厌氧氨氧化颗粒污泥研究进展

厌氧氨氧化(Anaerobic ammonium oxidation,Anammox)工艺是一种新的生物脱氮技术。一经问世即得到人们青睐,现已成为废水脱氮的升级技术。厌氧氨氧化菌(Anaerobicammoniumoxidation bacteria,AnAOB)是Anammox工艺的功能之源。以颗粒污泥形态存在的AnAOB是Anammox颗粒污泥床脱氮系统的重要支柱。由于AnAOB生长缓慢且对环境条件变化敏感,Anammox脱氮系统不仅启动缓慢,而且运行极易失稳甚至崩溃。值得庆幸的是,AnAOB可自主选择、组合和固定功能菌群落而形成Anammox颗粒污泥,并通过其优良的重力沉降性能和高效的基质转化性能保障Anammox脱氮系统的持续工作。本文综述了AnAOB的种类和特性及Anammox颗粒污泥的组成、结构和功能,以期为Anammox工艺的优化和拓展提供参考。     

中试厌氧氨氧化反应器的启动与调控

研究了中试厌氧氨氧化(Anaerobic ammonium oxidation,Anammox)反应器的启动性能。结果表明,以硝化反硝化污泥、短程硝化污泥、厌氧絮体污泥和厌氧颗粒污泥混合接种,经过255d的运行,可在常温下(5oC～27oC)成功启动中试Anammox反应器,反应器的基质氮去除速率可达1.30kg/(m3·d)。厌氧氨氧化是致碱反应,厌氧氨氧化成为反应器内的主导反应后,进水pH宜控制在厌氧氨氧化适宜范围的偏低水平(6.8左右)。亚硝酸盐既是Anammox菌的基质,也是抑制剂,控制进水亚硝酸盐浓度(13～36mg/L)有助于厌氧氨氧化反应。菌种是生物反应器的功能之源,向中试装置投加少量厌氧氨氧化污泥(投加比2%),可大大加速中试Anammox反应器的启动进程。     

厌氧氨氧化反应器的启动研究

目的：对UASB-生物膜反应器进行厌氧氨氧化反应的启动研究。方法：以自配含氨氮和亚硝氮的废水为进水,以氧化沟工艺城市污水处理厂回流污泥为接种污泥。结果：反应器内部菌群进行了竞争,在运行至第66d时氨氮、亚硝酸盐氮的去除率分别达到了60.4%、58.7%,同时有硝酸盐氮生成,表明厌氧氨氧化反应已经成为反应器内的主导反应。结论：厌氧氨氧化反应器实现了快速启动。     

保藏温度对厌氧氨氧化颗粒污泥特性的影响

为考察保藏温度对厌氧氨氧化污泥颗粒特性的影响,同时优化保藏厌氧氨氧化颗粒污泥温度参数,本试验首先通过HRT调控进水基质负荷培养厌氧氨氧化颗粒污泥,并采用KHCO3和Na HCO3交替提供无机碳源。然后分别在–40℃、4℃、(27±4)℃室温和35℃条件下避光保藏。结果表明,Na HCO3可代替KHCO3作为厌氧氨氧化菌生长的无机碳源。相比于其他保藏温度,4℃保藏能够较好地维持生物量和生物活性,同时能较好地维持颗粒污泥的沉降性能、颗粒污泥和细胞结构完整性。在保藏过程中,一阶衰减指数模型可拟合厌氧氨氧化颗粒污泥生物量及活性的衰减过程,衰减指数与胞溶程度正相关,而且生物量的衰减比活性的衰减更快。同时,颗粒污泥胞外聚合物中蛋白质与多糖的比值(PN/PS)和血红素不能有效指示保藏过程中颗粒污泥沉降性能和活性的变化,而生物活性与胞溶程度呈负相关。     

气提式内循环硝化反应器运行性能的研究

气提式内循环反应器具有很好的生物硝化性能,能承受高进水氨浓度（78.49mmol/L）,具有高容积转化效率（163.18 mmol/L·d）,运行性能稳定（氨去除率保持在94.42%以上）。在气提式内循环反应器的运行过程中,可产生硝化颗粒污泥。颗粒污泥开始出现的时间约为45d,颗粒污泥的粒径平均值0.83 mm,沉降速度55.53m/h,氨氧化活性0.95mmol (NH⁺₄-N)/g(VS)·d。硝化颗粒污泥也具有厌氧氨氧化活性,氨氧化速率0.23mmol (NH⁺₄-N)/g(VS)·d,亚硝酸还原速率0.24mmol (NO^-₂-N)/g(VS)·d。     

