水厂砂滤池内氨氧化菌对氨氮去除的效能

介绍在常规工艺条件下饮用水氨氮去除难题,利用分子生物学技术对饮用水处理工艺中滤池内不同滤料样品的微生物量和氨氧化菌进行了初步探索。发现氨氧化细菌在滤池硝化去除氨氮中起主导作用;DS水厂砂滤池滤料表面氨氧化细菌占细菌总数的比例最大;各滤池内氨氧化古菌占滤料表面古菌的比例均较低,这为生物硝化作用去除饮用水中氨氮提供了理论依据。     

古菌氨氧化与amoA基因的扩增

氨氧化过程是由变形菌纲中的一小部分细菌类群所进行的专性好氧的化能自养过程,氨氧化细菌(AOB)是硝化反应中负责将NH4+转化为NO2-的一类无机自养微生物,氨氧化古菌(AOA)是独立于AOB进化枝之外的能进行氨氧化作用的古菌。介绍了AOA古菌的发现过程及其氨氧化作用,提取、纯化了amoA基因并利用amoA基因的特征,对它进行扩增,证实了AOA古菌的存在,并为后续研究提供了依据。     

厌氧氨氧化工艺在高氨氮废水处理的研究应用进展

厌氧氨氧化(Anammox)具有节省曝气、剩余污泥产量小和无需外加碳源等优点,是极具发展前景的高氨氮废水处理工艺。但厌氧氨氧化菌世代周期长、低细胞产率、随出水流失以及一体式部分亚硝化-厌氧氨氧化系统中氨氧化细菌和厌氧氨氧化菌耦合难点阻碍了其推广应用。本文综述了高氨氮废水处理中厌氧氨氧化反应器构建及其启动、厌氧氨氧化菌富集和活性强化。认为需进一步探讨和研究的内容有:系统中厌氧氨氧化菌生物量停留时间的增强;新型填料的开发;生物膜系统中亚硝酸盐氧化细菌的有效清除;高氨氮废水的预处理;厌氧氨氧化的低温启动运行。     

人工湿地或中水灌溉对土壤微生物的影响

人工湿地和中水灌溉目前应用广泛,但对土壤的原有生态环境可能造成影响,这可以反映在土壤微生物的种类、数量等方面。本文首先从中水的PH值、耗氧有机物含量、氯化物含量等进行分析,探究不同成分的中水在灌溉土壤后,微生物的数量与种类是否发生变化。结果表明,氯化物浓度过高将会导致微生物群落及数量普遍减少;碱性土壤中氨氧化细菌数量明显增加而氨氧化古菌并无太大变化;在酸性土壤中结果却恰恰相反,氨氧化古菌数量增加,氨氧化细菌数量无明显变化;耗氧有机物的增加会导致好氧微生物的减少。另外,对人工湿地也分别从植被种类、重金属、氮、硫、磷、铁等元素进行分析比较,结果发现植被覆盖土壤会对微生物繁衍起促进作用;低浓度的重金属含量使抗性微生物增加,敏感性微生物减少,但在高浓度的重金属下,微生物总体大幅减少;人工湿地中丰富的离子含量能使硝化细菌、硫细菌、铁细菌等数量增加。     

铁元素对厌氧氨氧化反应脱氮性能的影响

厌氧氨氧化工艺是一种新型的低能耗、高效生物脱氮技术。然而,厌氧氨氧化细菌活性较低、世代时间长,使得厌氧氨氧化工艺启动时间较长、运行效果较差,限制了厌氧氨氧化工艺的实际应用。铁元素不仅能够满足微生物的生长繁殖,而且能够促进厌氧氨氧化细菌活性,强化厌氧氨氧化工艺脱氮效果。综述了不同价态的铁元素对厌氧氨氧化工艺的影响,旨在探究和阐释铁元素如何影响厌氧氨氧化菌活性及脱氮性能。     

