Effect of recurrent sediment resuspension-deposition events on bioavailability of polycyclic aromatic hydrocarbons in aquatic environments

Abstract

a b s t r a c tTo investigate the effect of recurrent sediment resuspension-deposition events (RSRDEs) on bioavailability of polycyclic aromatic hydrocarbons (PAHs) in aquatic environments, a modified device was used to simulate three resuspension-deposition events with the sediment collected from the Yellow River. The results showed that the dissolved organic carbon (DOC)-water distribution coefficients of PAHs decreased with time during the first resuspension-deposition period. It indicates that some PAHs associated with organic carbon (OC) in suspended sediment (SPS) desorbed with the release of OC and became DOC-associated PAHs in the overlying water, then the PAHs desorbed from the DOC and became freely dissolved. After first 2-h suspension, only 1.90% of phenanthrene, 2.98% of pyrene, and 0.33% of chrysene in the overlying water came from pore-water; at least 61.6%, 89.6%, and 95.3% came from DOC-associated PAHs in SPS and the rests were released from the insoluble OC in SPS. The maximum desorption ratios in the original sediment were 20%, 12%, and 14% for phenanthrene, pyrene, and chrysene, respectively during the first resuspension-deposition event. The SPS concentration followed the sequence of the third > second > first resuspension event. This was because RSRDEs changed the SPS particle size and enhanced floc formation. There was no significant difference in the total dissolved PAH concentrations among the three resuspension events, while their freely dissolved concentrations followed the sequence of the third > second > first resuspension event. During deposition periods, more than half of the total/freely dissolved PAHs released during suspension still existed in the overlying water after 70-h deposition. This study suggests that the RSRDEs will increase the bioavailability of PAHs in aquatic environments, especially near the sediment-water interface, and the potential effects of PAHs during RSRDEs on fish/human in rivers and lakes should be considered in future management.

Remobilization of polycyclic aromatic hydrocarbons and organic matter in seawater during sediment resuspension experiments from a polluted coastal environment: Insights from Toulon Bay (France)

“…Nonetheless, humic-like material was evidenced in these Toulon sediments by Dang et al (2014) and we can reasonably make the assumption of a high presence of sedimentary soot BC because of PAHs originating mainly from combustion-residue-sources (Fig. S2, Readman et al, 1987;Zhou et al, 1999) that can be both released in seawater during our SRE (Dong et al, 2016;Kaal et al, 2016).…”

“…Because subsamples were taken several minutes after stopping agitation, the loss of sediment particles from this successive subsampling was estimated to be negligible over the course of the SRE (Dang et al, 2015b). Also, according to Dong et al (2016), such short stops cannot be considered as successive sediment resuspension-deposition events. It should be noted that the biological activity was not stopped in these experiments since (i) any added poison could have affected OM measurements and (ii) our aim was to mimic the PAH and OM sorption/desorption as close as possible to the natural conditions.…”

“…Due to the complexity of interactions driving the PAH partitioning between water and sediment, it is very likely that such contaminants were distributed into three phases: the first phase (solid phase, sediment), the second phase (solution phase, water) and the third phase (colloidal or DOM-associated phase) (Delle Site, 2001). Within the third phase, the formation of PAH-DOM complexes may increase the transfer of PAHs towards the dissolved phase (Dong et al, 2016). The effect of the third phase is known to be more pronounced for compounds exhibiting higher hydrophobicity (log K ow > 5) (Delle Site, 2001;Dong et al, 2016).…”

High‐turbidity events in Western Lake Erie during ice‐free cycles: Contributions of river‐loaded vs. resuspended sediments

“…Resuspension is initiated by the combined effects of currents, surface-gravity waves, and high-frequency linear internal waves, among which the surface-gravity waves predominate in shallow lakes and coastal zones (Hawley and Eadie 2007;Green and Coco 2014;Valipour et al 2017). During the resuspension, resuspended materials can alter the biomass distributions by reintroducing and redistributing nutrients throughout the water column (Zamparas and Zacharias 2014;Dong et al 2015Dong et al , 2016Paytan et al 2017;Li et al, 2018), which in turn can impact the dissolved oxygen levels (Moriarty et al 2017). Given that suspended sediments from river loading and resuspension have distinct ecological functions and driving mechanisms, it is critical to understand their relative contributions to HTEs by tracking their origins explicitly.…”

Contributions of Catchment and In-Stream Processes to Suspended Sediment Transport in a Dominantly Groundwater-Fed Catchment

“…negative impacts on water quality, especially, by facilitating transport of sediment-associated contaminants, such as heavy metals (Mukherjee, 2014;Peraza-Castro et al, 2016;Quinton and Catt, 2007) and hydrophobic organic pollutants such as polycyclic aromatic hydrocarbons (PAHs) (Rügner et al, 2014;Schwientek et al, 2013;Dong et al, 2015;Dong et al, 2016), polychlorinated biphenyls (PCBs), and other persistent organic pollutants (Meyer and Wania, 2008;Quesada et al, 2014).…”