外源自诱导物对厌氧氨氧化的影响

厌氧氨氧化作为污水生物脱氮新工艺,存在着菌群倍增时间长,一旦随水流失,脱氮性能会急剧下降的问题.N-酰基高丝氨酸内酯（AHLs）作为一类典型的诱发群体感应效应的自诱导物,可能会激活部分基因的表达.有研究表明两种常见的AHLs：C6-HSL和C8-HSL对厌氧氨氧化菌群的成膜机制有促进作用.本试验通过外添加C6-HSL和C8-HSL两种自诱导物,深入探究其对厌氧氨氧化菌群的影响.结果表明浓度为0.5g/L的AHLs会抑制厌氧氨氧化菌群的生长,但能提高其脱氮性能,并显著促进联氨合成酶（hydrazine synthase subunit A,hzsA）基因的表达,但两种AHLs的促进作用有所差别,相同浓度的C8-HSL较C6-HSL对hzsA基因表达的促进作用更为明显.     

低温下AHLs对多级A/O工艺中好氧生物膜特性的影响

针对低温条件下多级A/O工艺出水氨氮容易超标问题,进行外源添加酰基高丝氨酸内酯类信号分子（AHLs）对低温下多级A/O工艺好氧段生物膜特性的影响研究.结果表明:添加100nmol/L的己酰基高丝氨酸内酯（C6-HSL）后生物膜硝化效率提高了22.34%,十二烷酰基高丝氨酸内酯（C12-HSL）则将生物附着量提高了24.47%,且C6-HSL和C12-HSL对生物膜硝化效率和生物附着量的提高作用均具有长期性.这是因为C6-HSL能够将低温下好氧段生物膜硝化活性提高17.56%,而C12-HSL可以将胞外聚合物（EPS）中蛋白质（PN）的含量提高67.37%.此外,C6-HSL和C12-HSL均能促进对应信号分子的内源释放,因此对生物膜硝化活性和附着性能具有长期积极影响.高通量测序分析表明C6-HSL可提高Nitrosomonas（亚硝化单胞菌）的丰度,故能提高R2中生物膜硝化活性;而外源添加C12-HSL对Rhodobacter（红杆菌属）丰度影响较大,这是实验组R5生物膜EPS中PN含量增加的重要原因.     

外源群体感应-好氧反硝化菌强化生物膜脱氮研究

重点研究了外源添加高AHLs调控能力的群体感应-异养硝化好氧反硝化菌(QS-HNAD)过程中生物膜反应器的运行、生物膜生理生化特征、信号分子浓度、脱氮功能基因含量、群落组成和空间结构的变化.结果表明,高C/N比(8～14)条件更有利于其促进反应器脱氮效能:添加群体感应Pseudomonas mendocina促进了反应器的反硝化,而添加Pseudomonas putida提高了氨氮的去除.与水相比,生物膜相信号分子对于环境变化具有更灵敏的响应,C6-HSL是潜在调控生物膜修复和强化脱氮的信号分子.荧光定量qPCR表明,外源添加QS-HNAD有效促进了氨氧化、硝酸盐还原和一氧化氮还原过程.微生物群落结构分析表明,添加不同外源QS-HNAD菌的生物膜微生物群落结构差异较大,P.mendocina菌促进了放线菌、TM7、变形菌在生物膜中富集.     

有机负荷对污泥胞外聚合物(EPS)分泌特性及信号分子释放差异的影响

考察了连续流A2/O系统在3个有机负荷[0.29,0.58,1.16 kg COD/(m3·d)]条件下,胞外聚合物(EPS)分泌特性及信号分子(AHLs)的释放差异.结果表明:TB-EPS是污泥系统中EPS主要成分,TB-EPS组分具有较高的分子量,且分子量分布更广.有机负荷对LB-EPS各组分的影响大于TB-EPS...     

