微纳米曝气氧传质特性及对景观水体修复效果研究

发布时间：2018-04-15 13:16

本文选题：微纳米曝气 + 氧传质速率　；参考：《广西大学》2015年硕士论文

【摘要】：近年来随着国家城镇化建设的发展,及人们对生活质量及居住环境要求的提高,中心城市、乡镇中开发建造了人造景观水体,以满足人民物质文化需求。在景观水体富营养化、黑臭现象频繁发生的背景下,本文通过对去氧水及景观污染水体的曝气实验,考察了微纳米曝气技术修复城市景观水体效果,并对其氧传质特性及影响因素进行了研究。主要研究结果如下：(1)改变微纳米曝气器通气量,其氧传质系数(KLa)随着空气流量增大而增加。标准氧传质效率(SOTE)随着曝气流量增加而减小。进行水体温度对KLa的影响,微纳米曝气组的KLa和SOTE随着温度升高而增加,KLa随着pH增加先下降后上升,在pH=7.2达到最小。曝气组KLa随着NH4Cl增大而下降,随着浊度的增大而增大。而SOTE随着温度升高而增加,鼓风微孔曝气组趋势与其相同,但值比微纳米曝气组小。相对于其他影响因素而言,微纳米曝气KLa与SOTE对于曝气通气量变化更敏感。(2)通过对实际景观水体进行曝气模拟修复实验,微纳米曝气法的氧传质特性较鼓风微孔曝气要好。经过21天的实验可知,微纳米曝气能有效改善水体环境,其21天平均气含率为1.09%。(3)在模拟实验中,对于景观水体水质处理效果方面,微纳米曝气组中CODCr、TP、NH4+-N、TN最终去除率为67.59%、17.30%、70.20%、66.75%,Chl-a上升了14.03%。鼓风微孔曝气组CODCr、TP、NH4+-N、TN最终去除率为56%、13.46%、54.35%、55.6%,Chl-a上升了15.69%。(4)通过记录微纳米曝气在不同曝气时间下水体DO的变化规律,建立了水体DO与不同影响因素和时间之间的经验模型。该模型可以结合水体条件因素计算达到饱和DO所需曝气时间。通过对水体DO经验方程进行反算,可得到曝气KLa预测模型。本研究探讨微纳米曝气技术对景观污染水体进行修复的可行性。研究微纳米曝气KLa的影响因素及DO变化规律等,建立的经验模型对曝气溶氧规律研究具有指导意义,同时为曝气氧传质特性的研究提供了思路
[Abstract]:In recent years, with the development of national urbanization construction and the improvement of people's requirements for quality of life and living environment, artificial landscape water bodies have been developed and built in central cities and towns to meet the material and cultural needs of the people.Under the background of eutrophication of landscape water body and frequent occurrence of black-odor phenomenon, the effect of micro-nano aeration technology on the restoration of urban landscape water body was investigated through aeration experiments of deoxygenated water and polluted water body.The oxygen mass transfer characteristics and influencing factors were studied.The main results are as follows: 1) the oxygen mass transfer coefficient (KLa) increases with the increase of air flow rate.Standard oxygen mass transfer efficiency (SOTEE) decreases with the increase of aeration rate.Under the influence of water temperature on KLa, the KLa and SOTE of micro-nano aeration group increased with the increase of temperature, and then decreased with the increase of pH, and reached the minimum in pH=7.2.The KLa of aeration group decreased with the increase of NH4Cl and increased with the increase of turbidity.However, SOTE increased with the increase of temperature, and the trend of blast micropore aeration group was the same, but the value was smaller than that of micro-nano aeration group.Compared with other influencing factors, micronano aeration KLa and SOTE are more sensitive to aeration volume change. Through aeration simulation restoration experiment of the actual landscape water body, the oxygen mass transfer characteristics of micro nano aeration method is better than that of blast micro pore aeration.After 21 days of experiments, the results show that micro-nano aeration can effectively improve the water environment, and the average gas holdup in 21 days is 1.09. in the simulation experiment, the final removal rate of CODCrN TPN NH _ 4-NTN in the micro-nano aeration group is 67.590.70.200.2066.75Chl-a increased 14.033.In the simulation experiment, the final removal rate of COD _ (rn) TPN _ (NH _ 4-NTN) in the micro-nano aeration group is 67.59% and 17.30%, and 66.75% Chl-a increases 14.03%.The final removal rate of CODCrTP-NH4-NTN in microporous aeration group was 56 and 54.3554.35. Chl-a increased 15.69.4. by recording the variation of do in water under different aeration time, an empirical model was established between water body do and different influencing factors and time.The aeration time needed to reach saturation do can be calculated by this model combined with water condition factors.The KLa prediction model of aeration can be obtained by inverse calculation of do empirical equation of water body.In this study, the feasibility of micro-nano-aeration technology for remediation of polluted landscape water was discussed.The influence factors of micro and nano aeration KLa and the variation law of do are studied. The established empirical model is of guiding significance for the study of aeration dissolved oxygen law, and also provides a way for the study of aeration oxygen mass transfer characteristics.
【学位授予单位】：广西大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X52

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