In 2012 the Capital Region of Denmark bought a formerly industrial site, heavily contaminated with chlorinated solvents. The intent is to use the site as a testing ground for novel methods for investigation and remediation of contaminated soil and groundwater. Since then, about 15 methods have been tested and new projects are constantly in the pipeline. Moreover, the test site is fitted with meeting and office spaces, an “innovation lab” and kitchen facilities, to support a creative environment at the site. At the time of the Aquaconsoil conference we expect to be able to show several ongoing pilot projects. This includes in situ remediation using thermally activated persulfate as well as alternative water treatment methods for the site’s pump-and-treat plant.
Site visit Skuldelev: EK-BIO method for remediation of chlorinated solvents in clay soils
Remediation of low permeable soils contaminated with chlorinated solvents presents a big challenge, which very few methods have been able to meet so far. The novel method EK-BIO (Electrokinetically Enhanced Bioremediation) offers a solution to create contact between reagents and contamination in low permeable settings.
Successful pilot test let to full-scale remediation project
In 2011, the first field tests of the method were carried out in the Danish town of Skuldelev with such success that it was decided to use the method in a full-scale remediation project of the site. The full-scale application was initiated in December 2012 and is expected to operate for three to five years. Results from the first 2½ years of operation are truly encouraging. The method is based on electrokinetically enhanced bioremediation. Bioremediation of chlorinated solvents is most often implemented by adding dechlorinating bacteria to the soil and increasing their performance by adding substrates. In clayey soils, which have a very low permeability, the challenge is to ensure contact between the bacteria, the substrate, and the contamination.
What does EK-BIO offer?
Using the EK-BIO method, an electric field is established in the part of the soil targeted for remediation in order to ensure that the remediation reagents can migrate through the soil and come into contact with the contamination regardless of soil hydraulic properties. The amended substrate is polar and is transported through the soil by ion migration. The bacteria are transported by electro osmosis, i.e. transport with pore water, induced by the electrical field. The electrokinetic transport mechanisms are relatively independent on hydraulic permeability. Use of electrokinetics can thus facilitate an effective distribution of substrate and bacteria at sites with low permeable or heterogeneous geology.
Skuldelev project first in the world
The full-scale implementation of EK-BIO in Skuldelev is the first of its kind worldwide and is undertaken by the Danish consultancy NIRAS in collaboration with the American consultancy Geosyntec Consultants and funded by the Capital Region of Denmark. Since the first successful application of the method in Denmark, the EK-BIO method has achieved widespread recognition by experts abroad, and has won a prize for best ‘green innovation’ in the United States.
Time table for Tour 1B
12.30 - 13.00 Transport to Skovlunde
13.00 - 14.00 Visit at the Innovation Garage
14.00 - 14.45 Transport to Skuldelev
14.45 - 16.00 Visit EK-Bio remediation site
16.00 - 17.00 Transport back to the Bella Centre
Version: 20 April 2015