Effects of ferrous and manganese ions on anammox process in sequencing batch biofilm reactors

Ferrous and manganese ions, as essential elements, significantly affect the synthesis of Haem-C, which participates in the energy metabolism and proliferation of anammox bacteria. In this study, two identical sequencing batch biofilm reactors were used to investigate the effects of ferrous and manganese ions on nitrogen removal efficiency and the potential of metal ions serving as electron donor/acceptors in the anammox process. Fluorescence in situ hybridization analysis was applied to investigate the microbial growth. Results showed that the nitrogen removal increased at high concentrations of Fe2＋ and Mn2＋ and the maximum removal efficiency was nearly 95% at Fe2＋ 0.08 mmol/L and Mn2＋ 0.05 mmol/L, which is nearly 15% and 8% higher than at the lowest Fe2＋ and Mn2＋ concentrations （0.04 and 0.0125 mmol/L）. The stabilities of the anammox reactor and the anammox bacterial growth were also enhanced with the elevated Fe2＋ and Mn2＋ concentrations. The Fe2＋ and Mn2＋were consumed by anammox bacteria along with the removal of ammonia and nitrite. Stoichiometry analysis showed Fe2＋ could serve as an electron donor for NO3-N in the anammox process. Nitrate could be reduced with Fe2＋ serving as the electron donor in the anammox system, which causes the value of NO~-N/NH4-N to decrease with the increasing of N-removal efficiency.     

有机物对厌氧氨氧化生物膜反应器脱氮效能及微生物群落的影响

为考察有机物对厌氧氨氧化生物膜反应器脱氮效能的影响,采用MPN（most probable number）法和高通量测序技术,结合处理效果数据,对比分析了有无有机物影响下生物膜中微生物群落差异.试验表明：在进水有机物（COD）为30和60 mg·L^-1作用下,总氮去除率与进水COD为0 mg·L^-1时的84.10%相比较分别提高了5.08%和10.41%;COD为90 mg·L^-1时,总氮去除率降至89.05%.由MPN法和高通量测序结果可知,相对于无有机物,60 mg·L^-1有机物使反应器中反硝化菌数量增加,浮霉菌门和变形菌门丰度明显提高,且微生物群落更加丰富.有机物能影响反应器中厌氧氨氧化、反硝化脱氮效能及微生物菌落丰度,适宜的有机物浓度可使厌氧氨氧化与反硝化作用有效耦合,提高反应器的脱氮效能.本研究可为厌氧氨氧化生物膜反应器处理含有机物的实际污水提供参考价值.     

Inhibition factors and Kinetic model for ammonium inhibition on the anammox process of the SNAD biofilm

The aim of the present work was to evaluate the anaerobic ammonium oxidation (anammox) activity of simultaneous partial nitrification, anammox and denitrification (SNAD) biofilm with different substrate concentrations and pH values. Kaldnes rings taken from the SNAD biofilm reactor were incubated in batch tests to determine the anammox activity. Haldane model was applied to investigate the ammonium inhibition on anammox process. As for nitrite inhibition, the NH₄⁺-N removal rate of anammox process remained 87.4% of the maximum rate with the NO₂⁻-N concentration of 100 mg/L. Based on the results of Haldane model, no obvious difference in kinetic coefficients was observed under high or low free ammonia (FA) conditions, indicating that ammonium rather than FA was the true inhibitor for anammox process of SNAD biofilm. With the pH value of 7.0, the r_max, Ks and K_I of ammonium were 0.209 kg NO₂⁻-N/kg VSS/day, 9.5 mg/L and 422 mg/L, respectively. The suitable pH ranges for anammox process were 5.0 to 9.0. These results indicate that the SNAD biofilm performs excellent tolerance to adverse conditions.     

信号分子对高负荷UASB中ANAMMOX颗粒特性的影响

针对高负荷反应器中ANAMMOX颗粒污泥易上浮流失的问题,进行外源添加酰基高丝氨酸内酯类信号分子（AHLs）对污泥特性的影响研究.结果表明添加30mg/L辛酰基高丝氨酸内酯（C8-HSL）可对颗粒污泥沉降性能产生长期影响,能够有效控制高负荷UASB中ANAMMOX颗粒污泥上浮.仅在实验初期（0~20d）向反应器R2中添加C8-HSL,在实验进行至100d时R2中颗粒污泥B-EPS含量相比对照组R1降低15%,PN/PS值由4.22下降至2.14,同时污泥颗粒表面疏水性提高了26%,因此R2中颗粒污泥的沉降性能大幅提高（颗粒污泥密度增加了24%,沉速提高了90%）.实验进行至100d,R2未发生较明显污泥上浮现象,此时氮容积负荷NLR为12.9kg-TN/（m³·d）,氮容积去除率NRR高达11.3kg-TN/（m³·d）,氮去除率达88%.己酰基高丝氨酸内酯（C6-HSL）可使污泥颗粒的活性有所提高,而十二烷酰基高丝氨酸内酯（C12-HSL）则对高负荷反应器中颗粒污泥的特性没有影响.     

