Assessment Of a Novel, In-Situ Remediation Technology For Immobilizing Arsenic (As) In Aerobic Soil Systems.

In near-surface soil environments, Arsenic (As) will commonly form complexes with soil minerals such as metal oxides and clays. Under such conditions, As remains a risk to human and ecosystem health either through leaching to groundwater or incidental dust ingestion. Contaminated topsoil can be removed and replaced with clean fill, but this is very costly and warrants research into alternative methods. One such technique involves application of Iron (Fe) salt solution to soil with a lime buffer to induce rapid, in-situ ferrihydrite (FH) precipitation. This has been shown to coat soil particles and may offer long-term sequestration of As(V) by physical and/or chemically recalcitrant iron oxides. This remediation technique is under development and will be initially tested in a simple bench-top system. The treated residue will be evaluated for its effect on As leachability, speciation and human bioaccessibility and suitability for further trials assessed.