Abstract

DEFLUORIDIZATION USING A NATURAL ADSORBENT, CISSUS QUADRANGULARIS

S.Rayappan, B.Jeyaprabha, P.Prakash,*

ABSTRACT

Fluoride exists naturally in water. It is 13th most common element in earth crust. Fluoride helps to prevent tooth decay at early stages, but excess of fluoride level causes various diseases such as dental fluorosis, Alzheimer diseases, skeletal fluorosis, thyroid cancer and chronic insomnia. By studying the impact of fluoride on health, low cost deflourination technique has been developed. The removal of fluoride from aqueous solution by using Cissus Quadrangularis (CQ) has been studied in batch technique. Influence of pH, adsorbent dose, contact time, co ions, speed and initial concentration on the adsorption were investigated. The maximum removal of fluoride ion is obtained at pH 7. The removal of fluoride is expressed with Langmuir and Freundlich isotherm. It is found that the sufficient time for adsorption equilibrium of fluoride ion is 1 hour. The maximum removal of fluoride ions for the adsorbent dosage of CQ is 10mg/50ml. The fluoride adsorption is maximum at 60min in the shaking speed of 120 rpm. The presence of interfering ions such as nitrate shows positive effect while carbonate, sulphate, chloride show little negative effect and phosphate show high negative effect for the adsorbent. The optimum initial F concentration for CQ adsorbent is 5mg/50ml.

Keywords: Fluoride, CQ- Cissus quadrangularis , low-cost natural adsorbent.