The performance of a combined nitritation-anammox reactor treating anaerobic digestion supernatant under various C/N ratios

A combined nitritation–anammox reactor was developed to treat the digestion supernatant under various C/N ratios. Due to the difficulties for heterotroph to utilize the refractory organics, the reactor presented relatively stable performance with increasing supernatant addition. Nevertheless, the adverse effects of supernatant would accumulate during the long-term operation and thus weakened the activity and shock resistance of microbes,which further led to the gradual decrease of reactor performance after 92 days' operation.Under this circumstance, supernatant with volatile fatty acids(VFAs) residuals was further introduced into the reactor to investigate the performance of combined nitritation–anammox process with VFA addition. With the appearance of VFAs, the nitrogen removal performance gradually restored and the reactor finally achieved stable and efficient performance with C/N ratio of 0.35. The VFA residuals within 150 mg/L in the supernatant served as the extra electron donors and stimulated the heterotrophic denitrification process, which was vital for the enhancement of reactor. The nitrogen removal rate and total nitrogen removal efficiency reached 0.49 kg N/(m3·day) and 88.8% after 140 days' operation, respectively. The combined nitritation–anammox reactor was proved suitable to treat digestion supernatant.     

MnO2强化厌氧氨氧化工艺启动及其微生物机理研究

通过对照试验考察了添加MnO₂对厌氧氨氧化污泥驯化和培养的影响,并采用16S rRNA基因高通量测序技术和定量PCR分析其机理.结果表明,添加MnO₂粉末能够显著提高容积氮负荷及运行性能,其脱氮速率高达848.04 mg·L^-1·d^-1,几乎是对照组反应器的2倍.16S rRNA基因高通量测序技术和定量PCR结果表明,添加MnO₂粉末促进了典型厌氧氨氧化菌Candidate Brocadia的富集,厌氧氨氧化菌16S rRNA基因和功能基因hzsB的丰度显著提高.     

复合式厌氧氨氧化反应器脱氮性能研究

采用低速机械搅拌装置,以无纺布作为固定床的填料,把搅拌床与固定床的优点有机结合起来,设计一种复合式厌氧氨氧化反应器.在反应器中,生物滞留量相对较高,微生物的性状由接种时的碎絮状很快转变成颗粒状,短期内反应器系统的脱氮性能迅速提高,启动时间大为缩短.仅用38d,反应器中总氮去除速率稳定增长至1.9kg·m·-3d-1.随...     

胞外聚合物和信号分子对厌氧氨氧化污泥活性的影响

为了探究胞外聚合物（EPS）对厌氧氨氧化颗粒污泥活性的影响,分别向厌氧氨氧化颗粒污泥中投加30mg/L的总胞外聚合物（IN-EPS）,松散结合型胞外聚合物（LB-EPS）和紧密结合型胞外聚合物（TB-EPS）.结果表明,3种EPS均可提高厌氧氨氧化颗粒污泥的活性.对于添加了IN-EPS,LB-EPS和TB-EPS的实验组,厌氧氨氧化颗粒污泥的氨氮去除速率分别增加了6.68%,10.5%和19.29%,厌氧氨氧化菌的生长速率分别增加了18.25%,21%,16.3%.三维荧光光谱法分析发现3种EPS的组成基本相同,以芳香族蛋白质和可溶性微生物产物为主.对EPS中的高丝氨酸内酯类（AHLs）信号分子进行检测,发现EPS中含有3种信号分子,分别是C4-HSL,C6-HSL和C10-HSL,外源投加这3种AHLs到厌氧氨氧化颗粒污泥中,结果发现C4-HSL和C6-HSL可以提高厌氧氨氧化颗粒污泥的活性和生长速率,这是EPS可以提高厌氧氨氧化菌活性的原因.     

