电絮凝法处理三次采油废水的研究

发布时间：2018-01-08 23:22

本文关键词：电絮凝法处理三次采油废水的研究　出处：《华东理工大学》2017年硕士论文　论文类型：学位论文

【摘要】：随着石油资源的减少和聚驱采油技术的发展,我国大部分油田已进入三次采油阶段,每年产生大量的聚合物废水,这类废水粘度大、可生化性非常差,现有的水处理设施的处理效果难以达到到新的排放标准。本课题选择大庆油田的三次采油废水作为研究对象,采用电絮凝法对其进行处理,考察了电絮凝过程中各个关键影响因素对三次采油废水的处理效果以及相应的处理成本大小,得到了电絮凝处理三次采油废水最佳操作条件,同时,实验还对比了化学混凝法、酸沉降法对三次采油废水的处理效果,从而为电絮凝应用于三次采油废水的处理提供了依据与借鉴,同时也为其他含有PAM的废水以及其他高聚合物的废水的处理提供了借鉴。研究对三次采油废水进行了水质分析,并对三次采油废水的性质进行了初步的探索。对于电絮凝处理三次采油废水,实验对比了不同种类极板的处理效果,探讨了 pH、电流密度、反应时间、极板间距、搅拌速度、极性交换周期对电絮凝处理效果的影响,并在此基础上通过正交试验考察了几个主要影响因素对处理效果的影响以及因素之间存在的相互作用,为了优化实验条件得到最佳的处理效果和最经济的处理成本,实验进一步考察了温度、电解质投加量、阴极极板类型、水质条件、面体比、不同极板组合方式、电流输出方式等对电絮凝处理效果及处理成本的影响。研究表明,电絮凝对于三次采油废水有很好的处理效果,电絮凝实验中当以铝板作为电极、pH=4、极板间距=1cm、搅拌速度=600r/min、反应时间=20min、通电量=1.848A·min、面体比=37.33cm2/cm3、单级式连接方式、采用直流电源供电时,处理效果最好且具有最低的处理成本。同时通过对三次采油废水的主要性质和电絮凝处理三次采油废水的作用机理分析发现,COD主要通过絮凝沉降作用去除,而电化学氧化作用对COD的去除效果并不显著,且COD的去除主要与铝的析出量以及pH值相关。其中铝的析出量主要与电流密度和反应时间相关,当其他条件一定时,铝的析出量基本与通电量呈线性相关,另外,铝的析出不仅发生在阳极,当铝板为阴极时,阴极也有显著的铝析出现象,除此之外,电絮凝的其他以影响因素的变化也会对铝的析出产生一定的影响,从而影响电絮凝最终的处理出水效果。实验对比研究了化学混凝法与电絮凝法处理三次采油废水的效果,通过分析发现,电絮凝处理效果和化学混凝法不仅在处理效果上比较接近,而且处理成本也基本一致,但是当废水中含油量增多时,电絮凝因具有气浮作用将会体现出比普通化学混凝法更大的优势,如果进一步优化电絮凝电极结构以及电极类型,将会使得电絮凝的处理效果进一步提升,具有比普通化学混凝法更为广阔的应用前景。
[Abstract]:With the decrease of petroleum resources and the development of polymer flooding technology, most oil fields in China have entered the stage of tertiary oil recovery, producing a large number of polymer wastewater every year. The viscosity of this kind of wastewater is high and the biodegradability is very poor. The treatment effect of the existing water treatment facilities is difficult to reach the new discharge standard. This topic chooses the tertiary oil recovery wastewater of Daqing Oilfield as the research object and uses the electric flocculation method to treat it. The treatment effect of each key factor in the process of electroflocculation on the tertiary oil recovery wastewater and the corresponding treatment cost were investigated. The optimal operating conditions of the treatment of the tertiary oil recovery wastewater were obtained. The experiment also compared the treatment effect of chemical coagulation method and acid deposition method on tertiary oil recovery wastewater, thus providing the basis and reference for the application of electroflocculation in the treatment of tertiary oil recovery wastewater. At the same time, it also provides a reference for the treatment of other wastewater containing PAM and other high polymer wastewater. For the treatment of tertiary oil recovery wastewater by electrocoagulation, the effects of different kinds of plates were compared, and the pH, current density and reaction time were discussed. The effects of plate spacing, stirring speed and polarity exchange period on the effect of electroflocculation. On the basis of this, the influence of several main factors on the treatment effect and the interaction between the factors were investigated by orthogonal experiment. In order to optimize the experimental conditions to obtain the best treatment effect and the most economical treatment cost, the experiment further investigated temperature, electrolyte dosage, cathode plate type, water quality conditions, surface ratio, different polar plate combination methods. The effect of current output mode on the treatment efficiency and cost of electroflocculation. The study shows that electroflocculation has a good treatment effect on tertiary oil recovery wastewater. In the electroflocculation experiment, aluminum plate should be used as the electrode for pH ~ (4). The electrode plate spacing is 1 cm, the stirring speed is 600 r / min, the reaction time is 20 min, the charge is 1.848 A 路min, the surface ratio is 37.33 cm ~ 2 / cm ~ 3. Single-stage connection mode, when using DC power supply. The treatment effect is the best and has the lowest treatment cost. At the same time, through the analysis of the main properties of tertiary oil recovery wastewater and the mechanism of electroflocculation treatment of tertiary oil recovery wastewater. The removal of COD was mainly through flocculation sedimentation, but the removal of COD by electrochemical oxidation was not significant. The removal of COD is mainly related to the amount of aluminum and pH value, in which the amount of aluminum is mainly related to the current density and reaction time, when other conditions are fixed. The amount of aluminum precipitation is linearly related to the electric flux. In addition, the precipitation of aluminum occurs not only in the anode, but also in the cathode when the aluminum plate is the cathode. In addition, there is also a significant phenomenon of aluminum precipitation in the cathode. The change of other factors of electroflocculation will also have a certain effect on the precipitation of aluminum. The effect of chemical coagulation and electroflocculation on the treatment of tertiary oil recovery wastewater was studied. The treatment effect of electroflocculation is not only close to that of chemical coagulation, but also the cost of treatment is basically the same, but when the oil content in wastewater increases. Electroflocculation because of the effect of air floatation will reflect a greater advantage than the common chemical coagulation method. If the structure and type of electroflocculation electrode are further optimized, the treatment effect of electroflocculation will be further improved. It has a wider application prospect than the common chemical coagulation method.
【学位授予单位】：华东理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X741

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