Particle bound pollutants in rivers: Results from suspended sediment sampling in Globaqua River Basins

Abstract

Transport of hydrophobic pollutants in rivers such as polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and heavy metals is often facilitated by suspended sediment particles, which are typically mobilized during high discharge events. Suspended sediments thus represent a means of transport for particle related pollutants within river reaches and may represent a suitable proxy for average pollutant concentrations estimation in a river reach or catchment. In this study, multiple high discharge/turbidity events were sampled at high temporal resolution in the Globaqua River Basins Sava (Slovenia, Serbia), Adige (Italy), and Evrotas (Greece) and analysed for persistent organic pollutants such as PAHs (polycyclic aromatic hydrocarbons) or PCBs (polychlorinated biphenyls) and heavy metals. For comparison, river bed sediment samples were analysed as well. Further, results are compared to previous studies in contrasting catchments in Germany, Iran, Spain, and beyond. Overall results show that loadings of suspended sediments with pollutants are catchment-specific and relatively stable over time at a given location. For PAHs, loadings on suspended particles mainly correlate to urban pressures (potentially diluted by sediment mass fluxes) in the rivers, whereas metal concentrations mainly display a geogenic origin. By cross-comparison with known urban pressure/sediment yield relationships (e.g. for PAHs) or soil background values (for metals) anthropogenic impact - e.g. caused by industrial activities - may be identified. Sampling of suspended sediments gives much more reliable results compared to sediment grab samples which typically show a more heterogeneous contaminant distribution. Based on mean annual suspended sediment concentrations and distribution coefficients of pollutants the fraction of particle facilitated transport versus dissolved fluxes can be calculated.

Compositional dynamics of suspended sediment in the Rhine River: sources and controls

“…Geographic differences in the element concentrations in suspended sediment are mostly related to differences in parent material, weathering types and rates, river discharge, organic matter content, and additional natural or anthropogenic sources, including inputs of aerosols and diffuse and point source contaminant inputs, between catchments or river basins (Martin and Meybeck 1979;Savenko 2007). The elemental composition of suspended sediment shows generally less variability in time than in space (Nasrabadi et al 2018;Rügner et al 2019), although the sediment composition may change considerable in response to individual discharge events (e.g. Vale 1990; Schleichert and Keller 1997;Coynel et al 2007;Berner et al 2012;Pulley et al 2016).…”

“…Vale 1990; Schleichert and Keller 1997;Coynel et al 2007;Berner et al 2012;Pulley et al 2016). Both long-and shortterm temporal variations in the suspended sediment composition are mostly linked to variations in sediment supply from different source areas with different bedrock and associated weathering types and rates, variations in direct inputs of anthropogenic contaminants, remobilisation of previously deposited polluted sediments and variations in particle size and organic matter content of the suspended sediment (Van der Weijden and Middelburg 1989; Zwolsman and Van Eck 1999;Quinton and Catt 2007;Ma et al 2015;Van der Perk 2013;Hamers et al 2015;Rügner et al 2019). Thus, to reliably quantify contaminant transport, detailed information on the temporal variation in sediment composition is essential.…”

Raman spectroscopy to investigate the speciation and origin of hazardous elements associated to suspended particulate matter during a large flood event

“…[6] The transport of HEs in rivers is often associated with the transport of suspended particles. [7,8] In fact, the increase of the total concentrations of HEs in water during flood events comes from the high amount of HEenriched SPM entering the river during these periods, as it has been observed for mercury and other heavy metals. [9] SPMs in rivers have provided information on particle related pollution within river reaches all over the world.…”

Water Quality and Pollution Index in Grenjeng River, Boyolali Regency, Indonesia

“…Water quality pollutants such as TSS are affected by land use activities in the upstream area. Although the pollutants are not toxic, excessive suspended material can inhibit the penetration of sunlight which influences photosynthesis in the waters (Effendi, 2003;Widiadmoko, 2013;Rügner et al, 2019;Tanjung et al, 2019;Tian et al, 2019). Based on the suitability of waters for fisheries, the TSS content of the Grenjeng River water in dry season has little effect on fishery interests but is still suitable for class IV water needs (Effendi et al, 2015;Gashi et al, 2016).…”