情性载体厌氧颗粒污泥培育及某些性质的研究

研究了在焦碳颗粒上起动和育成厌氧颗粒污泥(或称厌氧附着膜),及其在分批反应器和膨化床反应器内的某些运转特性。在一定的选择压力(Selection pressure)下,从悬浮态种子污泥成长为颗粒污泥的过程中,其微生物相发生了明显变化。颗粒污泥的比反应速率常数K比出发悬浮态种子污泥的增大了100％左右。从而断定,除菌体浓度很高外,菌体质量的改进是这类系统（如AAFEB和uAsB等)效率特别高的另一重要原因．     

厌氧氨氧化菌内含物——糖原颗粒

厌氧氨氧化菌(anaerobic ammonium-oxidizing bacteria, AnAOB)是分类学上新近建立的细菌类群。由于生长缓慢,培养困难,迄今没有获得纯培物。与已知细菌类群相比,AnAOB具有诸多特异性细胞结构和功能。AnAOB是化能自养型细菌,但在其细胞内经常可见贮藏性的内含物——糖原颗粒。探讨这种糖原颗粒的性状与动态,可深化人们对AnAOB的认识。本文结合文献报道及前期研究基础,对厌氧氨氧化菌糖原颗粒的结构、代谢和功能特性进行了探讨,分析认为AnAOB糖原颗粒分布于核糖细胞质内,且处于多途径合成与多位点消耗的动态平衡中;此外,糖原颗粒具有提供能量、碳架和应激保护等能力,对逆境下AnAOB的生存具有重要意义。本综述可为厌氧氨氧化菌的深入研究和工程应用提供支撑。     

厌氧氨氧化颗粒污泥聚集机制研究进展

厌氧氨氧化(anaerobic ammonium oxidation,anammox)工艺被认为是当前污水生物脱氮领域最经济的处理工艺,有利于实现污水处理厂的能源自给。厌氧氨氧化菌是该工艺的核心功能微生物。以厌氧氨氧化菌为主导微生物形成的厌氧氨氧化颗粒污泥具有沉速大、污泥持留能力强及对不利环境抵抗能力强等突出优势,是实现厌氧氨氧化工艺最有前景的污泥形态。本论文围绕厌氧氨氧化颗粒,介绍了厌氧氨氧化菌的特性、种类及代谢途径,综述了厌氧氨氧化颗粒污泥的形成假说及与厌氧氨氧化颗粒污泥聚集密切相关的胞外聚合物(extracellular polymeric substance,EPS)和群体感应研究现状,并对今后厌氧氨氧化颗粒的研究进行了展望,以期为后续厌氧氨氧化颗粒的研究及厌氧氨氧化颗粒工艺的优化提供参考。     

厌氧氨氧化菌的研究进展

近年来,有关厌氧氨氧化过程这一特殊的生化机制以及微生物类群的研究引起了人们的极大关注,尤其是这类微生物的生态生境可能比人们预想的范围更加广泛,因而在自然界N循环中可能具有重要意义。对这类菌结构特征、系统发育地位以及厌氧氨氧化小体和厌氧氨氧化机制的更深入认识将大大促进它们在污水处理工程中的应用。综述了近年来有关厌氧氨氧化菌的生理特性、生化机制、结构特点、生态生境以及工程应用等方面的最新进展。     

三种接种物启动Anammox-EGSB反应器的性能

为了优选接种物和加速Anammox反应器启动,分别以厌氧产甲烷污泥 (Anaerobic methanogenic sludge,AMS)、新鲜厌氧氨氧化污泥 (Fresh Anammox sludge,FAS) 和储藏厌氧氨氧化污泥 (Stored Anammox sludge,SAS) 作为接种物,研究了厌氧氨氧化膨胀颗粒污泥床 (Anammox-EGSB) 反应器 (R1、R2和R3) 的启动性能。结果表明：3种接种物均能成功启动Anammox-EGSB反应器,启动性能的优劣次序为：R2 (接种物为     

内循环颗粒污泥床硝化反应器临界曝气强度的研究

内循环颗粒污泥床硝化反应器是一种新型高效硝化反应器 ,在反应器运行过程中 ,液体循环临界曝气强度和颗粒污泥流化临界曝气强度是两个重要操作参数。建立了升流区表观液速Ulr与曝气强度Ugr之间的关系 ,并测定了有关的模型参数 ,得到了具体的数学表达式 :U_lr=(2.613-0.024 )U^0.871_gr 0.276U^0.871_gr-0.28。根据该模型 ,计算得到的液体循环临界曝气强度为1.017cm/min ,颗粒污泥流化临界曝气强度为 2.662cm/min。实测结果证明 ,求得的两个临界曝气强度具有较高的准确性 ,能够用于指导内循环颗粒污泥床硝化反应器的操作优化.     

