河道底泥中荧蒽污染的植物—微生物联合修复研究

发布时间：2018-05-10 17:11

本文选题：河道底泥 + 荧蒽　；参考：《天津工业大学》2017年硕士论文

【摘要】：多环芳烃(PAHs)作为"三致"污染物严重危害人类的健康,我国河道底泥中存在着严重的PAHs污染问题,高分子量多环芳烃(H-PAHs)因其具有更强的毒性和难降解性,是河道底泥中PAHs污染治理的重点和难点。本文选择了H-PAHs中检出频率和丰度都很高的荧蒽作为H-PAHs的代表物,研究了植物-微生物联合修复的方式对底泥中荧蒽污染的去除机理。首先在受荧蒽污染的底泥中种植常见的挺水植物菖蒲、芦苇、茭白荀、千屈菜,监测结果发现菖蒲对荧蒽的去除效果最好,经过90d的生长期,菖蒲试验组荧蒽去除率达到55.36%。进一步分析表明,菖蒲主要是靠植物降解作用去除荧蒽,因为菖蒲有庞大的根系,根系菌群密度更高,且经过高通量分析后确定在种植菖蒲后底泥菌群结构发生明显改变,由原来的Bacillus、Hydro、Candida等优势菌群转变为Rhodococcus、Mycobacterium、Penicillium等优势菌群。通过对菖蒲根际菌群的筛选获取两株对荧蒽降解效率最高的菌株。根据形态学观察和基因序列分析后确定两株菌种分别为Rhodococcus aetherivorans strain IcdP1(简称红球菌 IcdP1)、Penicillium purpurogenum stain DTQ-HK1(简称青霉素菌DTQ-HK1)。对培养条件进行优化确定荧蒽浓度为50mg/L,温度为30℃C,pH为7时为两菌株最适生长条件,且Zn2+、Cu2+的存在会对两种菌株产生抑制作用,其中Cu2+抑制作用强于Zn2+。为进一步了解荧蒽降解菌对荧蒽的降解机制,试验选择葡萄糖、麦芽糖、菖蒲根系分泌物、HA和蒽-菲混合物分别作为外加碳源,研究外加碳源对荧蒽降解的影响。试验发现当C葡萄糖:C荧蒽=1:1时外加碳源对红球菌IcdP1降解荧蒽的强化效果最明显,当C麦芽糖:C荧蒽=3:5时外加碳源对青霉素菌DTQ-HK1强化降解荧蒽的效果最好,且葡萄糖与麦芽糖强化降解机理主要是通过促进荧蒽溶出及促进菌株生长实现的。虽然投加外加碳源前后菌株对荧蒽的降解过程均遵循一级动力学,但降解速率明显不同。在C葡萄糖:C荧蒽=1:1的投加比例下,经过42d培养,红球菌IcdP1对荧蒽降解率达到76.30%,与未加碳源的降解率(37.46%)相比提高了38.84%;在C麦芽糖:C荧蒽=1:1的投加比例下,青霉素菌DTQ--K1对对蒽降解率达到81.75%,与未加碳源的降解率(52.22%)相比提高了 29.53%。通过对外加碳源投加方式的研究发现,采用分段式投加方式较一次性投加方式能够进一步提高降解菌对荧蒽的降解效率。对荧蒽降解产物进行GC-MS分析发现,单独以荧蒽作为唯一碳源时降解菌对荧蒽的分解并不彻底,产物多为含苯环、杂环或长链化合物,投加外加碳源后荧蒽的降解更为彻底,尤其是青霉素菌DTQ-HK1在外加麦芽糖碳源后,降解荧蒽的产物多以短链小分子物质为主。外加碳源和荧蒽降解菌强化植物-微生物联合修复底泥中荧蒽的降解试验表明,在被荧蒽污染的河道底泥中栽种菖蒲,并在其根际投加青霉素菌DTQ-HK1和麦芽糖(青霉素菌DTQ-HK1菌悬液浓度为OD600=2,投加量为40mL;麦芽糖投加量C麦芽糖:C荧蒽=3:5),经连续90d的生长期,底泥中荧蒽的去除效果可以达到100%。
[Abstract]:Polycyclic aromatic hydrocarbons (PAHs) seriously endangers human health as a "three" pollutant. There is a serious problem of PAHs pollution in the sediment of the river. High molecular weight polycyclic aromatic hydrocarbons (H-PAHs) are the key and difficult points for the treatment of PAHs pollution in the sediment of the river channel because of their stronger toxicity and difficult degradation. The detection frequency and abundance in H-PAHs are selected in this paper. High fluoranthene as the representative of H-PAHs, the mechanism of the removal of fluoranthene in the sediment by the method of plant microorganism combined repair was studied. First, the common Acorus calamus, reed, Zizania Zizania and rhizome of Acorus Acorus were planted in the sediment polluted by fluoranthene. The results showed that the removal effect of Acorus calamus on fluoranthene was the best, and the growth of the Acorus Acorus was the growth of 90d. The fluorescence anthracene removal rate of Acorus Acorus test group reached 55.36%. further analysis showed that the Acorus calamus was mainly based on plant degradation to remove fluoranthene, because the Acorus calamus had a large root system, and the density of root flora was higher. After high throughput analysis, the structure of the bacteria group in the bottom mud of Acorus was obviously changed, from the original Bacillus, Hydro, Candida and so on. The dominant bacteria group changed into Rhodococcus, Mycobacterium, Penicillium and other dominant bacteria groups. Through the screening of the Chang Pugen flora, two strains with the highest efficiency of fluoranthene