Phosphorus transportation in runoff as influenced by cationic non-classic polarization: a simulation study

摘要: Phosphorus (P) transportation from agricultural soil to surface water is a major contributor P pollution in the environment, and particle phosphorus (PP) total transportation. The intensity of interaction strongly influenced by ion-surface reactions; however, quantitative study regarding influence interactions on during runoff still lacking. A simulation an Entisol was conducted this study. To quantitatively characterize non-classic polarizability cations transport runoff, first saturated with Li+, Na+, K+. layer (5 cm × 5 cm area, 3-cm thickness) packed synthetic glass tray for each experiment, slope set as 30°. replaced electrolyte solutions KNO3, NaNO3, LiNO3 concentrations 0.0001, 0.001, 0.01, 0.1 mol/L, respectively, solution temperature 298 K. height dropping 3 cm. Each experiment lasted 90 min. Runoff sediment were collected time, solids suspensions separated high-speed centrifuge. dissolved (DP) supernatant PP measured. amount K+ treatment 45 or 69 times smaller than that Na+ Li+ treatment. DP 1.7 higher Additionally, increasing concentration decreased both water. Cationic polarization could explain observed experimental results Soil enhance cations; polarizabilities K+, reached 507, 124, 45.8 A3, but their classic values are only 0.814, 0.139, 0.0285 A3, respectively. decrease because had strongest polarizability. cationic electric field around particles, thus decreasing electrostatic repulsive forces between adjacent particles aggregate, which runoff. cation larger polarizability, relative specific ion effects found play important role