Screening of Polyphosphate Accumulating Organisms and Their Phosphorus Removal Performance

[Objectives]To study the phosphorus removal performance of phosphate accumulating organisms(PAOs).[Methods]Activated sludge from domestic sewage treatment plant was used as the strain source,and phosphate accumulating organisms were screened by plate streaking method and dilution coating plate method.Six kinds of excellent phosphate accumulating organisms were obtained by metachromatic granule staining experiment,total phosphorus experiment and simulated sewage phosphorus removal experiment to assist the observation of bac-terial morphology and experiment of phosphorus removal capacity.In addition,the influencing factors of phosphorus removal capacity(nitrogen source,trace metal ions)were analyzed.[Results]In the case of simulated sewage,the phosphorus removal rate of strain b was the highest,reaching 66.25%,while the phosphorus removal rate of strain e and f was about 10%lower than that of the phosphorus uptake experiment.[Conclusions]This study is expected to provide a theoretical reference for the gradual optimization of the screening method of phosphorus re-moval bacteria in domestic sewage treatment.

Biomass Fraction of Phosphate-Accumulating Organisms Grown in Anoxic and Aerobic Stages under Optimum Nitrate Concentration

The effects of nitrate concentration on the capability of phosphorus uptake in the main anoxic stage were investigated.Meanwhile, the biomass fractions — heterotrophs, phosphateaccumulating organisms( PAOs),and nitrifying organisms in a pilot-scale enhanced biological phosphorus removal( EBPR) system— were both experimentally and theoretically evaluated( from the mass balance calculations of organic matter, nitrogen and phosphorus),under optimum nitrate concentration in the main anoxic stage,in which the influent chemical oxygen demand( COD)concentration was stabilized at( 290 ± 10) mg·L- 1and the influent total phosphorus( TP) concentration was stabilized at( 7. 0 ± 0. 5)mg · L- 1. In long term operations,the process exhibited high performance in removing organic matter, nitrogen, and phosphorus. Approximately 46. 41% of organic matter,57. 21% of nitrogen,and 48. 14% of phosphorus were removed from the influent in the form of carbon dioxide,nitrogen gas,and polyphosphate,respectively. XH( heterotrophs),XPAO( PAOs),and XAUT( autotrophs) were regarded as the major organisms responsible for biomass production. The yield fractions of XHgrowth in the first anoxic,the second anoxic,and the aerobic stages were 10. 24%,19. 11%,and 19. 71%,respectively; the yield fractions of XPAO growth in the second anoxic and the aerobic stages were 24. 34% and19. 86%,respectively; the yield fraction of XAUTgrowth in the aerobic stage was 6. 74%. These results showed that XHand XPAOformed the major community. Moreover,a higher amount of XPAOgrowth on stored poly-hydroxyalkanoates( PHAs) under the anoxic condition was seen in this EBPR system for municipal wastewater treatment.

Demystifying polyphosphate-accumulating organisms relevant to wastewater treatment: A review of their phylogeny, metabolism, and detection

Currently,the most cost-effective and efficient method for phosphorus(P)removal from wastewater is enhanced biological P removal(EPBR)via polyphosphate-accumulating organisms(PAOs).This study integrates a literature review with genomic analysis to uncover the phylogenetic and metabolic diversity of the relevant PAOs for wastewater treatment.The findings highlight significant differences in the metabolic capabilities of PAOs relevant to wastewater treatment.Notably,Candidatus Dechloromonas and Candidatus Accumulibacter can synthesize polyhydroxyalkanoates,possess specific enzymes for ATP production from polyphosphate,and have electrochemical transporters for acetate and C4-dicarboxylates.In contrast,Tetrasphaera,Candidatus Phosphoribacter,Knoellia,and Phycicoccus possess PolyP-glucokinase and electrochemical transporters for sugars/amino acids.Additionally,this review explores various detection methods for polyphosphate and PAOs in activated sludge wastewater treatment plants.Notably,FISH-Raman spectroscopy emerges as one of the most advanced detection techniques.Overall,this review provides critical insights into PAO research,underscoring the need for enhanced strategies in biological phosphorus removal.