degradation were obtained. According to the morphological observation and gene sequence analysis, the two strains were identified as Rhodococcus aetherivorans strain IcdP1, respectively, Penici, Penici. Llium purpurogenum stain DTQ-HK1 (abbreviated penicillin DTQ-HK1). The culture conditions were optimized to determine that the concentration of fluoranthene was 50mg/L, the temperature was 30, C, and pH was 7, the optimum conditions for growth of the two strains, and Zn2+, the existence of Cu2+ would inhibit the two strains, and Cu2+ inhibition was stronger than Zn2+. for further understanding of fluoranthene degrading bacteria. The effect of glucose, maltose, root exudates of Acorus root, HA and anthracene phenanthrene mixture as additional carbon sources were selected to study the effect of external carbon source on the degradation of fluoranthene. It was found that when C glucose: C fluoranthene =1:1 was the most obvious enhancement effect on IcdP1 degradation of fluoranthene by IcdP1, when C maltose: C fluoranthene =3:5 The effect of carbon source on the degradation of fluoranthene by penicillin DTQ-HK1 was the best. The enhanced degradation mechanism of glucose and maltose was achieved by promoting the dissolution of fluoranthene and promoting the growth of strains. Although the degradation of fluoranthene was followed by first order kinetics before and after adding carbon source, the degradation rate was obviously different. In C grapes, the degradation rate of fluoranthene was obviously different. Sugar: C fluoranthene =1:1, after 42d culture, the degradation rate of fluoranthene by IcdP1 was 76.30% and 38.84% compared with the degradation rate of non carbon source (37.46%). In C maltose: C fluoranthene =1:1, the degradation rate of penicillin DTQ--K1 against anthracene was 81.75%, compared with the degradation rate of carbon source (52.22%) by 29. .53%. through the study of adding carbon source to the external carbon source, it is found that the degradation efficiency of fluoranthene can be further improved by the method of subsection addition. The analysis of fluoranthene degradation products by GC-MS analysis shows that the decomposition of fluoranthene is not thorough when fluoranthene is the sole carbon source, and most of the product is benzene containing benzene. After adding external carbon source, the degradation of fluoranthene was more thorough, especially when the penicillin DTQ-HK1 was added to the maltose carbon source, the products of the fluoranthene degradation were mainly short chain and small molecules. The external carbon source and fluoranthene degrading bacteria enhanced the degradation test of fluoranthene in the plant microorganism combined repair sediment. Acorus calamus was planted in the sediment of anthracene polluted river, and the penicillin DTQ-HK1 and maltose were added to its rhizosphere (OD600=2, 40mL, C maltose, C fluoranthene =3:5), and the removal of fluoranthene in the sediment could reach 100%. in the growth period of continuous 90d.

【学位授予单位】：天津工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X522

【参考文献】