闭矿条件下矿井水中微生物群落分布及菲的生物降解特性

发布时间：2018-07-09 10:38

  本文选题：废弃矿井 + 多环芳烃　； 参考：《中国矿业大学》2016年硕士论文

【摘要】：废弃矿井停产关闭后,井下压力、通气条件发生改变,矿井微生态环境结构及功能也随之变化,进而影响污染物的迁移转化过程。煤炭开采期间遗留的机油、乳化剂中含有多环芳烃类有机污染物,具有三致性、生物蓄积性、难降解性等污染风险,为保障关闭矿井地下水的安全性,有必要研究关闭矿井地下水系统中微生物群落结构的变化规律,研讨多环芳烃的生物修复规律及可行性。本文通过静态模拟实验,研究闭矿条件下矿井水中微生物群落分布特征及演化规律,从微观上探寻人类活动对矿井生态环境结构与功能的影响。从河流底泥中得到一株菲优势降解菌,探讨不同条件下其对菲的降解规律,探究不同闭矿条件下矿井水中菲的降解途径。主要研究内容如下:(1)矿井水封闭模拟实验结果表明,封闭、半封闭条件下矿井水中可培养微生物以细菌为主,占比逐渐增大,真菌、放线菌占比逐渐减小。硫酸盐还原菌数量在封闭环境中不断增大,半封闭环境中不断减少。通过16S rDNA细菌多样性分析,样品中的优势细菌为芽孢杆菌(Bacillus)和乳球菌(Lactococcus)。随着时间变化,好氧菌逐渐衰亡,厌氧菌量逐渐增加。完全封闭条件下菌群多样性逐渐增加,而半封闭条件下菌群多样性不断波动。(2)通过初筛、分离、纯化、复筛,从江苏省徐州市郊区某河流底泥中得到一株能够降解多环芳烃菲的优势降解菌J-2。经过培养观察、革兰氏染色、16S rDNA菌种鉴定等过程,确定属于微杆菌属,与Microbacterium sp.Atl-19同源性达到97%,15天内对菲的降解率达到46.97%。(3)温度对降解菌J-2降解菲的效果影响明显,30℃时,菲降解效率最高,28天降解率达到52.85%。pH值在7~8范围内,菲降解效率较高,降解率可达53.94%。菲初始浓度与降解效率成负相关关系,浓度越小,降解效率越高。添加表面活性剂吐温-80对菲生物降解速率促进显著,提高近20%。开放条件下,菲高效降解菌J-2的降解效果最好,28天内开放、封闭、半封闭条件下菲的降解速率依次降低。另外,分析得到菲的降解产物有1-羟基-2-萘甲酸和邻苯二酚。(4)不同环境条件下菲的生物降解均符合一级动力学模型。温度、pH值、菲初始浓度、不同闭矿条件对菲生物降解过程均有显著性影响。当吐温-80添加浓度大于0.1%时,吐温-80浓度对菲生物降解效率影响不显著。
[Abstract]:After the abandoned mine was shut down and closed, the underground pressure and ventilation conditions changed, and the structure and function of mine micro-ecological environment changed, which affected the process of pollutant migration and transformation. The oil and emulsifiers left over during coal mining contain polycyclic aromatic hydrocarbons (PAHs), which are at risk of pollution, such as triple-induced, bioaccumulative, refractory, etc., in order to ensure the safety of underground water in closed mines, It is necessary to study the variation law of microbial community structure in underground water system of closed mine and the bioremediation law and feasibility of polycyclic aromatic hydrocarbons (PAHs). In this paper, the distribution characteristics and evolution law of microorganism community in mine water under the condition of closed mine are studied by static simulation experiment, and the influence of human activities on the structure and function of mine ecological environment is explored from the microscopic point of view. A strain of phenanthrene dominant degrading bacteria was obtained from river sediment, the degradation law of phenanthrene was discussed under different conditions, and the degradation ways of phenanthrene in mine water under different closed ore conditions were explored. The main contents are as follows: (1) the experimental results of mine water closure show that the main culturable microorganisms in mine water are bacteria, the proportion of fungi and actinomycetes decreases gradually. The number of sulfate reducing bacteria increased in the closed environment and decreased in the semi-closed environment. By analyzing the diversity of 16s rDNA bacteria, the dominant bacteria in the sample were Bacillus and Lactococcus. With the change of time, aerobic bacteria gradually decays, and the amount of anaerobic bacteria increases gradually. Under the condition of complete closure, the diversity of flora increases gradually, but under semi-closed condition, the diversity of flora fluctuates continuously. (2) through primary screening, isolation, purification, re-screening, A dominant degrading bacterium J-2 was obtained from sediment of a river in the suburb of Xuzhou, Jiangsu Province, which could degrade phenanthrene polycyclic aromatic hydrocarbons (PAHs). After culture and observation, the microbacilli were identified as microbacilli by Gram-stain 16s rDNA identification. The degradation rate of phenanthrene reached 46.97% within 15 days after homology with microbacterium sp.Atl-19. (3) temperature had a significant effect on the degradation effect of phenanthrene J-2 at 30 鈩，

本文编号：2109090