Trace Metal Dynamics in Reducing Aquatic Sediments: Determination of Adsorption and Coprecipitation on Undisturbed Sediment Core Sections Using a Plug-Through Reactor

EPA Grant Number: R825397
Title: Trace Metal Dynamics in Reducing Aquatic Sediments: Determination of Adsorption and Coprecipitation on Undisturbed Sediment Core Sections Using a Plug-Through Reactor
Investigators: Cappellen, Philippe Van
Institution: Georgia Institute of Technology
EPA Project Officer: Hiscock, Michael
Project Period: December 15, 1996 through December 14, 1999
Project Amount: $264,669
RFA: Exploratory Research - Water Chemistry and Physics (1996) RFA Text |  Recipients Lists
Research Category: Water , Land and Waste Management , Engineering and Environmental Chemistry

Description:

Whole-sediment adsorption coefficients of Cu, Cd, Co, Ni, As, Sb and Mo, as well as rates of coprecipitation of the metals with iron sulfides will be determined in organic-rich, reducing aquatic sediments. The study will rely on a newly developed sediment plug flow-through reactor technique which is designed to preserve the structural, geochemical and microbiological integrity of sediment core sections. Thus, the emphasis will be on the extraction of reaction parameters that apply directly to natural, heterogeneous sediments. The experiments will be conducted on suboxic to anoxic salt marsh sediments from Sapelo Island, Georgia. The geochemistry and microbiology of these sediments have been thoroughly characterized. In particular, sulfate reducing and iron reducing bacteria have been shown to be major components of the microbial populations. The equilibrium adsorption coefficients, the rate expressions for iron sulfide precipitation, and the kinetic trace metal partition coefficients obtained in the experimental study will be included in an existing multi-component model for reactive transport in sediments. Numerical simulations will be used to determine the degree of retention of trace metals in aquatic sediments under variable depositional conditions. The results of the project will provide a scientific basis for the development of sediment quality criteria that take into account the dynamic nature of toxic trace metal cycling in surface sediments.

Supplemental Keywords:

environmental chemistry, contaminated sediments, water, analytical, modeling, Georgia, GA, region 4, Southeast, Scientific Discipline, Geographic Area, Waste, Water, Hydrology, Ecology, Contaminated Sediments, Environmental Chemistry, Chemistry, State, Engineering, Chemistry, & Physics, EPA Region, region 4, coprecipitation, salt marshes, microbiological reactor, plug through reactor, sediment, Georgia (GA), contaminated sediment, trace metal dynamics

Progress and Final Reports:

  • 1997
  • 1998
  • Final