Ilektra Drygiannaki, Ph.D. (Illinois) presented “Assessing Sediment Recontamination and Bioaccumulation by Stormwater Heavy Metals” at the 8th European Bioremediation Conference at the Minoa Palace Hotel in Chania, Crete, Greece at on June 13, 2022.

Ilektra Drygiannaki, is a Senior Staff Professional with Geosyntec Consultants in the Oak Brook, Illinois office. Her expertise is in the assessment and management of contaminated sediments, management of stormwater discharges, and contaminant source investigation, as well as the assessment of stormwater impacts on sediment recontamination. Ilektra also has experience in the assessment of ecological impacts in contaminated sediments using biota accumulation and passive sampling. Ilektra has also worked on bioremediation of marine oil spills using indigenous hydrocarbon degraders.

The European Bioremediation Conferences started in 2001 organized by TU-Crete. Since then, seven conferences managed to bring together scientists and engineers from all over the world to present their findings and exchange information on recent advances in environmental remediation technologies, especially focusing on bioremediation and phytoremediation of contaminated sites including the marine environment.

Abstract

Recontamination of sediments by stormwater is a major concern when evaluating the potential effectiveness of sediment remediation. Simultaneous stormwater and receiving water and sediment monitoring were undertaken in a mixed-use watershed at Paleta Creek in San Diego, CA during 2015- 2017. The stormwater samples were fractionated by size to relate discharges to sediment recontamination and analyzed for the metals Cd, Cu, Ni, Zn, Pb, Hg, and the metalloid As. Sediment traps with hyper- saline brine were deployed to help relate discharges with those impacts. Ex situ bioaccumulationexposures using the clam macoma nasuta as well asvinorganic passive sampling using DGTs were applied to extend bulk sediment impacts to assess availability and biological impacts. Cd in the downstream Creek location was associated with larger particles (>63 μm) mostly associated with highway/residential sources, that settled directly to the near shore sediment. By contrast, Cu settled throughout the receiving waters due to both to association with smaller particles and evidence of additional sources or sediment resuspension and settling from elsewhere. Other metals showed similar behavior to varying degrees. Size-segregated contaminant loads of intensively monitored storm events with settling traps in the receiving waters were best able to link discharges to sediment recontamination. Although sediment core concentrations were either similar or increasing between the pre-storm season conditions and post-season conditions, bioassays showed that the tissue concentrations of all metals decreased significantly (p<0.05, α=0.05) at all monitored locations in post-wet season samples compared to pre-storm season samples.

More Information

About the event: Home – 8th European Bioremediation Conference (tuc.gr)
For consultation regarding Bioremediation, contact Ilektra Drygiannaki at idrygiannaki@geosyntec.com.
Learn more about Ilektra Drygiannaki: (2) Ilektra Drygiannaki, PhD | LinkedIn