一株氨氧化菌的分离鉴定及氨氧化特性研究

氮可以在水体、环境中逐渐扩散与累积,当其含量超过环境所能容纳量是就会对生态系统造成负面影响。目前常用的处理工艺之一为微生物的氨氧化。在整个过程(生物脱氮)起氨氧化作用的主导菌群为氨氧化细菌(Ammonia Oxidizing Bacteria.AOB),受污染水体的脱氮效率与氨氧化速率有关。目前对AOB的研究大多只基于几株模式菌株,研究广度与深度还有很大的发展空间。本研究以广州某河涌底泥为菌源通过富集培养、分离纯化的方式筛选到一株氨氧化菌A1。随后,进行扩增16S r RNA基因并测定扩增产物序列,与数据库Gen Bank对应比较,同时进行系统发育学分析,结果表明菌株A1与Providencia rettgeri DSM 4542(T)相似性达99%。检测了其生长曲线与氨氧化性能,结果显示A1在60小时内OD600值达1.18±0.02,计算得到菌株A1的氨氧化速率为1.49±0.14 mg/L/h,与其他常见的AOB的氨氧化速率相比菌株A1的效果处于中等水平。     

低温下超声波强度对厌氧氨氧化污水处理工艺性能的影响

厌氧氨氧化技术是一种新型污水处理工程技术,广泛用于含氮工业废水的处理中,保持高厌氧氨氧化菌活性是该技术的关键。为明确低温下采用低强度超声波强化厌氧氨氧化反应时,超声强度对厌氧氨氧化菌活性的影响。通过批次试验的方法,研究了低温15℃下分别采用0.1W/cm~2、0.2W/cm~2、0.3W/cm~2、0.4W/cm~2、0.5W/cm~2、0.6W/cm~2的超声强度时,污泥的比厌氧氨氧化活性、EPS的含量以及EPS的变化规律。结果表明:初期随着超声强度的提升,厌氧氨氧化菌的活性有提高,细菌在超声波的刺激下EPS的含量也有所提高。后期随着超声强度继续提高,厌氧氨氧化菌活性有所下降,EPS含量急剧升高。当超声强度为0.3W/cm~2时,厌氧氨氧化菌活性最高。     

厌氧氨氧化过程毒性物质的胁迫及其活性强研究

厌氧氨氧化工艺作为一种新型脱氮工艺,较传统脱氮工艺更加节能、经济,为废水中氮的有效去除提供了新途径。而在实际应用过程中,厌氧氨氧化菌会受到废水中有毒物质的胁迫,从而导致其脱氮效果受到影响。因此,本文简述了厌氧氨氧化工艺的脱氮机理;阐述了底物基质、金属、有机物等胁迫因子对厌氧氨氧化菌活性、污泥胞外聚合物、微生物群落等的影响;并提出了厌氧氨氧化细菌活性受到抑制时活性恢复的策略,以及添加介孔材料、微量元素以及新型反应器研发等强化措施。     

厌氧氨氧化应用于城市主流污水处理工艺的研究进展

厌氧氨氧化(Anammox)技术作为近年来新兴的自养脱氮工艺,具有无需外加碳源、低污泥产量、低能耗等优势.文中总结了厌氧氨氧化应用于主流污水处理工艺时面临的困难挑战,分析了厌氧氨氧化处理污水的最新研究进展,阐述了厌氧氨氧化菌(AnAOB)的截留、硝酸盐氧化菌(NOB)的抑制、有机物的不利影响等问题的具体解决方案.在节能...     

