Characterization of microplastics in sediments from the submarine outfall of the wastewater treatment plant, Mar del Plata city (Argentina)

MAURICIO DÍAZ JARAMILLO; FLORENCIA RODRÍGUEZ; MARÍA SOLEDAD ISLAS; MARIANA GONZÁLEZ

Lanzarote

Conferencia; MICRO 2020, Fate and impacts of Microplastics: Knowledge and responsibilities; 2020

Despite widespread detection of microplastic pollution in the marine environment, datadescribing microplastic inputs to the coast of Argentina are scarce. Particularly, the discharge of municipal wastewater treatment plant is considered an important pathway formicroplastic to aquatic environments, but only a few studies are available. Mar del Platacity (38o S, 57o W), is the main touristic resort of the Atlantic coast of Argentina. Wastewater plant from Mar del Plata city (Argentina) discharges into marine environment (4 kmoffshore) by a submarine outfall. Although this outfall is working since 2014, diminishingthe biological and chemical pollution of nearest coastal areas, its role as microplastics sourceto the marine environment was not evaluated. This work, showed a preliminary study ofmicroplastic occurrence and characteristics in subtidal sediments (11-21 mt deep) from twosites located close to the submarine outfall of wastewater plant. The microplastic content (n:3 samples per site) was determined by floating method using a zinc chloride (ZnCl2) solution. No significant differences were found between sites (p> 0.05). Mean total microplasticabundance in sediments between both sampling sites ranged from 411 to 547 items per kgd.w. The presence of fibers (40-72%), fragments (12-31.5%), films (12.1-29%) and foam (0-4%) were detected as probable microplastic particles. Transparent (34.7%), white (24.2%),black (13.8%) and red (10.8%) type particles were observed as the main color contributionof microplastic. The results obtained represent a first approach to determine the presenceof microplastics in sediments under the influence of the submarine outfall from wastewatertreatment plant in Argentinian coastal cities. This work is part of UE-CONICET project"Coastal ecosystems: Structure, functioning, dynamics and management strategies".