填埋场生物反应器以及不同处理工艺对渗滤液抗性基因的去除研究

发布时间：2018-05-20 01:46

本文选题：填埋场渗滤液 + 抗性基因　；参考：《华东师范大学》2017年硕士论文

【摘要】：近几年来,随着抗生素在畜牧业与医疗卫生领域的广泛使用,环境中逐渐增加的残留抗生素加速了抗性基因(ARGs,antibiotic resistance genes)的传播扩散,从而导致抗性基因的泛滥已成为威胁公共安全和生态健康的潜在风险。作为当前城市固体垃圾的主要集中处理场所,垃圾填埋场中含有大量的过期抗生素及抗性基因,并随着固体废弃物的处理进入到垃圾渗滤液中。如果渗滤液不能得到有效处理,其中的ARGs会随着渗滤液尾水的排出而进入到环境中,从而造成潜在环境危害。因此,研究渗滤液中的ARGs处理就显得很有必要。本研究采用上海市老港垃圾填埋场的陈垃圾作为填料构建了实验室填埋场生物反应器。设计了好氧条件下三种不同的水力负荷(25L/m3·d,50L/m3·d,100 L/m3·d)以及50L/m3·d水力负荷下的好氧和厌氧条件这两种工况参数,研究了反应器不同运行条件下ARGs去除率的变化。此外,本研究还通过对三种不同处理工艺下的渗滤液ARGs的去除研究,探讨了不同工艺对于ARGs去除的影响。本文的主要结论如下:(一)研究了不同水力负荷和好氧状态下填埋场生物反应器对营养元素、重金属和抗性基因的去除效果,并通过相关分析得出抗性基因去除率与环境因子的关联性。(1)研究了稳定运行81天的好氧反应器运行状态。对比水力负荷为25、50、100 L/m3·d下反应器的总氮、氨氮和COD去除率,发现较低的运行负荷可得到较高的氨氮和总氮去除率,而COD去除呈现出随水力负荷增加先增大后减小的趋势。50L/m3·d的水力负荷下,对比好氧和厌氧状态对反应器运行的影响,结果表明好氧条件有利于氨氮和COD的去除,厌氧条件有利于总氮的去除。其原因是有机物好氧呼吸和硝化过程在好氧条件下进行,而厌氧条件对反硝化脱氮有促进作用。不同水力负荷对重金属总量的去除对比,发现25 L/m3·d水力负荷下反应器对于重金属的去除率要高于50 L/m3·d和100 L/m3·d,说明低水力负荷更有利于重金属的去除。比较好氧和厌氧条件下的系统运行,发现好氧条件更有利于重金属的去除。(2)不同水力负荷下反应器中的抗性基因去除实验对比,发现25 L/m3·d的水力负荷下反应器对于sull,strB,aadA1,intl1的去除率要高于50 L/m3·d和100 L/m3·d,说明低水力负荷更有利于ARGs的去除。对比不同好氧状态下的反应器运行效果,发现好氧条件下sul1,sul2,strB,aadA1,intl1的去除率都明显高于厌氧,说明好氧环境更有利于ARGs的去除。(3)相关性分析结果表明重金属、水质与ARGs的去除效果具有显著相关关系。其中As,Pb,N03--N和ARGs对数去除率之间主要表现为显著性正相关,其余环境因子和ARGs之间主要表现为显著性负相关。说明在本研究中,水质和重金属对于ARGs的去除有较大的影响。(二)比较了三个渗滤液处理厂不同处理工艺对抗性基因去除效果的影响,并分析了水质参数、重金属对抗性基因去除效果的影响。(1)MBR、三级A/O以及两级A/O工艺对新鲜渗滤液中氮素和COD具有较高的去除率(90%)。两级A/O工艺具有最高的总氮和COD去除效率,而MBR则在氨氮的去除具有明显优势。比较三种工艺中重金属的去除情况,发现三种工艺中的Cu,Ni去除率无显著性差异。两级A/O工艺使出水中Cd和Zn的浓度增加,但相比MBR和三级A/O对其他几种重金属具有更好的去除效果。说明两级A/O工艺对于重金属的去除率要优于MBR工艺和三级A/O工艺。(2)三种工艺中ARGs研究结果发现,MBR工艺对于四环素类基因和大环内酯类基因有较高的去除率(1.76～3.07个数量级),两级A/O工艺对于磺胺类,氨基糖苷类,β-内酰胺类和多重抗性基因以及整合子基因都有较好的去除效果。三级A/O工艺03出水中sul1,sul2,aadA1,mexF,intl1基因丰度都增加。说明两级A/O工艺对于多数目标基因都有很高的去除率,MBR工艺更适合四环素类和大环内酯类基因的去除。
[Abstract]:In recent years, with the widespread use of antibiotics in the field of animal husbandry and health care, the increasing residual antibiotics in the environment have accelerated the spread of the resistance gene (ARGs, antibiotic resistance genes), resulting in the proliferation of resistant genes that have become a potential risk to public safety and ecological health. A large number of overexpired antibiotics and resistance genes are contained in the landfill site, and the landfill leachate enters into the leachate with the treatment of solid waste. If the leachate can not be treated effectively, the ARGs will enter into the environment with the discharge of the tail water of the percolation fluid, resulting in the potential environmental danger. Therefore, it is necessary to study the ARGs treatment in leachate. In this study, a laboratory landfill bioreactor was constructed by using the old garbage in old port landfill in Shanghai as a filler. Three different hydraulic loads (25L/m3 D, 50L/m3. D, 100 L/m3 d) and 50L/m3. D hydraulic load under aerobic conditions were designed. The changes of the ARGs removal rate under different operating conditions of the reactor were studied and the changes in the ARGs removal rate under different operating conditions were studied. In addition, the effect of different processes on the removal of ARGs was also studied through the study of the removal of ARGs from the Leachate under three different processing techniques. The main conclusions of this paper are as follows: (1) the study of different hydraulic loads and good results The removal efficiency of nutrient elements, heavy metals and resistance genes in the landfill bioreactor and correlation analysis were used to obtain the correlation between the resistance gene removal rate and the environmental factors. (1) the aerobic reactor operating state for 81 days stable operation was studied. The total nitrogen, ammonia nitrogen and CO of the reactor