新型无机高分子混凝剂聚硅酸铝铁的应用及动态模拟实验研究

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	新型无机高分子混凝剂聚硅酸铝铁的应用及动态模拟实验研究
	傅平青
	2001
学位授予单位	中国科学院地球化学研究所
学位授予地点	中国科学院地球化学研究所
学位名称	博士
学位专业	环境工程
关键词	废水处理无机高分子混凝剂水解形态 Ζ电位粘度残留铝混凝效果混凝机理印染废水造纸废水垃圾渗滤液动态模拟实验
摘要	目前在废水处理领域，其处理方法有生物化学法、离子交换法、化学氧化法、电渗析法和混凝沉淀法等，而应用最普遍、并且成本较低的处理方法仍然是混凝沉淀法。它几乎可以用于各种工业废水和城市污水的预处理、中间处理和最终处理，以及污泥处理当中。混凝剂性能是影响混凝沉淀处理效果的关键因素。因此，研制和开发高效能、低毒无公害、低能耗、低成本的新型混凝剂就显得非常重要。我们自行研制成功的聚硅酸铝铁类系列混凝剂(PSAFC、PSAFS、PSAFCS)，作为新型的无机高分子复合型混凝剂，属于水溶性无机高分子物质。其实质为铝、铁盐类水解过程的中间产物与硅酸根阴离子等基团的结合体。本文在前人工作的基础上，主要研究了复合型聚硅酸铝铁类混凝剂(PSAFCS)的配制、各类不同配比混凝剂的粘度、ζ电位与混凝效果的关系、以及对印染废水、垃圾渗滤液和造纸废水的静态和动态混凝处理效果等，得到了以下相应的认识和结论。1．在聚硅酸铝铁类混凝剂配制阶段，由于SiO_2的引入将影响混凝剂的聚合度、Zeta电位、存放时间和混凝处理效果等，本论文测定出水玻璃模数K，其值为2.86。而且，硅的存在使混凝剂形态发生了改变，吸附架桥能力增强，增加了混凝剂聚合度，但在某种程度上降低了混凝剂的电中和能力。2．考虑到铝和铁在聚合反应中速度的差异，铁具有极强的亲OH~-能力，能极快地与OH~-形成多羟基聚合物；而铝的亲OH~-能力相对较弱，聚合反应速度缓慢。为了能够使铝盐与铁盐交叉共聚，在配制混凝剂时需采取先加含铝原料，稳定后再加含铁原料的方式。碱化度B是在制备混凝剂时的一个重要操作指标，寻求最佳的碱化度值有利于制备出高效的混凝剂。3. 在PSAFCS中，硫酸根的引入在某种程度上可以增加混凝剂的聚合度和稳定性，增强絮凝能力。并且不同SO_4~(2-)/CI~-比的混凝剂在混凝效果上存在差异。另外，目前市场上工业硫酸与工业盐酸价格相差不大，而工业硫酸的当量数是工业盐酸的1.94倍，故用硫酸代替部分盐酸可降低酸耗成本。4．Ferron逐时络合比色法被广泛应用于铝盐、铁盐溶液的形态分析，并且可得出较好的分析结果。但是在铝铁共存的溶液中进行形态分析，尚有一定困难。5．混凝剂的表观分子量与粘度之间存在着正比关系，通过测定，聚硅酸铝铁类混凝剂的增比粘度随着存放时间有一定的上升趋势，其中硫酸盐型混凝剂(PSAFS)的趋势最明显，存放时间相对较短。盐酸盐型混凝剂(PSAFC)的增比粘度与PSAFS和PSAFCS相比最小。说明其聚合度最小，硫酸根的介入可使聚硅酸铝铁类混凝剂的聚合度增大。比浓粘度与质量浓度之间存在着一定的正相关关系。6. 混凝剂的ζ电位值由于硅的引入而变得有正有负，这与不同类型混凝剂中硅、铝、铁的相对含量有关。一般SiO_2:(Al+Fe)比值大于1:2时，ζ电位为负值。7．系统阐述了PSAFC和PSAFS在印染废水处理中的应用，经过混凝处理的印染废水出水中，残留硅的含量在0.16mg／L～1.68mg／L之间；残留铁的含量在22.4 μg／L～0.52mg／L之间；残留铝的含量在0.1lmg／L～2.60mg／L之间，而且残留铝含量与碱化度B值之间有着很好的负相关关系，即随着混凝剂碱化度值的增大，残留铝含量降低。系列聚硅酸铝铁类混凝剂对印染废水的色度、浊度、COD等都有较好的去除效果。8．第一次把聚硅酸铝铁类混凝剂应用于垃圾填埋场渗滤液的处理上，通过混凝一臭氧氧化处理后，垃圾渗滤液的BOD_去除率达75.4％、COD去除率达70．6％、色度去除率达94％，其出水水质基本接近我国生活垃圾填埋场污染控制标准(GBl6889--1997)二级标准。9．首次在实验室内进行动态模拟实验，我们用自行设计的动态处理装置，选用13号PSAFCS型混凝剂对造纸废水进行试验，混凝剂SiO_2:Al:Fe比值为1:0.75:0.75，ζ电位为10.8毫伏。在最佳水力条件和最佳混凝剂投量的情况下，对造纸废水的COD去除率达92.5％、色度去除率达96.9％，达到国家造纸工业污染物排放一级标准，说明复合型聚硅酸铝铁类混凝剂(PSAFCS)对造纸废水有着优异的去除效果。
其他摘要	Nowadays, many methods belonging to physics、chemistry and biology are employed in the wastewater treatment, but the most widely used and less-cost method is the way of precipitation and coagulation by using flocculant in the processes of pretreatment、secondary treatment and advanced treatment. Obviously, the coagulation effect is hugely affected by which fioculant we choose to use and how effective the flocculant is. Consequently, it is important to study and manufacture high-effect、low-toxicity、low energy consumed and low-cost flocculant in the field of environmental engineering. Successfully manufactured by ourselves, the Polysiliceous aluminous ferric flocculants (PSAFC、PSAFS、PSAFCS) which fall into water-solubility substance are parts of inorganic polymer flocculants, what are the combined styles of hydrolyzed species of polyaluminum、polyferric salt and polysilicate. This paper mainly study the manufacture of PSAFCS, the variety of viscosity among the different style flocculants, the relationship between ζ potential and coagulation effect. We