Rapid anaerobic biological degradation
Tauw Italia has published an article on the rapid anaerobic biological degradation of chlorinated solvents in source areas. Together with the Dutch company BioSoil Tauw Italia has performed a successful pilot experiment.

Tauw Italia en BioSoil International BV worked on an anaerobic biodegradation pilot test. The test was performed at an industrial site, north of Milan, Italy, where an extensive soil and groundwater contamination was found.

The objectives of the pilot field tests were:

• To prove that it is possible to create the required anaerobic conditions for biological degradation in the soil and that anaerobic dehalogenation of various chlorinated solvents is feasible

• To determine the effectiveness of the remediation system for source zone treatment

• To gain experience with the implementation of an in-situ remediation at the site, upon which the full scale remediation design can be made

The pilot test was performed during 6 months to demonstrate that stimulation of anaerobic reductive dechlorination is an effective remediation technique for the removal of various chlorinated solvents.

The rapid decrease of the redox potential, which is a prerequisite for anaerobic dehalogenation, demonstrated that favourable conditions for anaerobic dehalogenation could be achieved by the injection of the electron donor Percol®. The effectiveness of the electron donor was also illustrated by the fact that the redox potential and the contaminant concentrations increased a little towards the end of the pilot, which corresponded with decreased COD levels.

After this successful pilot test, the system at the site was kept operational, in order to maintain the active biological population and to remove as many contaminants as possible. Based upon the results of this pilot the client intends to enlarge the set-up to remediate the whole contaminated site.



Authors:

M. Slooijer, BioSoil International BV

J.A. Dijk, BioSoil R&D BV

G. Buscone, Tauw Italia


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