of LDPE - low-density polyethylene, PET - poly(ethylene terephthalate), or uPVC - unplasticized poly(vinyl chloride). The organic micropollutants (OMPs) selected as sorbates comprise a diversified group of priority substances and contaminants of emerging concern, including pharmaceutical substances (florfenicol, trimethoprim, diclofenac, tramadol, citalopram, venlafaxine) and pesticides (alachlor, clofibric acid, diuron, pentachlorophenol), analyzed at trace concentrations (each <= 100 mu g L-1). Sorption kinetics and equilibrium isotherms were obtained, as well as the confirmation that the aging degree of microplastics plays a major role in their sorption capacities. The results show an increased sorption of several OMPs on aged microplastics when compared to pristine samples, i.e. the sorption capacity increasing from one or two sorbed substances (maximum 3 mu g g-1 per sorbate) up to nine after aging (maximum 10 mu g g-1 per sorbate). The extent of sorption depends on the OMP, polymer and the effectiveness of the aging treatment. The modifications (e.g. in the chemical structure) between virgin and aged microplastics were linked to the increased sorption capacity of certain OMPs, allowing to better understand the different affinities observed. Additionally, phytotoxicity tests were performed to evaluate the mobility of the OMPs sorbed on the microplastics and the potential effects (on germination and early growth) of the combo on two species of plants (Lepidium sativum and Sinapis alba). These tests suggest low or no phytotoxicity effect under the conditions tested but indicate a need for further research on the behavior of microplastics on soil-plant systems.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 10