Interactions between selenium species and pyrogenic carbonaceous materials in water and soil relevant to selenium control and remediation: A molecular-level perspective

In the environment, selenium (Se) has dual impacts on living organisms, as it is an essential element but high concentrations can be toxic. Current technologies for treating Se in real applications are not cost effective. Pyrogenic carbonaceous materials (PCM) with high surface area and redox properties have been proposed to remove Se. The objective of this review is to evaluate recent developments in fabrication of PCM and functionalized PCM for Se sorption and reduction in environmental remediation, as well as their potential impacts on crop growth. The sorptive removal of Se by PCM depends on the combined effects of electrostatic interactions, steric constraints, and complexation with metal species. The reduction property of PCM facilitates the conversion the ionic Se into solid state. The sorption of Se on PCM can also find applications in crop growth and the inhibition of heavy metal ions. We provide an outlook of terminal treatment of Se on PCM including immobilizing Se as solid species or applying PCM with sorbed Se as micronutrient soil amendment.