An anion exchange resin(MWS

modified wheat straw) was prepared by chemical modification of wheat straw grafting epichlorohydrin

triethylamine and diethylenetriamine to improve MWS performance

particularly for adsorption of NO-3 in water.The results showed that amine groups with positive-charge had been introduced into the structure of MWS

which resulted in improving significantly adsorption capacity for NO-3 in water.The analysis of zeta potential and surface elemental as well as FTIR and Raman spectra indicated that the adsorption mechanism of MWS for NO-3 was ion exchange.The adsorption data could be well fitted with the Langmuir model and the correlation coefficient(R2) was higher than 0.988.The results of competition adsorption indicated that the adsorption efficiency for co-present ions followed an order as SO2-4>H2PO-4>NO-3>NO-2.The maximum adsorption capacity(Qmax) of MWS for NO-3 was 52.1 mg·g-1

which could compared with that of commercial resin

and showed that there was a significant increase than that of raw WS(1.3 mg·g-1).In addition

column adsorption test showed that the breakthrough adsorption capacity for NO-3 was about 45.2 mg·g-1

and both 0.1 mol·L-1 NaCl and HCl solutions could be used as regenerating agent for the desorption of NO-3 from the MWS.