废水脱硫反硝化工艺运行及微生物特性研究

发布时间：2018-01-10 07:15

本文关键词：废水脱硫反硝化工艺运行及微生物特性研究　出处：《大连海事大学》2017年硕士论文　论文类型：学位论文

【摘要】：随着工业的快速发展,含高浓度氮、硫废水的排放量日益增加。这些废水若不及时处理直接排放,将会严重污染水体及其周边环境,并对人类健康造成威胁。在此背景下,本研究建立两套反应系统——自养脱硫反硝化系统和兼养脱硫反硝化系统,实现对水体中硫、氮和碳的同步去除。在两套反应装置内,改变进水底物中含氮物质,使反应系统从硝酸盐型逐渐转变为亚硝酸盐型,对比两套反应装置,分析含氮物质的类型及有机物对反应器效能的影响。实验结果表明:自养系统中,N02-利于S2-的不完全氧化,N03-/N02-为1/3时,反应器运行效能达到最高,S2-、NO3-和NO2-的去除率分别达到99.68%、98.26%和95.21%;但仅添加N02-且高负荷运行时,系统却无法正常工作;兼养系统中,有机物的投加使得亚硝酸盐型系统在高负荷条件下仍能高效稳定运行,对S2-、N02-和 TOC 的去除率分别达到 99.86%、94.08%和 87.95%。在反应系统运行不同时期的稳定阶段,提取自养和兼养两套系统活性污泥样本,通过Chao指数、Shannon指数、OUTs、门相对分布以及细菌在属水平上热图分析,探讨不同环境条件下微生物的群落特征;分析含氮物质的改变和有机物的加入对微生物群落结构变化的影响。结果表明:反应系统从硝酸盐型转变为亚硝酸盐型过程中,自养和兼养环境内微生物种类和丰度均有变化;各阶段微生物种类有明显差异;门水平上相对丰度较大的细菌有Proteobacteria、Bacteroidetes、Firmicutes和Chloroflexi;运行效能较好阶段相对丰度较大的功能菌有Thiobacillus、Thiovirga、Thauera和Geobacter;相比于含氮物质的改变,有机物的投加对微生物群落结构变化引起的影响较小。在反应器高效运行时期,分离、纯化培养系统内的功能性微生物,对纯菌株的脱氮除硫功能进行确认;通过16SrDNA测序、BLAST比对,制作系统发育树确认分离菌株的菌属。结果表明:分离出一株具有脱氮除硫功能的菌株,该菌株对S2-的去除率可达到89.20%,脱氮效率为48.21%。通过序列比对,确认该菌株为 Pseudomonas。
[Abstract]:With the rapid development of industry, the discharge of wastewater containing high concentration of nitrogen and sulfur is increasing day by day. If these wastewater are not discharged directly in time, they will seriously pollute the water body and its surrounding environment. Under this background, two reaction systems-autotrophic desulfurization and denitrification system and simultaneous culture desulfurization and denitrification system were established to realize sulfur in water. The simultaneous removal of nitrogen and carbon. In two sets of reactor, the nitrogen-containing substances in the influent substrate were changed, so that the reaction system gradually changed from nitrate type to nitrite type, compared with two sets of reaction equipment. The types of nitrogen-containing substances and the effect of organic matter on the reactor efficiency were analyzed. The experimental results showed that in the autotrophic system, the partial oxidation of N _ (02-) in favor of S _ 2 ~ (-) was N03-r / N _ (02-) = 1/3. The operation efficiency of the reactor reached the highest removal rate of no ~-_ 3- and no _ 2- reached 99.68% and 95.21%, respectively. However, when N02- was added only and the system was running at high load, the system could not work properly. The addition of organic compounds can make the nitrite system operate efficiently and stably under high load, and the removal rates of S2-N02- and TOC are 99.86% respectively. 94.08% and 87.95. in the stable stage of the reaction system, two sets of activated sludge samples were collected from autotrophic system and simultaneously fed system, and the Chao index was obtained by Shannon index. The relative distribution of OUTs, phylum and the thermal map of bacteria at the generic level were analyzed to study the community characteristics of microbes under different environmental conditions. The effects of the changes of nitrogen-containing substances and organic compounds on the changes of microbial community structure were analyzed. The results showed that the reaction system changed from nitrate type to nitrite type. The species and abundance of microorganism in autotrophic and co-cultured environment were all changed. There were obvious differences in the species of microbes in different stages. The bacteria with relatively high abundance at the gate level were Proteobacteriae Bacteroidetes-Firmicutes and Chloroflexi. The functional bacteria with relatively high abundance at better operation stage were Thiobacillus thiovirgagaa Thauera and Geobacter. Compared with the changes of nitrogen-containing substances, the addition of organic compounds had little effect on the changes of microbial community structure. In the period of efficient operation of the reactor, the functional microorganisms in the culture system were separated and purified. The function of denitrification and sulfur removal of pure strain was confirmed. By comparing 16s rDNA sequence with blast, a phylogenetic tree was made to confirm the genus of the isolated strains. The results showed that a strain with nitrogen and sulfur removal function was isolated. The removal rate of S2- was 89.20 and the denitrification efficiency was 48.21.The strain was identified as Pseudomonas by sequence alignment.
【学位授予单位】：大连海事大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X703

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