Effects of humic acid and kaolinite on copper transport in water‐saturated porous media

Abstract

AbstractMobile organic macromolecules and inorganic particles may act as carriers of strongly sorbing contaminants in subsurface materials, posing a potential facilitated transport risk. This study examined the influence of humic acid (HA) and kaolinite colloid on copper ion transport in saturated porous media. Column experiments were conducted to investigate the migration behavior and interactions of HA, kaolinite and copper under different experimental conditions in saturated porous media. The results showed that the individual presence of HA promoted the transport of Cu. However, the mixture of kaolinite and HA has less effect on Cu migration than HA alone. The presence of Cu reduced the mobility of kaolinite through the saturated porous media sand column by increasing the deposition rate of kaolinite. The transport of kaolinite increased significantly in the presence of HA, while kaolinite slightly decreased HA transport in the sand column. Compared with kaolinite, HA has a stronger ability to desorb copper from copper‐bearing sand. Considering the presence of kaolinite and HA, this study provides a reference for the fate, migration and risk assessment of heavy metal pollutants.