FLUORIDE SORPTION USING Cynodon dactylon-BASED ACTIVATED CARBON

This study deals with the application of Cynodon dactylon-based thermally activated carbon for fluoride toxicity. The batch adsorption technique was followed at neutral pH as a function of contact tune, adsorbent dose, adsorbate concentration, temperature and the effect of co-anions. The data indicate that the prepared adsorbent surface sites are heterogeneous in nature and that fits into a heterogeneous site-binding model. The present system followed the Redlich-Peterson isotherm as well as the Langmuir adsorption isotherm model. Lagergren pseudo-first-order, pseudo-second-order, infra particle diffusion and Elovich kinetics were modeled to describe the adsorption rate of fluoride, and determined as this scheme followed pseudo-second-order kinetics. The calculated enthalpy change, Delta H degrees, and entropy change, Delta S degrees, for the adsorption process were 8.725 kJ/mol and 0.033 J/mol K, respectively, and showed endothermic experience. Instrumental analysts of XRD, FTIR and SEM gives an idea about the fluoride binding ability of adsorbent.