内循环颗粒污泥床硝化反应器流动模型研究

采用脉冲刺激响应技术,对稳态内循环颗粒污泥床硝化反应器进行了示踪试验。根据试验结果,分别运用轴向扩散模型和多釜全混流反应器串联模型,对反应器沉淀区和循环区的流态进行了分析和判断。结果表明,反应器沉淀区的分散数D/uL为0.00148,该区域的流态接近于平推流反应器（PFR）;反应器循环区的串联级数为1.021,该区域的流态接近于全混流反应器（CSTR）。稳态时,反应器的理论水力停留时间为360min,实际水力停留时间为341.2min,反应器中死区所占的体积百分比为5.22％,其中生物体死区为0.75%,水力死区为4.47%,表明反应器结构性能良好。根据试验和分析结果,建立了内循环颗粒污泥床硝化反应器的流动模型,即全混流和平推流的串联组合模型。由流动模型所得的理论停留时间分布曲线与由试验所得的实际停留时间分布曲线吻合良好,两者的平均相对误差为8.56%,表明所建模型具有较高的准确性。     

Modeling a granule‐based anaerobic ammonium oxidizing (ANAMMOX) process

A mathematical model was developed to describe the anaerobic ammonium oxidation (ANAMMOX) process in a granular upflow anaerobic sludge blanket (UASB) reactor. ANAMMOX granules were cultivated in the UASB reactor by seeding aerobic granules. The granule‐based reactor had a great N‐loading resistant capacity. The model simulation results on the 1‐year reactor performance matched the experimental data well. The yield coefficient for the growth and the decay rate coefficient of the ANAMMOX granules were estimated to be 0.164 g COD g^?1 N and 0.00016 h^?1, respectively. With this model, the effects of process parameters on the reactor performance were evaluated. Results showed that the optimum granule diameter for the maximum N‐removal should be between 1.0 and 1.3 mm and that the optimum N loading rate should be 0.8 kg N m^?3 d^?1. In addition, the substrate micro‐profiles in the ANAMMOX granules were measured with a microelectrode to explore the diffusion dynamics within the granules, and the measured profiles matched the predicted results well. Biotechnol. Bioeng. 2009;103: 490–499. © 2009 Wiley Periodicals, Inc.     

Development of a novel process for the biological conversion of H2S and methanethiol to elemental sulfur

The feasibility of anaerobic treatment of wastewater containing methanethiol (MT), an extremely volatile and malodorous sulfur compound, was investigated in lab-scale bioreactors. Inoculum biomass originating from full-scale anaerobic wastewater treatment facilities was used. Several sludges, tested for their ability to degrade MT, revealed the presence of organisms capable of metabolizing MT as their sole source of energy. Furthermore, batch tests were executed to gain a better understanding of the inhibition potential of MT. It was found that increasing MT concentrations affected acetotrophic organisms more dramatically than methylotrophic organisms. Continuous reactor experiments, using two lab-scale upflow anaerobic sludge bed (UASB) reactors (R1 and R2), aimed to determine the maximal MT load and the effect of elevated sulfide concentrations on MT conversion. Both reactors were operated at a hydraulic retention time (HRT) of about 7 hours, a temperature of 30 degrees C, and a pH of between 7.3 and 7.6. At the highest influent MT concentration applied, 14 mM in R1, corresponding to a volumetric loading rate of about 50 mM MT per day, 87% of the organic sulfur was recovered as hydrogen sulfide (12.2 mM) and the remainder as volatile organic sulfur compounds (VOSCs). Upon decreasing the HRT to 3.5 to 4.0 h at a constant MT loading rate, the sulfide concentration in the reactor decreased to 8 mM and MT conversion efficiency increased to values near 100%. MT conversion was apparently inhibited by the high sulfide concentrations in the reactor. The specific MT degradation rate, as determined after 120 days of operation in R1, was 2.83 +/- 0.27 mmol MT g VSS(-1) day(-1). During biological desulfurization of liquid hydrocarbon phases, such as with liquefied petroleum gas (LPG), the combined removal of hydrogen sulfide and MT is desired. In R2, the simultaneous addition of sodium sulfide and MT was therefore studied and the effect of elevated sulfide concentrations was investigated. The addition of sodium sulfide resulted in enhanced disintegration of sludge granules, causing significant washout of biomass. Additional acetate, added to stimulate growth of methanogenic bacteria to promote granulation, was hardly converted at the termination of the experimental period.     

