Details

Autor(en) / Beteiligte

• Miranda, Mariana N.
• Lado Ribeiro, Ana R.
• Silva, Adrián M.T.
• Pereira, M. Fernando R.

Titel

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

Ist Teil von

• The Science of the total environment, 2022-12, Vol.850, p.158073-158073, Article 158073

Ort / Verlag

Elsevier B.V

Erscheinungsjahr

2022

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• 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 μg 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 μg g−1 per sorbate) up to nine after aging (maximum 10 μg 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. [Display omitted] •Sorption assessment of 10 organic micropollutants on virgin or aged microplastics•Ozone exposure or urban weathering increased the sorption capacity of microplastics.•Most substances studied showed a higher affinity for LDPE and uPVC than for PET.•Pentachlorophenol equilibrium sorption isotherms on LDPE or PET were studied.•Null or low phytotoxicity for organic micropollutants-sorbed microplastics