【作者】 王元芳；

【导师】 高宝玉；

【作者基本信息】 山东大学 ， 环境工程， 2011， 博士

【摘要】 在采用化学混凝法处理染料及印染废水的过程中,混凝剂是决定化学混凝效果的关键。目前,阳离子型有机高分子絮凝剂受到国内外研究者的广泛关注。因为在处理染料及印染废水时,阳离子型有机高分子絮凝剂具有以下优点：脱色效果好、适用范围广、用量少、产生的污泥量少等。其中,阳离子型季铵盐聚合物是一类具有很大发展前景的水处理药剂,对其混凝性能开展全面系统的研究是很有必要的。在综合国内外大量相关文献的基础上,本文以环氧氯丙烷和二甲胺为原料合成聚环氧氯丙烷胺(EPI-DMA)系列絮凝剂。通过混凝烧杯实验研究EPI-DMA处理各种染料的混凝效果,明确不同特征的EPI-DMA对不同处理对象的混凝性能及混凝机理。通过在线监测混凝剂的混凝动态过程,研究EPI-DMA的絮体形成过程、絮体抗剪切能力及恢复能力。为了得到更高效的混凝脱色效果,本文以聚合氯化铝(PAC)和EPI-DMA为原料制备了聚合铝基无机-有机复合混凝剂(PAC-EPI-DMA)。通过研究有机组分的粘度(η)、有机组分的含量(P)及无机组分的碱化度(B)对PAC-EPI-DMA的混凝脱色过程及混凝动力学过程的影响,明确η、P和B对PAC-EPI-DMA的混凝效果、混凝机理、絮体强度、恢复能力等的影响,揭示复合絮凝剂在无机有机组分相互作用的条件下高效的混凝效果,为复合混凝剂的开发应用提供理论指导。主要研究结论如下：1.利用红外光谱分析技术研究了环氧氯丙烷单体及聚环氧氯丙烷胺的分子结构,证实季铵盐的形成。通过对絮凝剂、染料及絮体的红外光谱对比分析发现,EPI-DMA中的季铵基R4N+与染料中的磺酸基-SO3-发生静电相互作用。通过透射电镜观察研究PAC-EPI-DMA与EPI-DMA的结构形貌,发现复合絮凝剂形成更为密集的枝网状结构,证实了PAC与EPI-DMA之间的相互作用。采用Zetasizer3000HSA型zeta电位仪测定EPI-DMA与PAC-EPI-DMA的zeta电位,研究混凝剂表面的荷电情况。结果表明η值中等的EPI-DMA的表面电荷最高,而且与PAC复合后,其zeta电位明显升高,复合混凝剂的表面电荷随着P值的增大而增大。2.利用EPI-DMA与PAC-EPI-DMA处理各种模拟染料水样,研究pH值以及无机盐对其混凝脱色效果的影响。实验结果表明,EPI-DMA对水体pH值有很强的适应性,在很大pH值范围内都具有良好的混凝效果；但受水体中无机盐浓度的影响较大。PAC-EPI-DMA对水体pH值亦有很强的适应性,尤其在碱性条件下具有更好的脱色效果,不过PAC的加入却导致PAC-EPI-DMA的脱色效果受到水体离子强度的更大影响。3.通过混凝烧杯实验考察不同η值和阳离子度(τ)值的EPI-DMA对各种模拟染料水样的混凝效果,并利用JS94F型微电泳仪分析絮体的zeta电位变化情况,研究EPI-DMA处理不同水样的混凝机理。对于水溶性染料,EPI-DMA首先通过静电作用、疏水作用以及氢键等与水溶性染料分子发生相互作用,然后依靠吸附架桥或电中和作用对染料进行絮凝脱色；EPI-DMA的吸附架桥及电中和能力与其η和τ密切相关。对活性染料水样的处理结果表明,较高η值和τ值的EPI-DMA可获得高效的脱色效果,主要混凝机理是吸附架桥作用和电中和作用,而且在混凝前期吸附架桥作用占主导地位。对直接染料水样的处理结果表明,较高η值和τ值的EPI-DMA可在低投药量下获得高效的脱色效果,主要混凝机理是吸附架桥作用。对酸性染料水样的处理结果表明,低η值和τ值的EPI-DMA即可在低投药量下获得高效的脱色效果,主要混凝机理是吸附架桥作用。对分散染料水样的处理结果表明,较高η值和τ值的EPI-DMA可在低投药量下获得良好的脱色效果,吸附架桥作用是其主要的混凝机理。4.通过混凝烧杯实验考察η值、P值和B值对PAC-EPI-DMA处理活性染料水样混凝性能的影响。结果表明,复合絮凝剂的脱色效果明显优于EPI-DMA的脱色效果,而且有机组分的η值和P值是影响PAC-EPI-DMA混凝性能的主要因素。PAC-EPI-DMA (η=2400 mPa·s)的混凝脱色效果明显优于粘度过低或过高的PAC-EPI-DMA。对于水溶性染料,PAC-EPI-DMA首先通过静电作用、氢键等与水溶性染料分子发生相互作用,然后依靠吸附架桥和电中和作用对染料进行絮凝脱色,而吸附架桥作用随着P值的增大发挥越来越重要的作用。5.利用PDA2000光散射颗粒分析仪在线监测EPI-DMA及PAC-EPI-DMA的混凝动力学过程,研究混凝过程中絮体的聚集特性。对活性、分散、酸性等模拟染料水样的处理结果表明,η值较高的EPI-DMA生成絮体的粒度较大,且絮体的生长速度及沉降速度较快,絮体间的差异性较小。对直接染料水样的处理结果表明,低η值的EPI-DMA的絮体粒度较大,絮体生长速度较快,絮体间的差异性较小。PAC-EPI-DMA的使用可以提高絮体的生长速度及沉降速度,缩短混凝剂与污染物反应时间,并提高絮体的粒度。而且η值、P值及B值对PAC-EPI-DMA的絮体聚集特性均有一定的影响,其中P值对絮体生长速度和絮体粒度的影响较为明显,而η值和B值的影响较小。当采用η=3200 mPa·s、P=10%、B=1.5的PAC-EPI-DMA处理水样时,能够以较快的生长速度得到较大的絮体,而且絮体以较快的速度沉降。6.利用PDA2000光散射颗粒分析仪考察EPI-DMA和AC-EPI-DMA的絮体抗剪切及恢复能力。对于活性和直接染料水样的处理结果表明,较高η值的EPI-DMA能够提高絮体的强度及恢复能力。对分散染料水样的处理结果表明,EPI-DMA(η=3200 mPa·s)能够生成具有较高强度及恢复能力的絮体。对于酸性染料水样的处理结果表明,利用高η值的EPI-DMA虽然使絮体强度略有升高但却降低了其恢复能力。提高η值和B值,可以在一定程度上提高PAC-EPI-DMA的絮体强度及恢复能力。上述研究从多方面系统的探讨了EPI-DMA及PAC-EPI-DMA对各种染料的混凝效果、混凝行为和混凝机理。结果表明,二者均是适用于染料废水处理的新型高效混凝剂,且复合混凝剂是一种更为高效节约的混凝剂。本论文的研究为高效脱色混凝剂的研制奠定了理论基础,并为开发应用提供理论指导。更多还原

【Abstract】 During the chemical coagulation process for treating dyeing and printing wastewater, coagulation efficiency is mainly dependent on the coagulant used. At present, cationic organic polymer has received wide attention. Because its advantages for treating dyeing and printing wastewater:high color removal, wide application, low chemical cost and low sludge, etc. Among them, cationic quaternary ammonium polymer is one floccuant that has great development foreground, and so systematic study on its coagulation is necessary. Synthesizing a number of references and literature, epichlorohydrin-dimethylamine