CsA-7 was chose to investigate the isothermal adsorption for Cu2+.
Each sample approximately 10mg was put into a 100mL conical flask containing 50mL Cu2+ aqueous solution (30–240mg/L) over 12 h at 25◦C with 150 rpm shaken. The adsorption data were fitted to both the Langmuir model (Eq. (5)) and the Freundlich model (Eq. (6)). The maximum adsorption capacity (qm) was obtained from the Langmuir model.