Fluoride sorption using organic–inorganic hybrid type ion exchangers

Research in defluoridation of drinking water has thrown more technologies, with adsorption as more popular alternative among the fluoride endemic habitations across the globe. This paper describes the fluoride removal potential of novel sorbent, synthetic hybrid type ion exchangers from drinking water. Synthesized hybrids were characterized using FTIR studies. Batch adsorption studies were performed as a function of contact time, pH and influence of other interfering anions. The values of defluoridation capacities (DCs) of synthesized polyacrylamide Al(III) phosphate (Al-Ex), polyacrylamide Ce(IV) phosphate (Ce-Ex) and polyacrylamide Zr(IV) phosphate (Zr-Ex) were found to be 2144, 2290 and 2166 mg F−/kg, respectively. Ce-Ex has slightly higher DC than Al-Ex and Zr-Ex. The equilibrium data were fitted with isotherm models. Thermodynamic parameters viz., ΔG°ΔG°, ΔH°ΔH° and ΔS°ΔS° were calculated to understand the nature of sorption. Field studies were carried out to find the suitability of these sorbents at field condition.

Graphical abstractIncorporation of an organic polymer into inorganic exchangers provides a class of hybrid ion exchangers which showed promising fluoride removal capacity.Figure optionsDownload full-size imageDownload as PowerPoint slide