PAC-PDMDAAC杂化絮凝剂的制备、表征及絮凝性能研究

发布时间：2018-03-07 00:02

本文选题：杂化絮凝剂　切入点：制备　出处：《重庆大学》2014年博士论文　论文类型：学位论文

【摘要】：混凝是重要的水处理工艺之一，混凝剂的开发是混凝工艺的核心技术，混凝剂的优劣是决定混凝效果甚至整个水处理效果的关键因素。随着水和废水处理规模的迅猛发展，对混凝剂的质量和品种需求也越来越大。开发新型高效低耗、安全无害的混凝剂以提高水处理效果、降低成本一直是水处理领域的研究重点。聚合氯化铝-聚二甲基二烯丙基氯化铵（PAC-PDMDAAC）杂化絮凝剂是基于聚合氯化铝较强的电中和作用和聚二甲基二烯丙基氯化铵有机高分子絮凝剂优异的吸附架桥能力的协同作用而开发的新型高效絮凝剂。与传统的无机絮凝剂相比，它具有絮体形成快，颗粒密度大，沉降速度快等特点，且无二次污染，高效低耗，适用范围广，可取代价格昂贵的有机高分子絮凝剂。PAC-PDMDAAC杂化高分子絮凝剂有着良好的发展和应用前景，可以用于饮用水处理和纺织、印染废水等处理工艺中。论文的主要研究内容和结论如下: （1）采用原位聚合法以聚合氯化铝、二甲基二烯丙基氯化铵为原料，以过硫酸铵为引发剂制备了离子型PAC-PDMDAAC杂化絮凝剂，并进行Box-Behnken中心组合实验和响应面分析，得出最佳制备条件：DMDAAC质量分数为37%，引发剂质量分数为0.6%，反应温度为75℃，反应时间为5h。在对絮凝剂结构表征分析中，FT-IR及TGA测试结果表明杂化絮凝剂有机-无机组分间是由PDMDAAC链端（-SO42-）与带正电荷的羟基铝粒子以离子键性质键合。SEM结果显示，杂化絮凝剂PAC-PDMDAAC颗粒尺寸和比表面积均比其复合型絮凝剂更大。（2）采用溶胶-凝胶法以硅烷偶联剂KH570为无机改性剂，以聚合氯化铝、二甲基二烯丙基氯化铵为原料，以过硫酸铵为引发剂制备了共价型PAC-PDMDAAC杂化絮凝剂，并用响应面设计预测并根据实际情况得到最优制备条件为：DMDAAC质量分数为33%，引发剂质量分数为0.6%，反应温度为64℃，反应时间为3h。在对絮凝剂结构表征分析中，电导测试、FT-IR、13C-NMR及TGA结果表明PAC-PDMDAAC杂化絮凝剂的有机-无机组分间以共价键形式键合，性质稳定；其SEM照片显示其结构疏松，粒度较大。（3）分别通过高岭土模拟水的混凝烧杯实验和硅藻土模拟水的量筒沉降实验，考察了PAC和自制两种杂化絮凝剂的电中和能力和絮凝性能。高岭土模拟水的混凝烧杯实验结果表明，两种PAC-PDMDAAC杂化絮凝剂的电中和能力突出。硅藻土模拟水的量筒沉降实验结果表明，两种PAC-PDMDAAC杂化絮凝剂的絮体粒度和沉降速度明显高于PAC，絮凝性能优异。对重庆嘉陵江和长江原水的混凝效果表明，两种杂化型絮凝剂对浊度、UV254和CODMn均表现出优异的去除效果。（4）使用激光粒度分析仪对杂化絮凝剂处理高岭土模拟水样进行混凝动态过程研究，采用两种杂化絮凝剂时，，随投加量的增加，pH越接近中性，形成的絮体粒径越大。相比PAC，形成稳定絮体所需时间短。两种杂化絮凝剂絮体抗剪切强度高于PAC，且在相同条件下恢复能力强。随破碎时间的延长，杂化絮凝剂形成絮体的强度因子和恢复因子均呈下降趋势。（5）应用扫描电子显微镜对杂化絮凝剂絮凝后絮体进行观察，将絮体分为絮粒、絮团和絮网三个不同的生长阶段,通过假设颗粒结合位置符合正四面体,建立了絮体结构模型,在一定程度上能够反映杂化高分子絮凝剂絮凝高岭土颗粒生成的絮体结构。
[Abstract]:Coagulation is one of the important water treatment process, development is the core technology of coagulant coagulation process, coagulant quality is a key factor to determine the coagulation effect and the effect of water treatment. With the rapid development of water and wastewater treatment scale, quality and variety of coagulant development demand is also growing. New type of high efficiency and low consumption, safe and harmless coagulant to improve the water treatment effect, reduce the cost has been a focus of research in the field of water treatment.
Polyaluminumchloride two poly dimethyl diallyl ammonium chloride (PAC-PDMDAAC) polymer is a new type of high efficient flocculant and the development of synergistic effect of polyaluminium chloride strong charge neutralization and two poly dimethyl diallyl ammonium chloride organic polymer flocculant with excellent adsorption ability based on. Compared with traditional inorganic flocculants, it has formed flocs soon, the particle density, sedimentation speed and other characteristics, and no two pollution, high efficiency and low energy consumption, wide application range, has a good foreground of development and application to replace the expensive organic polymer flocculant.PAC-PDMDAAC hybrid polymer flocculating agent, can be used for drinking water treatment and textile, printing and dyeing wastewater treatment process.
The main contents and conclusions of this paper are as follows:
