Dynamic of microplastics in the Suquía River basin (Córdoba, Argentina).

MEIER, M.; YUNES, PABLO; KITTNER, M.; PFLUGMACHER, S; AMÉ, MARÍA VALERIA; WUNDERLIN, DANIEL ALBERTO

San Luis

Congreso; VII Congreso Argentino de la Sociedad de Toxicología y Química Ambiental (SETAC); 2018

Sociedad de Toxicología y Química Ambiental (SETAC) Capítulo Argentino

The presence of microplastics (MP) in both water and sediments has been extensively reported in marine environments, with fewer studies on their presence in rivers, particularly in rivers affected by semi-arid conditions. It is likely to expect a different behavior of MP in the sea with respect to a river, mainly because of differences in the hydrology, salinity, etc. Thus, our main goal was to evaluate the presence and behavior of MP in a river belonging to a semi-arid region (Province of Córdoba, Argentina), looking to assess the main sources of MP and verifying their changes along a river sectionthat includes a big city and its wastewater treatment plant (WWTP). For this purpose, water and sediments samples were collected at five sampling sites along the Suquía river including areas upstream from Córdoba City (site 1, reference area), within the city but upstream from its WWTP (sites2 and 3, accounting for urban run-off from the city) and downstream the WWTP (sites 4 and 5, accounting for sewage pollution not retained at the WWTP). Samples were taken during the dry season of 2016 and 2017, with the river at its lower flow. Water samples were filter through a sieves array,dried and digested by H2O2. Sediments samples were first dried, then sieved and digested as water samples. Plastic particles were separated by an overflow method and the retained material classified in fibers and particles by optical microscopy. Results show that MP are present in high amount throughout the studied river basin, even upstream from the main city, being the WWTP the mainsource of MP to the stream, but the city run-off was the responsible for the higher amount of MP in sediments. Our current results show qualitative and quantitative differences with previous reports on MP in water and sediment of rivers, having a range of MP that exceeds most previous reports in rivers.Furthermore, among MP found, fibers were more abundant than microparticles, triggering the need for a deep evaluation of probable negative effects of fibers on the aquatic biota.