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。     

Anammox反应器启动过程中颗粒污泥性状变化特性

以厌氧颗粒污泥作为接种物,通过185 d的运行,成功启动了上流式厌氧氨氧化污泥床(Upflow anaerobic sludge blanket,UASB)反应器。反应器的进水氨氮与亚硝氮浓度分别提升至224 mg/L和255 mg/L,容积氮去除速率提升至3.76 kg/(m3·d)。采用红外光谱、扫描电镜和透射电镜等对厌氧氨氧化颗粒污泥的性状进行观察,发现颗粒污泥在启动过程中经历了污泥颗粒裂解到污泥颗粒重组的过程,且厌氧氨氧化颗粒污泥表面含有丰富的官能团,说明厌氧氨氧化颗粒污泥可能具有良好的吸附性能。采用宏基因组测序的方法对启动前后颗粒污泥的生态结构进行分析,发现原接种污泥优势菌群(变形菌门、厚壁菌门、拟杆菌门)丰度大幅减少,厌氧氨氧化菌所属的浮霉状菌门丰度则由1.59%提升到23.24%。     

厌氧氨氧化启动过程Anammox菌富集规律和差异分析

为明确厌氧氨氧化反应器启动过程中Anammox菌的富集规律,采用荧光原位杂交(FISH)和实时荧光定量PCR(q-PCR)分析技术,对未添加填料、添加多面空心球以及添加竹炭的3个UASB反应器厌氧氨氧化启动过程中Anammox菌的增长规律进行分析。研究表明,Anammox菌的相对数量和绝对数量均随着启动时间呈逐渐递增趋势,在稳定运行阶段的第123天,无填料、多面空心球和竹炭反应器中Anammox菌分别占总细菌的23.3%、32.6%和43.7%,单位VSS污泥中Anammox菌16S rRNA基因拷贝数分别为(25.64±2.76)×107、(47.12±2.76)×107和(577.99±27.25)×107拷贝数g–1 VSS。竹炭反应器中Anammox菌最大生长率和最短倍增时间分别为0.064 d?1和10.8 d,最大生长率分别是无填料和多面空心球反应器的1.78倍和1.88倍。因此,填料添加特别是竹炭的添加可极大地促进Anammox菌的选择性生长和繁殖。FISH和q-PCR分析技术均适用于Anammox菌的富集规律研究,但因其检测目标存在差异,造成两者表征结果有所不同。     

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。     

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。     

厌氧氨氧化膨胀床反应器的运行性能

试验研究了以竹炭为载体的厌氧氨氧化膨胀床反应器的运行性能.接种反硝化污泥,用模拟废水可成功启动该反应器:运行至144 d时,容积总氮去除率达到3.02 kg N/m3/d.这是国内文献报道的最高水平.动力学分析表明.这种反应器的最大容积总氮去除率可迭12.77 kg N/m3/d.具有很大的脱氮潜能.反应器的启动过程可分为菌体自溶、活性延滞和活性提高三个阶段.与此相应,污泥性状也从黄褐色絮状污泥变为棕灰色颗粒污泥和红色颗粒污泥.红色颗粒污泥以杆茵和球菌为主.厌氧氨氧化活性可达0.56mg TN/(mgprotein)/h,它们是反应器厌氧氨氧化功能的主要承载者.     

厌氧氨氧化体的组成、结构与功能

厌氧氨氧化(Anammox)是微生物和环境领域的研究热点之一。厌氧氨氧化菌(AnAOB)是Anammox的功能载体。不同于大部分原核微生物,AnAOB具有独特的细胞器——厌氧氨氧化体,它是进行Anammox代谢的场所。研究厌氧氨氧化体有助于探明厌氧氨氧化菌的代谢特性。本文综述了厌氧氨氧化体的组成、结构与功能,以期为从事Anammox研究的同行提供参考。     

改性生物填料载体强化厌氧氨氧化反应器脱氮研究

以上流式厌氧污泥床(UASB)为研究对象,主要探究2种改性生物填料载体对厌氧氨氧化反应器脱氮性能的影响,并以电子扫描显微镜(SEM)、脱氢酶活性检测及菌群结构分析等微观方面解析影响脱氮性能差异的原因.结果 表明:活性炭聚氨酯及改性聚乙烯塑料填料2种生物填料载体的投加均能在一定程度上提高厌氧氨氧化反应器的脱氮性能,当反应...     

