Quantitative Thermodynamic Exposure Assessment (QTEA) Supporting Resilient Contaminated Sediment Site Restoration

Abstract

An integrated, comprehensive capability for evaluating the effect of contaminant influx on the performance of in situ remedies, the Quantitative Thermodynamic Exposure Assessment (QTEA) was developed. Using ex situ equilibrium sampling, and in situ passive samplers, in combination, resilience of in situ sediment remedies challenged by ongoing sources of PCB contamination was assessed using experimental multi-species mesocosms. No remedy using AC or thin-layer capping was resilient (e.g. significant reduction >50%) to ongoing inputs of contamination. Therefore, the in situ remedies evaluated may only partially succeed under conditions of ongoing inputs at contaminated sites. Ongoing inputs must be controlled or at least minimized. Different polymer methods (in situ passive sampling with PRCs and ex situ equilibrium sampling with multiple polymer thicknesses) provided similar results. Overall, polymers were successful to monitor remediation as an important augmentation to bioaccumulation measurements. Fully successful remedy by AC was likely not achieved because of temporal factors. Sorption kinetics were slow from the sediment to the AC, especially for the most hydrophobic PCB congeners. Reductions in bioavailability by AC required a dose equal to about half the natural total organic carbon (TOC) of the sediment. The results of this work showed AC and thin-layer capping can provide value separately and in combination beyond what may be achievable by monitored natural recovery alone.

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Document Details

Document Type
Technical Report
Publication Date
Apr 01, 2022
Accession Number
AD1187013

Entities

People

  • Alan J. Kennedy
  • Alice Wang
  • Allyson Wooley
  • Carlos E. Ruiz
  • Charles H. Laber
  • Guilherme R Lotufo
  • Loretta A. Fernandez
  • Mark L. Ballentine
  • Nicolas L. Melby
  • Philip Mayer
  • Philip T. Gidley
  • Robert M Burgess
  • Stine Schmidt
  • Todd S. Bridges
  • Upal Ghosh

Organizations

  • United States Army Corps of Engineers

Tags

Communities of Interest

  • Biomedical

DTIC Thesaurus Topics

  • Aquatic Organisms
  • Aromatic Hydrocarbons
  • Chemical Synthesis
  • Chemistry
  • Ecology
  • Ecosystems
  • Ecotoxicology
  • Engineering
  • Environment
  • Environmental Pollutants
  • Environmental Protection
  • Fish
  • Groundwater
  • Habitats
  • North America
  • Polychlorinated Biphenyls
  • Water Quality

Fields of Study

  • Environmental science

Readers

  • Groundwater Contamination Remediation.