Geotechnics and environmental
Geotechnics and Environmental
Within the UK there is a significant amount of land, estimated to be in the excess of 300,000 hectares, which has been considerably abused and polluted by industry. With current government restrictions placed on Greenfield development and the implementation of the EU landfill directive in July 2004, restricting the disposal of contaminated soils to landfill; alternative remediation technologies have become more cost effective. An example of one of these processes is thermal desorption (TD) which is a process of separating contaminants from the soil. This is achieved by applying heat to the contaminated soil so that the contaminants and some metals are vaporised, but not oxidised. The residue soil that is left after this technique has a consistency of ash and may still contain trace contaminates. These contaminates would however be of a less sinister nature and the residual soil may be suitable for reuse as fill material in an embankment.
This research project has been concerned with investigating a novel form of remediation to remove trace contamination from thermally desorbed soil. It has involved the use of a variety of vegetable fibres, knitted together to form a geotextile structure, which gradually degrade with time. As they degrade, the fibres have the potential to remove trace contaminants. In addition to removing contaminants from soil, these environmentally friendly, vegetable fibre geotextiles (VFGs) have the potential to reinforce and stabilise embankments built over soft compressible soils. To date VFGs have only really been employed in the erosion control industry and only a limited range of products are available. This project has developed and investigated the performance of these VFGs to temporarily strengthen TD soils in a range of embankments as well as assessing the level and type of bioremediation that can be achieved from the degrading vegetable fibre matter.