Study of a New Adsorbent for Fluoride Removal from Waters

Abstract
A new adsorbent for fluoride removal is reported in this study. The process and mechanism of removing fluoride are also reported. The adsorbent was characterized as having high selectivity for fluoride, large adsorption capacity, applicability to neutral medium and much better adsorption at high temperature. The floride removal mechanism is a typical chemisorption which is different from the one used for activated alumina. Adsorption rate was considerably faster at the beginning of the adsorption process, followed by a much slower porous diffusion process. Results of field tests showed that the adsorbent was much more suitable for treating high temperature geothermal water with high fluoride content. It also had the advantages of reducing turbidity, decolorizing, dealkalizing, and removing iron from drinking water.