生物质阴离子树脂的合成、表征及吸附性能

采用环氧氯丙烷、二乙烯三胺和三乙胺等对麦草秸秆进行化学改性,制备改性麦草秸秆阴离子交换树脂（改性麦秸树脂），研究改性麦秸树脂的性能指标并重点考察其对水体中NO^-₃的吸附性能及效果。 研究结果表明,改性麦秸树脂引入了带正电荷的胺基基团,可以显著提高对NO^-₃的吸附性能；拉曼、红外光谱及zeta电位分析证明改性麦秸树脂对NO^-₃的吸附机理为离子交换；吸附过程符合Langmuir等温吸附模式；竞争吸附实验结果表明，改性麦秸树脂对不同阴离子的竞争吸附顺序为SO^2-₄>H₂PO^-₄>NO^-₃>NO^-₂,改性麦秸树脂对NO^-₃的最大吸附量为52.1 mg·g^-1,与商业树脂相当；柱吸附实验表明，改性麦秸树脂对NO^-₃的柱饱和吸附量为45.2 mg·g^-1，0.1 mol·L^-1的NaCl及HCl溶液均可有效再生改性麦秸树脂。

Preparation, characteristics and adsorption properties of anion resin prepared from biomass

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.