应用T-RFLP技术研究五氯酚对好氧颗粒污泥中细菌组成的影响

研究了五氯酚(PCP)对好氧颗粒污泥处理生活污水的影响,借助末端限制性酶切片段长度多态性(T-RFLP)技术考察了PCP存在时好氧颗粒污泥细菌组成的变化.结果表明,PCP对氨氮去除率的影响大于对COD去除率的影响,好氧颗粒污泥中微生物的种群数量随着PCP浓度的增加而逐渐减少,氨氮和COD去除率的变化与微生物种群数量变化相吻合.根据对PCP的敏感程度,好氧颗粒污泥中的微生物可分以下几类:①对PCP高度敏感的微生物,可能是Microbacterium或Streptococcus等以及2种未被报道的菌种;②对PCP中度敏感的微生物,可能是Corynebacterium或Nevskia等以及1种未被报道的菌种;③对PCP低度敏感的微生物,可能是Mycoplasma或Exiguobacterium等以及1种未被报道的菌种;④对PCP耐受性强的微生物,这类微生物主要是13个末端限制性片段(69、71、82、175、198、241、229、232、233、240、245、269、449bp)所代表的微生物,PCP浓度为30mg/L时,长度为82bp和175bp的片段的相对面积分别22.7%和13%,所代表的微生物已经演替为优势菌群.     

好氧颗粒污泥和絮状污泥脱氮性能及细菌种群分析

比较了SBR反应器中好氧颗粒污泥和絮状污泥对不同浓度氨氮废水的去除情况,并采用定量PCR(RT-PCR)和末端限制性酶切片段长度多态性(T-RFLP)技术研究了2种污泥中氨氧化细菌数量和细菌组成的变化.结果表明,100～500mg/L的氨氮对2种污泥去除COD的影响不大,而氨氮的去除率随着其浓度的上升而下降,絮状污泥的氨氮去除率略高于颗粒污泥(10%～16%).絮状污泥和颗粒污泥中氨氧化细菌的数量分别为2.80×10⁴～3.44×10⁴,7.83×10⁴～1.18×10⁵个/g干污泥.絮状污泥中细菌种群数量高于颗粒污泥,且两者的变化趋势与氨氮去除率的变化基本一致.     

降解五氯酚(PCP)的微氧颗粒污泥的形成机理

在微氧条件及剧毒性的五氯酚存在下,研究了活性污泥的颗粒化机理.在污泥培养过程中对污泥性质、外观进行观察,并利用扫描电镜对微生物相进行分析.结果表明,在颗粒化初始阶段诱导核的存在对絮体起着凝集作用,该阶段的微生物以丝状菌为主;在形成阶段,二价金属阳离子含量以及ECPs中PN/PS比值增加,丝状菌形成三维框架结构;而在颗粒污泥形成后的增长阶段,SVI值下降至较低的水平,形成表面光滑的完整颗粒,颗粒内杆菌、球菌占优势,含水率的明显下降表明质子跨膜迁移引起的细胞脱水作用变得显著.     

降解五氯酚厌氧生物反应器微生物种群结构的分子特性研究

采用PCR—DGGE技术，对降解PCP厌氧生物反应器污泥颗粒化过程微生物种群结构的时空分布变化特性进行了初步研究．结果表明，随着PCP负荷增加与污泥的颗粒化，污泥真细菌、古细菌组成均发生明显变化．当反应器稳定运行时，反应器内上下层污泥微生物种群结构组成相似，真细菌相似性Cs在71．4～77．6之间，古细菌Cs在70．4～76．7之间．反应器一旦受污染物负荷冲击干扰，反应器上下层污泥真细菌组成相似性Cs降至43．3，古细菌降至35．2．测序表明，颗粒污泥中存在不可培养的脱氯细菌，优势产甲烷细菌为Methanosaeta concilii、Methanobacterium sp．、Methanobrevibacter sp．和Methanothfix soehngenii．     

