Fig. 4. Adsorption isotherms of the prepared adsorbent PEI-RCSA for removal of Cu(ii), Zn(ii) and Pb(ii) in their respective single-component aqueous solutions (conditions: 25 ± 1 °C; pH 5.5; adsorbent dosage: 1 g L−1; contact time: 8 h; shaking speed: 130 rpm). Simulation by Langmuir model (····) and Freundlich model (—).
