有机/无机复合弱碱性阴离子交换树脂合成及应用研究

【作者】 李凤刚；

【导师】 李长海；

【作者基本信息】 长春工业大学 ， 高分子化学与物理， 2010， 硕士

【摘要】 β—萘磺酸是重要的染料中间体。伴随着p—萘磺酸的生产,产生了大量含磺酸基的芳香族有机化合物的废水。离子交换与吸附作为一种有效的化学分离方法,具有优越的分离选择性和很高的浓缩倍数,操作方便,效果突出。采用化学沉淀法对大孔弱碱性阴离子树脂D301R进行水合氧化铁复合反应,并对水合氧化铁负载的大孔弱碱性阴离子交换树脂HFO-D301R进行表征。采用水合氧化铁复合大孔弱碱性阴离子交换树脂法处理β—萘磺酸混合废水,并对该过程进行系统的研究。对各种不同因素影响下水合氧化铁复合树脂HFO-D301R对β—萘磺酸废水交换吸附进行热力学实验研究,分别考察了时间、温度、pH值、盐含量等对该过程的影响。实验结果表明,复合离子交换树脂对β—萘磺酸废水的吸附平衡时间为5h；该交换吸附过程为放热过程,温度越高树脂吸附交换量越低,低温有利于树脂吸附交换反应的进行；pH=4有利于交换吸附的进行；含盐量对该过程的影响主要是来自于废水中大量的Cl-、SO42-和SO32-离子的竞争交换作用。随着溶液pH值的增加,溶液的β—萘磺酸的浓度升高,表明pH值过高不利于交换吸附反应。除了上述静态因素,考察了动态因素对交换吸附的影响。流速低时,处理效果较好,随着流速的增加,穿透时间提前,并且穿透曲线的形状趋于平坦,完全穿透时间延长。当含浓度加倍时,穿透时间大大提前。并且在流速以2BV/h时作了β-萘磺酸混合酸废水穿透曲线。以β—萘磺酸为代表物研究其在HFO-D301R树脂上的吸附交换过程。分别应用Langmuir模型、Freundlich模型采用非线性最小二乘法对等温平衡吸附数据进行拟合,结果发现Freundlich模型能更准确反映该交换吸附过程。以Van’t Hoff方程、Gibbs方程和Gibbs-Helmholtz方程描述该交换吸附过程,获得了不同温度时HFO-D301R吸附交换β—萘磺酸的标准自由能变以及不同交换吸附量下的交换吸附焓变,从理论上证明了该交换吸附过程是放热过程。β—萘磺酸在HFO-D301R树脂上的静态交换吸附显示了良好的动力学特征。对动态交换吸附实验数据进行拟合,其符合一级反应动力学过程。进一步研究测定交换率(F)与时间(t)的关系,发现实验数据按“[1-3(1-F)2/3+2(1-F)]-t”标绘,呈良好的线性关系,线性相关系数为0.94769,说明该过程为颗粒扩散控制。更多还原

【Abstract】 A large amount of wastewater characterized by high concentration of organic substances is discharged as the production ofβ-naphthalenesulfonic acid, which is an important intermediate in the production of fluorescent whitening agents, direct dyes, and fungicides. The ion exchange technology has shown great selectivity and easy manipulation in the separation process.The macroporous weakly anion exchang resin are composited hydrated ferric oxide by a way of chemical precipitation and represented the characteristic of that loaden hydrated ferric oxide on.With themβ-naphthalenesulfonic acid mixture wastewater are treated and studied systematicly.Lauching a variety of different factors (3-naphthalenesulfonic acid are adsorbed and exchanged by the resin(HFO-D301R) loaden hydrated ferric oxide,and are investigated thermodynamics and time, temperature, pH and salt content that impacted of them. The experimental results showed that the equilibium time of composite ion-exhanger absorbed P-naphthalenesulfonic acid wastwater is about 5h.The absorption and exchang process is exomthermic, and if the temperature of the process is higher the absorption and exchange capacity is low.So a lower temperarure is conducive to the conduct of exchanger. "pH=4" is positive for the adsorption. Salinity major impacted of the process that a mass of ions(Clˉ,SO42-,SO32-) in the wastewater are competitive.In addition to the static factors, the dynamic factors on adsorption exchange is researched. Velocity is lower, the better results, as the increase of the velocities penetrating time is ahead, and the shape of the penetrating curve is flattened, fully penetrating time is extended. When you double the containing concentrations, penetrating time bring forward significantly. And in the flow velocity to 2BV/h aβ-naphthalene sulfonate mixed acid waste water penetrating curve is worked.Theβ-naphthalenesulfonic acid was chosen to study the behavior of the resin adsorption and exchange process. Freundlich isotherm was best to simulate the adsorption among the isotherm models of Langmuir and Freundlich. A first-order adsorption kinetics equation was developed for the process, and relevant parameters were calculated. Furthermore, results showed that the process was controlled by the particle diffusion, i.e. PDC.更多还原