【作者】 宁岩岩；

【导师】 石先阳；

【作者基本信息】 安徽大学 ， 环境科学， 2012， 硕士

【摘要】 本文研究了不同浓度抑制剂对厌氧污泥发酵产氢的影响,运用DGGE技术分析了微生物多样性的变化,从而构建起最佳产氢微生物群落。基于动力学模型分析了苯甲酸底物浓度对厌氧发酵产甲烷的影响及其厌氧降解过程。在间歇实验的基础上,研究了如何强化UASB反应器中产氢产乙酸过程。运用FISH技术分析UASB反应器中产氢产乙酸菌的相对丰度并结合SMA的测定表明产氢产乙酸菌群得到富集,主要结论如下：(1)利用CHCl3和苯酚可以有效抑制产甲烷菌活性,提高厌氧污泥的发酵产氢能力,且对微生物群落结构具有选择作用。通过控制添加的有机抑制剂浓度,获得最佳产氢微生物群落。最适产氢的CHCl3和C6H5OH浓度分别为0.050%和800mgCOD·L-1。(2)以苯甲酸为唯一碳源进行厌氧发酵产甲烷获得的甲烷产率和比产甲烷速率分别在底物浓度为1.Og·L-1和1.2g·L-1时达到最大值。基于Han-Levenspiel模型分析表明产甲烷菌发酵产甲烷的底物浓度上限为2.79g·L-1。苯甲酸浓度在0-2.0g·L-1时,其厌氧降解过程符合一级动力学。(3) UASB反应器运行条件设置为：温度(37±1)℃、出水pH=6.8～7.2、水力停留时间30h；通过在进水中添加乙酸钠(进水COD:N:P=300:5:1)可有效强化厌氧反应系统中产氢产乙酸作用。强化后厌氧污泥的SMA及产氢产乙酸菌群的相对丰度较强化前及对照系统均有显著提高。更多还原

【Abstract】 In this paper, the effects of different concentrations of depressants on anaerobic H2production were investigated and microbial community structure was also examined by using DGGE. Thus the favorable microbial communities for fermentative H2production by anaerobic sludge were obtained. The effects of benzoate concentration on CH4production and benzoate anaerobic degradation were analyzed with kinetic mode. The continuous experiments were conducted to explore how to enhance the activity of H2-producing acetogens in UASB reactor on the basis of the results of batch experiments. The analysis results for relative abundances of H2-producing acetogens using FISH approach along with the SMA determination demonstrated that the bacteria were enriched. The main conclusions are as follows:(1) The H2production ability by anaerobic sludge could be improved through repressing methanogenic activity with CHCl3and phenol pretreatment. Correspondingly, the favorable microbial community structures for H2production by anaerobic sludge were formed by controlling organic inhibitors concentration in appropriate level. The optimal concentration of CHCl3and phenol for H2production were0.050%and800mg COD-L-1, respectively.(2) With benzoate as the sole carbon source, the maximum CH4yield and specific CH4production rate were achieved at substrate concentration of1.Og-L-1and1.2g-L-1, respectively. The maximum benzoate concentration for CH4production was2.79g·L-1according to Han-Levenspiel model analysis. The benzoate degradation rate was found to be the first order within range of substrate concentration from0-2.Og·L-1.(3) The UASB reactors were operated at internal temperature of37±1℃, pH of6.8-7.2, and HRT of30h. The activity of hydrogen-producing acetogens could be effectively enhanced by adding sodium acetate in influent (COD:N:P=300:5:1) of UASB. Both SMA of anaerobic sludge and relative abundances of H2-producing acetogens through augmentation were improved significantly compared to control system.更多还原