Devonian Clay Modification for the Improvement of Heavy Metal Sorption Properties

Abstract

Contamination with heavy metals is an important problem as bioaccumulation effects of those are creating direct and indirect hazards to environment and human health. Contaminated soil remediation can be done by various technologies and using of soil amendments is the one. Clay modification experiments were done to study heavy metal sorption from spiked solutions and leaching from contaminated soils. The aim of this paper is to give an overview of Devonian clay modification possibilities in order to improve heavy metal sorption capacity and immobilization options. Modification was done by using Ca, Na salts, HNO₃ (protonated forms), Fe-oxyhydroxide. Research has shown better sorption due to improved properties of clay through the process of modification. Kinetic experiments have shown good results of Pb removal by using CaCl₂ modified clays as the sorption capacity increases comparatively to raw and other types of modified clay. Modified clay as amendments in spiked soils also show negligible improvement of heavy metal immobilization properties comparably to raw Devonian clays. More detailed further research in order to prove batch experimental results should be done in future.