M.O. Rodrigues, N. Abrantes, F.J.M. Gonçalves, H. Nogueira, J.C. Marques, A.M.M. Gonçalves,

Spatial and temporal distribution of microplastics in water and sediments of a freshwater system (Antuã
River, Portugal),

Science of The Total Environment, Volume 633, 15
August 2018, Pages 1549-1559, ISSN 0048-9697,

Abstract:

Microplastics (particles with a size < 5 mm), one of the most emerging
aquatic pollutants, are of particular concern since they can reach high
densities and interact with biotic and abiotic environment. The
occurrence of microplastics in freshwater systems is less understood
than in marine environment. Hence, the present study aims to provide new
insights into microplastics abundances and distribution in Antuã River
(Portugal) by applying the isolation method of wet peroxide oxidation
with addition of zinc chloride to water and sediment samples collected
in March and October 2016, in three sampling sites. The abundance of
microplastics in water ranged from 5 to 8.3 mg m−3 or 58–193 items m−3
in March and from 5.8–51.7 mg m−3 or 71–1265 items m−3 in October. In
sediments, the abundance ranged from 13.5–52.7 mg kg−1 or 100–629 items
kg−1 in March and from 2.6–71.4 mg kg−1 or 18–514 items kg−1 in October.
The water and sediment samples with the greatest abundances were from
São João da Madeira and Aguincheira, respectively. Spatio-temporal
distribution showed different pattern according to methodological
approaches, seasonal and hydrodynamic conditions and the proximity to
urban/industry areas. Analysis of plastics by Fourier transform infrared
spectroscopy underline polyethylene and polypropylene as the most common
polymer types identified in this work. The low medium high oxidation
ratio was 56:22:22 (%) in March and 61:31:8 (%) in October. Foams and
fibers were the most abundant type in São João da Madeira, while fibers
and fragments were the most abundant in Aguincheira and Estarreja in
water and sediment samples, respectively. This study emphasizes the
importance of rivers as carriage systems of microplastics. Further
studies should be performed to identify point sources in order to
mitigate the microplastics contamination in aquatic systems.

https://drive.google.com/open?id=1nH49vUagp8VOyd9POU59LpI_a_WKpxsc
https://doi.org/10.1016/j.scitotenv.2018.03.233.(https://www.sciencedirect.com/science/article/pii/S0048969718309926)