2,4-二硝基苯甲醚的零价铁强化生物还原技术研究

发布时间：2018-01-26 06:19

本文关键词： 2 4-二硝基苯甲醚还原硝基芳香族化合物上流式厌氧反应器零价铁　出处：《南京理工大学》2015年硕士论文　论文类型：学位论文

【摘要】：为了提高2,4-二硝基苯甲醚(I)NAN)废水的厌氧处理效率,采用零价铁(ZVI)与生物厌氧耦合工艺对DNAN模拟废水进行还原降解,研究零价铁与生物的耦合作用,探究零价铁强化厌氧生物还原DNAN机制。在序批实验中,)NAN浓度为40mg/L,污泥浓度5 g MLVSS/L, ZVI1g/L时,ZVI/厌氧污泥耦合体系可在4小时内可完全降解DNAN,其中2-氨基-4-硝基苯甲醚(2-A-4NAN)是最主要的中间还原产物,最终还原产物2,4-二氨基苯甲醚(DAAN)可达27.69 mg/L,中间产物和最终产物的质量平衡大于98%。而单独厌氧污泥体系中的最终产物DAAN含量只有3.88 mg/L,单独ZVI体系反应主要停留在2-A-4NAN的还原产生阶段,基本没有DAAN产生。耦合体系和单独厌氧污泥体系下的产气主要为CH4气体,最大累积量分别约为1.0599 mmol和0.0289 mmol,耦合体系产气量远大于单独厌氧污泥体系,并且耦合体系最终氧化还原电位(ORP)值为-265.0 mV,明显低于两种单独体系,为厌氧微生物提供了更为适宜的厌氧环境。对于连续流实验,在进水DNAN浓度为120 mg/L, COD浓度为2500 mg/L时,ZVI/上流式厌氧反应器(UASB)耦合体系相较于传统UASB体系,COD去除效率稳定(85%),DNAN还原降解更彻底,并可在短时间内适应水力停留时间(HRT)、盐度等参数的波动,且体系pH更为稳定(6.4-7.0),为厌氧污泥提供更适宜的代谢环境。反应器内ZVI表面具有多种铁的腐蚀产物,这些铁的腐蚀产物与H+的反应既维持了反应器内pH的稳定,又会缓解了ZVI的钝化,保持ZVI在反应器内的活性,体现了ZVI与生物的耦合效应。耦合体系中污泥颗粒形貌相对于传统UASB体系,轮廓清晰,结构密实而又稳定,污泥颗粒具有双层结构,为内层产甲烷菌的生长繁殖提供了有利条件。通过高通量测序技术分析,耦合体系内微生物群落相较于传统体系,多样性更高,物种更丰富,系统具有更高的抗冲击负荷能力,保证体系的稳定运行。
[Abstract]:In order to improve the anaerobic treatment efficiency of 2N _ 4-dinitrophenyl methyl ether (Igna _ N) wastewater, the DNAN simulated wastewater was reduced and degraded by the coupling process of zero-valent iron (ZVI) and biological anaerobics. The interaction between zero-valent iron and biological was studied, and the mechanism of zero-valent iron enhanced anaerobic biological reduction DNAN was explored. In the sequencing batch experiment, the concentration of nan was 40 mg / L. Sludge concentration of 5 g MLVSS / L, ZVI1g/L / anaerobic sludge coupling system can completely degrade DNAN within 4 hours. 2-Amino-4-nitrophenyl methyl ether (2-A-4NAN) is the main intermediate reduction product, and the final reduction product is 2. The DAANs of 4-diaminobenzene methyl ether can reach 27.69 mg/L. The mass balance between the intermediate and the final product was greater than 98, while the DAAN content of the final product in the anaerobic sludge system was only 3.88 mg/L. The reaction of single ZVI system mainly stayed at the stage of 2-A-4NAN reduction, and there was no DAAN production. The gas production in coupling system and anaerobic sludge system was mainly CH4 gas. The maximum accumulative capacity was about 1.0599 mmol and 0.0289 mmol, respectively, and the gas production of the coupling system was much larger than that of the anaerobic sludge system alone. The ORP value of the coupled system is -265.0 MV, which is obviously lower than that of the two separate systems, which provides a more suitable anaerobic environment for anaerobic microbes. When the influent DNAN concentration is 120 mg / L and COD concentration is 2 500 mg/L. Compared with the traditional UASB system, the coupling system of ZVI / UASB is more complete than the traditional UASB system. It can adapt to the fluctuation of HRT and salinity in a short time, and the pH of the system is more stable (6.4-7.0). A more suitable metabolic environment for anaerobic sludge is provided. There are many kinds of iron corrosion products on the surface of ZVI in the reactor. The reaction of these iron corrosion products with H not only maintains the stability of pH in the reactor. It also alleviates the passivation of ZVI, keeps the activity of ZVI in the reactor, and reflects the coupling effect of ZVI and biology. Compared with the traditional UASB system, the profile of sludge particles in the coupling system is clear. The structure is dense and stable, the sludge granule has double layer structure, which provides favorable conditions for the growth and reproduction of methanogenic bacteria in the inner layer. Through high-throughput sequencing analysis, the microbial community in the coupling system is compared with the traditional system. Diversity is higher, species is more abundant, system has higher ability to resist shock load and ensure stable operation of the system.
【学位授予单位】：南京理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X703

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