磁性离子交换树脂去除水源水中腐殖酸的特性与机制研究

发布时间：2018-03-10 10:39

本文选题：腐殖酸　切入点：MIEX树脂　出处：《安徽工业大学》2014年硕士论文　论文类型：学位论文

【摘要】：腐殖酸是地表水源水体中的典型天然有机物。在氯消毒过程中，腐殖酸可与氯发生作用生成多种对人体有毒害作用的消毒副产物，是氯消毒副产物的主要前驱物，严重威胁饮用水安全。因此，去除水源水中的腐殖酸是解决消毒副产物的根本途径。本研究以磁性离子交换树脂（MIEX）为吸附剂，腐殖酸为吸附质，在表征腐殖酸及树脂的基础上，采用静态吸附方法，，通过单因素试验、正交试验、响应曲面试验、等温吸附平衡试验、动力学试验以及热力学试验，对腐殖酸在MIEX树脂上的吸附特性与去除机理进行了系统研究。单因素影响试验表明，腐殖酸在MIEX树脂上的吸附量随腐殖酸初始浓度的增加而增加，树脂投加量增加促进腐殖酸的去除，150r min-1的搅拌强度可使腐殖酸与树脂充分混合，溶液pH4或10时，腐殖酸在MIEX树脂上的吸附去除效果较好，温度升高对腐殖酸的去除有促进作用，离子强度的增加有利于腐殖酸的吸附去除；PO3-4、Cl-、CO-3、BrO--3和Br等共存阴离子对腐殖酸的去除有促进作用，而HCO-2-3和SO4对腐殖酸的去除有抑制作用；Ca2+、NH++4、Na和Mg2+等共存阳离子对腐殖酸的去除均存在不同程度的促进作用；Cu2+、Pb2+、Zn2+等重金属离子对腐殖酸的去除也存在不同程度的促进作用，而Cr6+和Mn2+的存在对腐殖酸的去除有抑制作用。正交试验表明，影响MIEX树脂去除腐殖酸的主次因素顺序为：树脂用量＞溶液起始pH＞（溶液起始pH×吸附时间）＞（树脂用量×吸附时间）＞吸附时间＞（树脂用量×溶液起始pH）；腐殖酸去除的最佳工艺参数为：MIEX树脂用量1.0mL L-1，pH值为2，吸附时间为40min。据响应曲面试验结果建立了腐殖酸去除的二次多项式回归模型，方差分析表明模型准确度好、可信度高，可对腐殖酸在MIEX树脂上的去除进行有效预测。影响因素之间的交互作用分析表明，树脂用量和pH值、吸附时间和pH值以及树脂用量和吸附时间的交互作用对腐殖酸去除率的影响不显著。10min内0.1mol L-1的NaCl溶液对腐殖酸吸附饱和的MIEX树脂可完成再生，多次吸附-再生循环后可重复利用。动力学试验结果表明，拟二级动力学模型和伊洛维奇模型可以很好地描述腐殖酸在MIEX树脂上的吸附动力学过程。液膜扩散是主要速率限制步骤。化学吸附是控制MIEX树脂吸附腐殖酸的主要因素。分形研究结果表明，腐殖酸在MIEX树脂上的吸附为非线性吸附。吸附平衡及热力学研究表明，Freundlich和Sips等温线模型可以较好地描述283K、293K、303K、313K温度下腐殖酸在MIEX树脂上的吸附平衡规律。Freundlich吸附分形模型计算结果表明，MIEX树脂表面并不是二维的均匀表面，而是有着复杂结构的表面；腐殖酸在MIEX树脂上的吸附是一个热力学自发的熵增加吸热过程。表征分析结果表明，MIEX树脂是以苯环为骨架，包含丙烯酸酯、二乙烯苯、季胺基、甲基、亚甲基等官能基团的树脂，其对分子量小于300Da的腐殖酸有很好的去除效果，吸附后，腐殖酸的三维荧光强度显著降低。腐殖酸在MIEX树脂上的吸附是多分子层吸附，吸附腐殖酸后树脂的孔隙数量和大小都不同程度的减小。树脂对腐殖酸的去除除离子交换外还存在电荷吸引、氢键及苯环之间的-作用。
[Abstract]:Humic acid is the surface water in the water. The typical natural organic matter in the chlorine disinfection process, disinfection by-products of humic acid and chlorine effect of generating a variety of toxic effects on the human body, is the main precursor of chlorine disinfection by-products, a serious threat to the safety of drinking water. Therefore, the removal of humic acid in water solution the fundamental way of disinfection by-products.
The study on the magnetic ion exchange resin (MIEX) as adsorbent for adsorption of humic acid, based on the characterization of humic acid and resin, using static adsorption method by single factor test, orthogonal test, response surface test, isothermal adsorption equilibrium test, dynamic test and thermodynamic test on the adsorption characteristics of humic acid on MIEX resin and removal mechanism were studied.
Show that the single factor experiment, adsorption of humic acid on MIEX resin increased with the increase of initial concentration of humic acid increased, resin dosage increased to promote the removal of humic acid, stirring intensity 150r min-1 can make the humic acid resin and fully mixed solution of pH4 or 10, adsorption of humic acid on MIEX resin good removal effect, temperature on the removal of humic acid can promote the increase of ionic strength, is conducive to the adsorption of humic acid removal; PO3-4, Cl-, CO-3, BrO--3 and Br anions on the removal of humic acid has a promoting effect, while HCO-2-3 and SO4 on the removal of humic acid has inhibitory effect; Ca2+, NH++4 Mg2+, Na and other coexisting cations on the removal of humic acid showed promotion effect; Cu2+, Pb2+, Zn2+ and other heavy metal ions on the removal of humic acid also has different effect, while Cr6+ and Mn2+ in the presence of Humic The removal of acid has an inhibitory effect.
