电催化氧化—混凝法联合处理油田含聚污水的研究

发布时间：2018-04-11 12:25

  本文选题：电催化氧化 + DSA电极　； 参考：《东北石油大学》2017年硕士论文

【摘要】：随着聚丙烯酰胺在油田开采过程中的广泛应用,使得采出水的水量不断增加,油田采出水中含有油类、聚丙烯酰胺和活性剂等大量污染物,使废水的处理加大了难度,常规的处理工艺难以有效的处理水中的大量污染物,油田含聚污水的处理问题日益突出,成为人们关注的焦点。传统的物化法、生物法、化学法除聚效果并不理想,因此试图寻找一种效率高、成本低的处理方法。电催化氧化技术是一种效率较高的绿色水处理技术,但是处理成本较高,阻碍了其发展,所以本文将电催化氧化和混凝联合使用,旨在取得良好的处理效果的同时,还能够降低成本。形稳电极(DSA)是目前电催化氧化反应中最受关注的一类阳极,因其具有特殊的金属氧化物的催化活性,对于难降解的有机污染物依然可以达到很好的效果。本课题分别利用扫描电子显微镜(SEM)、X射线能谱仪(EDS)和X射线衍射仪(XRD)对Ti/Ir O2-Ta2O5-SnO2电极的表面涂层的形貌、元素组成及各元素的原子比及涂层的晶体结构进行了表征分析。结果表明,稀土的掺杂可使电极表面晶粒细化,增加涂层的比表面积,提高电极的催化活性和析氧电位,但电极的稳定性略有降低。首先用Ti/IrO2-Ta2O5-SnO2电极处理了模拟含聚废水,证明了电催化氧化降解聚丙烯酰胺的可行性。然后,以Ti/IrO2-Ta2O5-SnO2电极为阳极,以FeSO4·7H2O为絮凝剂,采用电催化氧化-混凝法联合处理油田含聚污水,通过单因素实验和正交试验考察了除聚时电极的最优工作参数,包括絮凝剂投加量、电流密度、pH、电解时间等,得出如下结论:絮凝剂投加量为1500mg/L,电流密度为50mA/cm2,pH值为6,电解时间为90min的条件下,其对聚丙烯酰胺的去除率达到了92.3%。采用紫外光谱和高效液相色谱对PAM模拟废水电解液进行分析,推测PAM电催化氧化降解的历程:大分子的聚丙烯酰胺先是断裂成小分子的聚合物片段,之后在电催化氧化的作用下,被降解成丙烯酰胺和丙烯酸,最终转化为H2O和CO2。采用半衰期法确定了降黏和降解的动力学方程。计算了电催化氧化-混凝法联合处理含聚污水的能耗为90kWh/m3。
[Abstract]:With the wide application of polyacrylamide in oilfield production process, the water quantity of produced water is increasing, and a large number of pollutants, such as oil, polyacrylamide and active agent, are contained in the produced water of oil field, which makes the treatment of wastewater more difficult.The conventional treatment process is difficult to effectively treat a large number of pollutants in water, and the problem of treatment of oilfield polymerized sewage becomes increasingly prominent, which has become the focus of attention.The traditional physicochemical method, biological method and chemical method are not ideal for depolymerization, so we try to find a method with high efficiency and low cost.Electrocatalytic oxidation is a kind of green water treatment technology with high efficiency, but the cost of treatment is high, which hinders its development. In this paper, electrocatalytic oxidation and coagulation are combined in order to obtain good treatment effect.It can also reduce costs.Form-stabilized electrode (DSA) is one of the most concerned anodes in electrocatalytic oxidation reaction. Because of its special catalytic activity of metal oxides, it can still achieve good results for organic pollutants that are difficult to degrade.The morphology, composition, atomic ratio and crystal structure of Ti/Ir O2-Ta2O5-SnO2 electrode were characterized by scanning electron microscopy (SEM) and X-ray diffractometer (XRD).The results show that rare earth doping can refine the surface grain of the electrode, increase the specific surface area of the coating, improve the catalytic activity and oxygen evolution potential of the electrode, but the stability of the electrode is slightly reduced.Firstly, the simulated polymer wastewater was treated with Ti/IrO2-Ta2O5-SnO2 electrode, which proved the feasibility of degradation of polyacrylamide by electrocatalytic oxidation.Then, Ti/IrO2-Ta2O5-SnO2 electrode was used as anode, FeSO4 7H2O as flocculant, electrocatalytic oxidation-coagulation method was used to treat oilfield polymerized sewage. The optimum working parameters of depolymerization electrode, including the dosage of flocculant, were investigated by single factor experiment and orthogonal test.Under the conditions of current density pH, electrolysis time and so on, the flocculant dosage is 1500 mg / L, the current density is 50 Ma / cm ~ (2) and pH value is 6, and the electrolysis time is 90min, the removal rate of polyacrylamide can reach 92.3%.UV spectrum and high performance liquid chromatography (HPLC) were used to analyze the electrolyte of PAM simulated wastewater. The mechanism of electrocatalytic degradation of PAM was inferred: the macromolecular polyacrylamide was first broken into small molecular polymer fragments.It was then degraded into acrylamide and acrylic acid under the action of electrocatalytic oxidation, and then converted to H2O and CO _ 2.The kinetic equations of viscosity reduction and degradation were determined by half-life method.The energy consumption of combined treatment of polymeric wastewater by electrocatalytic oxidation and coagulation was calculated to be 90 kWhs / m3.
【学位授予单位】：东北石油大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X741
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本文编号：1736032