Remediation techniques

Solvent extraction is a treatment technology that uses a solvent (a fluid that can dissolve another substance) to separate or remove hazardous organic contaminants from sludges, sediments, or soil. (Sludge is a mud-like material produced from industrial or sewage waste, and sediment is fine-grained rock and mineral fragments which have settled to the bottom of a water body such as a river or lake.) Solvent extraction does not destroy contaminants. It concentrates them so they can be more easily recycled or destroyed by another technology.

Solvent extraction can be both an effective and cost-efficient process for separating hazardous contaminants from non-hazardous materials and concentrating the hazardous materials for further treatment. Because the contaminants are separated, the treatment selected can be targeted to the contaminant. As a result of solvent extraction, some contaminants may be recycled or reused in manufacturing, thus minimising disposal requirements. The process has been effective in removing organic contaminants from paint wastes, synthetic rubber process wastes, coal tar wastes, drilling muds, wood treating wastes, pesticide/insecticide wastes and oily wastes.

Will it work at every site?

Solvent extraction can be effective at separating hazardous organic contaminants from some contaminated soils, sludges and sediments. It does not reduce the toxicity of the contaminants, so the final product of the process (the concentrated residuals) still requires treatment or disposal.