pH冲击对降解五氯酚(PCP)微氧颗粒污泥产气及代谢能力的影响

分别在pH为6.0和9.0的冲击条件下,对降解五氯酚(PCP)微氧颗粒污泥系统的产气及代谢能力进行了研究.结果发现,在pH=6.0的条件下冲击8d,污泥系统的产气量降至400mL·d-1以下,甲烷含量为0.而后将pH调至7.0并经过6d的恢复实验,产气情况基本恢复正常.而在pH=9.0的冲击下,污泥系统的产气量及甲烷含量急剧下降至0,经过6d的恢复过程仍然没有达到正常水平.在不同pH冲击的第8d,对PCP和COD去除率及脱氯中间产物进行了研究,结果表明,PCP及COD降解率均在较低的水平,且发生了PCP及其脱氯中间产物的严重积累.与pH=9.0相比,pH=6.0的冲击对系统代谢的影响要小得多.     

剪切应力对好氧颗粒污泥形态结构和微生物活性的影响机制研究

对不同剪切应力(0.189、0.267、0.327和0.377 N/m2)下4个序批式反应器(SBR)中好氧颗粒污泥的形态结构、比耗氧速率(SOUR)以及胞外聚合物进行了对比分析.结果表明,好氧颗粒污泥具有稳定的基本形态特征,其微生物主要由杆菌、球菌和丝状菌组成;其中杆菌能承受高剪切作用.是剪切应力为0.377 N/m2时的优势菌群.4个反应器中污泥粒径分布范围分别为0.2-0.5、0.5-1.5、0.5-1.5和0.3-0.5 mm;SOUR分别为34.54、40.08、46.26和46.42 mg/(g·h),胞外多聚糖分别为59.71、66-81、80.88和109.99 mg/g,胞外蛋白质分别为9.29、9.80、12.35和17.02 mg/g.好氧颗粒污泥比耗氧速率SOUR和胞外聚合物与剪切应力有很好的正相关性.确定了好氧颗粒污泥微生物活性与剪切应力的响应关系.     

温度对好氧颗粒污泥系统污泥膨胀的影响

为探究温度对好氧颗粒污泥系统污泥膨胀的影响以及微生物群落结构特征,采用序批式反应器,进水为人工合成废水,利用Illumina测序技术分析10℃、18℃和25℃3种温度下好氧颗粒污泥系统微生物群落结构及细菌的动态变化.结果表明,18℃条件下好氧颗粒污泥沉降性能良好SVI值维持在40mL/g左右.而10和25℃条件下好氧颗粒污泥均发生膨胀现象,SVI值分别为194.67和100mL/g.通过q PCR分析可知,10℃条件下,特定的丝状菌里Sphaerotilusnatans丰度值最高,该菌大量繁殖导致SVI值极高.Illumina测序结果表明,温度导致好氧颗粒污泥系统的优势菌属具有显著差异性,18℃条件下,好氧颗粒污泥优势菌属为Tsukamurella和unclassified＿f＿Comamonadaceae,系统具有良好的污染物去除能力;10℃条件下,其优势菌属为Sphaerotilus,该菌属不能利用复杂的有机物;25℃条件下,优势菌属为Tsukamurella和unclassified＿f＿Microbacteriacea.从微观角度分析好氧颗粒污泥系统脱氮性能,利用FAPROTA...     

