Investigation of heavy metals release from sediment with bioturbation/bioirrigation

Abstract

Bioturbation/bioirrigation can affect the remobilization of metals from sediments. In this study, experiments were performed to examine the effect of bioturbation/bioirrigation by different organisms on cadmium (Cd), copper (Cu), zinc (Zn) and lead (Pb) releasing from the spiked sediment. The diffusive gradient in thin films technique (DGT) revealed that at the end of exposure time, the labile heavy metals concentrations in the pore water for all metal and organisms combinations except Cu and chironomid larvae were much lower than that in the control group. However, the concentrations of heavy metals detected by the DGT were virtually indistinguishable among the treatments with tubificid, chironomid larvae and loach. The correlation analysis of heavy metals with iron (Fe) and manganese (Mn) suggested that Cd, Zn and Pb were most likely bound as Fe-Mn oxidation form in the pore water, but Cu was in other forms. After 28 d of exposure, bioturbation/bioirrigation produced a significant release of particulate heavy metals into the overlying water, especially in the treatment with loach. The bioturbation/bioirrigation impact on the Pb remobilization was less than the other three heavy metals. The effects of bioturbaiton/bioirrigation on the heavy metals remobilization in the sediment were complex that with studying the heavy metals remobilization in the sediment and water interface, the biological indicators should be recommended.

Trophic transfer of CuO NPs from sediment to worms (Tubifex tubifex) to fish (Gasterosteus aculeatus): a comparative study of dissolved Cu and NPs enriched with a stable isotope tracer (65Cu)

“…1) The conveyer-belt feeding behavior of T. tubifex, where sediment is ingested at depth and egested as fecal matter above the sediment surface, 62 can increase the concentration of metals in top sediment layers facilitating their remobilization into the overlying water. 63,64 Thus, differences in remobilization between treatments may be owed to differences in feeding activity (resulting in a lower amount of fecal pellets deposited on the surface in 65 CuCl 2treatment) or differences in gastrointestinal 65 Cu absorption 18,42 (resulting in lower 65 Cu concentration in fecal pellets egested in 65 CuCl 2 -treatment). 2) Cu stress can induce caudal autotomy (tail loss), 49 which precludes worms from defecating until the posterior end has been regenerated and is operational again (often after more than five days).…”

Role of Bioroughness, Bioirrigation, and Turbulence on Oxygen Dynamics at the Sediment‐Water Interface

“…Water Resources Research heavy metal mobilization, such as Cd and Cu (He et al, 2017;Schaller, 2014), likely due to oxidation of reduced forms of Cd and Cu in the sediments (Hong et al, 2011a). The influence of hydrodynamics and bioirrigation on metal release can be further investigated by incorporating metal redox chemistry and transport into the current model.…”

How can interspecific interactions in freshwater benthic macroinvertebrates modify trace element availability from sediment?

“…Moreover, redox-related biogeochemical processes facilitate the transition of the particle bound TE to the pore water and then to the pelagic zone (Xie et al, 2018). Remobilization of TE from sediments depends on many factors, including the physico-chemical characteristics of the TE itself, the content of organic matter and clay in the sediment, the hydrological flow, and non-the least the bioturbation by the benthic community (Blankson and Klerks, 2017;He et al, 2017He et al, , 2019Xie et al, 2018).…”