Remediation of chromium-containing soils by heap leaching: Column study

Efforts are being made to devise technologies and treatment systems to remediate contaminated soil on site without generating significant wastes for off-site disposal. Heap leaching, a technique used extensively in the mining industry, has been investigated as a method for remediation of hazardous metal contamination of the vadose zone. In the mining industry, metal bearing ore is excavated and mounded on a pad. The metals are removed by passing a special leaching solution through the ore. In this study, the removal of Chromium (VI) from four New Mexico soils (sand, sandy loam, and clay) using heap leaching was evaluated at a column scale. The heap leaching study demonstrated greater than 99% removal of Cr(VI), using tap water as the leaching agent. The soils were typical of arid climate soils with low organic content (<1%).