This document is available in the Adobe Acrobat PDF Format. Contaminated soil is screened to remove coarse rock and debris.
Water is added to the remaining soil to form a slurry.
Surfactants, acids, bases, and chelators may be added to improve contaminant solubility. The slurry is fed into an attrition scrubber followed by other mechanical equipment designed to remove silts and clays from granular particles. Settling tanks and cyclones improve particle separation. The coarse clean fraction can be backfilled or incorporated into concrete or asphalt. The fine and humic fractions are typically de-watered before treatment or, as appropriate, disposal.