环丙沙星废水的膜生物反应器处理特性及污泥中抗性基因的变化研究

发布时间：2018-04-09 02:24

本文选题：环丙沙星　切入点：污泥活性　出处：《上海师范大学》2017年硕士论文

【摘要】：环丙沙星(Ciprofloxacin,CIP)是一种广谱抗生素,在全国的抗生素使用中占据很大的比重,在环境中检出率高。CIP稳定性好,难生物降解,且极其微量浓度下即可通过诱导抗性基因等对生态安全和人体健康产生危害。因此,控制CIP的环境排放至关重要。膜生物反应器(MBR)是一种高效的废水生物处理装置,在对抗生素的去除方面,表现出比传统的生物处理技术更高的处理效率。环丙沙星生产废水中含有高浓度的环丙沙星,浓度高达数mg·L-1至数十mg·L-1。本研究采用MBR技术处理模拟的环丙沙星生产废水,考察不同CIP浓度下(0 mg·L-1、5 mg·L-1、10 mg·L-1、15 mg·L-1)MBR中活性污泥浓度的变化以及氨氮(NH3-N)、化学需氧量(COD)、总有机碳(TOC)和CIP的去除特性;并基于物料衡算分析了CIP的去除途径,研究了活性污泥中抗性基因与微生物群落的变化。结果表明:(1)随着进水CIP浓度的增加,MBR中污泥浓度呈现先减少再平衡后增加的趋势,这与微生物逐渐适应CIP冲击和较长的污泥停留时间有关。(2)随着进水CIP浓度的增加,氨氮去除率持续降低,表明硝化活性受到抑制;TOC去除效果略有下降,但整体较为稳定;COD去除效果逐渐降低,由于CIP抑制了微生物活性或破坏了微生物细胞。(3)物料衡算结果表明,MBR中的CIP主要通过微生物降解和污泥吸附去除。随着进水CIP浓度的增加,微生物降解对CIP的去除作用先减少后增加,而污泥比吸附速率则先增加后减少。(4)随着驯化时间的延长,污泥中针对CIP的四种抗性基因gyrA、gyrB、parC和parE均有先降低后升高的变化趋势,污泥中抗性基因gyrA和gyrB的变化波动较大。(5)高通量测序结果显示,进水中CIP浓度的增加和胁迫时间的增长,不仅对微生物种群丰度产生了影响,也对微生物种群多样性产生了影响;从门、纲、目、科、属级别分别对污泥中微生物群落进一步分析表明,微生物分类单位越小,CIP胁迫所引起的数量变化越明显。
[Abstract]:Ciprofloxacinine (CIPP) is a broad-spectrum antibiotic, which accounts for a large proportion of antibiotics used in China. The detection rate of ciprofloxacin in the environment is high. CIP is stable and difficult to biodegrade.And extremely small concentration can induce resistance genes to the ecological safety and human health hazards.Therefore, it is very important to control the environmental emission of CIP.Membrane bioreactor (MBR) is an efficient biological treatment device for wastewater treatment, which has higher efficiency than traditional biological treatment technology in the removal of antibiotics.Ciprofloxacin production wastewater contains high concentration of ciprofloxacin, the concentration of which is as high as several mg L ~ (-1) to several tens mg L ~ (-1).In this study, simulated ciprofloxacin production wastewater was treated with MBR technology. The change of activated sludge concentration in 0 mg / L ~ (-1) 5 mg / L ~ (-1) 10 mg / L ~ (-1) L-1)MBR and the removal characteristics of NH _ 3-N ~ (3 +), COD ~ (2 +), total organic carbon (TOC) and total organic carbon (TOC) in different concentrations of CIP were investigated.Based on the material balance, the CIP removal pathway was analyzed, and the changes of resistance genes and microbial communities in activated sludge were studied.The results showed that the sludge concentration in CIP increased with the increase of influent concentration. The sludge concentration decreased first and then increased, which was related to the microbial adaptation to CIP impact and the longer sludge residence time (CIP) concentration increased with the increase of influent CIP concentration.The removal rate of ammonia nitrogen decreased continuously, which indicated that the removal efficiency of TOC decreased slightly, but the removal efficiency of COD decreased gradually.Because CIP inhibited microbial activity or destroyed microbial cells, the results showed that CIP in MBR was mainly removed by microbial degradation and sludge adsorption.With the increase of influent CIP concentration, the removal of CIP by microbial degradation decreased first and then increased, while the specific adsorption rate of sludge increased first and then decreased.The results of high-throughput sequencing showed that the concentration of CIP and the time of stress increased with the increase of CIP concentration and the change of gyrA and gyrB in sludge.It not only has an effect on the abundance of microbial population, but also on the diversity of microbial population.The smaller the microorganism taxonomic unit, the more obvious the change of quantity caused by CIP stress.
【学位授予单位】：上海师范大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X703

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