Remediation of Contaminated Land

• Introduction• Engineering Methods• Biological methods• Physical/ Chemical/ Thermal

Contaminated Land Remediation Referenceshttp://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/matrix2/section1/toc.html#Sec4

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 lowcost, and simple.

Considerableexperience.

Expensive, complex,EmergingTechnologies

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