【作者】 熊辉；

【导师】 苗蕾；

【作者基本信息】 华中科技大学 ， 建筑与土木工程， 2021， 硕士

【摘要】 厌氧氨氧化工艺由于低能耗、无污染且经济效益好等优势,使其在污水脱氮中具有较好的应用前景。但厌氧氨氧化系统在处理实际污水时会受到有机物的影响。适当浓度的有机物能够提高系统的总氮去除率,然而实际污水中的有机物种类较多,既包括挥发性脂肪酸等易生物降解的有机物,也包含腐殖酸等难生物降解的有机物。不同种类的有机物对厌氧氨氧化系统产生的影响也不同。因此,本研究分别选择丙酸盐和腐殖酸作为易生物降解和难生物降解有机物,通过考察不同有机物条件下,系统脱氮性能、胞外聚合物以及菌群结构的变化规律,从宏观和微观的角度深入探究不同种类的有机物对厌氧氨氧化系统的影响。当厌氧氨氧化生物膜系统中存在低浓度丙酸盐（30 mg/L）时,丙酸盐优先参与到硝态氮的短程反硝化过程,出现亚硝态氮的积累,当进水NH₄⁺-N和NO₂^--N为100mg/L和130 mg/L时,系统的总氮去除率仍然维持在90%,同时丙酸盐对厌氧氨氧化的活性也产生了一定的影响,使得厌氧氨氧化反应速率从7.24 mg/（L·h）降至5.56mg/（L·h）。当系统中丙酸盐浓度提高到60 mg/L时,丙酸盐的影响会随着系统初始硝态氮浓度的变化而变化。在系统初始硝态氮浓度较低时（<15 mg/L）,丙酸盐除了参与硝态氮的短程反硝化,还有部分参与到亚硝态氮的反硝化过程,同时进一步抑制厌氧氨氧化的活性,然而此时的总氮去除率提高到93%以上;在保持初始硝态氮浓度30 mg/L左右时,丙酸盐又只参与到硝态氮的短程反硝化过程,使得总氮去除率降至90%左右。根据丙酸盐浓度调整进水基质浓度配比,能够提高总氮去除率到94%。对不同条件下厌氧氨氧化系统的微生物种群进行分析,发现厌氧氨氧化的主要菌属为Candidatus＿Kuenenia和Candidatus＿Brocadia。随着丙酸盐浓度的增加（30 mg/L）,Candidatus＿Kuenenia和Candidatus＿Brocadia相对丰度逐渐下降,最终分别从8.83%和1.78%降至2.88%和0.2%,而反硝化菌属Thauera的比例从最初的0%上升到19.39%。但当系统处在进水基质最佳浓度配比时,Candidatus＿Kuenenia和Candidatus＿Brocadia相对丰度再次出现小幅度上升（6.76%和0.3%）,而Thauera相对丰度则出现小幅度下降（14.82%）。当厌氧氨氧化生物膜系统内存在腐殖酸（100～1000 mg/L）时,厌氧氨氧化未受到明显的抑制,总氮去除率基本均维持在90%左右,但反应周期较添加腐殖酸前延长了2 h。不同浓度的腐殖酸对厌氧氨氧化生物膜系统的影响几乎没有差别。微生物种群结构表明,在添加腐殖酸后,Candidatus＿Kuenenia和Candidatus＿Brocadia相对丰度分别从最初的15.01%和2.1%降至8.32%和0.6%,而Thauera相对丰度从最初的0%大幅度上升至8.86%。这表明腐殖酸不会对厌氧氨氧化的系统产生明显的抑制作用,但会对其中的微生物种群结构产生影响。本研究通过分别探究不同浓度的丙酸盐和腐殖酸条件下,厌氧氨氧化生物膜系统的脱氮性能和微生物种群结构的变化,深入阐明不同种类有机物对厌氧氨氧化系统的影响,从而为厌氧氨氧化工艺在污水处理的实际应用和优化运行提供理论指导。更多还原

【Abstract】 Anaerobic ammonium oxidation（Anammox）process has a good application prospect in nitrogen removal from wastewater due to its low energy consumption,no secondary pollutions and high cost-effectiveness;while,it will be affected by organic matters when treating the actual wastewater.The appropriate concentration of organic matters can improve the total nitrogen（TN）removal efficiency.However,there are many kinds of organic matters in the actual wastewater,including the biodegradable organic matters（e.g.volatile fatty acids）and the refractory organic matters（e.g.humic acid）.Different kinds of organic matters could make different effects on the Anammox system.Therefore,in this study,the propionate and humic acid were selected as the biodegradable and refractory organics,respectively.The variations of TN removal efficiency,extracellular polymeric substances（EPS）and microbial community structures under different organics were investigated,to clarify the effects of different organics on Anammox biofilm system from the macro and micro perspectives.When the low concentration of propionate（30 mg/L）was added into the Anammox biofilm system,the propionate was prior to participate in the partial denitrification process of nitrate,resulting in the accumulation of nitrite.When the influent NH₄⁺-N and NO₂^--N were 100 mg/L and 130 mg/L,respectively,the TN removal efficiency still remained at 90%,and the activity of Anammox was inhibited slightly,with the reaction rate decreasing from7.24 mg/（L·h）to 5.56 mg/（L·h）.When the concentration of propionate in the system increased to 60 mg/L,the effect changed with the initial concentration of nitrate in the system.Under the low condition of initial nitrate nitrogen concentrations（<15 mg/L）,part of propionate served as the electron donor for the partial denitrification of nitrate,and the other involved in the denitrification of nitrite.Although the activity of Anammox bacteria was further inhibited,the TN removal increased to more than 93%.Under the initial nitrate concentration of about 30 mg/L,propionate involved in the partial denitrification process of nitrate once again,which led to the TN removal falling to 90%.Based on the effect of propionate,the initial influent concentration was optimized to make the TN removal reaching about 94%.The microbial diversity analysis showed that the dominant genera of Anammox bacteria was Candidatus＿Kuenenia and Candidatus＿Brocadia.With the addition of propionate concentration,the relative abundance of Candidatus＿Kuenenia and Candidatus＿Brocadia decreased from 8.83%and 1.78%to 2.88%and 0.2%,respectively.However,the relative abundance of denitrifying bacteria Thauera increased from 0 to19.39%.When the system was fed with the optimal influent,the relative abundance of Candidatus＿Kuenenia and Candidatus＿Brocadia increased slightly to 6.76%and 0.3%,respectively,and the relative abundance of Thauera decreased slightly（14.82%）.When the humic acid（100～1000mg/L）was added into the Anammox biofilm system,the Anammox was not inhibited significantly,and the TN removal efficiency still maintained at about 90%.However,the reaction period was prolonged by 2 hours.There was no significant difference among the experiments of different humic acid concentrations.The microbial population structure analysis showed that the relative abundance of Candidatus＿Kuenenia and Candidatus＿Brocadia decreased from 15.01%and 2.1%to 8.32%and 0.6%,respectively,after adding humic acid,and the relative abundance of Thauera significantly increased from 0 to 8.86%.This indicated that the humic acid did not make significant effect on the Anammox process,while it would change the microbial population structure.In this study,the variations of nitrogen removal performance and microbial population structures under different concentrations of propionate and humic acid were investigated,to deep understand the effects of different organic matters on the Anammox biofilm system.This would be helpful to provide theoretical guidance for the practical application and optimization of Anammox process in wastewater treatment.更多还原