Stability and reproducibility of low-temperature anaerobic biological wastewater treatment

The reproducibility of low-temperature anaerobic biological wastewater treatment trials was evaluated. Two identical anaerobic expanded granular sludge bed bioreactors were used to treat synthetic volatile fatty acid-based industrial wastewater under ambient conditions (18-20 degrees C) and to investigate the effect of various environmental perturbations on reactor performance and microbial community dynamics, which were assessed by chemical oxygen demand removal or effluent volatile fatty acid determination and terminal restriction fragment length polymorphism analysis, respectively. Methanogenic activity was monitored using specific methanogenic activity assays. Reactor performance and microbial community dynamics were each well replicated between Reactor 1 and Reactor 2. Archaeal dynamics, in particular, were associated with reactor operating parameters. Terminal restriction fragment length polymorphism data suggested dynamic acetoclastic and hydrogenophilic methanogenic populations and were in agreement with temporal specific methanogenic activity data. Putative psychrophilic populations were observed in anaerobic bioreactor sludge for the first time.     

分段组合式厌氧反应器预警性能

采用模拟有机废水,研究了分段组合式厌氧反应器 (Compartmentalized anaerobic reactor,CAR) 的预警性能。试验结果表明：高效厌氧反应器的运行稳定性低于常效厌氧反应器。在高效工况下,进水的化学需氧量 (Chemical oxygen demand,COD) 浓度的小幅提升 (平均相对标准偏差为8.08％) 可引起出水COD浓度 (平均相对标准偏差为32.95％) 和出水挥发性脂肪酸 (Volatile fatty acids,VFA) 浓度 (平均相对标准偏差为40.46％) 的大幅增加。容积负荷饱和度和VFA饱和度与反应器工况密切相关,可用于厌氧反应过程的预警。常负荷工况下 (容积负荷饱和度和VFA饱和度低于0.89与0.40),反应运行性能稳定;满负荷工况下 (容积负荷饱和度和VFA饱和度趋近1),反应运行性能波动增大;超负荷工况下 (容积负荷饱和度和VFA饱和度超过1),反应运行性能恶化。     

Performance and Microbial Structure of a Combined Biofilm Reactor

A novel combined biofilm reactor was established and applied as a single treatment unit for carbon and nitrogen removal of wastewater. The nitrogen removal performance of the reactor at different levels of organic carbon (COD) loading was investigated when the influent total nitrogen (TN) loading was 0.74 g TN/m² day. Continuous experimental results demonstrated that 80% nitrogen was eliminated when the influent COD loading ranged between 2.06 g and 3.92 g COD/m² day. Microbial composition in the reactor was analyzed using fluorescent in situ hybridization (FISH) and conventional batch tests. The relative abundance of ammonia-oxidizing bacteria in the aerobic zone of the reactor measured by FISH was consistent with the result from conventional batch tests.     

Formation of metabolites during biodegradation of linear alkylbenzene sulfonate in an upflow anaerobic sludge bed reactor under thermophilic conditions.

Biodegradation of linear alkylbenzene sulfonate (LAS) was shown in an upflow anaerobic sludge blanket reactor under thermophilic conditions. The reactor was inoculated with granular biomass and fed with a synthetic medium and 3 micromol/L of a mixture of LAS with alkylchain length of 10 to 13 carbon atoms. The reactor was operated with a hydraulic retention time of 12 h with effluent recirculation in an effluent to influent ratio of 5 to 1. A sterile reactor operated in parallel revealed that sorption to sludge particles initially accounted for a major LAS removal. After 8 days of reactor operation, the removal of LAS in the reactor inoculated with active granular biomass exceeded the removal in the sterile reactor inoculated with sterile granular biomass. The effect of sorption ceased after 185 to 555 h depending on the LAS homologs. 40% of the LAS was biodegraded, and the removal rate was 0.5 x 10(-6) mol/h/mL granular biomass. Acidified effluent from the reactor was subjected to dichloromethane extraction followed by gas chromatography/mass spectrometry. Benzenesulfonic acid and benzaldehyde were detected in the reactor effluent from the reactor with active granular biomass but not in the sterile and unamended reactor effluent. Benzenesulfonic acid and benzaldehyde are the first identified degradation products in the anaerobic degradation of LAS.