When implementing combined remedies for site remediation, it is critical to assess the relative contributions of each component of the combined remedy. This is particularly important for the remedies involving bioremediation.
Molecular biology-based monitoring tools (quantitative polymerase chain reaction (Q-PCR) analyses, denaturing gradient gel electrophoresis, fluorescent in situ hybridization, DNA microarrays) are evolving tools for the identification of the important microbial species and biodegradation pathways at a number of contaminated sites.
With the recent opening of BioZone (directed by Professor Edwards), a Centre for Collaborative Bioengineering Research at the University of Toronto, this project team will have access to tremendous analytical and molecular biology resources for monitoring and analysis of microbial communities in both bench scale and field scale studies planned for this project. Challenges remain for the development of these monitoring tools for application to real field samples with complex microbial communities in complex media, but the potential value of comprehensive diagnostic molecular biology monitoring tools is tremendous as microbial activity may be an important component of remediation at a majority of contaminated sites.
Fractionation patterns of the stable isotopes of carbon and hydrogen can provide great insight into the transformation processes occurring at a site. The preferential degradation of bonds between the lighter isotopes compared to the heavier isotopes (for example, C12 versus C13) occurs to different degrees for different chemical transformation pathways, and is not greatly affected by processes of dissolution, volatilization, or diffusion. The isotope fractionation patterns can therefore be used to identify transformation pathways and quantitatively track rates of biotic and abiotic transformation at contaminated sites (Elsner et al., 2010). The Stable Isotope Lab at the University of Toronto (directed by Professor Sherwood Lollar) has pioneered many of the developments in this field and will be directly involved in this project. This will be particularly valuable for students working with the combined remedies of bioremediation and NZVI, and bioremediation and ISCO.