Fluoride removal by mixtures of activated carbon prepared from Neem (Azadirachta indica) and Kikar (Acacia arabica) leaves

Abstract

Fluoride removal from aqueous solution was investigated using activated carbon developed from mixture of Neem (Azadirachta indica) and Kikar (Acacia arabica) leaves. In this study, the mixture of sizes 0.3 mm and 1.0 mm (1:1, 2:1 and 1:2) adsorbent were prepared by mixing the thermally activated Neem (Azadirachta indica) leaves carbon and thermally activated Kikar (Acacia arabica) leaves carbon, according to their efficiency for fluoride removal. Batch type experiment was carried out for the adsorption of fluoride using mixture adsorbent. In the batch study influence of pH, adsorbent dose and contact time were investigated. Adsorption of fluoride was pH dependent and was found to be maximum at pH 6. Fluoride removal increased with increased dose of carbon. The adsorption process obeyed Freundlich adsorption isotherm, Langergren’s equation and intraparticle diffusion. Fluoride removal increased with decreasing particle size of carbon. In mixture, adsorbent ratio 2:1 had slightly higher capacity than the 1:1 and 1:2.