New insight into mechanism of Cr(VI) migration and transformation in typical soils of chromite ore processing residue (COPR) contaminated sites

Chromite ore processing residue (COPR) storage sites are widely distributed all over the world, causing serious soil and groundwater pollution. However, differences in constituents properties different regions significant, dynamic migration transformation of Cr(VI) types under alkaline condition COPR site is still unclear. In this study, typical black soil, red loess China were chosen to investigate adsorption kinetics thermodynamics original pH conditions then solution was introduced into column simulate process at sites. According results, breakthrough curve predicted by solid–liquid distribution coefficient Kd based on static isotherm experiments significantly underestimated overestimated retention effect migration, respectively. For dominated reduction, which a slow reaction compared with adsorption. Therefore, reduction during experiment cannot be neglected. With respect outlet concentration turned higher than inlet alkalization, indicated that adsorbed desorbed again, main reason for overestimation soil. This study shows environmental risks Cr quite different, mainly related valence occurrence form governed properties. addition, stable after indicates organic matter can used as potential environmentally friendly remediation material contaminated soils