Physical treatment technologies separate contamination from soil and groundwater by exploiting the different physical and chemical properties of the contaminants.  Once separated and contained, the contaminants can be disposed of or, in some instances, recycled. Physical treatment can also be combined with biological or chemical treatments to optimise remediation at your site. Common Physical Treatment Techniques applied by Soilfix include:

• Soil Vapour Extraction

• Air Sparging

• Product Recovery

• Soil Washing

• Containment & Solidification

• Disposal

Call Soilfix today to discuss the physical treatment options available at your site.

Soil Vapour Extraction

An induced airflow increases the volatilisation of organic contaminants from the soil unsaturated zone. This can be applied in-situ or ex-situ within an engineered treatment bed.

Air Sparging

Injection of air beneath the water table encourages volatilisation and diffusion of contaminants which can then be recovered using a vapour extraction system.

Product Recovery

Exploiting the different densities of undissolved liquids enables direct recovery from groundwater. Liquid contaminants can either be separated at source or recovered with groundwater and separated within treatment plant at surface level.

Soil Washing

Developed from mineral and mining processing industries, most soil washing systems rely on a favourable distribution of contaminants within the soil matrix (e.g. particle size or density). This distribution can be exploited to enable separation of contaminated soils from uncontaminated through washing, scrubbing, filtration and floatation processes. Chemicals (e.g. surfactants) are often used to aid separation of contaminants.

Containment and Solidification

Breaking the pathway between the contaminant source and receptor can often provide the most cost effective remedial solution for contaminated land. Capping and in-ground containment systems are one of the most tried and tested forms of pathway interruption. With robust engineering design, these systems can provide an effective long term solution and should not be overlooked in your remedial options appraisal.

Stabilisation and solidification processes immobilise contaminants within the soil matrix by either physical and/or chemical processes.  They generally involve the application of a binding agent (e.g. cement, lime) which react with the soil/contaminant and moisture within the soil. Chemically, contaminants can be precipitated as hydroxides or incorporated within cement hydrates. Physically, the contaminants are encapsulated within the cement matrix. Stabilisation processes are often used to provide a capping system where they can also improve the engineering properties of a surface soil.

Disposal (“Dig and Dump”)

With the phasing out of exemptions from landfill tax for remediation between 2008 and 2012, the portion of remediation completed through excavation and disposal is set to decrease. However, disposal will continue to play an important role for “untreatable” soils/residues. Minimising this volume wherever possible through the successful application of other treatment technologies will become key to reducing overall remediation costs.