污水处理系统中厌氧氨氧化菌分布及影响因素

基于厌氧氨氧化的污水生物脱氮工艺近年来发展迅速,污水处理系统中厌氧氨氧化菌的分布和多样性成为了重要的研究方向。目前,在污水处理系统中曾检测出多种厌氧氨氧化(Anaerobic ammonium oxidation,Anammox)菌,最常被检测出的是待定布罗卡地菌Candidate Brocadia和待定斯图加特库氏菌Candidate Kuenenia的Anammox菌,并且研究发现单一生境下往往只存在一种类型的Anammox菌,但是影响Anammox菌分布和多样性的因素与机制目前仍不明确。系统总结了污水处理系统中,不同工艺形式和运行条件下的Anammox菌分布情况,归纳分析了关键因素对Anammox菌分布的影响,包括底物浓度和微生物比生长速率、污泥性质与微生物生境、多重因素的联合作用和影响等。在此基础上,阐述了Anammox菌分布机制研究的工程意义,并对该领域的研究方向和思路进行了展望。     

Anammox反应器启动前后微生物群落结构差异性

接种A^2/O回流污泥启动Anammox-UASB反应器,研究了上升流速对系统脱氮性能影响,利用高通量测序对反应器中微生物群落结构变化进行了研究。结果表明,历时35 d成功启动Anammox反应器。上升流速升高可以明显促进脱氮效果,在最佳上升流速为1.14 m/h时TN去除率达84.74%,去除速率高达0.766 gTN/(L·d)。高通量分析表明,Anammox污泥群落Alpha多样性较接种污泥明显减少,Anammox污泥中的Anammox菌主要为Candidatus Jettenia和Candidatus Brocadia两个属,同时检测到大量的其他脱氮微生物菌属,系统中这些脱氮微生物的大量增值使系统脱氮能力逐步提高。     

Start-up and inhibition analysis of the Anammox process seeded with anaerobic granular sludge

The longer start-up period of the Anammox process is due to the very low cellular yield and growth rates of Anammox bacteria. Nitrite inhibition is considered to be the key factor in the instability of the Anammox process during the operation. However, little attention was paid to the inhibitory effect of pH and free ammonia. This paper presents start-up and inhibition analysis of an Anammox biofilm reactor seeded with anaerobic granular sludge. Results showed that the start-up period could be divided into the sludge lysis phase, lag phase, propagation phase, stationary phase and inhibition phase. Optimization control could be implemented correspondingly to accelerate the start-up of Anammox bioreactors. Effluent pH increased to 8.7–9.1 when the nitrogen removal rate was higher than 1,200 mg l⁻¹ day⁻¹. The free ammonia concentration was accompanied with a higher level of 64–73 mg l⁻¹. Inhibitory effects of high pH and free ammonia on Anammox bacteria contributed to the destabilization of the Anammox bioreactor during the first 125 days with influent KHCO₃ of 0.5 g l⁻¹. Increasing the suffering capacity in the inlet by dosing 1.25 g KHCO₃ l⁻¹ effectively reduced the pH variation, and the nitrogen removal performance of the reactor was further developed.     

Anaerobic oxidation of ammonium is a biologically mediated process.