有机物作用的厌氧氨氧化菌代谢特性研究进展

厌氧氨氧化（Anammox）工艺是近年来废水生物脱氮领域的新技术,非常适合于处理含有机物的废水。本文介绍了厌氧氨氧化工艺的特点,详细介绍了有机物对厌氧氨氧化菌的抑制和促进机制。有机物对厌氧氨氧化菌的抑制主要来自两个方面：一是有机物促进异养菌反硝化菌的大量繁殖形成基质竞争抑制;二是废水中的醇类、抗生素等有毒有害有机物会对厌氧氨氧化菌产生毒性抑制。有机物对厌氧氨氧化菌代谢的促进作用也有两种：一是特定的有机物可作为能源被厌氧氨氧化菌利用,促进厌氧氨氧化菌的代谢;二是通过控制废水处理系统中的碳氮比,使厌氧氨氧化菌和反硝化菌在废水处理系统中协同互生。最后指出开发有毒有机废水预处理、驯化厌氧氨氧化污泥、菌种流加等是解决问题的途径。     

氨氧化古细菌（AOA）的研究进展

一直以来,氨氧化细菌（AOB）是硝化反应中负责将NH4^＋转化成为NO2^-的一类无机自养微生物。近几年来国外一些学者于海洋中发现氨氧化古细菌（AOA）存在,它们同样广泛存在于土壤、自然水体、污水处理厂、垃圾渗滤液等产生硝化反应的环境中,负责将氨转化为亚硝酸盐。甚至在某些生态环境中,AOA占主导地位。概述了国外对不同环境下氨氧化古细菌种群多样性的差异,以及各类环境中共有的氨氧化古细菌种类。最后,对今后氨氧化菌深入研究的方向及其功能作了进一步的展望。     

常温下接种回流污泥实现BAF一体化自养脱氮工艺

为实现高氨氮废水的高效低耗稳定去除,在常温条件下,对曝气生物滤池（BAF）中实现与稳定短程硝化-厌氧氨氧化自养脱氮工艺进行了研究。研究结果表明：常温条件下,BAF接种二沉池回流污泥,采用闷曝-连续运行结合的接种挂膜方式,可成功实现短程硝化-厌氧氨氧化一体化自养脱氮。闷曝阶段使种泥活性恢复,而连续流运行过程中游离氨（FA）浓度高,可抑制亚硝酸盐氧化菌（NOB）,实现BAF中亚硝酸盐累积;通过调整BAF回流方式,降低回流液中NO₂^--N,防止NOB生长,并通过厌氧氨氧化（Anammox）滤池出水回流方式,接种微量Anammox菌,运行80 d可实现短程硝化-厌氧氨氧化,140 d后系统运行稳定,总氮（TN）去除率达76.62%。生物滤池有利于短程硝化-厌氧氨氧化工艺的实现与稳定,生物膜中不同厚度存在好氧缺氧环境,利于氨氧化菌（AOB）和Anammox菌共存;滤料的过滤作用有效地防止了Anammox菌流失,使其在系统中不断累积生长。不仅如此,AOB和Anammox菌均为自养菌且生长缓慢,避免了生物滤池的频繁反冲洗,简化了生物滤池的运行。气水比是BAF中一体化运行的关键参数,本研究中最佳的气水比为12：1,氨氮去除负荷达到0.91 kg N·m^-3·d^-1,氨氮和TN去除率分别可达96.86%和85.47%。     

低强度超声波对短程硝化污泥的影响

以周期性超声辐照的污泥为研究对象,在序批式反应器（SBR）中开展超声波对短程硝化效果的研究,并进一步研究超声波对酶活性、脱氮速率、胞外聚合物的影响。结果表明,0.1~0.7W/mL的超声波均可促进短程硝化,最高亚硝酸盐积累率（NAR）达98.21%。超声波通过强化氨单加氧酶（AMO）活性,抑制亚硝酸盐氧化酶（NXR）活性促进短程硝化,AMO活性最高同比增长63.84%,NXR活性最高下降89.03%。比脱氮速率、反应器脱氮速率并不完全与酶活性变化趋势一致,AOB关键酶活性仅与比氨氧化速率（SAOR）变化一致,而NOB关键酶活性与反应器亚硝酸盐氧化速率（NOR）一致,超声波引起的污泥减少对AOB菌群数量的负面影响大于NOB。周期性超声后,污泥EPS的总量随声能密度先增加后减少,超声波对LB-EPS的剥离大于TB-EPS,对多糖的剥离大于蛋白质,较高的声能密度会造成蛋白质的积累。     

