Remediation of Contaminated Land Introduction Engineering Methods Biological

Remediation of Contaminated Land • • Introduction Engineering Methods Biological methods Physical/ Chemical/ Thermal

Contaminated Land Remediation References http: //www. staff. ncl. ac. uk/p. j. sallis/ USER/PASSWORD = cassie • Policy and Legal – Converging Policy Approaches to Contaminated land - Paul Steadman (see copy at http: //www. staff. ncl. ac. uk/p. j. sallis/teach. html) – http: //www. environment-agency. gov. uk/gwcl/LC_Policy. htm – Contaminated Land - Tom Graham – Contaminated Land - Stephen Tromans & R Turrall-Clarke • Remediation – Reclamation of contaminated land Paul C Nathanail (2004) – Selection of remedial treatments for Contaminated Land D Rudland (2004) – Geoenvironmental Engineering H Sharma & KR Reddy (2004) – Natural & enhanced remediation systems S Suthersan (2002) – Remedial processes for contaminated land D Evans (2001) – Remediation engineering of contaminated soils Donald L. Wise (2000) – Contaminated Land - Tom Cairney (1998) – Full Scale Treatment Technologies for the Remediation of Contaminated Land - Ian Martin & Paul Bardos 628. 55 MAR – Several Publications by Robert E. Hinchee – US EPA site http: //www. frtr. gov/matrix 2/section 1/toc. html#Sec 4

Remediation Strategy Conceptual model and the “Pollutant Linkage” • Source – permanent reduction of risks – numerous technical approaches • Pathway – risks managed in short to medium term – several different engineering approaches • Target – not usually applicable or practicable

Remediation Technologies non-technical high technology • Soil Disposal Off-Site – Excavation, Landfill • Containment – Capping, Barriers • Restructuring – Redistribution and Dilution of Material • Contaminant Stabilisation, Removal and Destruction – Numerous Biological, Physical, Chemical, Thermal Methods Relatively low cost, and simple. Considerable experience. Expensive, complex, Emerging Technologies

Remediation Technologies • In-Situ Treatment without physically removing the soil – Advantage - less disturbance, emissions, buildings, buried services – Disadvantage - out of sight, monitoring, heterogeneity of contamination, soil structure (occluded clay lenses), mass transfer limitations, toxic hot-spots. • Ex-Situ Treatment after physical removal of soil – Advantage - Mixing distributes contaminants, mass transfer, process control, treat graded fractions, representative sampling, improved rate, protects groundwater. – Disadvantage - more work, space requirement, emissions, avoid buried services, aesthetic appearance

Remediation Technologies • Intensive Process – Aim to achieve a rapid rate of remediation – uses complex equipment – consume considerable resources • power, reactants, labour, monitoring – Generally detrimental to soil structure – Examples - Soil Washing, Solidification & Stabilisation, Incineration • Extensive Process – Slower to Work – Low capital and Maintenance Costs – Soil Structure retained (Improved) – Examples - Phytoremediation, Bioremediation