淀粉微球对苯酚的吸附性能研究

以可溶性淀粉为原料,N,N’-亚甲基双丙烯酰胺(MBAA)为交联剂,通过反相悬浮聚合得到淀粉微球作为吸附载体,研究了pH、吸附时间、温度对其苯酚吸附性能的影响,以及淀粉微球吸附苯酚的热力学和动力学特性,并利用扫描电镜仪、红外光谱仪对淀粉微球的结构进行了表征。结果表明,淀粉微球粒度分布均匀,表面粗糙多孔,具有相当大的孔容积和比表面积,具有较好的吸附性能;在20℃、pH为5.3时,吸附30 min后,淀粉微球对苯酚的吸附容量达到饱和,最大吸附量为18.71 mg/g;采用准二级吸附动力学方程能更好地描述淀粉微球对苯酚的吸附行为,淀粉微球对苯酚的吸附是以化学吸附为主控步骤的作用过程,淀粉微球对苯酚的吸附主要是通过氢键作用来完成的。

Study on adsorption behavior of starch microspheres for phenol

The starch microspheres(CSM) were synthesized from soluble starch by inverse suspension polymerization with N, N'-methylenebisacrylamide (MBAA) as crosslinker. The effect of pH, reaction time and temperature on adsorption capability were investigated, the kinetics and thermodynamics characteristics were also studied. The starch microspheres were characterized by fourier transform infrared spectroscopy (FTIR) and scan electron microscope (SEM). The SEM photographs showed that the obtained CSM presented homogeneous particle size distribution; the CSM had perfect adsorption capability for it was rough and porous in surface and contained largish surface area and total pore volume. The adsorption capability, which decreased with increasing temperature, reached the highest of 18. 71 mg/g after 30 min of adsorption at 20 ℃ when solution pH was 5. 3. The dynamic adsorption capability data were well described by the pseudo second order reaction rate model, phenol adsorption was mainly by chemical adsorption, and the hydrogen bond was the driving force of phenol adsorption on microspheres.