The aluminum carboxyl methyl konjac glucomannan gel microspheres(CMKGM-Al) were prepared by crosslinking aluminum ion (Al3+) and carboxyl methyl konjac glucomannan(CMKGM). The adsorption capacity of CMKGM-Al for fluoride ion was studied. Several parameters including adsorption time, the concentration of CMKGM, the mass ratio of Al3+, microsphere size, pH, temperature, and the concentration of F-, which effect the adsorption performance, were investigated. The compound of CMKGM-Al/F-was characterized by IR spectrometry. The results showed that the adsorption equilibrium could be established about 6 hours when the temperature was 293 K. The adsorption capacity reached 47.02 mg/g, while the concentration of CMKGM was 1.2%, the mass ratio of Al3+was 2.0% and the concentration of F-was 90.5 mg/L. The thermodynamic parameters of adsorption process were calculated according to isotherms at different temperatures. The experimental data were fitted using the Freundlich equation, and it was found that the equation was applicable to the studied adsorption system. The system was a spontaneous exothermic process and the entropy of the system decreased. The low temperature was favorable for adsorption.
