生物滤池中铁—锰生物氧化物的生成及其对地下水中砷锑的吸附、氧化作用

发布时间：2018-03-08 01:07

本文选题：生物铁锰氧化物　切入点：氧化吸附　出处：《西安建筑科技大学》2015年硕士论文　论文类型：学位论文

【摘要】：与地球化学作用生成铁锰矿物相比,生物产生的铁锰氧化物结晶程度弱、粒径小、沿c轴堆积无序、较多的Mn4+空缺、带负电和表面积较大,因而具有更强的吸附和氧化活性。近年来生物源氧化锰对一些重金属污染物的作用受到极大关注。地下水中常常含有铁、锰、砷、锑,相伴而生,常规技术难以同时去除,但生物锰氧化过程形成的铁锰氧化物却可以作用于砷、锑。本文研究了锰氧化菌Pseudomonas sp.QJX-1生成的铁锰氧化物对砷、锑离子的竞争氧化吸附,同时研究了生物滤池中附着有锰氧化菌的滤料所生成的铁锰氧化物对砷锑的氧化吸附,为开发地下水同时去除砷锑工艺奠定基础。通过研究,得到以下结果:(1)经过48h培养,锰氧化菌Pseudomonas sp.QJX-1可通过氧化吸附作用将水中As3+浓度从0.6mg/L降至0.1mg/L;同时,Sb3+浓度从1.5 mg/L降至0.0 mg/L。此现象表明锰氧化菌生成的生物铁锰氧化物可同时氧化吸附水体中的砷、锑。运用实时荧光定量PCR对比得出Mn2+的存在增大了锰氧化基因Cum A的活性,As3+、Sb3+的存在减小了锰氧化基因Cum A的活性。(2)运用生物滤池对含有铁、锰、砷、锑的地下水进行处理,试验结果表明生物滤池对含砷锑废水具有良好的去除效果,并且发现滤池中加入锰氧化菌Pseudomonas sp.QJX-1(附着有生物铁锰氧化物的滤池)与不加时(未附着有生物铁锰氧化物的滤池)对铁锰去除效果相差不大,但发现附着有生物铁锰氧化物的滤池对砷锑的去除效果较好;另外发现锰氧化菌所生成的生物铁锰氧化物能够加快生物滤池的成熟,并可增强生物滤池的去除效果。(3)利用umu对滤池进、出水的遗传毒性进行评价,发现砷锑的存在增大了原水体的遗传毒性,但是加入锰氧化菌Pseudomonas sp.QJX-1的滤柱中出水的毒性明显小于未加菌滤柱的出水。此结果表明高效锰氧化菌Pseudomonas sp.QJX-1生成的生物铁锰氧化物可相对降低水体的遗传毒性。(4)生物滤池运行稳定后,对滤料进行研究,发现锰氧化菌Pseudomonas sp.QJX-1是在生物滤池中可优势生长。运用荧光定量PCR技术对生物滤池中锰氧化基因的活性大小进行分析,结果表明加入锰氧化菌的滤柱锰氧化基因的活性明显大于未加锰氧化菌的。(5)试验探索了一种新技术,即将原位荧光杂交技术和纳米离子二次探针技术结合(FISH-Nano SIMS)对纯培养体系(锰氧化菌以及加锰后的锰氧化菌)、复杂环境体系(活性污泥和表层土壤)进行研究。结果表明该技术能够运用于将纯菌培养体系及复杂环境样品体系中微生物的分布与其结构功能分析,但相比之下,该技术用于纯菌体系检测结果更精确。
[Abstract]:Compared with the ferromanganese minerals produced by geochemistry, the ferromanganese oxides produced by biology have weak crystallinity, small particle size, disordered accumulation along the c-axis, more Mn4 vacancies, negative charge and larger surface area. In recent years, the effect of biogenic manganese oxide on some heavy metal pollutants has attracted much attention. The groundwater often contains iron, manganese, arsenic, antimony, and it is difficult to remove them simultaneously by conventional techniques. However, the ferromanganese oxides formed in the process of biological manganese oxidation can act on arsenic and antimony. The competitive oxidation adsorption of arsenic and antimony ions by ferromanganese oxides produced by manganese oxidizing bacteria Pseudomonas sp.QJX-1 has been studied in this paper. At the same time, the oxidation adsorption of arsenic and antimony by ferromanganese oxide produced by the filter media attached to manganese oxidizing bacteria in the biofilter was studied, which laid a foundation for the development of the process of removing arsenic and antimony from groundwater at the same time. Through the research, the following results were obtained: 1) after 48 hours culture, Manganese oxidizing bacteria Pseudomonas sp.QJX-1 can reduce the concentration of As3 in water from 0.6 mg / L to 0.1 mg / L, and the concentration of SB 3 from 1.5 mg/L to 0.0 mg / L through oxidative adsorption. This phenomenon shows that the biological ferromanganese oxides produced by manganese oxidizing bacteria can oxidize and adsorb arsenic in water simultaneously. Antimony. By using real-time fluorescence quantitative PCR, the existence of Mn2 increased the activity of manganese oxidizing gene Cum A and decreased the activity of manganese oxidizing gene Cum A. The biological filter was used to treat the groundwater containing iron, manganese, arsenic and antimony. The results show that the biological filter has a good effect on the removal of arsenic and antimony wastewater. It was also found that there was no significant difference in iron and manganese removal efficiency between Pseudomonas sp. QJX-1 (filter with biological ferromanganese oxide attached) and those without biological ferromanganese oxide. But it was found that the filter with biological ferromanganese oxide could remove arsenic and antimony, and the biological ferromanganese oxide produced by manganese oxidizing bacteria could accelerate the maturation of biofilter. Umu was used to evaluate the genotoxicity of the filter inlet and effluent. It was found that the presence of arsenic and antimony increased the genetic toxicity of the original water body. However, the toxicity of the filter column added with manganese oxidizing bacteria Pseudomonas sp.QJX-1 was obviously less than that of the effluent without the filter column. The results showed that the biological ferromanganese oxide produced by the high efficiency manganese oxidizing bacteria Pseudomonas sp.QJX-1 could reduce the genotoxicity of the water body relatively. After the operation of the filter is stable, The filter media was studied, and it was found that manganese oxidizing bacteria (Pseudomonas sp.QJX-1) could grow preferentially in biofilter. The activity of manganese oxide gene in biofilter was analyzed by fluorescence quantitative PCR. The results showed that the activity of manganese oxidizing gene in the filter column was significantly higher than that in the non-manganese oxidizing bacteria, and a new technique was explored in the experiment. The in situ fluorescence hybridization technique and nanoscale ion secondary probe technique combined with FISH-Nano SIMSs were used to study the pure culture system (manganese oxidizing bacteria and manganese oxidizing bacteria after adding manganese, complex environment system (activated sludge and surface soil)). The results show that this technique can be used to analyze the distribution and structure function of microorganisms in pure bacteria culture system and complex environmental sample system. By contrast, this technique is more accurate for the detection of pure bacteria.
【学位授予单位】：西安建筑科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X523

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