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

• AN/DVB/VBC-ED was prepared and used for the removal of F− for the first time.
• Maximum sorption capacity was observed at 30 min contact time.
• NH3+ group in the polymer matrix responsible for the removal of fluoride.
• The fluoride removal is by electrostatic attraction.
• DC is more for AN/DVB/VBC-ED resin is due to more NH2 groups than other two resins.

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.

The synthesized polymeric resins such as vinylbenzyl chloride/divinylbenzene-ethylenediamine (VBC/DVB-ED), styrene/divinylbenzene/vinylbenzylchloride-ethylenediamine (ST/DVB/VBC-ED), acrylonitrile/divinylbenzene/vinylbenzylchloride-ethylenediamine (AN/DVB/VBC-ED) resins were characterized by FTIR, SEM with EDAX studies and were employed as adsorbents for the removal of fluoride ions from aqueous solution by the batch sorption method.Figure optionsDownload as PowerPoint slide