Adsorption and mobility of Cr(III)-organic acid complexes in soils

► The forms of Cr(III) and Cr(III)-organic acid which greatly depend on pH affect their adsorption and mobility in soils. ► Cr(III) exists mainly as Cr3+, [CrOH]2+ and [Cr(OH)2]+, resulting in high adsorption and very low mobility in soils. ► Cr(III)-EDTA and Cr(III)-cit exist as negatively charged and neutral molecules, respectively, leading to weak adsorption and high mobility in soils. ►