Development of amine functionalized co-polymeric resins for selective fluoride sorption

This study describes the development of various synthetic co-polymeric resins modified by ethylenediamine such as vinylbenzyl chloride/divinylbenzene-ethylenediamine (VBC/DVB-ED), styrene/divinylbenzene/vinylbenzylchloride-ethylenediamine (ST/DVB/VBC-ED) and acrylonitrile/divinylbenzene/vinylbenzylchloride-ethylenediamine (AN/DVB/VBC-ED) for the removal of fluoride in water. Fluoride sorption experiments were carried out in batch mode. Among the synthetic resins, AN/DVB/VBC-ED resin possessed higher defluoridation capacity (DC) than ST/DVB/VBC-ED and VBC/DVB-ED resins. The fluoride removal studies were carried out to optimize the various equilibrium parameters viz., contact time, pH, co-anions, different initial fluoride concentration and temperature. The equilibrium data were fitted with isotherms and kinetic models to find the best fit for the sorption process. The sorbents were characterized using FTIR, elemental analysis, BET surface area and SEM with EDAX analysis. Field trial studies indicated that the synthesized resins could be used as effective sorbents for fluoride removal.