A novel quaternized resin with acrylonitrile/divinylbenzene/vinylbenzyl chloride skeleton for the removal of nitrate and phosphate

A copolymer with acrylonitrile/divinylbenzene/vinylbenzyl chloride (AN/DVB/VBC) matrix was prepared and quaternary ammonium chloride functional group was introduced in it using ethylenediamine and glycidyl trimethyl ammonium chloride (GTMAC) to utilize it for the removal of nitrate and phosphate. The physico-chemical properties of this quaternized resin named as ADVEGR was analyzed using the techniques like FTIR, SEM, EDAX, XRD, TGA, DTA, BET surface area and water regain property. Batch studies were carried out to optimize the conditions for adsorption. ADVEGR was found to be selective towards nitrate. The nitrate and phosphate removal capacity of resin from 1000 mg/L of respective aqueous solutions were 167.54 and 183.18 mg/g respectively. Langmuir, Freundlich and Dubinin-Radushkevich adsorption isotherms were used to fit the equilibrium data. Effect of Cl-, HCO3- and SO42- on the adsorption capacity of the resin towards nitrate and phosphate was analyzed in batch and column mode. The order of selectivity of ADVEGR towards various anions was as follows: NO3- > SO42- > H2PO4- > Cl- > HCO3-. The resin has been applied for the real water sample treatment and the values obtained after treatment showed that the adsorbent had a total anion removal efficiency of 100% which validates the method. The resin regained its 100% efficiency even after 10th regeneration cycle. (C) 2014 Elsevier B.V. All rights reserved.