ABSTRACT
Chelant-enhanced extraction has been widely applied in removing potentially toxic elements (PTEs) in soil because of its efficiency. However, there are still some limitations that can be improved. For example, the complexation capacity of chelants of PTEs is varied, meaning that a chelant has different capacities to form complexes with different PTEs. Chelants can accelerate the dissolution of Fe/Mn/Al oxides and organic matter at different levels. The dissolution can release the PTEs bound to these parts and can contribute to higher removal metal/metalloid efficiencies. In addition, the remaining metal-chelant complexes or chelant in the treated soil might lead to increasing leachability and mobility of PTEs and degradation of soil physicochemical properties. This chapter provides an introduction to some potential pathways to advance chelant-enhanced extraction in view of different evaluation endpoints, such as integrated application of chelants, selective dissolution before chelant-enhanced extraction, and immobilization by low-cost amendments after chelant-enhanced extraction.
