Evaluation of Methods Used for Reducing Heavy Metal Leaching from Sandy Soil

• Published in: Geotechnical and geological engineering Vol. 34; no. 5; pp. 1413 - 1423
• Main Authors: Omar, Maher, Shanableh, Abdallah
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 01-10-2016; Springer Nature B.V
• Subjects: Aqueous solutions; Chelates; Chelating agents; Chelation; Chemical extraction; Civil Engineering; Earth and Environmental Science; Earth Sciences; Economics; Feasibility studies; Geotechnical Engineering & Applied Earth Sciences; Heavy metal content; Heavy metals; Hydrogeology; Immobilization; Land pollution; Land reclamation; Leaching; Metals; Methods; Microorganisms; Organic chemistry; Original Paper; Oxidation; Pozzolans; Risk reduction; Sandy soils; Soil contamination; Soil lime; Soil properties; Soil stabilization; Stabilization; Sulfur; Sulphur; Technical feasibility; Terrestrial Pollution; Urban areas; Waste Management/Waste Technology; Zeolites; Mobilization; Human health; Sandy soils; Stabilization; Immobilization; Environment; Heavy metals
• ISSN: 0960-3182; 1573-1529
• DOI: 10.1007/s10706-016-0051-5

Excessive heavy metal content in sandy soils poses risk to human health and the environment. The rapid expansion of urban areas makes it imperative to manage contaminated sites so that land can be reclaimed for beneficial purposes. Several methods have been proposed to control the leaching of heavy metals from contaminated soils. In this study, four techniques for mobilization and immobilization of metals in sandy soil were compared. The assessed mobilization techniques included chemical extraction using aqueous solutions of acids and chelating agents as well as biochemical extraction using sulfur-oxidizing microorganisms. The evaluated immobilization techniques included lime-cement-pozzolan stabilization and natural-zeolite stabilization. The immobilization techniques do not involve removing metals from soil and instead focus on addition of substances to the soil that alter its composition, volume, and properties. On the other hand, mobilization techniques entail the removal of metals from soil and changes in the soil properties. The findings confirmed that both mobilization and immobilization are effective in controlling the leaching of metals from sandy soils and thereby minimize the risk to the environment and human health. However, the appropriate technique for application at a given site should be chosen on a case-by-case basis, while accounting for the economic and technical feasibility, the necessary level of cleanup, and effect of residual metals on human health and the environment.