REMOVAL OF FLUORIDE FROM DRINKING WATER USING LOW COST ADSORBENTS

Abstract

Fluoride is a poison that accumulates in our bones. It has been associated with cancer in young males; osteoporosis; reduced I.Q; and hip fractures in the elderly, to name a few. Fluoride in nature exists as mineral deposits and, naturally, contaminates our ground water resources. Besides, surface water is also being polluted by fluoride due to various anthropogenic activities. The permissible limit of fluoride concentration in drinking water is 1.5mg/L according to WHO guidelines. Therefore, knowledge of its removal, using best technique with maximum efficiency is needed. Among various techniques adsorption occupies a prominent place in fluoride removal. As cost is an important consideration in most developing countries, efforts have been made to explore the possibility of using various low cost adsorbents that are abundant, readily available and are derived from waste materials. In this study, the adsorption behaviour of sawdust and Banana peel powder has been studied in order to consider its application for fluoride removal. The batch adsorption method was employed: Laboratory investigation of the potential of sawdust and Banana peel powder to remove fluoride from aqueous solution has been studied. The effects of various experimental parameters, such as pH , adsorbent dosage, particle size, contact time and initial concentration were investigated . The equilibrium data have been analyzed by the Langmuir, Freundlich and Tempkin isotherm models. The adsorption kinetics also investigated by the pseudo-first-order, pseudo-second-order, intraparticle diffusion and Elovich model.