A newly discovered process by which ammonium is converted to dinitrogen gas under anaerobic conditions (the Anammox process) has now been examined in detail. In order to confirm the biological nature of this process, anaerobic batch culture experiments were used. All of the ammonium provided in the medium was oxidized within 9 days. In control experiments with autoclaved or raw wastewater, without added sludge or with added sterilized (either autoclaved or gamma irradiated) sludge, no changes in the ammonium and nitrate concentrations were observed. Chemical reactions could therefore not be responsible for the ammonium conversion. The addition of chloramphenicol, ampicillin, 2,4-dinitrophenol, carbonyl cyanide m-chlorophenyl-hydrazone (CCCP), and mercuric chloride (HgIICl2) completely inhibited the activity of the ammonium-oxidizing sludge. Furthermore, the rate of ammonium oxidation was proportional to the initial amount of sludge used. It was therefore concluded that anaerobic ammonium oxidation was a microbiological process. As the experiments were carried out in an oxygen-free atmosphere, the conversion of ammonium to dinitrogen gas did not even require a trace of O2. That the end product of the reaction was nitrogen gas has been confirmed by using 15NH4+ and 14NO3-. The dominant product was 14-15N2. Only 1.7% of the total labelled nitrogen gas produced was 15-15N2. It is therefore proposed that the N2 produced by the Anammox process is formed from equimolar amounts of NH4+ and NO3-.     

Start-up and stabilization of an Anammox process from a non-acclimatized sludge in CSTR

Development of an Anammox (anaerobic ammonium oxidation) process using non-acclimatized sludge requires a long start-up period owing to the very slow growth rate of Anammox bacteria. This article addresses the issue of achieving a shorter start-up period for Anammox activity in a well-mixed continuously stirred tank reactor (CSTR) using non-acclimatized anaerobic sludge. Proper selection of enrichment conditions and low stirring speed of 30 ± 5 rpm resulted in a shorter start-up period (82 days). Activity tests revealed the microbial community structure of Anammox micro-granules. Ammonia-oxidizing bacteria (AOB) were found on the surface and on the outer most layers of granules while nitrite-oxidizing bacteria (NOB) and Anammox bacteria were present inside. Fine-tuning of influent NO₂ ⁻/NH₄ ⁺ ratio allowed Anammox activity to be maintained when mixed microbial populations were present. The maximum nitrogen removal rate achieved in the system was 0.216 kg N/(m³ day) with a maximum specific nitrogen removal rate of 0.434 g N/(g VSS day). During the study period, Anammox activity was not inhibited by pH changes and free ammonia toxicity.     

Accelerating effect of hydroxylamine and hydrazine on nitrogen removal rate in moving bed biofilm reactor

In biological nitrogen removal, application of the autotrophic anammox process is gaining ground worldwide. Although this field has been widely researched in last years, some aspects as the accelerating effect of putative intermediates (mainly N?H? and NH?OH) need more specific investigation. In the current study, experiments in a moving bed biofilm reactor (MBBR) and batch tests were performed to evaluate the optimum concentrations of anammox process intermediates that accelerate the autotrophic nitrogen removal and mitigate a decrease in the anammox bacteria activity using anammox (anaerobic ammonium oxidation) biomass enriched on ring-shaped biofilm carriers. Anammox biomass was previously grown on blank biofilm carriers for 450 days at moderate temperature 26.0 (±0.5) °C by using sludge reject water as seeding material. FISH analysis revealed that anammox microorganisms were located in clusters in the biofilm. With addition of 1.27 and 1.31 mg N L?1 of each NH?OH and N?H?, respectively, into the MBBR total nitrogen (TN) removal efficiency was rapidly restored after inhibitions by NO??. Various combinations of N?H?, NH?OH, NH??, and NO?? were used as batch substrates. The highest total nitrogen (TN) removal rate with the optimum N?H? concentration (4.38 mg N L?1) present in these batches was 5.43 mg N g?1 TSS h?1, whereas equimolar concentrations of N?H? and NH?OH added together showed lower TN removal rates. Intermediates could be applied in practice to contribute to the recovery of inhibition-damaged wastewater treatment facilities using anammox technology.     

