Spatial Variations in Microfiber Transport in a Transnational River Basin

Abstract

Five countries share the catchment of the Tisza River (Central Europe). In most households electricity and water are available, and by washing synthetic clothes they can produce a large number of microfibers. However, in many sub-catchments of the river, the wastewater treatment is insufficient; therefore, microplastics (MP), especially plastic microfiber emissions into rivers, represent a problem. Our goal was to analyze the suspended sediment and microfiber transport at the low stage, making repeated (2021 and 2022) measurements in the Tisza River (946 km) at 26 sites across three countries. Water sampling was performed by pumping 1 m3 of water through sieves (90–200 µm). The mean MP transport in 2021 was 19 ± 13.6 items/m3, but it increased by 17% in 2022 (22.4 ± 14.8 items/m3). The most polluted sections were the Upper Tisza (Ukraine, Hungary) and the Lower Tisza (Serbia), where wastewater treatment is not satisfactory, whereas the Middle Tisza (Hungary) was less polluted. The tributaries increased the sediment and MP budget of the main river. Microfibers dominate (84–97%) the suspended MP transport, and thus it can be determined that they originated from wastewater. The MP transport was influenced by the availability of wastewater treatment plants, dams, tributaries, and mobilization of bottom sediments. At the low stage, no connection was found between the suspended sediment and MP particle transport.

Microplastic Contamination of Fine-Grained Sediments and Its Environmental Driving Factors along a Lowland River: Three-Year Monitoring of the Tisza River and Central Europe

“…Therefore, our goal was to understand the spatiotemporal changes in MP deposition and their driving factors. The previous results of the MP pollution of the Tisza River [7,14,21,22] suggest that the mobilization of MP in the water system could be significant, leading to dynamic changes in hotspots. The aim of the present study was to analyze the long-term temporal and spatial evolution of MP contamination of freshly deposited sediments in the river system of the Tisza River by analyzing clayey sediments collected in 2021-2022 and using previous data (2019 and 2020).…”

“…The catchment (157,200 km 2 ) is shared by five countries: Ukraine (8.1%), Slovakia (9.7%), Romania (46.2%), Hungary (29.4%) and Serbia (6.6%) [21]. The Tisza River was divided into five sections based on the hydrological and geomorphological conditions [14,22]. The Upper Tisza (260 km) stretches from its source in Ukraine to Tivadar (No.…”

Comparative Analysis of Riverine Plastic Pollution Combining Citizen Science, Remote Sensing and Water Quality Monitoring Techniques

“…The microplastic content of sediments of the Tisza and its tributaries has been studied systematically since 2019 [30][31][32][33][34][35]. Each summer, a sampling campaign was performed from the source of the Tisza in Ukraine to its confluence in Serbia and in the near-confluence sections of the main tributaries.…”

“…In the same year, the largest MaP accumulation (18.8 thousand m 2 ) was detected upstream of the Kisköre Dam [22]. Still, the microplastic fragments contribute just to 2-33%, as micro-fibers dominate in the sediments within the water system of the Tisza [30,34,35]. As the MaPs are widely distributed on the globe, but their spatial distribution could change in time, a citizen science approach has been increasingly applied to study marine [4,36] and riverine litter [5,37,38].…”

“…The MaP pollution of the Tisza and the mountainous areas of the catchment were documented by Liro et al [16], Mohsen et al [22] and Magyar et al [27]. Besides, one of the longest and most detailed microplastic surveys of the world was performed in the river system of the Tisza, revealing the MiP transport in the river and its accumulation in the sediments [30][31][32][33][34][35].…”