13/05/2009 - Low carbon society symposium. Professor Mark Dyer - The wasteful way of treating polluted land.

Professor Mark Dyer from TrinityHaus gave a talk on sustainable remediation of contaminated land. `Mark opened his talk with some startling statistics, 2% of the EU’s agricultural soil is lost annually due to construction and 75 billion tonnes of soil is lost globally every year. Clearly this is not a sustainable approach. Contaminated sites can be remediated and development on such treated sites may be preferable to development on green field sites.

In the past the tendency when remediating brown field sites has been to dig up the contaminated soil and dump it somewhere, but in situ remediation is also possible using a multidisciplinary approach of biology, chemistry and engineering. Mark discussed a site in North London of what was once a furniture factory and the soil there had become contaminated with chlorinated solvents. Rather than digging up the contaminate soil he used sulphur reducing bacteria to degrade the solvent. The site was also contaminated with hydrocarbons which the bacteria could use as a food source and then transfer electrons to the chlorinated solvents and degrade them. This provides a much more sustainable approach to the treatment of contaminated soil especially as the majority of soil that is disposed of is sent to countries like Germany or the Netherlands which creates a greater carbon footprint to the remediation process. The development of bioremediation in Ireland offers a great business opportunity.