ABSTRACT
Soil washing as used in this chapter refers to a reclamation technique designed to remove soil contaminants by leaching or concentration of contaminants onto a small quantity of fine particles of the soil. Generally, but not always, the leaching liquid is water or an aqueous solution containing chemicals designed to enhance the leaching process. Leaching of chemicals within and through the soil profile occurs under many conditions, some natural and some engineered. For example, leaching of dissolved salts and other chemicals occurs naturally in soil as a result of the downward movement of natural precipitation and irrigation water. The fundamental strategy of soil washing is to extract unwanted contaminants from soil through washing or leaching the soil with liquids, generally aqueous solutions. The extraction process includes two primary steps. Soil is in reality a three-phase system comprising solid particles, gas, and liquid.
