Stabilisation/solidification (S/S) is a soil remediation technology that relies on the reaction between a binder and soil to reduce the mobility of contaminants. Stabilisation involves the addition of reagents to a contaminated material (e.g. soil or sludge) to produce more chemically stable constituents. Solidification - involves the addition of reagents to a contaminated material to impart physical/dimensional stability to contain contaminants in a solid product and reduce access by external agents (e.g. air, rainfall).
Soil Stabilisation/Solidification (S/S) treatments include a wide range of similar processes that usually involve mixing inorganic cementitious binders, such as Portland cement or lime, into the waste or soil to transform it into a new, solid, non-leachable material. The treated material encapsulates potentially hazardous contaminants, reducing contact between the waste and any potential leachant In addition to encapsulation, various waste-binder interactions and chemical effects occur that lock contaminants into the product, further reducing the potential for pollutant transfer into the environment. Binders are usually selected according to some mix design criteria which depend on the application, which could be landfilling, redevelopment of a contaminated site or reuse of waste as aggregate in construction.
Immobilisation of contaminants in the ground using soil stabilisation treatment is emerging as viable and economic because of its advantages over other containment and soil remediation methods. None of the other contaminated soil remediation methods are completely effective and typical characteristics such as heterogeneity in soil and contaminant conditions, particularly in made ground soils, pose serious problems. Soil stabilisation/solidification is a soil remediation method, which without removal of the contaminants, prevents their further spreading and hence offers an immediate solution. It also offers rapid implementation of the treatment hence enabling immediate redevelopment of contaminated sites or reuse of waste materials. In addition, it is a cost effective remediation method which is competitive with all other remediation methods including land filling.