Anionic b-CD/Fe3O4 magnetic microspheres (b-CDM) were prepared by modified b-cyclodextrin. The adsorption thermodynamics

kinetics and recycle about the adsorption of Cu2+ by b-CDM were studied. With a mathematical fitting method

adsorption thermodynamic and kinetic parameters were obtained

and adsorption mechanism was discussed. Thermodynamic studies show that the adsorption of Cu2+ by b-CDM is spontaneous and it is an exothermic process. Further study indicates that it is appropriate to use Langmuir and Freundlich isothermal adsorption models to study the adsorption process. Kinetic study shows that the adsorption of Cu2+ by b-CDM is a process consisting of three stages

which are external diffusion

pore diffusion and adsorption reaction. Both physical adsorption and chemical adsorption take place. The value of apparent adsorption activation energy is 24.12 kJ·mol-1. At adsorption temperature of 298 K

308 K

and 318 K

the adsorption rate constants are 0.0906

0.1161

0.1674 g·mmol-1·min-1

respectively. As the equilibrium absorption capacity of Cu2+ increases

the driving force of adsorption varies from enthalpy change to entropy change. After b-CDM was reused for 8 times

the removal rate declined from 95.20% to 88.21%.