好氧颗粒污泥形成过程中群感效应的作用研究

通过观察污泥颗粒化过程中胞外聚合物和水解氨基酸的变化情况,同时监测在好氧颗粒污泥形成过程中不同种类酰化高丝氨酸内酯类化合物（AHLs）在AGS形成过程的变化规律,协同研究群感效应对胞外聚合物产生的影响,进而揭示颗粒化过程中污泥变化特征.结果表明,絮状污泥颗粒化过程中,AGS最终平均粒径约为150 μm,胞外聚合物中蛋白质增幅较大且以紧密结合型胞外聚合物及Pellet层胞外聚合物增加为主.污泥胞外聚合物中芳香族类物质及酪氨酸蛋白物质的生成是AGS形成的物质基础;丙氨酸、甲硫氨酸等疏水性物质可促进AGS的生成并维持其稳定.在AGS形成过程中,群感效应整体呈现为加强趋势,其中C4-HSL呈现明显浓度下降趋势,C6-HSL,3OC6-HSL及C8-HSL与胞外聚合物,蛋白质及多糖均呈现正相关趋势,其中C6-HSL和C8-HSL与紧密结合型胞外聚合物中的蛋白质及多糖呈现极显著正相关.     

Impact of soluble organic matter and particulate organic matter on anammox system: Performance,microbial community and N2O production

In this study,the effects of soluble readily biodegradable COD (sCOD) and particulate slowly biodegradable COD (pCOD) on anammox process were investigated.The results of the longterm experiment indicated that a low sCOD/N ratio of 0.5 could accelerate the anammox and denitrification activity,to reach as high as 84.9%±2.8% TN removal efficiency.Partial denitrification-anammox (PDN/anammox) and denitrification were proposed as the major pathways for nitrogen removal,accounting for 91.3% and 8.7% o...     

Influence and mechanism of N-(3-oxooxtanoyl)-L-homoserine lactone (C8-oxo-HSL) on biofilm behaviors at early stage

N-acyl-homoserines quenching, enzymatic quenching of bacterial quorum sensing, has recently applied to mitigate biofilm in membrane bioreactor. However, the effect of AHLs on the behavior of biofilm formation is still sparse. In this study, Pseudomonas aeruginosa biofilm was formed on ultra-filtration membrane under a series of N-(3-oxooxtanoyl)-L-homoserine lactone (C₈-oxo-HSL) concentrations. Diffusing C₈-oxo-HSL increased the growth rate of cells on biofilm where the concentration of C₈-oxo-HSL was over 10^-7 g/L. The C₈-oxo-HSL gradient had no observable influence on cell density and extracellular polymeric substances of biofilm with over 10^-7 g/L C₈-oxo-HSL. Surprisingly, 10^-11-10^-8 g/L of C₈-oxo-HSL had no effect on cell growth in liquid culture. The cell analysis demonstrated that the quorum sensing system might enhance the growth of neighboring cells in contact with surfaces into biofilm and may influence the structure and organization of biofilm.     

自然生境中厌氧氨氧化功能微生物生态学研究进展

自然生境中发生的厌氧氨氧化过程是继反硝化和好氧氨氧化后的又一条氮损失途径,对全球生态系统氮循环具有重要意义,但不同自然生态系统中存在不同种类的厌氧氨氧化微生物.通过阐述厌氧氨氧化反应发生的生理机制,并对不同自然环境中发现的厌氧氨氧化功能微生物进行梳理,分析了厌氧氨氧化菌分布的空间异质性成因.结果表明,适量的无机氮可以促进厌氧氨氧化的发生,有机碳含量低和低氧条件更有利于厌氧氨氧化菌的生存且厌氧氨氧化的活性较高,这与厌氧氨氧化菌的化能自养代谢途径有着紧密的联系,低养分条件下反硝化菌的活性受到短暂抑制,促进了厌氧氨氧化的发生.同时,适当的高盐环境会提高厌氧氨氧化活性并促进厌氧氨氧化菌群落结构转变,高盐度环境下Scalindua属占优势,低盐度环境下Brocadia属更占优势.厌氧氨氧化菌对温度变化有很好的适应性,大部分厌氧氨氧化菌（如Scalindua属、Kuenenia属和Brocadia属）对于极端环境均有较强的环境适应性;此外,悬浮颗粒物浓度、含水量等因素也会影响厌氧氨氧化菌的分布及其代谢活性.建议今后从基因组学、蛋白组学和转录组学相结合的角度对自然环境中的厌氧氨氧化菌开展生理生态机理的研究,并探明厌氧条件下Fe3+、Mn4+、SO₄2-等电子受体与厌氧氨氧化过程的生物化学联系,以更好地应用于工程技术研究,并为生态环境修复提供理论依据.      