不同好氧颗粒污泥中微生物群落结构特点

为了探讨活性污泥好氧颗粒化过程对微生物种群的影响、不同底物及不同颗粒化方法培养的好氧颗粒污泥中微生物群落结构的差异,以接种污泥、模拟废水好氧颗粒污泥和分别投加粉末活性炭和硅藻土的实际生活污水好氧颗粒污泥为研究对象,利用PCR-DGGE对比分析了接种污泥和好氧颗粒污泥中的微生物群落结构.结果表明:活性污泥好氧颗粒化过程会减少微生物种群多样性,影响颗粒污泥稳定性的细菌被淘汰,而聚磷菌、反硝化菌、难降解有机物降解菌等污水处理功能微生物都在颗粒化过程中得到保留.活性污泥好氧颗粒化过程中能够实现亚硝化细菌(AOB)一定程度的富集.与接种活性污泥相比,好氧颗粒污泥中AOB的多样性指数与均匀性指数均有提高.好氧颗粒污泥中的优势菌群主要分布于变形菌门(Proteobacteria)、拟杆菌门(Bacteroidetes)和未培养菌(uncultured bacterium).其中AOB均属于β-Proteobacteria的亚硝化单胞菌属(Nitrosomonas).     

好氧颗粒活性污泥的培养及理化特性研究

研究厌氧－好氧交替工艺中好氧颗粒活性污泥的培养和理化特性,在普通好氧曝气条件下,反应顺内培养出了好氧颗粒活性污泥,颗粒直径０．５－１．５ｍｍ,比重１．００７左右,含水率９７－９８％,ＭＬＳＳ４．０４－６．８８％ｇ／Ｌ,ＳＶ１２０－４５ｍｌ／ｇ,一般约３０ｍｌ／ｇ,颗粒污泥受阻沉降层的均匀沉降速度ｖｓ约２．１５ｃｍ／ｍｉｎ,临界浓度时沉降速度值ｖ２约０．３５ｃｍｉｎ,颗粒污泥的耗氧速率ＯＵＲＷ１．２     

好氧颗粒污泥对有机物吸附类型的研究

为探索好氧颗粒污泥对有机物的去除机制,进行好氧颗粒污泥对有机物的吸附性能及吸附类型研究,在实验室条件下,采用动态吸附方式,利用SBAR反应器分析好氧颗粒污泥对有机物的去除情况。结果表明,好氧颗粒污泥存在初期吸附作用,最佳吸附时间为30~45 min,COD去处率60%;通过对失活前后好氧颗粒污泥对有机物吸附性能测定以及红外光谱分析,探究好氧颗粒污泥对有机物的吸附类型,表明好氧颗粒污泥对有机物的吸附是一个包含生物吸附和化学吸附的复杂过程。     

Molecular characterization of bacterial community in aerobic granular sludge stressed by pentachlorophenol

To characterize the effects of pentachlorophenol (PCP) on the performance and microbial community of aerobic granular sludge in sequencing batch reactor (SBR), the web-based terminal restriction fragment length polymorphism (T-RFLP) and real-time PCR (RT- PCR) techniques were used to explore the bacterial community structure. When PCP increased from 0 to 50 mg/L, the COD removal rate changed little, while the ammonia removal rate dropped from 100% to 64.9%. The results of molecular characterization showed t...     

The biological effect of metal ions on the granulation of aerobic granular activated sludge

As a special biofilm structure, microbial attachment is believed to play an important role in the granulation of aerobic granular activated sludge (AGAS). This experiment was to investigate the biological effect of Ca^2 +, Mg^2 +, Cu^2 +, Fe^2 +, Zn^2 +, and K⁺ which are the most common ions present in biological wastewater treatment systems, on the microbial attachment of AGAS and flocculent activated sludge (FAS), from which AGAS is always derived, in order to provide a new strategy for the rapid cultivation and stability control of AGAS. The result showed that attachment biomass of AGAS was about 300% higher than that of FAS without the addition of metal ions. Different metal ions had different effects on the process of microbial attachment. FAS and AGAS reacted differently to the metal ions as well, and in fact, AGAS was more sensitive to the metal ions. Specifically, Ca^2 +, Mg^2 +, and K⁺ could increase the microbial attachment ability of both AGAS and FAS under appropriate concentrations, Cu^2 +, Fe^2 +, and Zn^2 + were also beneficial to the microbial attachment of FAS at low concentrations, but Cu^2 +, Fe^2 +, and Zn^2 + greatly inhibited the attachment process of AGAS even at extremely low concentrations. In addition, the acylated homoserine lactone (AHL)-based quorum sensing system, the content of extracellular polymeric substances and the relative hydrophobicity of the sludges were greatly influenced by metal ions. As all these parameters had close relationships with the microbial attachment process, the microbial attachment may be affected by changes of these parameters.     