ploymer (EPI-DMA) was prepared by the polycondensation of epichlorohydrin and dimethylamine with amines as the modifying agent. The flocculation efficiency of EPI-DMA for various dyes was investigated, and the flocculation performance and mechanism of EPI-DMA with different characteristics were clearly studied in the treatment of different pollutants. Through on-line monitoring the flocculation dynamic process of EPI-DMA, floc growth process, breakage resistance capability of floc and the regrowth ability of broken floc were studied. In order to improve the decolorization efficiency, a series of composite flocculants polyaluminum chloride-epichlorohydrin-dimethylamine ploymer (PAC-EPI-DMA) with different intrinsic viscosity (η), organic mass fraction (P) of EPI-DMA and basicity (B) of PAC, were prepared. The effect ofη, P and B on the flocculation efficiency, flocculation mechanism, floc growth process, breakage resistance capability of floe, and the regrowth ability of broken floc were investigated. The improved flocculation efficiency of the composite flocculant was revealed, based on the combination organic with inorganic component, which provides theoretical guidance for the development and application of composite flocculant.The main conclusions are as follows:1. Infrared spectral analysis technology was used to investigate the molecular structure of epichlorohydrin monomer and EPI-DMA. The results confirmed the formation of quaternary ammonium. Based on the IR analysis of flocculants, dyes and flocs, the results showed that quaternary ammonium R4N+ of EPI-DMA reacted with sulfonic group-SO3- of dye molecule. TEM was used to study the flocculant morphology. The results showed that the appearance of the composite flocculant PAC-EPI-DMA was denser branch network structure, indicating the interaction between PAC and EPI-DMA. The zeta potential of EPI-DMA and PAC-EPI-DMA was determined using a Zetasizer3000HSA analyzer. The results showed that EPI-DMA with an intermediateηhad the highest surface charge. The zeta potential of PAC-EPI-DMA was higher than that of EPI-DMA, and increased with the increse of P value.2. The effect of pH and inorganic salt on the flocculation efficiency of EPI-DMA and PAC-EPI-DMA was studied for the removal of various dyes. The experimental results showed that high flocculation efficiency of EPI-DMA could be achieved within a wide pH range, but was influenced by the inorganic salt in treated water. PAC-EPI-DMA also could obtain high flocculation efficiency within a wide pH range, especially under alkaline condition. However, the negative effect of ionic strength on the decolorization of PAC-EPI-DMA was exacerbated due to the exsit of the inorganic content.3. The flocculation efficiency of EPI-DMA with differentηand cationicity (τ) was stuied in the treatment of various simulation dyeing wastewater, and the variation of zeta potential was also investigated using a JS94F micro-electrophoresis analyzer, which explained the flocculation mechanism. In the treatment of water-soluble dye, EPI-DMA interacted first with dye molecules by electrostatic, hydrophobic as well as hydrogen bonding, after then, adsorption bridging or charge neutralization of EPI-DMA played a role for the