Comparative Study of Powdered Activated Alumina with Granular Polymer-Agglomerated Alumina in Fluoride Removal from Drinking Water

Abstract

The characteristics of commercially available powdered activated alumina for defluoridation of drinking water in batch process have been investigated. The powdered form of activated alumina possesses enhanced defluoridation capacity compared to granular form but could not be used in column process as it is reported to cause pressure drop in column operations. To overcome this drawback powdered activated alumina was agglomerated with neutral and nontoxic polymer poly(vinyl acetate) to get the granular polymer-agglomerated alumina. Using synthetic fluoride solution the effect of pH, adsorbent dose, kinetics of adsorption process and adsorption isotherm for fluoride removal by granular polymer-agglomerated alumina were investigated in batch experiments and compared with that of powdered activated alumina. Column experiments were performed using granular polymer-agglomerated alumina to find out the effect of co-existing anions in water and the suitability of the adsorbent for repeated cycles after regeneration.