Effect of seed sludge on characteristics and microbial community of aerobic granular sludge

Aerobic granular sludge was cultivated by using different kinds of seed sludge in sequencing batch airlift reactor.The influence of seed sludge on physical and chemical properties of granular sludge was studied;the microbial community structure was probed by using scanning electron microscope and polymerase chain reaction-denaturing gradient gel electrophoresis(PCR-DGGE).The results showed that seed sludge played an important role on the formation of aerobic granules.Seed sludge taken from beer wastewater treatment plant(inoculum A) was more suitable for cultivating aerobic granules than that of sludge from municipal wastewater treatment plant(inoculum B).Cultivated with inoculum A, large amount of mature granules formed after 35 days operation, its SVI reached 32.75 mL/g, and SOUR of granular sludge was beyond 1.10 mg/(g·min).By contrast, it needed 56 days obtaining mature granules using inoculum B.DGGE profiles indicated that the dominant microbial species in mature granules were 18 and 11 OTU when inoculum A and B were respectively employed as seed sludge.The sequencing results suggested that dominant species in mature granules cultivated by inoculum A were Paracoccus sp., Devosia hwasunensi, Pseudoxanthomonas sp., while the dominant species were Lactococcus raffinolactis and Pseudomonas sp.in granules developed from inoculum B.     

好氧颗粒污泥的研究进展

污泥颗粒化(granulation)是指废水生物处理系统中的微生物在适当的环境条件下,相互聚集形成一种密度较大、体积较大、体质条件较好的微生物聚集体.按照微生物代谢过程中电子受体的不同,颗粒污泥可分为好氧颗粒污泥和厌氧颗粒污泥两类.目前对污泥颗粒化的研究主要集中在两个方面:一方面是从宏观层面探讨颗粒化的形成模式,优化运行参数以达到更好的颗粒化效果;另一方面是从微观层面去研究颗粒化的机理、微生物菌群及其他化学成分在颗粒化过程中所起的作用.本文综述了好氧颗粒污泥近年来的研究进展.主要包括:好氧颗粒污泥的性质(形态及粒径、沉降性能、密度与强度、生物活性、细胞表面疏水性、胞外多聚物等)及结构,颗粒污泥的培养条件、形成机理及影响因素(有机负荷、基质成分、剪切力、沉淀时间、运行周期、进水模式、微生物饥饿期、反应器结构、溶解氧、温度等),以及颗粒污泥的应用(工业废水处理、城市污水处理、有毒污染物降解、脱氮除磷、重金属及放射性核素的去除等).此外,还介绍了全自养颗粒污泥,如硝化颗粒污泥方面的研究.分析表明,随着对好氧颗粒污泥研究的不断深入,将好氧颗粒污泥应用于实际废水处理得到越来越多的关注.好氧颗粒污泥的形成机理、颗粒污泥的微生物特性、颗粒污泥的长期运行稳定性及其工业化应用是今后需要重点关注的研究方向.     

