NDA-150树脂吸附对硝基苯甲腈的行为研究

Adsorption of 4-nitrobenzonitrile on NDA-150 resin

对硝基苯甲腈是一种重要的医药中间体,由于其低的可生化性,生物法的处理效率并不高,目前也很少见到关于含对硝基苯甲腈废水处理的文献报道.文中分别采用静态吸附和动态吸附的方法系统研究了NDA-150大孔树脂对对硝基苯甲腈的吸附和解吸行为.结果表明:该树脂在pH值在1～7时有较好的吸附效果,并在pH为2.0时的吸附效果最佳.静态吸附动力学显示,该树脂在24h内吸附达到平衡,干树脂的吸附容量为180.8mg/g.吸附等温线符合Freundich方程,拟合方程的相关系数R2达到99%以上.吸附反应属于自发性的,吸附量随着温度的升高而减少,表明吸附是放热过程.动态吸附动力学显示,动态吸附量可达439.4mg/g.在流速1BV/h条件下,先后用8%NaOH(2BV),4%NaOH(2BV),蒸馏水(3BV)在353K温度条件下对动态吸附饱和的树脂进行脱附,脱附率仅为42.8%,脱附效果不理想.

4-Ntrobenzonitrile was a kind of important pharmaceutical intermediates.Due to its poor biochemical purification efficiency,it has not been possible to isolate 4-nitrobenzonitrile biochemically.Besides,there are limited published techniques for the treatment of 4-nitrobenzonitrile waste water.In this paper,the characters of sorption and desorption of 4-nitrobenzonitrile on NDA-150 resin were thoroughly studied using static and dynamic methods,respectively.A good adsorption behaviors of the macroporous resin to 4-Ntrobenzonitrile were observed with pH ranging from 1 to 7,and the optimum pH was 2.0.The results of static adsorption dynamics showed that the adsorption reached equilibrium in 24 hours,the adsorption capacity of NDA-150 resin towards 4-nitrobenzonitrile was 180.8 mg/g.The adsorption isotherms of 4-Ntrobenzonitrile on the macroporous resin fit well to the Freundlich equation and the values of R2 were greater than 99%.The adsorption occurred on the resin was spontaneous.The adsorption capacity decreased with increasing temperature,indicating that the adsorption was an exothermic process.The dynamic adsorption capacity was 439.4 mg/g.Finally,the dynamically adsorbed and saturated resin was leached at a flow of 1 BV/h at temperature of 353 K with 8% NaOH（2 BV）,4% NaOH（2 BV）,and distilled water（3 BV）in turn,however the effeciency of elution was not very good with a low desorption rate of 42.8%.