温度和游离氨对絮状和颗粒污泥硝化系统的短期影响(英文)

The short-term effects of temperature and free ammonia (FA) on ammonium oxidization were investigated in this study by operating several batch tests with two different partial nitrification aggregates, formed as either granules or flocs. The results showed that the rate of ammonium oxidation in both cultures increased significantly as temperature increased from 10 to 30 °C. The specific ammonium oxidation rate with the granules was 2-3 times higher than that with flocs at the same temperature. Nitrification at various FA concentrations and temperatures combination exhibited obvious inhibition in ammonium oxidation rate when FA was 90 mg·L 1 and tempera- ture dropped to 10 °C in the two systems. However, the increase in substrate oxidation rate of ammonia at 30 °C was observed. The results suggested that higher reaction temperature was helpful to reduce the toxicity of FA. Granules appeared to be more tolerant to FA attributed to the much fraction of ammonia oxidizing bacteria (AOB) and higher resistance to the transfer of ammonia into the bacterial aggregates, whereas in the floc system, the bacteria distributed throughout the entire aggregate. These results may contribute to the applicability of the nitrifying granules in wastewater treatment operated at high ammonium concentration.     

Three-Dimensional Stratification of Bacterial Biofilm Populations in a Moving Bed Biofilm Reactor for Nitritation-Anammox

Moving bed biofilm reactors (MBBRs) are increasingly used for nitrogen removal with nitritation-anaerobic ammonium oxidation (anammox) processes in wastewater treatment. Carriers provide protected surfaces where ammonia oxidizing bacteria (AOB) and anammox bacteria form complex biofilms. However, the knowledge about the organization of microbial communities in MBBR biofilms is sparse. We used new cryosectioning and imaging methods for fluorescence in situ hybridization (FISH) to study the structure of biofilms retrieved from carriers in a nitritation-anammox MBBR. The dimensions of the carrier compartments and the biofilm cryosections after FISH showed good correlation, indicating little disturbance of biofilm samples by the treatment. FISH showed that Nitrosomonas europaea/eutropha-related cells dominated the AOB and Candidatus Brocadia fulgida-related cells dominated the anammox guild. New carriers were initially colonized by AOB, followed by anammox bacteria proliferating in the deeper biofilm layers, probably in anaerobic microhabitats created by AOB activity. Mature biofilms showed a pronounced three-dimensional stratification where AOB dominated closer to the biofilm-water interface, whereas anammox were dominant deeper into the carrier space and towards the walls. Our results suggest that current mathematical models may be oversimplifying these three-dimensional systems and unless the multidimensionality of these systems is considered, models may result in suboptimal design of MBBR carriers.     

Quantitative and qualitative studies of microorganisms involved in full‐scale autotrophic nitrogen removal performance

Autotrophic nitrogen removal systems have been implemented at full‐scale and provide an efficient way for nitrogen removal from industrial and urban wastewaters. Our study present qualitative and quantitative analysis of archaeal and bacterial amoA genes and Candidatus Brocadiales bacteria analyzed in six full‐scale autotrophic nitrogen removal bioreactors. The results showed that ammonium oxidizing bacteria (AOB) were detected in all bioreactors. However, ammonium oxidizing archaea (AOA) were detected only in the non‐aerated technologies. Conversely, different Candidatus Brocadiales phylotypes appeared due to differences in influent wastewater composition and hydraulic retention time (HRT). In the same terms multivariate redundancy analysis confirmed that AOA was positively correlated with temperature, ammonium concentration and low HRT. However, AOB population was positively correlated with pH, temperature, and dissolved oxygen concentration. Our data suggested a correlation between the microorganisms involved in the nitrogen removal performance and the operational conditions in the different full‐scale bioreactors. © 2017 American Institute of Chemical Engineers AIChE J, 64: 457–467, 2018     

