异养和电化学氢自养协同降解水中高氯酸盐的研究

发布时间：2018-05-14 16:51

本文选题：异养 + 氢自养　；参考：《河南工业大学》2017年硕士论文

【摘要】：水中高氯酸盐的去除已经成为当前水处理领域的研究热点。由于高氯酸盐特殊的理化性质导致常规处理方法难以将其有效去除。生物法具有去除效率高、成本低、转化彻底等优点而被广泛应用。异养微生物还原高氯酸盐反应速率快,微生物易于培养驯化,但有机碳源容易残余水中造成二次污染。氢自养微生物还原过程清洁,但氢气的产生与存储存在一定困难。本研究将异养还原过程与氢自养还原过程相结合,并引入电化学手段建立微生物异养和电化学氢自养协同作用的净化系统,该系统集异养过程的高效性与氢自养过程的清洁性于一体,在实现高氯酸盐高效降解的同时避免有机碳源残余造成二次污染,主要研究内容包括:1、异养还原水中高氯酸盐的菌群驯化、结构演替及其降解高氯酸盐效能分析。接种污水厂活性污泥,以乙酸钠为电子供体,通过序批式实验研究了微生物异养还原高氯酸盐的效果及相关影响因素,并通过高通量测序技术对驯化过程中微生物群落结构进行了分析。结果表明:随着驯化过程的进行,菌群α多样性逐渐降低,门水平上优势菌群包括Proteobacteria(变形菌门)、Bacteroidetes(拟杆菌门)、Chlorofexi(绿弯菌门)等。高氯酸盐降解动力学研究结果显示,米-门方程可以较好地描述微生物还原高氯酸盐过程,动力学参数qmax为4.03~6.27mgClO4-/gVSS,Ks为7.69~14.29 mg/L,[CH3COO-]/[ClO4-]=1.77(质量比)为最佳投加量,最适pH值为7.0。当溶液中硝酸根与高氯酸盐共存时,微生物会优先降解硝酸盐。2、氢自养还原水中高氯酸盐的效能及菌群结构分析。研究结果表明:接种的活性污泥经过驯化能够在短时间内实现对高氯酸盐的稳定降解。米-门方程可以较好地描述微生物还原高氯酸盐过程,动力学参数qmax和Ks分别为2.52~3.25mg ClO4-/gVSS h和5.44~8.23 mg/L,最适pH值为9.0。此外,驯化的氢自养高氯酸盐还原混合菌体系对溶液中共存的NO3-和SO42-仍有降解作用,对电子供体选择的先后顺序为:NO3-ClO4-SO42-。高通量测序结果表明,接种污泥经过9个周期的驯化,菌群结构逐渐稳定,Thauera菌属为氢自养高氯酸盐优势菌属。3、建立基于膜电解电化学氢自养MBBR生物反应器(移动床生物膜反应器:Moving Bed Biofilm Reactor),用于水中高氯酸盐的深度去除。反应体系中阴极室发生析氢反应,微生物利用氢气将高氯酸盐还原为氯离子,阳极室发生电化学氧化反应,氯离子转化为氯气溶于水生成活性氯,实现了高氯酸盐的深度转化。考察施加电流对高氯酸盐降解效能的影响。结果表明:HRT(水力停留时间)为4 h,通过调节施加电流大小(6 mA~20 mA),反应器内能够建立氢自养还原高氯酸盐所需的厌氧环境。进水ClO4-浓度为4.98 mg/L,当施加电流由6 mA增加至15 mA时,出水ClO4-去除率由39.75%增加至98.75%以上。高通量测序结果表明生物反应区优势菌群结构与直接氢自养研究结果类似,Thauera菌属是优势菌属。4、建立异养-膜电解氢自养协同作用深度降解高氯酸盐的反应体系。通过改变异养段乙酸根浓度和电化学氢自养段电流大小实现了异养段和电化学段对高氯酸盐处理负荷的调配。结果表明:当进水ClO4-浓度为10 mg/L,HRT=3.0 h,乙酸根投加量为5.9 mg/L,施加电流为130 mA时,异养段对高氯酸盐的去除率为12.13%,电化学段高氯酸盐去除率为86.86%,高氯酸盐总去除率为99.06%,出水无有机物残留。随着施加电流的增加,电化学段对高氯酸盐的去除率呈增加态势。当电化学段施加电流过高导致阴极室内pH值超过微生物的耐受值时(pH9.70),电化学段对高氯酸盐的去除率降低。
[Abstract]:The removal of perchlorate in water has become a hot spot in the field of water treatment. Due to the special physical and chemical properties of perchlorate, it is difficult to remove the perchlorate, which has the advantages of high removal efficiency, low cost and thorough conversion. The reaction rate of the heterotrophic microorganism reduction perchlorate is fast and micro. The organism is easy to train and domesticate, but the organic carbon source is easy to cause two pollution in the residual water. The reduction process of hydrogen autotrophic microorganisms is clean, but the production and storage of hydrogen is difficult. This study combines the process of heterotrophic reduction with the process of hydrogen autotrophic reduction, and introduces the electrochemical methods to establish the synergistic action of microbial heterotrophic and electrochemical hydrogen autotrophic. The system uses the purification system, which integrates the efficiency of heterotrophic process with the cleanliness of the autotrophic process of hydrogen, and avoids the two pollution of the residual organic carbon source while achieving high chlorate degradation. The main contents include: 1, the acclimatization of the perchlorate in the heterotrophic reduction water, the structural succession and the degradation of the perchlorate efficiency. The effect of microbial heterotrophic reduction of perchlorate and related factors were studied by sequencing batch experiment. The microbial community structure in the process of domestication was analyzed by high throughput sequencing technology. The results showed that as the domestication process was carried out, the diversity of the bacteria was varied. Gradually, the dominant bacteria in the gate level include Proteobacteria (Proteus door), Bacteroidetes (Pseudomonas), and Chlorofexi (chlorochlorate gate). The results of chlorate degradation kinetics show that the mica gate equation can describe the process of microbiological reduction of perchlorate, the kinetic parameter Qmax is 4.03~6.27mgClO4-/gVSS, and Ks is 7.69~14. 