Microplastics abundance, distribution, and composition in freshwater and sediments from the largest Xijin Wetland Park, Nanning, South China

Microplastics (MPs) are ubiquitous plastic entities with sizes <5 mm, resistant to degradation and conventional removal processes, and exhibit adverse ecological and human health impacts. The last decade is well-capitalized to explore the occurrence, transportation, sources, and impacts of MPs in the aquatic environment; however, little is known about MPs contamination in wetland systems. Here, we investigated the pollution level of MPs in the surface freshwater and sediment samples collected from the Xijin Wetland Park, which is the largest wetland park in South China, located in Hengxian County, Nanning City, Guangxi Province. Our results showed that the MPs content was ranged from 150 to 1067 n/m3 and 4 to 148 n/kg dry weight (dw) in the surface water and sediment samples in the Xijin Wetland Park, respectively. The compositional profiling of MPs revealed ‘fiber’ as the most abundant shape and ‘<0.05 mm’ as the most copious particle size among both water and sediment samples. ‘blue’ was the most frequent color in water while sediment samples was‘white’, The attenuated total reflectance-Fourier-transform infrared spectroscopy (ATR-FTIR) was employed to analyze the polymer composition of MPs and results showed that rayon (14.55%), followed by polyester (9.09%) and polyethylene (8.18%) as the most frequently detects MPs polymers in the Wetland Park. In summary, this study not only provides the baseline data regarding MPs’ pollution and associated risk but also gives guidelines to control the plastic pollution in the Xijin Wetland Park.