Evaluation of physical separation techniques to remediate heavy metal contaminated soil from select military installations

The US military has historically conducted activities which contaminated sites with heavy metals. Metal contaminated soil has resulted from such military operations as weapons production, small arms training, metal cleaning, and metal plating. Soil washing is an innovative approach to the treatment of contaminated soils employing both physical and chemical separation techniques. Physical separation methods include screening, hydroclassification, attrition scrubbing and gravity concentration such as tabling and spiraling. Particle size separation using sieves and particle density separation using a shaker table were evaluated for effectiveness on eight selected soils. The effects of attrition scrubbing were also evaluated using a laboratory attrition scrubber. Results indicate that treatment by physical separation was most beneficial to soils contaminated from small arms training activity. Attrition scrubbing tended to be more effective on the chemically contaminated soils for particle size separation treatment.