抗生素生产废水与城镇污水的处理系统中抗药基因的分布及控制

发布时间：2018-01-01 10:26

本文关键词：抗生素生产废水与城镇污水的处理系统中抗药基因的分布及控制　出处：《北京交通大学》2017年硕士论文　论文类型：学位论文

【摘要】：抗生素抗药基因(抗药基因或ARGs)作为一种新型污染物,能通过水平转移进入人类致病菌内,严重威胁人类健康。已有研究表明,抗生素生产废水处理系统和城镇污水处理厂是环境中抗药基因的重要污染源及储存库。我国作为抗生素生产大国之一,所排放的抗药基因已经引起了国内外政府的高度重视。截至目前,我国关于这两种废水处理系统全流程中抗药基因分布情况的报道还较少。本论文采用PCR和定量PCR的方法,系统考察了河北省石家庄市某抗生素生产废水处理系统和某城镇污水处理系统全流程中抗药基因(tet 基因、sul 基因、bla基因)的种类及丰度,并从水平转移角度(intI1 转移因子)简要分析了抗药基因的分布;在此基础上,初步探讨了臭氧和热水解作为污泥厌氧消化预处理工艺,对污泥中抗药基因控制效果的差异。主要取得以下成果:(1)在抗生素生产废水处理系统中,出水和脱水污泥排放的ARGs(0～1.3×1017 copies/d 和 2.6×1014～5.6×1016 copies/d)总量比进水中的量升高了 120.10%～96607.07%(blaTEM除外);且出水排放的tet基因总量、sul基因总量和blaTEM分别占总排放量的67%、82%和80%,高于脱水污泥的排放量。从相对丰度来看,与进水相比,出水中大多数ARGs丰度升高(仅blaTEM除外),且出水与脱水污泥间ARGs丰度无显著性差异(P0.05),sul、tet基因总丰度可达10-1数量级。此外,该系统中intI1的丰度(8.24×10-3±2.19×10-4～1.44×100±1.24×10-2)比相应样品中大多数ARGs的丰度高,且除blaTEM外,其余6种ARGs均与intI1存在显著相关性(P0.03)。(2)在城镇污水处理系统中,出水和脱水污泥排放的ARGs(0～5.34×1015copies/d和0～4.31×1018copies/d)总量比进水中的量减少了 69.69%～98.08%,其中脱水污泥的排放量占总排放量的99%以上。从相对丰度角度来看,多种ARGs在出水中的丰度比进水中丰度下降了 0.3～1.74个数量级,主要是一级及三级处理工艺的贡献。此外,intI1的丰度(3.33×10-2±1.76×10-3～6.01×10-1±2.83×10-2)高于相应样品中抗药基因丰度最高的sul1和tetA丰度,且除blaTEM和tetW外,其余抗药基因均与iniI1存在显著相关性(P0.05)。(3)臭氧、热水解预单独处理后,制药污泥中ARGs分别下降了～0.5、1.6～4.7个数量级,城镇污泥中ARGs则分别下降了 0.2～0.7、1～3个数量级。与原泥直接厌氧消化相比,制药污泥热水解厌氧消化后丰度下降了 0.4～2.6个数量级(blaNDM-1无明显变化),臭氧厌氧消化后部分抗药基因丰度则升高;城镇污泥中tetA、tetG、tetW、tetX丰度在热水解/臭氧厌氧消化后均反弹,其余抗药基因丰度则下降不超1个数量级。而从相对丰度来看,制药污泥中大部分抗药基因(blaNDM-1、sul2除外)在热水解厌氧消化后的丰度比臭氧氧化厌氧消化后的丰度低0.2～1.8个数量级;而城镇污泥中部分抗药基因在臭氧/热水解厌氧消化处理后丰度比原泥直接厌氧消化丰度高。
[Abstract]:Antibiotic resistance genes (multidrug resistance gene or ARGs) as a model pollutant, can transfer into human pathogenic bacteria by level, a serious threat to human health. Studies have shown that the antibiotic production wastewater treatment system and urban sewage treatment plant is an important source of pollution and the repository of resistance genes in the environment. China is one of the the largest producer of antibiotics, drug resistant gene emissions have aroused the attention of the government at home and abroad. As of now, our country reports on drug resistance gene distribution system in the whole process of the two kinds of wastewater are few. The paper with the methods of PCR and quantitative PCR, investigated some antibiotic production wastewater treatment Hebei city of Shijiazhuang province and a system of urban sewage treatment system in the process of drug resistance gene (TET gene, Sul gene, BLA gene) of the species and abundance, and transfer from the perspective of the level of intI1 (for transfer A) a brief analysis of the distribution of drug resistance gene; on this basis, to explore the ozone and thermal hydrolysis as pretreatment of sludge anaerobic digestion process, the difference of drug resistance gene control effect in sludge. The main results are as follow: (1) in the treatment of antibiotic production wastewater system, water and sludge emissions ARGs (0 ~ 1.3 * 1017 copies/d and 2.6 * 1014 ~ 5.6 * 1016 copies/d) total amount increased by 120.10% ~ 96607.07% than in the influent quantity (except blaTEM); and the total discharge of Tet gene, Sul gene and total blaTEM accounted for 67% of the total emissions, 82% and 80%, higher than the emissions of dewatered sludge from the point of view. The relative abundance of water, and compared to most of the ARGs in the effluent increased abundance (only blaTEM), and the water and sludge between the abundance of ARGs had no significant difference (P0.05), Sul, tet gene abundance can reach 10-1 level. In addition, the system of int The abundance of I1 (8.24 * 10-3 + 2.19 * 10-4 to 1.44 * 100 + 1.24 * 10-2) than the corresponding samples in most of the ARGs abundance is high, except blaTEM, all the other 6 ARGs were significantly correlated with intI1 (P0.03). (2) in the urban sewage treatment system, effluent and sludge discharge ARGs (0 ~ 5.34 and 0 ~ 4.31 * 1015copies/d * 1018copies/d) total 69.69% ~ 98.08% less than the amount of water, the sludge emissions accounted for more than 99% of the total emissions. The relative abundance from the point of view, a variety of ARGs in the water in abundance by 0.3 to 1.74 orders of magnitude lower than the water inlet in abundance, is mainly a grade and three grade treatment process contribution. In addition, the abundance of intI1 (3.33 * 10-2 + 1.76 * 10-3 to 6.01 * 10-1 + 2.83 * 10-2) higher than that of drug resistant gene abundance samples of sul1 and the corresponding maximum abundance of tetA in addition to blaTEM and tetW, the drug resistance gene with the existence of iniI1 Significant correlation (P0.05). (3) ozone, water solution of pre treatment alone, pharmaceutical sludge ARGs decreased from 0.5,1.6 to 4.7 level, the town of ARGs in the sludge decreased by 0.2 ~ 0.7,1 ~ 3 orders of magnitude. Compared with the original direct sludge anaerobic digestion, pharmaceutical sludge thermal hydrolysis anaerobic digestion after the abundance decreased by 0.4 ~ 2.6 orders of magnitude (blaNDM-1 no change), part of the resistance gene of ozone abundance of anaerobic digestion was increased; tetA, tetW, tetG in urban sludge, tetX abundance in the water solution / ozone anaerobic digestion after rebound, drug resistance gene abundance remaining decreased not exceeding 1 orders from the point of view. The relative abundance, most pharmaceutical sludge resistance genes (blaNDM-1, except sul2) in the abundance of hot water solution after anaerobic digestion than the abundance of ozone oxidation of anaerobic digestion of low 0.2 ~ 1.8 orders of magnitude; and part of urban sludge resistance genes in the ozone / hot water The abundance of anaerobic digestion was higher than that of direct anaerobic digestion.

【学位授予单位】：北京交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X787;X703

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