氯贝酸在污水处理过程中的迁移转化规律研究

发布时间：2018-05-11 13:11

本文选题：难降解有机物 + 氯贝酸　；参考：《西安建筑科技大学》2015年硕士论文

【摘要】：药品及个人护理品(PPCPs)是环境中出现的一类微量新型有机污染物,来源广泛,种类繁多,目前在环境中存在的浓度特别小,但它们中的大多数在城市污水处理工艺中难以去除,随着二沉池出水及剩余污泥而排放,使之不断在环境中积累,对人类健康及环境存在着一定的风险。其中氯贝酸(clofibric acid)属于一类调节血脂类药物的代谢产物,具有环境持久和难降解特性,可作为难降解有机物的代表性物质以研究其在污水处理过程中的迁移转化规律。本研究通过建立两组好氧序批式反应器(SBR)来完成,其中SBR 1用来研究以氯贝酸为难降解有机物代表性物质在活性污泥处理系统中的去除特性及迁移转化规律,并探讨氯贝酸代谢产物的产生与变化情况;SBR 2作为实验参比对照,不添加氯贝酸物质。通过对水相及泥相中氯贝酸的分析监测表明,活性污泥对氯贝酸吸附作用微弱(仅占约6%),而其生物去除率则在10%~12%之间,大部分氯贝酸随着处理水而排出系统。通过液相色谱技术对氯贝酸的生物降解产物进行分析,结果表明氯贝酸生物降解过程中产生3种代谢产物:α-羟基异丁酸、乳酸、对氯苯酚。其中,α-羟基异丁酸是氯贝酸生物降解的主要产物,最大浓度约200μg/L左右;其次是乳酸,其最大浓度约70μg/L,这两种物质在水中均呈现先累积然后被微生物逐渐利用而减少的趋势;而对氯苯酚的含量最少。对两组反应器中的活性污泥经高通量测序分析,结果表明优势菌门均为变形菌门(Proteobacteria)、放线菌门(Actinobacteria)、拟杆菌门(Bacteroidetes)。其中放线菌门和拟杆菌门在添加氯贝酸之后,其含量分别由30.57%、28.01%下降为25.07%、24.28%,且此类菌门所包含的菌纲组分比例也有所下降,应该是受到氯贝酸一定程度的抑制所致;而变形菌门在两组工艺中的分布差别较小。对比两组反应器中的菌属组成,在添加氯贝酸的反应器中可发现一种有别于另一组反应器的Porphyromonadaceae菌属,该菌属可能与氯贝酸的生物降解有一定的关系。
[Abstract]:Pharmaceutical and personal care products (PPCPs) are a new class of micro-organic pollutants in the environment. They come from a wide range of sources and have a wide variety of sources. At present, the concentrations in the environment are especially small, but most of them are difficult to remove in municipal wastewater treatment processes. With the discharge of effluent and excess sludge from secondary settling tank, it accumulates in the environment, which has certain risks to human health and environment. Among them, clofibric acid) is a kind of metabolites which regulate blood lipids. It has the characteristics of environmental persistence and refractory degradation, and can be used as the representative substance of refractory organic matter to study its migration and transformation in the process of sewage treatment. In this study, two groups of aerobic sequencing batch reactors (SBRs) were established, in which SBR 1 was used to study the removal characteristics and the migration and transformation laws of chlorobenoic acid in the degradation of representative organic compounds in the activated sludge treatment system. The production and change of chlorobelic acid metabolites were also discussed. SBR2 was used as the experimental reference without adding chlorobenoic acid. The analysis and monitoring of chlorobenzoic acid in water and mud showed that the adsorption of chlorobelic acid by activated sludge was weak (about 6%), but its biological removal rate was between 10% and 12%, and most of chlorobenic acid was discharged with the treatment of water. The biodegradation products of chlorobelic acid were analyzed by liquid chromatography. The results showed that three metabolites were produced in the biodegradation process: 伪 -hydroxyisobutyric acid, lactic acid and p-chlorophenol. Among them, 伪 -hydroxyisobutyric acid is the main product of chlorobenoic acid biodegradation, the maximum concentration is about 200 渭 g / L, the second is lactic acid, the maximum concentration is about 70 渭 g / L, the two substances are accumulated in water and then gradually utilized by microorganisms. The content of p-chlorophenol was the least. The results of high throughput sequencing of activated sludge in two groups of reactors showed that the dominant bacteria were Proteobacteria, Actinobacter teriae and Bacteroidetes. After the addition of chlorobenic acid, the contents of actinomycetes and Bacteroides decreased from 30.57% to 25.07% to 24.28.1%, and the proportion of the bacteria contained in this kind of phylum also decreased, which should be caused by the inhibition of chlorobenic acid to some extent. However, the distribution of Proteus in the two groups was smaller. Comparing the composition of bacteria in two groups of reactors, we can find a Porphyromonadaceae genus in the reactor with chlorobenic acid, which may be related to the biodegradation of chlorobenic acid.
【学位授予单位】：西安建筑科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X703

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