Abstract: A method for treating chromium ore waste contaminated soils by detoxification, fixation, immobilization and stabilization comprising the steps of soil grinding, pre-activating, reducing chromium valiancy, forming insoluble metal hydroxides, and incapsulating the chromium compounds containing agglomerates to prevent potential chromium leaching from the soil according with the standard toxicity characteristic leaching procedure requirements. Additive agents such as an acidic solution, a bivalent iron sulfur containing salt, e.g. ferrous sulfate, an alkalifying agent, e.g. calcium lime slurry or lime kiln dust or caustic, a stabilizing agent, e.g. cement, cement kiln dust, silicates, polyelectrolytes, and the like are also disclosed as assisting in the chromium immobilization reactions by reacting with certain constituents in the soil.

Abstract: A process and associated apparatus for removing contaminants such as heavy metals from contaminated water, waste water, sludge or flushed soil elutriates, or leachates. The remediation method utilizes a combination of chemical oxidation/reduction reactions and physical separation techniques employing a pseudofluidized bed and is carried out in a unitary reactor comprising zones for activation, flocculation and phase separation.