Artificial zeolites (AZ) and AZ modified with zirconium cation (AZZ) were fabricated in this work. AZ and AZZ, which were characterized by SEM and XRD, showed that AZZ was the composite of AZ and ZrO2. The adsorption kinetics and isotherms of AZ and AZZ towards fluoride removal in water were consistent with the Langmuir and pseudo-second-order models, respectively. AZZ had better fluoride adsorption capacity than AZ. The maximal adsorption capacity of fluoride onto AZZ reached up to 128.2 mg/g. Moreover, the thermodynamic studies illustrated that the adsorption procedure was spontaneous and endothermic. The effect of solution pH on AZZ fluoride adsorption was also investigated, and the results showed that the more acidic the fluoride solution, the better the fluoride adsorption capacity. After five cycles of regeneration, the adsorption capacity of AZZ was maintained at 78 %. Based on zeta potential measurements, this work proposed that the electrostatic attraction between AZZ and fluoride ions (F-) should be the mechanism for F- adsorption onto AZZ in water.

Zanen Wu, Xia Chen and Shibiao Wu