also use the three flocculants to treat the printing and dying waste water、paper mill waste water、landfill leachate. The main conclusions obtained are as follows: 1. During the period of the manufacture, the value of K (modulus of soluble glass) is first tested and which is 2.86. Because the concentration of SiO_2 can severely influence the extent of polymer、the ζ potential、the period of keeping and the effect of coagulation. Furthermore, the existence of Si can change the forms of the coagulation. 2. The differences of velocities of A1 and Fe in the polymeric reaction are remarkable. The ferric ion has strong OH- affinity and can react more quickly than that of A1~(3+). So, we should put aluminiferous raw material first and then ferrous material Meanwhile, the value of basicity (B) should be strictly controlled. 3. To some extent, SO_2~(2-) can enhance and stable the IPF's polymeric grade. We also get the conclusion that different value of S0_4~(2-)/CI~- leads to different coagulation effect. In addition, the use of vitriol can lower the cost. 4. Dynamic transformation and stability of inorganic polymer flocculants in the coagulation and flocculation were studied by Ferron timed complex colorimetric method. We can get the good result of A1 or Fe respectively, but a problem to get a satisfactory result together. 5. The molecular weights ofPSAFC、PSAFS、PSAFCS are related to the viscosity. Through analysis and test we obtain that the value of viscosity of the flocculant is getting higher with the time goes on. The result shows that the kind of PSAFC's viscosity has the lowest value of viscosity. 6. Owing to the introduce of Si, especially the SiO_2/(AI+Fe) molar ratios that make the three series of IPF have a wide range of the value of the potential, some are above zero, some not. It also affect the polymerization degree: the higher the SiO_2/(Al + Fe) molar ratio, the larger the polymerization degree of PSAFC、PSAFS、PSAFCS. 7. This paper has a detailed study on the application ofPSAFC、PSAFS、PSAFCS. We apply the flocculants to deal with the dying and printing wastewater. The results show that these fiocculants are suitable to treat the wastewater. When the dosage is reasonable, the residual aluminum value is 0.1 lmg/L～2.60mg/L. 8. It is the first time to apply our flocculants together with ozone to treat the landfill leachate. We measured the 5-day BOD、COD、chroma(color) and turbidity under the suitable dosage. 70.6% of COD、 75.4% of BOD_5 and 94% of color are achieved. 9. We design a new equipment for dynamic simulation experiment. Choose No. 13 flocculant to treat paper mill wastewater. The flocculant's SiO_2:Al:Fe is 1:0.75:0.75, the value of ζ potential is 10.8mV. Under the optimal condition, 92.5% of COD、 96.9% of color are removed.
页数	67
语种	中文
文献类型	学位论文
条目标识符	http://ir.gyig.ac.cn/handle/352002/3580
专题	研究生_研究生_学位论文环境地球化学国家重点实验室
推荐引用方式 GB/T 7714	傅平青. 新型无机高分子混凝剂聚硅酸铝铁的应用及动态模拟实验研究[D]. 中国科学院地球化学研究所. 中国科学院地球化学研究所,2001.

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