decolorization. The adsorption bridging and charge neutralization of EPI-DMA was dependent on itsηandτ, respectively. In the treatment of reactive dye, higherηandτof EPI-DMA was more effictive based on its stronger adsorption bridging and charge neutralization ability, and adsorption bridge was dominant in the prophase of flocculation process. In the treatment of direct dye, higherηandτof EPI-DMA was more effictive based on its stronger adsorption bridging ability. In the treatment of acid dye, lowηandτof EPI-DMA could obtain high color removal based on its adsorption bridging ability. In the treatment of disperse dye, higherηandτof EPI-DMA was more effictive based on its stronger adsorption bridging ability.4. The effect ofη, P and B on the flocculation pefromance of PAC-EPI-DMA was investigated for the removal of reactive dye by jar test. The results showed that the decolorization of PAC-EPI-DMA was obviously superior to that of EPI-DMA. Theηand P value were the key factors affecting the flocculation pefromance of PAC-EPI-DMA. PAC-EPI-DMA (η=2400 mPa·s) exhibited the highest decolorization. For water-soluble dye, PAC-EPI-DMA interacted first with dye molecules by electrostatic interaction and hydrogen bonding, after then, adsorption bridging and charge neutralization ability played an important role in removing dye. Adsorption bridging ability of PAC-EPI-DMA was stronger with the increase of P.5. PDA2000 laser scatter analyzer was used to on-line monitor the floc growth process of EPI-DMA and PAC-EPI-DMA, and floc aggregation parameters were calculated and analyzed. In the treatment of reactive, disperse, acid dyes, larger average floc size, faster floc growth velocity and sedimentation velocity, and smaller floc variance were achieved by higherηof EPI-DMA. In the treatment of direct dye, lowηof EPI-DMA produced larger flocs with faster growth and sedimentation velocity, and smaller floc variance. The floc growth and sedimentation velocity, and average floc size of PAC-EPI-DMA were much larger than those of EPI-DMA. The effct of P and B on the floc growth velocity and average floc size was much more significant than that ofη. Faster floc growth and sedimentation velocity, and larger average floc size were achieved by PAC-EPI-DMA (η=3200 mPa·s, P=10%, B= 1.5).6. PDA2000 laser scatter analyzer was used to investigate the breakage resistance capability of floc and the regrowth ability of broken floc of EPI-DMA and PAC-EPI-DMA. In the treatment of reactive and direct dyes, higherηof EPI-DMA could improve floc strength and regrowth ability. In the treatment of disperse dye, stronger floc strength and regrowth ability was achieved by EPI-DMA (η= 3200 mPa·s). In the treatment of acid dye, although highηof EPI-DMA improved the floc strength, foc regrowth ability was decreased slightly. For PAC-EPI-DMA, higherηand B could increase floc strength and regrowth ability in a certain extent.The above research investigeted the flocculation behavior and dynamics process of EPI-DMA and PAC-EPI-DMA in the treatment of dyes, indicating that both of them are highly efficient floccualnt for the treatment of dyeing wastewater, and the composite flocculant was more efficient. This research provides theoretical basis for the practical application.更多还原