流加菌种对厌氧氨氧化工艺的影响

厌氧氨氧化工艺具有很高的容积氮去除速率,现已成功应用于污泥压滤液等含氨废水的脱氮处理,容积氮去除速率高达9.5 kg/(m3·d)。但由于厌氧氨氧化菌为自养型细菌,生长缓慢,对环境条件敏感,致使厌氧氨氧化工艺启动时间过长,运行容易失稳,并且不适合处理有机含氨废水和毒性含氨废水,极大地限制了该工艺的进一步推广应用。为了克服厌氧氨氧化工艺实际应用中存在的问题,结合发酵工业中常用的菌种流加技术,提出了一种新型的菌种流加式厌氧氨氧化工艺,研究了该新型工艺在厌氧氨氧化工艺的启动过程、稳定运行以及处理有机含氨废水和毒性含氨废水等方面的应用情况。结果表明,通过向反应器内补加优质厌氧氨氧化菌种,可提高厌氧氨氧化菌数量及其在菌群中的比例,强化厌氧氨氧化功能。据此研发的菌种流加式厌氧氨氧化工艺不仅可以实现快速启动,而且可以稳定运行,并突破了有机物和毒物所致的运行障碍,拓展了厌氧氨氧化工艺的应用范围。     

Assessment of partial nitrification reactor performance through microbial population shift using quinone profile, FISH and SEM

In engineered systems, biological nitrogen removal through partial nitrification to nitrite is of great interest. Accordingly, effect of operating parameters such as pH, DO and temperature on the accumulation of ammonia-oxidizers was investigated. pH of 8, DO of 0.3-0.5mg/l and temperature of 35 degrees C yielded a ratio of 0.9-1.5 of NO(2)N:NH(4)N in the effluent suitable as a feed for Anammox reactor. Microbial population shift during start-up was assessed using quinone profile, SEM and FISH. UQ-8 in the biomass, which is the predominant quinone in ammonia-oxidizers, increased from 24.8% on Day 1 to 61.2% on Day 136. Fluorescence in situ hybridization analysis in the reactor showed that ammonia-oxidizing bacteria gradually outcompeted other bacteria and was the dominant population. The morphology and inner structure of the granular sludge was observed using SEM and the photographs indicated that the aerobic granular sludge showed a shift towards spherical and small rod-shaped clusters.     

Cultivation of low-temperature (15°C), anaerobic, wastewater treatment granules

Aims: Anaerobic sludge granules underpin high‐rate waste‐to‐energy bioreactors. Granulation is a microbiological phenomenon involving the self‐immobilization of several trophic groups. Low‐temperature anaerobic digestion of wastes is of intense interest because of the economic advantages of unheated bioenergy production technologies. However, low‐temperature granulation of anaerobic sludge has not yet been demonstrated. The aims of this study were to (i) investigate the feasibility of anaerobic sludge granulation in cold (15°C) bioreactors and (ii) observe the development of methanogenic activity and microbial community structure in developing cold granules. Methods and Results: One mesophilic (R1; 37°C) and two low‐temperature (R2 and R3, 15°C) laboratory‐scale, expanded granular sludge bed bioreactors were seeded with crushed (diameter <0·4 mm) granules and were fed a glucose‐based wastewater for 194 days. Bioreactor performance was assessed by chemical oxygen demand removal, biogas production, granule growth and temporal methanogenic activity. Granulation was observed in R2 and R3 (up to 33% of the sludge). Elevated hydrogenotrophic methanogenesis was observed in psychrophilically cultivated biomass, but acetoclastic methanogenic activity was also retained. Denaturing gradient gel electrophoresis of archaeal 16S rRNA gene fragments indicated that a distinct community was associated with developing and mature granules in the low‐temperature (LT) bioreactors. Conclusions: Granulation was observed at 15°C in anaerobic bioreactors and was associated with H₂/CO₂‐mediated methanogenesis and distinct community structure development. Significance and Impact of the Study: Granulation underpins high‐rate anaerobic waste treatment bioreactors. Most LT bioreactor trials have employed mesophilic seed sludge, and granulation <20°C was not previously documented.