Journal of North Khorasan

Abstract Background & Objective: High concentrations of fluoride in drinking water can cause skeleton and dental crises, also create abnormalities at another widely in humans. Material & Methods: In this study, zeolite of clinoptilolite being modified by La3+ ions was used to remove fluoride from aqueous solution. In this study, contact was using a fixed bed column with upward flow. The residual fluoride content was measured using DR5000. The parameters of initial fluoride concentration, adsorbent concentration, pH solution was done between natural and synthetic samples. Result: Results showed that increasing the initial concentration of fluoride from 2.5 to 10 mg/L, result decreased of time to Breakthrough Curve and the volume of water but the absorption capacity adsorbent (qb) increased. By increased of adsorbent from 10 to 17 gr and reach to BTC, volume of water treated and sorbent adsorption capacity was increased. The natural pH (5-9) observed of little effect on the absorption, but at pH less than 3, significantly decreased absorption efficiency. Anions in natural samples cause reduce absorption of fluoride. Conclusion: Modified zeolite with fixed bed is an effective and economical method to remove fluoride from ground water.