Fluoride removal from water by granular ceramic adsorption

Autores: Nan Chen|Zhenya Zhang|Chuanping Feng|Norio Sugiura|Miao Li|Rongzhi Chen
Fuente: J. Colloid Interface Sci.
348 (2), 579-584
2010

A new media, granular ceramic, has been developed for fluoride removal from water. Granular ceramic is a solid phase media that produces a stable Al-Fe surface complex for fluoride adsorption. BET, SEM and EDS were used to characterize the physical attributes (particle size, pore size and distribution, surface roughness) of the granular ceramic. Fluoride adsorption characteristics were studied in a batch system with respect to changes in initial concentration of fluoride, pH of solution and co-existing ions. Fluoride adsorption was found to be pH dependent and the maximum removal of fluoride was obtained at pH 5.0-8.0. Equilibrium adsorption data were obtained at 293, 303 and 323 K, and interpreted in terms of the Langmuir and Freundlich isotherm equations. The experimental data revealed that the Freundlich isotherm equation give a more satisfactory fit for fluoride removal. The adsorption process was observed to follow a pseudo-second-order kinetic model and intra-particle diffusion was indicated to play a major role in fluoride uptake. Fluoride adsorption was reduced in the presence of phosphate and sulfate ions and increased slightly in the presence of chloride and nitrate ions.