The orthogonal test showed that the main factors affecting MIEX resin removal order of humic acid: resin dosage, initial solution pH > (solution initial pH adsorption time (x), the amount of resin adsorption time, adsorption time x) > (x amount of resin solution initial pH); the optimum process parameters for the removal of humic acid resin MIEX 1.0mL L-1, the pH value is 2, the adsorption time is 40min.
According to the response surface test results to establish the regression model of humic acid removal of two polynomial, variance analysis shows that the model is accurate, reliable, the removal of humic acid on MIEX resin effectively. The interaction between the influencing factors analysis showed that the resin amount and pH value, adsorption time and pH value and the interaction of resin dosage and adsorption time on the removal rate of humic acid was MIEX NaCl.10min 0.1mol L-1 resin solution of humic acid adsorption saturation can complete regeneration, several adsorption regeneration cycles can be reused.
The dynamic test results show that the pseudo two order kinetics model and ilovici model can well describe the adsorption kinetics of humic acid on MIEX resin. The film diffusion is the limiting step. The main rate of chemical adsorption is the main factor to control the MIEX adsorption of humic acid. The fractal research results show that the adsorption of humic acid on MIEX resin for nonlinear adsorption.
Balance and thermodynamic studies on the adsorption showed that the Freundlich and Sips isotherm model can describe the 283K, 293K, 303K, 313K results under the temperature of humic acid on MIEX resin adsorption equilibrium of.Freundlich adsorption fractal model showed that a uniform surface MIEX resin surface is not two-dimensional, but has a complex surface structure; adsorption of Humic acid the MIEX resin was a spontaneous endothermic process of increased entropy in thermodynamics.
Characterization results show that MIEX resin is a benzene ring skeleton, containing two ethylene acrylic ester, benzene, methyl, methylene quaternary amino resin, functional groups, the molecular weight of less than 300Da of humic acid removal, good adsorption, three-dimensional fluorescence intensity of humic acid significantly decreased the adsorption of humic acid in. MIEX resin is multi molecular layer adsorption, adsorption of humic acid resin pore number and size are all reduced in different degree. Resin for the removal of humic acid in addition to ion exchange is charge attraction, hydrogen bonds and ring -.

【学位授予单位】：安徽工业大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU991.2;X52

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