REMOVAL OF FLUORIDE USING MODIFIED KENAF AS ADSORBENT

Kenaf core fibers (KCF), one of the agricultural wastes were chemically modified by using N-(3-chloro-2-hydroxypropyl) trimethylammonium chloride (CHMAC) as quaternizing agent. The potential of quaternized kenaf core fibers (KCF) as an adsorbent for fluoride from aqueous solution was then studied. The modified kenaf core fibers (MKCF) were characterized by Fourier transform infrared spectroscopy (FTIR) and Scanning electron microscope (SEM). The effect of initial fluoride concentration, pH, contact time, and adsorbent dose on the fluoride sequestration was investigated. The results showed that with increasing of the adsorbent amount and contact time, improve the efficiency of fluoride removal. The maximum fluoride uptake was obtained at pH 6 and contact time of 72 hours. This study also showed that the maximum adsorption capacity per unit mass of MKCF was 13.98 mg/g. The adsorption equilibrium data were analyzed using Langmuir, Freundlich,Redlich-Peterson, Sips, Toth and Koble-Corrigan isotherm models. The obtained results in batch studies were best fitted with Freundlich isotherm. Eventually, MKCF is recommended as a suitable and low cost adsorbent for fluoride removal from aqueous solutions.