User:Andreas Houlberg Kristensen
Industrial Ph.D. student at Rambøll Denmark / Aalborg University
Description of Ph.D. study The area of the study is bioremediation of soil sites contaminated with volatile gasoline or diesel compounds in the unsaturated zone. Main focus is mapping and determination of the degradation capacity (degradation kinetics) existing in situ at 1-3 test sites. The improved process knowledge obtained at each site will be applied in evaluation of in situ bioremediation techniques such as monitored natural attenuation (MNA) and bioventing. The study contains the following main parts:
1.Development of state of the art multi-method approach for site characterization, involving sampling of intact drill cores, on-site determination of air permeability and water content in soil samples and geophysical EC/gamma logging in boreholes. Data obtained should contribute to a detailed 3D model of geological layers and pollutant spreading, providing the information required in order to select an appropriate remediation approach.
2.Study of distribution of biodegradation potential in the unsaturated zone at 1-3 project sites. Batch reactor degradation experiments using benzene as model chemical will be carried out on soil samples and correlations between degradation rates and various factors will be indentified. These include:
- Pollution history
- Geology and texture
- Redox conditions
- Water content
- Bioavailable nutrients (extractable phosphor and nitrogen)
- Organic matter
- Gas transport properties
- Biomass size (DAPI-staining)
3.Comparison of degradation rates obtained using different scales and systems (batch reactor, unsaturated soil column and in situ tests). The project will involve intact column experiments on simultaneous BTEX diffusion and biodegradation.