Humic acid enhances the co-transport of colloids and phosphorus in saturated porous media

Phosphorus (P) has been widely recognized as a substance that is difficult to transport due to its tendency to become easily fixed in the soil. However, many reports demonstrate that groundwater P pollution is rising in humus-rich areas. Research is urgently needed to confirm (or reject) the hypothesis that increased P pollution is related to humus, as there is currently limited quantitative research on this topic. In this study, we conducted a series of batch equilibrium adsorption-desorption experiments and column experiments to quantify the effects of montmorillonite colloids (MCs) and humic acids (HCs, the main components of humus) on the P transport behavior. The results indicate that P's adsorption and desorption behavior on MCs can be well simulated using the Langmuir and Temkin models (R