were compared with the hydraulic load of 25,50100 L/m3. D. The removal rate of D shows that higher ammonia nitrogen and total nitrogen removal rate can be obtained with lower operating load, while COD removal shows the effect of aerobic and anaerobic condition on the operation of reactor under the hydraulic load of the trend.50L/m3. D which increases first and then decreases with the increase of hydraulic load. The results show that aerobic conditions are beneficial to the removal of ammonia nitrogen and COD, anaerobic strips. The reason for the removal of total nitrogen is due to aerobic respiration and nitrification of organic compounds under aerobic conditions, while anaerobic conditions can promote denitrification and denitrification. The removal of heavy metals under different hydraulic loads by different hydraulic loads has been found to be higher than 50 L/m3. D and 100 L/m3 under 25 L/m3. D hydraulic load. D, indicating that low hydraulic load is more conducive to the removal of heavy metals. Compared with aerobic and anaerobic conditions, it is found that aerobic conditions are more conducive to the removal of heavy metals. (2) the experimental comparison of resistance genes in the reactor under different hydraulic loads has found that the reactor of 25 L/m3 / D is responsible for sull, strB, aadA1, intl1. The removal rate is higher than 50 L/m3. D and 100 L/m3. D, indicating that low hydraulic load is more conducive to the removal of ARGs. Comparing the operating effects of different aerobic conditions, the removal rates of sul1, sul2, strB, aadA1 and intl1 are obviously higher than anaerobic conditions under aerobic conditions, indicating that the aerobic environment is more conducive to the removal of ARGs. (3) correlation analysis results show heavy weight. Metal, water quality has a significant correlation with the removal of ARGs, among which As, Pb, N03--N and ARGs are mainly positive correlation between the logarithmic removal rates, and the other environmental factors and ARGs are mainly negative correlation. It shows that in this study, water quality and heavy metals have a greater impact on the removal of ARGs. (two) comparison The effect of three leachate treatment plants on the effect of antagonistic gene removal, and the effects of water quality parameters and heavy metal antagonistic genes were analyzed. (1) MBR, three A/O and two A/O processes have high removal rate of nitrogen and COD in fresh leachate (90%). The two A/O process has the highest total nitrogen and COD removal Efficiency, while MBR has obvious advantages in the removal of ammonia nitrogen. Comparing the removal of heavy metals in the three processes, it is found that there is no significant difference in the removal rate of Cu and Ni in the three processes. The concentration of Cd and Zn in water increases with the two level A/O process, but it has a better removal effect compared to the other heavy metals by MBR and three A/O, indicating two A/O The removal rate of heavy metals in the process is superior to the MBR process and the three stage A/O process. (2) the ARGs study in three processes found that the MBR process has a high removal rate (1.76 to 3.07 orders of magnitude) for the tetracycline and macrolide genes, and the two A/O process for the sulfonamides, aminoglycosides, beta lactam and multiple resistance genes. The three level A/O process 03 increased the abundance of sul1, sul2, aadA1, mexF and intl1, indicating that the two level A/O process has a high removal rate for most of the target genes, and MBR technology is more suitable for the removal of tetracycline and macrolides.
【学位授予单位】：华东师范大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X703

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