Abstract
BACKGROUND: The present study has concentrated on investigating the fluoride removal potential of nanoβscale aluminum oxide hydroxide (nanoβAlOOH). A series of batch adsorption experiments were carried out to assess parameters that influence the adsorption process. The different parameters investigated include the effect of contact time, initial fluoride concentration, adsorbent dose, pH of the solution and coβexisting anions.
RESULTS: Most of the adsorption took place during the first 30 min and kinetic and equilibrium adsorption data show that the process obeys a pseudoβsecondβorder kinetic equation and the Langmuir adsorption model. The fluoride removal efficiency is greater than 90% between pH 6 and 8 and decreases as pH values increase to 11. The presence of SO~4~^2β^ or PO~4~^3β^ in aqueous solution was found to reduce the fluoride uptake. Desorption studies showed that the fluoride can easily be desorbed at pH 13.
CONCLUSION: NanoβAlOOH possesses a maximum fluoride capacity of 3259 mg F^β^ kg^β1^, which is comparable with that of activated alumina. Maximum adsorption occurred at around pH 7, which makes nanoβAlOOH a potential adsorbent for drinking water treatment. Copyright Β© 2009 Society of Chemical Industry