29 mg/L, [CH3COO-]/[ClO4-]=1.77 (mass ratio) is the best dosage, and the optimum pH value is 7.0. when the nitrate root and perchlorate in the solution coexist, the microorganisms will degrade the nitrate.2, the efficiency of the autotrophic reduction of perchlorate in the water and the structure analysis of the bacteria. The results show that the inoculated activated sludge can be domesticated in a short time. The stable degradation of perchlorate can be achieved. The mica gate equation can describe the process of microorganism reduction of perchlorate. The kinetic parameters Qmax and Ks are 2.52~3.25mg ClO4-/gVSS h and 5.44~8.23 mg/L, and the optimum pH value is 9.0.. The domesticated hydrogen autotrophic perchlorate reduction mixed bacteria system is still reduced to NO3- and SO42- in the solution. The sequence of selective electron donor selection was: NO3-ClO4-SO42-. high throughput sequencing results showed that the structure of the inoculated sludge was gradually stabilized after 9 cycles of acclimatization, and the genus Thauera was a hydrogen autotrophic perchlorate dominant genus.3, and a membrane electrolysis electrochemical hydrogen autotrophic MBBR bioreactor (mobile bed biofilm reactor: Movi) was established. Ng Bed Biofilm Reactor) is used for the depth removal of perchlorate in water. Hydrogen evolution reaction in the cathode chamber of the reaction system is used in the reaction system. Microbes use hydrogen to reduce perchlorate into chloride ion, electrochemical oxidation of the anode chamber, chlorine ion converted to chlorine dissolved in water to produce active chlorine, and the depth conversion of perchlorate is realized. The effect of current on the performance of perchlorate degradation shows that HRT (hydraulic retention time) is 4 h. By adjusting the applied current size (6 mA~20 mA), the anaerobic environment needed for hydrogen autotrophic reduction of perchlorate can be established in the reactor. The influent ClO4- concentration is 4.98 mg/L, and the effluent ClO4- removal rate is 39.7 when the adding current is increased from 6 mA to 15 mA. 5% increased to more than 98.75%. High throughput sequencing results showed that the structure of dominant bacteria in the bioreactive region was similar to that of direct hydrogen autotrophic study. Thauera was a dominant genus.4, and a reaction system was established to degrade perchlorate with heterotrophic membrane electrolysis hydrogen autotrophic synergism. By changing the concentration of acetic acid in the heterotrophic segment and electrochemistry hydrogen autotrophic segment The flow size realized the allocation of perchlorate treatment load in heterotrophic and electrochemical segments. The results showed that when the influent ClO4- concentration was 10 mg/L, HRT=3.0 h, the dosage of acetic acid root was 5.9 mg/L and the applied current was 130 mA, the removal rate of perchlorate in heterotrophic section was 12.13%, the removal rate of perchlorate in electrochemical section was 86.86%, and the total perchlorate removal was removed. With the rate of 99.06%, there is no organic residue in the effluent. With the increase of current, the removal rate of perchlorate in the electrochemical section increases. When the current is too high in the electrochemical section, the pH value in the cathode chamber exceeds the tolerance value of the microorganism (pH9.70), and the removal rate of perchlorate is reduced by the electrochemical section.

【学位授予单位】：河南工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU991.2

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