微孔间歇性曝气充氧试验研究分析

发布时间：2018-05-22 08:01

本文选题：微孔曝气器 + 氧转移率　；参考：《浙江工业大学》2015年硕士论文

【摘要】：微孔曝气器以传统的曝气方式在处理废水时,电耗的费用占整个污水处理系统运行费用的40%,其中曝气系统约占污水处理系统电耗的60%以上。对曝气系统进行研究,寻求新的曝气运动方式来提高污水处理效率、降低运行成本,对推进水处理系统推广及运行具有重要意义。针对曝气池连续曝气过程中氧转移率低、能耗高的问题,本文结合污水处理中的实际情况,分析影响氧转移速率的因素,提出了利用盘式微孔曝气器间歇性充氧方法来提高氧的转移率的方法。本文一共分为五章,内容组织如下:第一章基于污水处理的工程系统及耗能因素现状分析,讨论了微孔曝气器现存的不足,提出微孔间歇性曝气器设计思想,详细分析了盘式微孔曝气的工作原理及特点,同时对微孔间歇性曝气和自激式曝气元件的工作原理进行简单的概述。第二章基于曝气充氧的原理,深入分析了氧传质经典理论,并研究了曝气膜片、孔口特性和参数对气泡生成的影响,从理论上得出间歇性曝气可减小气泡的尺寸,增加气液接触面积,从而提高氧转移率,建立了间歇性曝气氧传质模型,分析其影响因素。第三章详细分析了微孔间歇性曝气气泡生成理论,就柔性孔和刚性孔进行了气泡生成的对比和给出了发现了间歇性气泡生成的规律,讨论了间歇性曝气相对于连续曝气对曝气充氧性能的影响。第四章阐述了微孔间歇性曝气实验设计过程和实验方案的实施。详细介绍了利用PLC控制曝气结构装置和自激阀曝气结构装置,同时简述了用于曝气效果检测的实验仪器和药品,以及曝气性能测定的原理和方法。第五章基于实验数据进行了总结分析。利用图像处理分析气泡生成状况,得到间歇性曝气可以有效减小气泡尺寸;利用充氧性能评价标准对间歇性曝气和连续曝气实验数据分别进行处理,对比各项性能指标,验证微孔曝气器间歇性曝气可以提高曝气充氧效率、降低能耗,获得最佳间歇曝气周期。本文通过4组不同类型的盘式微孔曝气器分别在间歇性和连续曝气下的实验对比发现,间歇性曝气产生的是气泡簇,对生成的气泡进行图像统计分析,得出同一区域范围内间歇式曝气生成的气泡数量多、平均直径小。实验数据分析结果显示:虽然间歇性曝气达到氧饱和所需的时间较连续曝气方式增加了10%左右,但是氧的利用率增加了50%以上,动力效率大幅提高。结果显示间歇性曝气方式可有效提高氧的利用率,节约能耗的同时又具有更好的充氧效果,为活性污泥好氧生化处理系统工艺提供了新的研究思路。
[Abstract]:In the treatment of wastewater with the traditional aeration method, the cost of electricity consumption accounts for 40% of the total operating cost of the wastewater treatment system, in which the aeration system accounts for more than 60% of the power consumption of the wastewater treatment system. It is of great significance to promote the popularization and operation of water treatment system by studying aeration system and seeking new aeration movement mode to improve sewage treatment efficiency and reduce operation cost. In view of the problems of low oxygen transfer rate and high energy consumption in continuous aeration process of aeration tank, the factors affecting oxygen transfer rate are analyzed according to the actual situation in wastewater treatment. A method of increasing oxygen transfer rate by intermittent oxygenation of disc microporous aerator is proposed. This paper is divided into five chapters. The content is organized as follows: in Chapter 1, based on the analysis of wastewater treatment engineering system and energy consumption factors, the shortcomings of microporous aerator are discussed, and the design idea of microporous intermittent aerator is put forward. The working principle and characteristics of disc micropore aeration are analyzed in detail. At the same time, the working principles of micropore intermittent aeration and self-excited aeration element are briefly summarized. In the second chapter, based on the principle of aeration and oxygenation, the classical theory of oxygen mass transfer is deeply analyzed, and the effects of the characteristics and parameters of aerated diaphragm, orifice and orifice on bubble formation are studied. It is theoretically concluded that intermittent aeration can reduce the bubble size. The oxygen transfer rate was improved by increasing the gas-liquid contact area. The oxygen transfer model of intermittent aeration was established and the influencing factors were analyzed. In chapter 3, the theory of intermittent aeration bubble formation is analyzed in detail. The bubble formation is compared between flexible pore and rigid pore, and the regularity of intermittent bubble formation is found. The effect of intermittent aeration on aeration performance was discussed. The fourth chapter describes the design process of micropore intermittent aeration experiment and the implementation of experimental scheme. This paper introduces the aeration structure device controlled by PLC and the aeration structure device of self-excited valve in detail. At the same time, the experimental instruments and drugs used for aeration effect detection, as well as the principle and method of aeration performance measurement are briefly described. Chapter 5 is based on the experimental data. The bubble size can be effectively reduced by using image processing to analyze the bubble formation, and the experimental data of intermittent aeration and continuous aeration are processed separately by using the oxygenation performance evaluation standard, and the performance indexes are compared. It is proved that intermittent aeration of microporous aerator can improve aeration efficiency, reduce energy consumption and obtain optimal intermittent aeration cycle. In this paper, the experimental results of four different types of disc microporous aerators under intermittent and continuous aeration show that the bubbles produced by intermittent aeration are bubble clusters, and the generated bubbles are analyzed by image statistics. The results show that the number of bubbles generated by intermittent aeration in the same area is large and the average diameter is small. The experimental data show that although the time required for intermittent aeration to achieve oxygen saturation is increased by about 10% compared with continuous aeration, the utilization rate of oxygen is increased by more than 50%, and the dynamic efficiency is greatly improved. The results show that intermittent aeration can effectively improve the utilization rate of oxygen, save energy consumption and have better oxygenation effect. It provides a new research idea for aerobic biochemical treatment system of activated sludge.
【学位授予单位】：浙江工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X703

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