Isolation and Identification of Phosphate-accumulating Strain PAO3-1 and Its Phosphorus Removal Characteristics

A phosphate-accumulating bacteria strain PAO3-1 was isolated from biological phosphorus removal sludge supplied with sodium acetate as carbon source under stable performance. This strain has good enhanced biological phosphorus removal effect on normal activated sludge system. Phosphorus removal ratio was raised form 44% with no added strain to more than 82% with strain strengthening biological phosphorus removal. It is identified to be Alcaligenes sp. according to its morphology, biochemical characteristics and 16S rDNA sequence analysis. The cell of strain PAO3-1 is straight bacilli form, 0.4×1.1μm, no flagellum, gram negative and special aerobiotic. The optimal temperature and pH for growth are 32℃-37℃ and 5.5-9.5, respectively. The shape of slant clone is feathery. The phosphate accumulating rate of strain PAO3-1 was 8.1mgP/g cell·h, and 14.3 mgP/g cell·h when in phosphate-starving situation, which was 76.5% higher than that in non-starving situation. Its phosphate release rate of log course in anaerobic phase and in culture without phosphorus was 7.6mgP/g cell·h, while in stable course the rate was 6.1mgP/g cell·h. The rate in stable course was 19.7% lower than that in log course.

SPNED-PR系统内PAOs-GAOs的竞争关系及其氮磷去除特性

为研究同步短程硝化内源反硝化除磷(SPNED-PR)系统的脱氮除磷特性及系统内聚磷菌(PAOs)和聚糖菌(GAOs)在氮磷去除的贡献和竞争关系,本研究以实际低C/N比(4左右)生活污水为处理对象,考察了不同浓度的溶解氧(DO)(0.5~2.0mg/L)、NO2--N(4.7~39.9mg/L)和NO3--N(5.0~40.0mg/L)对延时厌氧(150min)/低氧(180min,溶解氧0.5~0.7mg/L)运行的SPNED-PR系统氮磷去除特性和底物转化特性的影响.结果表明,DO浓度均不影响PAOs和GAOs的好氧代谢活性,且两者之间几乎不存在DO竞争.不同NO2--N浓度条件下,GAOs较PAOs更具竞争优势,NO2--N主要是通过GAOs去除的(约占58%);且GAOs所具有的高内源反硝化活性和亚硝耐受力,减弱了高NO2--N浓度(26.2~39.9mg/L)对PAOs反硝化吸磷的抑制,保证了系统的脱氮除磷性能.不同NO3--N浓度条件下,PAOs较GAOs处于竞争优势,其在NO3--N去除中的贡献比例达61.2%.此外,SPNED-PR系统的PURDO>PURnitrate>PURnitrite,PAOs对DO的优先利用保证了低氧条件下系统的高效除磷,且GAOs的内源短程反硝化特性保证了系统的高效脱氮.

EBPR中两类细菌PAOs和GAOs竞争的研究进展

强化生物除磷(EBPR)工艺可以获取高效的除磷效果,已在很多污水处理厂得到广泛应用。但是大型污水处理厂在相当多的条件下,EBPR工艺也会出现周期性除磷效果的波动和不充分。针对这一难题,研究者试图采用许多手段来研究工艺中的主要微生物。文章针对典型的EBPR工艺和碳源、pH值、温度等因素对EBPR工艺中两类细菌聚磷菌(PAOs)和聚糖菌(GAOs)竞争的研究进展进行了论述,并展望了未来的研究方向。

