Characterization and Defluoridation Studies of Active Carbon Derived from Typha Angustata Plants

The sorption characteristics of acid (nitric acid) activated carbon derived from Typha angustata plants (Typha angustifolia var. angustata ) towards fluoride ions, have been explored as a function of physicochemical parameters such as pH, agitation time, adsorbent dosage and initial F- ion concentration. The conditions have been optimized for maximum extractability of F- ions. The adsorption data is modeled using Langmuir and Freundlich classical adsorption isotherms and it is found that Langmuir isotherm model fits well the observed data. The calculated dimensionless separation factor, RL indicates that the adsorption of F- ion onto the TAC is favorable. Of the various kinetic equations studied, the Pseudo-second order kinetic equation well described the adsorption data of F- ion. The BET surface areas and pore size distributions and other physicochemical parameters for the adsorbent are obtained by N2 adsorption at 77K. Surface morphology is examined using Scanning Electron Microscopy (SEM), Energy dispersive spectroscopy (EDX) and X-ray photo electron spectroscopy (XPS) before and after adsorption of F- ion. The chemical composition, elemental analysis and functional groups of the carbon surface are probed using XRD, and FT-IR techniques. The results indicate that Typha angustata activated carbon can be successfully employed as low cost alternative to the commercial adsorbents in the removal of F- ion from wastewaters.