Modification of an anion exchange resin with zero valent iron for the removal of Sb(lll) and (V) from waters

Abstract

Antimony is non-essential for life, a cumulative toxic element and accepted as a significant contaminant by the European Union which established a maximum admissible concentration of 5.0 μgL-1 total antimony in drinking water. There are usually two oxidation states of antimony in surface waters; namely, Sb(III) and Sb(V) where Sb(V) is generally the most commonly found form due to oxidative properties of these types of water. In this study, a new sorbent was developed for removal of inorganic antimony species from contaminated waters. For this purpose, Amberlite IRA 458 resin was treated with ferric ion and then the ferric ions were reduced by sodium borohydride in order to modifiy the resin surface with zero valent iron (ZVI). Both unmodified and nZVI modified IRA 458 resin were investigated for their sorption towards antimony species. Batch type sorption experiments were verified with ultrapure water spiked with 100.0 μgL-1 antimony species. Antimony content was determined by hydride generation atomic absorption spectrometry (HGAAS). The optimized sorption parameters for the new sorbent were determined to be 7.0 for pH, 50.0 mg for sorbent amount, 25 ˚C for sorption temperature, 60 min for shaking time for 20.0 mL of 100.0 μgL-1 of antimony species. With this methodology, an effective antimony removal was obtained to range between 94.5% and 97.7% for Sb(III), and 83.2% and 97.1% for Sb(V).