Fig. 6. Equilibrium isotherm models for the adsorption of IC onto APAN/Fe3O4–MPA. The solid and dashed lines are Langmuir, Freundlich, and Toth models fit of the experimental data using non-linear method. Experimental conditions: adsorbent amount = 10 mg, contact time = 60 min, pH = 5, temperature = 23 °C ± 1. The relative standard deviations of all measurements were less than 6%.
