Gentle remediation of contaminated soils EU-funded researchers have reviewed and evaluated environmentally friendly methods of remediating polluted soil. They also developed guidelines and a decision-support tool for stakeholders and decision-makers. Health © Thinkstock Soil contamination by trace elements continues to be a major environmental problem and has been listed by the European Commission as one of the eight major threats to Europe's soils. Soil remediation is therefore urgently needed for maintaining one of our most important natural resources, which supplies us with food, animal fodder and biomass for energy production. Conventional soil remediation technologies are often costly and energy intensive and may adversely affect soil quality. However, remediation of trace element-contaminated soil can be accomplished using so-called gentle remediation options (GROs), which employ plants, associated microbes and soil amendments as an environmentally friendly and cost-effective alternative. Although the effectiveness of GROs has been proven in both the lab and greenhouse, information on the long-term effectiveness of this approach was missing. The GREENLAND (Gentle remediation of trace element contaminated land) project was established to fill this knowledge gap via large-scale field demonstrations. Scientists used a network of 13 large contaminated sites to optimise new practices, biomass production, financial returns, and risk and efficiency assessment methods. Project partners thoroughly reviewed biomass processing that leads to economic returns (valorisation processes) and tested several promising options. These included combustion, anaerobic digestion and pyrolysis, thereby providing energy. Raw materials for further use were also investigated, such as polymetallic catalysts for chemo-catalytic processes. Researchers also developed and refined tests for the effectiveness, efficiency and progress of soil remediation. These were then used to evaluate various plants, microbes, soil amendments and agronomic practices as methods for remediation. GREENLAND also optimised GROs and demonstrated their feasibility in 16 large-scale field studies, which provided soil samples for testing and analysis. The results were collated and published together with detailed best practice guidelines for implementing GROs. These are available through the project website in English, French, German and Spanish. The outcomes also include tools for increasing efficiency by selecting the most effective plants, associated microorganisms, and mineral and organic soil amendments in accordance with site-specific conditions. A decision-support tool, accessible through the website, can be used to select the most suitable GRO for a site's particular conditions. The widespread uptake of this new approach will help reduce dangerous soil contamination in the EU, thereby improving the quality of life of people living near such areas. Keywords Gentle remediation, contaminated soil, trace elements, soil remediation, biomass