(1) using polyaluminium chloride by in situ polymerization, two dimethyl diallyl ammonium chloride as raw materials, ammonium persulfate ion type PAC-PDMDAAC hybrid flocculant prepared initiator system, and the Box-Behnken central composite experimental design and response surface analysis, the optimum preparation conditions: the mass fraction of DMDAAC is 37%, the mass fraction of the initiator 0.6%, reaction temperature 75 C, reaction time is 5h. in the flocculant structure characterization analysis, FT-IR and TGA test results show that the hybrid flocculant organic - inorganic portions by PDMDAAC chain end (-SO42-) and hydroxy aluminum particles with positive charge in ionic bonding properties of.SEM showed that the flocculant PAC-PDMDAAC particles hybrid size and specific surface area than the composite flocculant was greater.
(2) inorganic modified with silane coupling agent KH570 by sol-gel method, using polyaluminium chloride, two dimethyl diallyl ammonium chloride as raw materials, ammonium persulfate as covalent PAC-PDMDAAC hybrid flocculant prepared initiator system, and response surface design and forecast according to the actual situation to obtain the optimal preparation condition: the mass fraction of DMDAAC is 33%, the mass fraction of the initiator is 0.6%, reaction temperature 64 C, reaction time is 3h. in the flocculant characterization analysis, conductivity measurements, FT-IR, 13C-NMR and TGA results show that PAC-PDMDAAC polymer organic - inorganic composition between covalently bonding properties, stability; the SEM photograph shows its loose structure, large size.
(3) respectively by kaolin simulated water coagulation beaker experiment and diatomite water simulation cylinder sedimentation experiment, PAC and self-made two kinds of hybrid flocculant neutralization and flocculation performance were investigated. The kaolin simulated water coagulation beaker experiment results show that two kinds of PAC-PDMDAAC hybrid flocculant neutralization diatomite simulation is prominent. The water cylinder settlement. The experimental results show that the two kinds of PAC-PDMDAAC hybrid flocculant floc size and settling velocity was obviously higher than that of PAC. Show excellent flocculation coagulation effect of Chongqing Jialing River and Yangtze River water, two kinds of hybrid flocculant of turbidity, UV254 and CODMn showed excellent removal rate.
(4) the kaolin coagulation dynamic process of hybrid flocculant using laser particle size analyzer, using two kinds of hybrid flocculant, with the increase of the dosage of pH is close to neutral, the formation of floc size. Compared with PAC, the formation of a stable floc time required for two kinds of hybrid. Flocculant floc shear strength is higher than that of PAC, and under the same conditions the recovery ability. With prolonged crushing time, hybrid flocculant floc formation intensity factor and recovery factor decreased.
(5) observed by scanning electron microscopy of the hybrid flocculation flocs, the floc is divided into floc flocculation and floc, three different growth stages, by assuming that the particle binding position coincides with the tetrahedron, established the floc structure model can reflect the floc structure of the hybrid polymer flocculation of kaolin particles generation in a certain extent.

【学位授予单位】：重庆大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TU991.2

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