【作者】 魏锦程；

【导师】 高宝玉；

【作者基本信息】 山东大学 ， 环境工程， 2008， 硕士

【摘要】 为了保障饮用水安全、提高混凝工艺对地表水的处理效果,特别是对微污染水源水中有机物的去除效果,本论文制备出一系列具有不同聚合氯化铁(PFC)的碱化度(B)、不同二甲基二烯丙基氯化铵聚合物(PDADMAC)的质量分数(w(P))、不同PDADMAC黏度(η)的无机-有机复合混凝剂PFC-PDADMAC,并将其应用于地表水处理。通过将PFC-PDADMAC与PFC、PDADMAC单独投加或依次投加进行对比,揭示了该复合混凝剂在混凝性能方面的优势以及它与传统混凝剂在机理方面的异同,明确了PFC-PDADMAC在混凝过程中与水中污染物的作用方式以及PFC与PDADMAC间的相互作用对混凝效果的影响。此外,通过烧杯试验、zeta电位的测定、Ferron逐时络合比色法、静态光散射法等多种方法及技术考察了B值、w(P)及η值对PFC-PDADMAC的混凝效果、混凝过程中Fe(Ⅲ)水解聚合形态的分布规律、絮体形成过程、絮体抗破损能力、恢复能力、絮体形态以及混凝机理的影响。主要结论如下:(1)PFC-PDADMAC对地表水中浊度和有机物的去除效果优于PFC或PDADMAC,该复合混凝剂可以在低投加量下获得较好的混凝效果。与将PFC和PDADMAC以不同的顺序先后投加相比,PFC-PDADMA可以达到更好的浊度及有机物去除效果;同时,PFC-PDADMAC可以在更宽的投加量范围内保持较高的去除率,从而可以在一定程度上避免原水水质波动造成的处理效果的下降;而且PFC-PDADMAC所生成的絮体具有较好的沉降性能;此外,PFC-PDADMAC在混凝过程中可以生成更多的Fe(Ⅲ)有效水解形态。与PFC、PDADMAC依次投加相比,PFC-PDADMAC的电中和能力较弱,但是吸附架桥能力明显增强。因此,PFC-PDADMAC可以充分发挥PFC与PDADMAC的协同作用,在地表水处理过程中较传统混凝剂具有一定优势。(2)PFC-PDADMAC在低B值、高w(P)以及高η值下对地表水中的浊度和有机物具有相对较好的去除效果。其中w(P)对其性能的影响较为明显,而B值对混凝效果的影响较小。(3)B值对PFC-PDADMAC在混凝过程中Fe(Ⅲ)的水解形态分布具有显著影响,低B值的PFC-PDADMAC可以水解生成较多的有效形态。w(P)及η值对混凝过程中Fe(Ⅲ)的水解形态分布影响甚微。(4)对于实验中所采用的具有不同B值、w(P)及η值的PFC-PDADMAC,电中和作用均在其混凝过程中占主导地位。适当降低B值、提高w(P)以及η值可以在一定程度上提高PFC-PDADMAC的电中和能力。其中w(P)对其电中和能力影响较为明显。(5)低B值、高w(P)或高η的PFC-PDADMAC所形成的絮体生长速度较快,而且在稳定阶段可以获得较大的粒径。其中,w(P)对絮体生长速度和粒径的影响较为明显,而B值的影响较小。(6)在低B值、高w(P)或高η值下,PFC-PDADMAC絮体具有较强的抗破损能力、恢复能力以及较高的密实度。其中w(P)对絮体的上述特性具有显著影响,而B值对其影响较小。以上研究结果表明,PFC-PDADMAC是一种适用于地表水处理的新型、高效的无机-有机复合混凝剂。本论文的研究为PFC-PDADMAC的研制开发奠定了理论基础,并为其在地表水处理中的应用提供理论指导。更多还原

【Abstract】 In order to ensure the safety of drinking water and improve the coagulation efficiency in the treatment of surface water,and especially enhance the organic matter removal in micro-polluted source waters,a series of composite coagulants polyferric chloride(PFC)-polydimethyldiallyammonium chloride(PDADMAC)with different basicity(B)of PFC,different mass fraction(w(P))and intrinsic viscosity(η)of PDADMAC were prepared and applied to surface water treatment in this study.The advantage of PFC-PDADMAC over PFC,PDADMAC and successive addition of PFC and PDADMAC in coagulation efficiency and the difference of them in coagulation mechanism were revealed by comparative study of them.Further.the reaction between PFC-PDADMAC and pollutants and the interacting of PFC and PDADMAC in coagulation process were also explained.The effect of B value,w(P) andηvalue on coagulation efficiency,chemical species distribution of Fe(Ⅲ)in coagulation process,floc growth process,breakage resistance capability of floc.the regrowth ability of broken floc,shape of floc and coagulation mechanism were studied by a variety of methods and technology,such as jar test,zeta potential measurement,Fe-Ferron method and static light scatter technology.The main conclusions are as follows:(1)PFC-PDADMAC was more efficient than PFC and PDADMAC in turbidity and organic matter removal in surface water treatment,and it achieved high removal rate at lower coagulant dosage.Compared with successive addition of PFC and PDADMAC,PFC-PDADMAC gave higher turbidity and organic matter removal and achieved better coagulation efficiency within a broader dosage range which contributed to avoid deterioration of treated water resulted from the fluctuation of raw water quality to some extent;Further,the flocs formed by PFC-PDADMAC had better settling property,and PFC-PDADMAC yielded more active component of ferric salts coagulants in coagulation process.PFC-PDADMAC showed weaker charge neutralization ability but much stronger adsorption and bridging ability than succecive addition of PFC and PDADMAC.Consequently.PFC-PDADMAC achieved good performance in surface water treatmenr by synergic effect of PFC and PDADMAC.(2)PFC-PDADMAC achieved better turbidity and organic matter removal at lower B value,higher w(P)andηvalue.Moreover,The effect of w(P)on the coagulation performance was remarkable,while the effect of B value was relatively slight.(3)B value had significant effect on the chemical species distribution of Fe(Ⅲ)in coagulation process,and PFC-PDADMAC with lower B value yielded more active coagulating component of ferric salts coagulants.In contrast,w(P)andηonly had slight effect on it.(4)Charge neutralization is the dominant flocculation mechanism for PFC-PDADMAC with different B value,w(P)andηwhich were investigated in this study,and the charge neutralization ability of PFC-PDADMAC was enhanced to some extent by reducing B value,increasing w(P)orηvalue properly.(5)The flocs formed by PFC-PDADMAC with lower B value,higher w(P)orηvalue showed higher growth rate and achieved larger floc size in steady phase of coagulation process.Further,w(P)had significant effect on floc growth rate and floc size,while the effect of B value was relatively slight.(6)The flocs formed by PFC-PDADMAC with lower B value,higher w(P)orηvalue showed better breakage resistance capability,regrowth ability and had more compact structure.Moreover,The effect of w(P)on the aboving floc characteristic was remarkable,while the effect of B value was slight.The aboving results indicate that PFC-PDADMAC is a new-type and highly efficient inorganic-organic composite coagulant which applies to surface water treatment.Further.this thesis lays fundamental basis for the developing of PFC-PDADMAC and provides guidences for the practical application of it.更多还原