Neem leaf powder prepared from mature, dried Neem (Azadirachta indica) leaves was investigated to
assess its ability to remove
fluoride from aqueous solutions using batch adsorption process. Effects of
solution pH, contact time, adsorbent amount and solution temperature on
fluoride sorption had been
investigated. The biosorbent was effective at the pH range of 5.0–7.0 and its
fluoride removal capacity was
found to be above 80%. The equilibrium time for
fluoride sorption was found at 60 min and the process
followed the second order kinetic mechanism. The adsorption process was exothermic in nature and
obeyed Freundlich, Langmuir and Temkin isotherm models. SEM study of the biosorbent showed a
morphological change of the surface after sorption and FTIR study indicated the involvement of some
surface functional groups in
fluoride sorption. These results indicated that Neem leaf powder might be an
effective adsorbent for treatment of water contaminated with
fluoride.