How do you clean dirt?
Soil contamination is a major issue across Europe. Estimates from the European Environment Agency suggest there could be over 2.5 million sites contaminated with harmful pollutants, of which around 14 % are likely to be highly contaminated. This is concerning, as having ‘clean’ dirt is essential to sustainable development, and the foundation of a pollutant-free environment. “Healthy soil is fundamental to preventing and mitigating the impacts of climate change, increasing resilience against natural disasters and ensuring food security,” says Manuela Masutti, a technologist at the Area Science Park in Trieste, Italy. The EU soil strategy 2030 sets out a framework and concrete measures to protect and restore soils and to ensure they are used sustainably. It is further supported by the Nature Restoration Law, which aims to restore 20 % of the EU’s land and sea areas by 2030, and all degraded ecosystems by 2050. “The first step is to have a clear picture of the soil’s health, to understand how well the soil performs and, based on that, whether decontamination action is needed,” notes Masutti.
Technologies for removing, isolating or degrading soil pollution
If decontamination is required, authorities can choose from a range of methods and technologies to remove, isolate or break down pollutants found in soil. The most basic way to remediate a site is simply to remove the soil to a landfill where the pollutants can be contained and managed. Other common approaches include pumping reactive gases such as ozone into the soil, flushing the soil with liquids that can break down or absorb the contaminants, or growing plants that naturally accumulate problem chemicals, after which they are harvested and disposed of safely. The EU-funded POSIDON project, which Masutti helped coordinate, developed a number of new innovative and cost-effective solutions. These were field-tested across five brownfield sites, including a former oil refinery in Trieste, a shuttered steel processing plant in Lisbon and an old shipyard in Bilbao. Among the techniques is Soil-Omic®, a process that uses microbes to break down pollutants in the soil. By continually flushing the site and monitoring the microbes present, the optimum species of microbe for decontamination can be selected. Organic contaminants are degraded and transformed into non-harmful substances, while inorganic contaminants are extracted through leaching for chemical treatment.
Erasing the errors of the past
Another of POSIDON’s newcomers to the soil-cleaning market is ERASE. This remediation technology uses powerful electrodes to extract chemical pollution from the soil or transform it into innocuous substances. “The industrial revolution may have made dirt ‘dirty’, but today’s technological revolution has the potential to not only erase the pollution of the past, but help soil managers restore soil functions for the future,” concludes Masutti. Click here to find out more about the POSIDON project’s research results: Dealing with Europe’s contaminated soil.
Keywords
POSIDON, industrial waste, pollution, soil, soil contamination, dirt, brownfield, climate change, EU soil strategy