Superfund Research Program
Biosurfactant-Enhanced in Situ Metal Remediation
Project Leader: Raina M. Maier
Grant Number: P42ES004940
Funding Period: 1995-2010
Project-Specific Links
Project Summary (2005-2010)
The existence and fate of heavy metals in soil is of concern not only because of their potential impact on the microbial communities which comprise a healthy soil, but also because of the potential for groundwater contamination and hence, toxicological impact on human health. A major problem associated with remediating subsurface systems contaminated by heavy metals is the difficulty in delivering the metals to the surface for subsequent treatment. Typically, "pump and treat" remediation does not attain cleanup within predicted timetables due to a "tailing" effect once initial high heavy metal concentrations have been flushed out. Further complicating remediation of metal-contaminated sites is the fact that a large proportion of such sites are co-contaminated with organics. Such co-contaminated sites are difficult to bioremediate due to the nature of the mixed contaminants. Specifically, the presence of a co-contaminating metal imposes increased stress on indigenous populations already impacted by organic contaminant stress. The overall hypothesis of this project is that microbially-produced surfactants (biosurfactants) have the potential to reduce the tailing effect associated with "pump and treat" and hence the amount of water pumped. Further, biosurfactants will act to mitigate metal toxicity to biodegrading microbes in co-contaminated sites allowing more rapid bioremediation. These two effects will allow significant monetary savings in operating costs both in terms of amount of water pumped and a shorter period of operation for the remediation system.