焦化废水处理系统微生物群落结构动态的ERIC-PCR指纹图谱分析

ERIC-PCR群落指纹图谱监测与常规技术相结合，分析了焦化废水处理系统曝气池的微生物群落结构动态变化与污染负荷和主要污染物降解效果变化的关系，在每3d1次，连续8个时间点的监测中，待处理废水中苯酚负荷在35．53mg／L和132．82mg／L之间波动，氰化物负荷从0.96mg／L变化到34．75mg／L，CODcr最低为1044．10mg／L，最高时为7930．90mg／L，第4监测期间高浓度矿物油冲击使活性污泥的沉降能力和对CODcr的降解效率显著降低，但对苯酚和氰化物的降解能力造成的影响较小．监测期间2个曝气池微生物群落的ERIC-PCR指纹图谱的平均相似性系数(Cs)分别为94．1％和96．6％，多样性指数在177—2．34和1．60—2．16之间，表明用ERIC-PCR检测出的该系统中的活性污泥这部分微生物种群的结构比较稳定，可能构成了苯酚和氰化物去除效率在监测期间相对稳定的基础。     

好氧颗粒污泥耐受PFOS的结构稳定性及微生物响应

以好氧颗粒污泥为接种污泥,通过全氟辛烷磺酸(PFOS)长期驯化实现耐PFOS颗粒的培养,考察不同驯化时期的污泥基本特性,并结合微生物群落演替过程、微生物表型分布以及功能途径的变化情况,以揭示其耐受机制.结果表明,好氧颗粒污泥经历解体、再形成和成熟3个阶段后可在PFOS暴露下稳定维持.驯化成熟后的好氧颗粒污泥表面丝状菌减少,并且被大量胞外聚合物(EPS)所包裹,结构更加致密.驯化期间颗粒污泥中存在大量抗性细菌以及维持颗粒稳定相关细菌,主要包括unclassified＿f＿＿Comamonadaceae、Defluviicoccus、Dongia、Rhodoplanes、Flavobacterium、Thauera、Azospira、Candidatus＿Competibacter、Azoarcus和norank＿f＿＿A4b,且部分菌属间存在显著的正相关性.群体感应途径和细菌趋化途径相关基因丰度在解体期上调,在颗粒形成和成熟期恢复至初始水平,说明细菌的群体感应效应和趋化性能够在颗粒应激过程中起重要作用.因此,好氧颗粒污泥可以通过特定菌群积极响应、促进细菌趋化作用和群体感应作用、提高EPS...     

大分子有机物对除磷颗粒污泥特性及菌群结构的影响

分别采用NaAc(R1)、NaAc+胰蛋白胨(R2)和可溶性淀粉+胰蛋白胨(R3)为碳源模拟生活污水,研究大分子有机物对除磷颗粒污泥特性及菌群结构的影响.结果表明,在培养初期,大分子有机物有利于除磷污泥的凝聚,随着大分子有机物含量的增多,除磷污泥的颗粒化速度依次加快,经过120 d的培养R3反应器最先实现颗粒化.系统稳...     

Strategies to improve aerobic granular sludge stability and nitrogen removal based on feeding mode and substrate

A systemic strategy was proposed to improve aerobic granular sludge(AGS)stability and nitrogen(N)removal efficiency by optimizing feeding mode and substrate aiming at complicated wastewater characteristics.Key functional groups at the genus level identified by high-throughput sequencing were evaluated as well.The results showed that anaerobic feeding mode and acetate promoted the compact AGS formation with excellent total nitrogen(TN)removal efficiency(averaging 91.7%±4.1%)at various dissolved oxygen conditions.While the aerobic feeding mode led to a loose AGS structure with a vulnerable anaerobic core and poor TN removal efficiency(averaging58.8%±7.4%).Simultaneous nitrification and denitrification process played the dominant role in N removal in compact AGS over the alternating nitrification and denitrification process.High-concentration glucose undermined feast-famine condition with filamentous bacteria growth out of granule and decreased TN removal efficiency to 67.3%±15.2%.Lower food to microorganism ratio may result in a lower N removal rate attributed to the sharply increased biomass concentration fed by glucose.Ammonia-oxidizing bacteria,nitrite-oxidizing bacteria,denitrifying bacteria,and denitrifying phosphorus accumulation organisms enriched during AGS granulation also contributed to the efficient N removal.The proposed strategy provided insights into the relationship between various factors and stable AGS formation,and systemic operation methods for various complicated wastewater treatment.