Research Progress on Stabilization/Solidification Technique for Remediation of Heavy Metals Contaminated Soil

Abstract

The soil contamination by heavy metals significantly damages the environment, human health, plants and animals, which has become a burning issue recently. Several types of technology have long been in use to remedy the heavy metal contaminated soil. Among of them, solidification/stabilization was widely adopted to manage metal-contaminated soils due to its relatively low cost, easy use, comprehensive strength, and high resistance to biodegradation. In this paper, common binders and the mechanisms of heavy metal-soil-binder interaction were introduced based on literature studies. In general, the effectiveness of S/S process was studied by strength and leaching characteristics. Firstly, the unconfined compressive strength of solidified metal-contaminated soils was evaluated in terms of heavy metal content, curing time, metal type, binder content, soil property, binder type and nature condition. Furthermore, some strength prediction formulas of cement solidified heavy metal contaminated soils were summarized. Subsequently, the performance of the leaching test for S/S products was presented and the influence factors were the same as those of unconfined compressive strength, except for one more factor—soil-solution contact time. Finally, the cases of large-scale contaminated site restoration in China were introduced, and the restorative effects of which achieved the expected objectives.