Two hydroxy-aluminum pillared montmorillonites (Al-Mt-20 and Al-Mt-80) were prepared at 20°C and 80°C, respectively. The adsorption characteristics for fluoride by Al-Mt-20 and Al-Mt-80 were investigated. Results showed that the d (001) spacing of montmorillonite in Al-Mt-20 and Al-Mt-80 was 1.392 and 1.481 nm, respectively. The optimum pH value for fluoride adsorption was about 4-5. At pH 4.8, the Langmuir adsorption capacity (qmax) for fluoride of Al-Mont-20 and Al-Mont-80 was 7.12 mg/g and 9.78 mg/g, respectively. The adsorption data for fluoride by Al-Mont-20 and Al-Mont-80 could be fitted by Langmuir model (R2 =0.982-0.987), indicating that Langmuir model is suitable to fit the fluoride adsorption of Al-Mont-20 and Al-Mont-80.
