EGI OpenIR
新疆博斯腾湖人工湿地耐药基因污染
Alternative TitleThe contamination level of Antibiotic Resistance Genes in constructed wetlands of the Bosten Lake, Xinjiang
付家晖
Subtype硕士
Thesis Advisor潘响亮
2019-06-30
Degree Grantor中国科学院大学
Place of Conferral北京
Degree Discipline工程硕士
Keyword博斯腾湖 人工湿地 耐药基因,细菌群落结构 The Bosten Lake Constructed Wetland Antibiotic Resistance Gene Bacterial Community Structure
Abstract博斯腾湖是中国四大集中产苇区之一, 沼泽芦苇生长茂密,人工湿地众多。人工湿地是一个综合的生态系统,它利用生态系统中物种共生和物质循环再生等原理, 在遵循结构与功能协调原则下, 能够充分发挥净化污染和物质资源化的潜力, 获得污水处理与资源化的双重效益。本研究通过在博湖人工湿地各级处理池采样,分析其水体和沉积物中的抗生素浓度和耐药基因(ARGs)丰度,揭示博湖人工湿地的处理效果。 同时, 探究了自然水体中盐度对废水中抗生素、细菌群落结构和耐药基因的影响。 最后, 通过室内模拟实验, 研究了博湖人工湿地采集的藻菌生物膜的钙化除砷效果以及因此导致的藻菌生物膜中耐药基因和细菌群落结构的变化。本研究的主要结论有:(1) 湿地多级处理池抗生素总去除率为 78.7%,大部分耐药基因的去除率大于 80.6%,变形菌门和厚壁菌门是水样及沉积物样品中的优势菌群,综上所述,研究区湿地多级处理池对目标抗生素类污染物和耐药基因有较好的去除效果。(2) 研究发现盐度对 SMX 的含量有所影响, SMX 的去除可能是光催化降解与微生物降解共同作用,高盐度会使一些细菌致死从而影响细菌群落结构,也会抑制光降解催化效率,本实验研究得出盐度越高, SMX 的浓度越高。增加盐度可以有效地减少废水中的耐药基因丰度,随着盐度的变化,渗透脆性导致一些菌群随着盐度的增加而减少,细菌群落发生了显著变化。高盐度水体可能会抑制一些携带耐药基因的细菌的生长,从而降低耐药基因的丰度。人类活动较多的区域中抗生素和耐药基因的相对丰度更大,说明人类活动是抗生素和耐药基因污染与传播的重要途径。(3) 在砷胁迫下,生物膜的光合作用受到一定程度的抑制,导致 Ca2+沉淀速率减缓。生物膜可以通过钙化作用抑制砷的迁移,在利用生物膜的钙化能力除砷的实验中, 不加入 Ca2+时,不同砷浓度(1 mg/L 和 50 mg/L)实验组的去除率分别为 42.89%和 61.64%, 加入 Ca2+时,不同砷浓度(1 mg/L 和 50 mg/L)实验组的去除率分别为 48.11%和 60.97%,说明 Ca2+的加入并不能显著提高砷的去除率,但是会加强生物膜去除砷的稳定性,不易二次释放。砷的浓度会导致耐药基因丰度的变化。加入低浓度 As 时会对耐药基因起到促进作用,加入高浓度 As 时会对耐药基因产生抑制作用。
Other AbstractThe Bosten Lake is one of the four concentrated calving areas of reeds in China.The marsh reeds grow densely and there are many artificial wetlands. Constructedwetland is a comprehensive ecosystem. It utilizes the principles of species symbiosisand material recycling in ecosystems. Under the principle of coordination of structureand function, it can fully exploit the potential of purifying pollution and materialresources, so as to obtain the dual benefits of sewage treatment and resource recycling.In this study, the contanmination levels of antibiotics and antibiotics resistance genes(ARGs) in water and sediment of the Bosten Lake were analyzed to uncover theremoval efficiency of the artificial wetlands. Meanwhile, the effects of salinity onantibiotics, bacterial communities’ structure and ARGs in wastewater were studied.Finally, through the indoor simulation experiment, the calcification and arsenicremoval effects of the algal biofilm collected from the artificial wetlands in theBosten Lake and the resulting changes in resistance genes and bacterial communitystructure in the algal biofilm were explored. The main conclusions of this study are asfollow:(1) The total removal rate of antibiotic in wetland multi-stage treatment tank is78.7%, and the removal rate of most ARGs is more than 80.6%. Proteobacteria andthick-walled bacteria are the main dominant bacteria in water and sediment samples.In general, the multi-stage treatment pool of the wetland in the study area has a goodremoval effect on the target antibiotic pollutants and ARGs.(2) It is found that salinity has an effect on the concentration of SMX. Theremoval of SMX may be due to the combination of photocatalytic degradation andmicrobial degradation. High salinity will kill some bacteria and affect the bacterialcommunity structure, and also inhibit the photocatalytic efficiency ofphotodegradation. This experimental study shows that the higher the salinity, thehigher the concentration of SMX. Increasing the salinity can effectively reduce the ARGs in the wastewater. With the change of salinity, the osmotic fragility causessome flora to decrease with the increase of salinity, and as well as the bacterialcommunity. High salinity waters may inhibit the growth of some bacteria carryingARGs, thereby reducing the concentration of ARGs. The relative abundance ofantibiotics and ARGs is greater in areas with more human activity, indicating thathuman activities are an important way to contaminate and spread antibiotics andARGs.(3) Under the stress of arsenic, the photosynthesis of biofilm was inhibited to acertain extent, which led to the slowing of Ca2+ precipitation. Biofilm can inhibit themigration of arsenic by calcification. In the experiment of removing arsenic by usingthe calcification ability of biofilm, when the Ca2+ was not added, the removal rates ofdifferent arsenic concentrations (1 mg/L and 50 mg/L) were respectively 42.89% and61.64%; when the Ca2+ was added, the removal rates of the experimental groups withdifferent arsenic concentrations (1 mg/L and 50 mg/L) were 48.11% and 60.97%,respectively, indicating that the addition of Ca2+ could not significantly improve theremoval of arsenic. However, the Ca2+ would strengthen the stability of removingarsenic in the biofilm and make arsenic not be easy to be released again. Theconcentration of arsenic causes changes in the species and abundance of ARGs. Lowconcentration of arsenic can promote the removal rate of ARGs, while highconcentration of arsenic would decrease it.
Subject Area环境工程
Language中文
Document Type学位论文
Identifierhttp://ir.xjlas.org/handle/365004/15326
Collection中国科学院新疆生态与地理研究所
研究系统
Affiliation中国科学院新疆生态与地理研究所
First Author Affilication中国科学院新疆生态与地理研究所
Recommended Citation
GB/T 7714
付家晖. 新疆博斯腾湖人工湿地耐药基因污染[D]. 北京. 中国科学院大学,2019.
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