变基质浓度下SBR亚硝化启动试验研究

采用SBR反应器,在低DO(<1.0 mg/L)及高氨氮浓度(220 mg/L)下,经过20周期(10 d)的连续运行,亚硝化率达到90%以上并且保持稳定。此后逐步降低氨氮浓度,深入研究6个不同水平下亚硝化效果和游离亚硝酸(FNA)及温度对亚硝化的影响。试验结果表明,高氨氮时,实施限时曝气且低DO、较高游离氨(FA)的联合抑制模式,低氨氮下,采取实时控制策略,避免过度曝气,经过130 d的运行,去除负荷稳定在0.301 kg NH 4+-N/(m3.d),污泥负荷稳定在0.374 kg NH4+-N/(kg MLSS.d),亚硝化率一直在95%以上,成功实现了低氨氮SBR亚硝化的启动。同时发现FNA对AOB的抑制具有可逆性,而缓慢升温对亚硝化效果影响不大。     

Autotrophic biological nitrogen removal from saline wastewater under low DO

BACKGROUND: This study was conducted to investigate the feasibility and performance of nitrogen removal through the complete autotrophic nitrogen removal over nitrite (CANON) process for saline wastewater in a continuous reactor, and to characterize microorganisms in the sludge from the reactor using DNA‐based techniques. RESULTS: The nitrogen removal experiment in the reactor was operated over five phases for 286 days treating a synthetic sewage of 1.2% salinity at 21–25 °C. At dissolved oxygen (DO) concentrations of 0.5–1.0 mg L^?1 and in the presence of glucose, NO₂^? was accumulated, indicating the activity of ammonia‐oxidizing bacteria (AOB). At DO concentration of 0.5 mg L^?1 without organic substrate, the anaerobic ammonium oxidation (Anammox) process was the major pathway responsible for nitrogen removal, with a total nitrogen removal of 70% and an ammonium conversion efficiency of 96%. A maximum ammonium removal rate of 0.57 kg‐N m^?3 d^?1 was achieved during the experimental period. The concentrations of AOB and Anammox bacteria were monitored over the operation of reactor using quantitative real‐time polymerase chain reaction (qRT‐PCR). CONCLUSION: In this study, autotrophic nitrogen removal process was achieved under salinity condition in a one‐reactor system. An over 100 fold increase of AOB was found due to the increased supply of ammonium at the beginning, then AOB concentration decreased temporarily in correspondence with the decreased DO, and the AOB resumed their concentration at the last phase. The Anammox bacteria abundance was about 150 fold higher than that at the beginning, indicating the successful enrichment of Anammox bacteria in the reactor. Copyright © 2010 Society of Chemical Industry     

一段式厌氧氨氧化工艺亚硝酸盐氧化菌抑制方法研究进展

近年来,厌氧氨氧化工艺（anaerobic ammonium oxidation, Anammox）作为一种新型的脱氮技术,由于其耗能少、效率高而被应用于高氨氮废水的处理中。然而,实际运行的厌氧氨氧化工程中有时会出现亚硝酸盐氧化菌（nitrite oxidizing bacteria, NOB）大量繁殖的情况,导致硝酸盐积累,脱氮效率下降。在一段式Anammox反应器中,通过控制某些影响因素,如调节体系中的溶解氧,控制游离氨和游离亚硝酸的浓度,调控碳源浓度以及外加中间产物（N₂H₄、NO和NH₂OH）等方式,能够在维持Anammox工艺脱氮效率的同时有效抑制NOB。除了系统地综述一段式Anammox工艺中NOB抑制手段以外,将进一步讨论实际Anammox工程应用中抑制NOB大量繁殖行之有效的手段。