Adsorption of the herbicide glyphosate on a metal-humic acid complex

摘要: Abstract The interactionof glyphosate with a pure iron-humic acid (Fe-HA) complex was studied by constructing adsorption isotherms at different shaking times. Freundlich equation better fitted the experimental data than Langmuir equation. maximum values (kf) showed that is adsorbed on Fe-HA to an extent similar found for whole soils and even higher shown other soil minerals. This suggests HA complexes polyvalent cations may represent main binding substrate in soils. S-type through application of equation, indicate low concentration ligand exchange mechanism involving phosphono group iron hydration sphere complex, whereas concentration, more continue be bound hydrogen bonding mechanism, already sorbed molecules. high strength interaction demonstrated lack any appreciable desorption time contact applied. A rapid increase slope times 48 h suggestive some microbial degradation.