Fe-Ti oxide nano-adsorbent synthesized by co-precipitation for fluoride removal from drinking water and its adsorption mechanism

摘要

A novel bimetallic oxide adsorbent was synthesized by the co-precipitation of Fe(II) and Ti(IV) sulfate solution using ammonia titration at room temperature. The influences of the washing and drying methods, Fe/Ti molar ratio, and calcination temperature used in the preparation on the morphology, crystallization, surface structure and adsorption capacity were investigated. An optimized Fe-Ti adsorbent had a Langmuir adsorption capacity of 47.0 mg/g, which was much higher than that of either a pure Fe oxide or Ti oxide adsorbent. There was a synergistic interaction between Fe and Ti in which Fe-O-Ti bonds on the adsorbent surface and hydroxyl groups provide the active sites for adsorption, and Fe-O-Ti-F bonds were formed by fluoride adsorption. The novel Fe-Ti adsorbent is efficient and economical for fluoride removal from drinking water.