一体化厌氧氨氧化反应器的优化及其稳定性研究

采用一体化厌氧氨氧化SBR反应器(120L)处理高氨氮废水,研究系统总氮去除负荷提高和稳定性的影响因素.长期试验结果表明:该一体化厌氧氨氧化SBR反应器的最大总氮去除负荷为1.1kg/(m³·d),影响反应器运行稳定性的主要因素有:游离氨浓度、溶解氧浓度、絮体污泥和颗粒污泥相对比例等.在一体化厌氧氨氧化反应器中保持AOB和Anammox活性的相互匹配是维持系统稳定运行的关键因素.大量淘洗絮体污泥会造成氨氧化活性降低和溶解氧升高,从而引起总氮去除负荷下降.限制反应器负荷增加的主要因素有:(1)污泥随出水流失,体系污泥浓度保持恒定;(2)受溶解氧影响AOB和Anammox活性不能同时提高;(3)传质效率难以进一步提高.试验中发现总氮去除负荷和曝气量之间具有很好的相关性,反应器负荷波动时通过调整曝气量来调控反应状态,有利于一体化工艺的稳定运行.     

红树林湿地污水消纳过程中厌氧氨氧化菌存在特征

厌氧氨氧化过程作为滨海生态系统氮去除的有效途径,对维持滨海生态系统氮元素收支平衡具有重要意义.本研究采用基于16S rRNA基因的荧光定量PCR(qPCR)技术,并结合环境因子,对红树林湿地中厌氧氨氧化菌基因丰度和相对丰度的存在特征进行考察.结果表明,在红树林湿地0～65 cm深度的沉积物中均检出厌氧氨氧化菌,随距排污口距离及深度的增加,本研究中厌氧氨氧化菌基因丰度和相对丰度未发现明显的分布规律.相关性分析表明,厌氧氨氧化菌基因丰度和相对丰度在红树林湿地沉积物中的空间分布与环境因子密切相关,厌氧氨氧化菌基因丰度与总氮(TN)、总有机碳(TOC)和总碳(TC)呈显著正相关,氨氮(NH~+_4-N)、亚硝氮(NO~-_2-N)、硝态氮(NO~-_3-N)和电导率(EC)是影响厌氧氨氧化菌基因丰度的重要因子;相对丰度与C∶P、N∶P比值呈显著正相关,C∶N比值、总碳(TC)和电导率(EC)是影响厌氧氨氧化菌基因相对丰度的重要因子.综上,针对厌氧氨氧化菌16S rRNA定量分析在一定程度上揭示了红树林湿地厌氧氨氧化菌基因丰度、相对丰度与环境因子的耦合关系.     

Inhibitive effects of chlortetracycline on performance of the nitritation-anaerobic ammonium oxidation (anammox) process and strategies for recovery

The short-and long-term effects of chlortetracycline(CTC) on the nitritation-anaerobic ammonium oxidation(anammox) process were evaluated. The half maximal inhibitory concentration of CTC in the batch tests of the nitritation-anammox process was 278.91 mg/L at an exposure time of 12 hr. The long-term effects of CTC on the process were examined in a continuous-flow nitritation-anammox reactor. Within 14 days, the nitrogen removal rate significantly decreased from 0.61 to 0.25 kg N/m~3/day with 60 mg/L CTC in the influent.The performance suppressed by CTC barely recovered, even after CTC was removed from the influent. Furthermore, the inhibition of CTC also reduced the relative abundance of ammonium oxidizing bacteria(AOB) and anaerobic ammonium oxidizing bacteria(An AOB)in the reactor, resulting in both a decreased amount of and an imbalance between AOB and An AOB. When fresh anammox sludge was reseeded into the nitritation-anammox reactor,the nitrogen removal rate recovered to 0.09 ± 0.03 kg N/m~3/day.