Objective The objective of the project is to identify plants that accumulate heavy metals, such as zinc, lead, nickel, and to study their application potential for extracting heavy metals from metal-contaminated soil of various levels of pollution, e.g. by sewage or industrial sludges. The accumulator plants will be grown like an arable crop on trial field plots, and harvesting and handling characteristics will be studied, as these will have a major impact on the cost of the treatment of contaminated soils.In situ biological ways of removing pollutants from contaminated soils are attractive from the point of view of environment protection, not requiring extensive reshuffling of contaminated soil and making use of the natural clean up potential of organisms. Of these naturally occurring organisms, metal hyperaccumulating plants are particularly interesting, as they protect the soil and the life in it.Plants were grown on soil polluted by heavy metals that were present in sewage sludge put on the soil. It turned out that only zinc could be removed by some of the plants to a degree that would allow a future commercial use on soils exclusively polluted by zinc above tolerable limits. In case of a topsoil concentration of 450 mg/kg, some 13 harvests would be sufficient to turn pollution down to less than 300 mg/kg which is considered acceptable in the UK, at a cost of some 6500 pounds sterling per hectare, which compares favourably against topsoil removal to 20 cm depth and landfill disposal, costing some 30 000 pounds per hectare. Thus, application of this in situ clean-up scheme may suggest itself for monopolluted land that is taken out of agricultural use for a couple of years. Significant improvements may be possible only upon the use of conventional breeding or gene technology techniques to enhance the performance of hyperaccumulating plants and to extend their potential to metals other than zinc, cadmium and nickel.In-situ biological, "soft" ways of removing pollutants from contaminated soils are attractive from the point of view of environment protection, not requiring extensive reshuffling of contaminated soil and making use of the natural clean-up potential of organisms. Of these naturally occurring organisms, metal-hyperaccumulating plants are particularly interesting, as they protect the soil and the life in it. The EC Commission has assisted the British INSTITUTE OF ARABLE CROPS RESEARCH at Harpenden, Hertshire, in its research studying the potential of hyperaccumulating plants for two years. Plants were grown on soil polluted by heavy metals that were present in sewage sludge put on the soil. It turned out that only zinc could be removed by some of the plants to a degree that lets one expect a future commercial use on soils exclusively polluted by zinc above tolerable limits. In case of, e.g. a topsoil concentration of 450 mg/kg, some 13 harvests would be sufficient to turn pollution down to less than 300 mg/kg which is considered acceptable in the UK, at a cost of some 6.500 pounds sterling per hectare, hich compares favourably against topsoil removal to 20 cm depth and landfill disposal, costing some 30.000 pounds per hectare. Thus, application of this in-situ clean-up scheme may suggest itself for mono-polluted land that is taken out of agridultural use for a couple of years. Thus, this project showed up very clearly the limits of this particular "soft" decontamination technology, with the result that its use will be probably limited. Significant improvements may be possible only upon the use of gene technology techniques to enhance the performance of hyperaccumulating plants and to extend their potential to metals other than zinc as well. Programme(s) ENV-ACE 2 - Action (EEC) by the Community relating to the environment (ACE), 1987-1991 Topic(s) Data not available Call for proposal Data not available Funding Scheme DEM - Demonstration contracts Coordinator Institute of Arable Crops Research EU contribution No data Address Rothamsted Experimental Station AL5 2JQ Harpenden United Kingdom See on map Total cost No data
