Bioremediation of chlorinated solvents at contaminated sites in The Netherlands occurs most often by Natural Attenuation (NA) nowadays.
More than 6000 sites contaminated with chlorinated solvents are mainly located in urban area. As the Natural Attenuation process is rather slow in general, these chlorinated solvent locations have a negative effect on the spatial planning developments at these sites. Furthermore the total number of probably contaminated sites in NL has increased up to 400.000 to 600.000. Therefore a site by site approach will not be effective and an area based approached is proposed for such urban areas.
Since about 1990 the sustainable energy technology known as Aquifer Thermal Energy Storage (ATES) has been developed. Until now about 1000 systems are installed. In the governmental policy on sustainability it is aimed at to have 10.000 to 20.000 ATES systems in 2020. As individual systems may interfere with each other also here an area based approach is aimed at.
Also in spatial planning a development is going on, in which spatial planning is expanded into the vertical and Masterplans are made for 3D-spatial planning.
Here we aim at the beneficial combination of ATES and bioremediation of the subsurface.
During Aquifer Thermal Energy Storage (ATES), heat is collected in buildings to cool the buildings and to store energy in the groundwater in the subsurface. In winter time the stored heat is pumped from the groundwater to the building resulting in a net neutral energy balance in the groundwater.
As groundwater in NL has a temperature of about 10oC, the microbial degradation in general can be speeded up by increasing the temperature.
Here we aim at the combination of heat storage and stimulation of the in situ bioremediation of chlorinated solvents in the subsurface.
In laboratory studies the key parameters involved in the optimization of the combination of ATES and chlorinated solvent biodegradation will be studied. Except effects of temperature also mixing, formation of chemical precipitations, nutrient additions etc., will be studied.
Also studies at field scale will be performed within an applied research project (Meer Met Bodemenergie (MMB) see website: www.meermetbodemenergie.nl).
Further implementation and area based approaches will be modeled related to integration in urban environments.