Summary
The groundwater in regions with a mining and industrial tradition, we frequently find a large of number of pollutants in high volumes and concentrations. These locations thus represent a major challenge for groundwater remediation. This research project aims to optimise existing remediation methods and to develop and test innovative combined methods. It studied whether they guarantee more efficient degradation of organic pollutants, particularly chlorinated hydrocarbons (CHCs) than conventional methods.
The following results were obtained for the methods studied:
Sequential aerobic / anaerobic activated carbon barrier:
- Degradation of CHCs in a two-stage activated carbon barrier is rated as effective and having long-term stability.
- The CHCs studied can be degraded using this method.
Combination of catalytic oxidation with aerobic microbial degradation:
- Stable in-situ use of the combined method was achieved.
- The preliminary attack on hard to degrade organic compounds using catalytic oxidation enables a significantly wider range of pollutants to be dealt with than with an aerobic biological purification stage alone. Conversely, this combination saves a significant proportion of the oxidation agent (H2O2) used in heterogeneous catalysis.
Use of colloidal iron catalysts:
- For palladium/iron colloids with a size in the nanometre range developed from iron (III) salts, the potential for very rapid and therefore efficient pollutant degradation was demonstrated.
- Separation of the colloids from the aqueous phase is possible using magnetic separation techniques, which means that regeneration is theoretically feasible.
Vacuum stripping with hollow fibre membrane modules:
- This is a very efficient method for remediation of water that is polluted with volatile to semi-volatile compounds.
