Fig. 3: Sorption experiment results of NCU-1.

a Equilibrium data for Pr3+, Nd3+, Gd3+, and Dy3+ adsorption of NCU-1 and fitted with the Langmuir isotherm models. b Kd values of metal ions captured by NCU-1 at various pH values from 2.0 to 6.0. c NCU-1 capture efficiency of metal ions in mine tailings collected from Ganzhou city. d Mine tailing breakthrough curves of metal ions. Error bars represent S.D. n = 3 independent experiments.