聚磷菌PAO1-1的筛选及除磷特性

从运行稳定的以生活污水为碳源的生物除磷污泥中筛选出一株聚磷菌PAO1-1,该菌株对普通活性污泥系统具有很好的强化作用,驯化10 d后可使除磷率由投菌前的44%提高到90%以上。对该菌株的形态、生理生化特征及16S rDNA序列进行分析后,鉴定该菌株为产碱杆菌属。该菌株对磷的平均吸收速率为13.8 mg/(g.h),处于“磷酸盐饥饿期”时对磷的吸收速率为19.2 mg/(g.h),比“非饥饿期”提高了39.1%。处于对数期的PAO1-1在厌氧条件下的无磷培养基中的释磷速率为11.8 mg/(g.h),稳定期释磷速率为7.0 mg/(g.h),释磷速率下降了40.7%。

宫保鸡丁菜肴的呈味特性研究

该研究采用高效液相色谱、电感耦合等离子发射光谱法等技术对宫保鸡丁中有机酸、呈味核苷酸及游离氨基酸等进行定性定量分析,并结合滋味活性值(taste active value,TAV)探究宫保鸡丁的特征滋味物质。结果显示,5种宫保鸡丁(A1~A5)中均检出6种有机酸、3种呈味核苷酸、6种无机离子、17种游离氨基酸及辣椒素,且均未检出二氢辣椒素。其中,A4样含有较高的有机酸和无机离子,其呈味核苷酸及游离氨基酸含量均高于其他4种样品,含量分别为1392.65 mg/kg和10567.80 mg/kg,滋味更浓厚。另外,富马酸、苹果酸、琥珀酸、乙酸、5′-肌苷酸、辣椒素、钠离子、钾离子、氯离子、磷酸根离子、谷氨酸及组氨酸12种呈味组分的TAV均大于1,表明其为宫保鸡丁的特征滋味物质,对产品整体滋味呈现至关重要。

有机固体废弃物堆肥过程中PAO及PNO的研究

研究了污水处理厂滤泥与甘蔗叶混合堆肥的过程及氮素转化规律。主要考察堆肥温度、pH、氨氮与亚硝酸盐氮的含量及氨氧化率(PAO)和亚硝酸盐氧化率(PNO)的转化规律。结果表明,堆肥温度在第4天达到最大值55.3℃;堆肥pH在第6天达到最大值7.89;氨氮和亚硝酸盐氮的含量随时间发生变化,高温阶段氨氮含量维持在较高水平,亚硝酸盐氮却在较低水平范围内波动。研究了PAO与PNO的变化趋势,二者与作用微生物的活性和所需反应底物的含量相关。

Strain Pseudomonas putida PAO-1 Isolate with Polyphosphate Accumulating and Elongation Ability

Filamentous bacteria(FB)overgrowth is an important cause of sludge bulking in wastewater treatment plants(WWTPs).However,to date,methods for the cultivation and preservation of isolated FB in the laboratory have not been completely described.Furthermore,research on whether FB can function as phosphorus accumulating organisms(PAOs)is limited.In this study,a pure strain,a Pseudomonas putida PAO-1(P.putida PAO-1)isolate with phosphorus removal functions was isolated from the biofilm of an alternating anaerobic/aerobic biofilter(AABF),and its physiological characteristics were studied.Nitrate or nitrite could be used by the strain P.putida PAO-1 as electron acceptors for denitrification during phosphorus anoxic uptake,and 0.63 mg NO-3-N was consumed to reduce 1 mg soluble orthophosphate(SOP)by P.putida PAO-1.The strain P.putida PAO-1 consumed phosphorus within the optimal pH range of 6 to 8 and the temperature range of 25℃to 35℃.Cell deformity was a main morphological trait of the strain P.putida PAO-1,and it could elongate(with an elongation rate of 300%-500%)when it was subjected to oligotrophic or high-salt stress(15 g·L-1 NaCl).The findings in this study provide a microbiological reference for understanding the special characteristics of a denitrifying PAO.

SRT对酪蛋白水解物为碳源的EPBR系统的影响

为了探究污泥龄(SRT)对以酪蛋白水解物(Cas aa)为唯一碳源的强化生物除磷(EPBR)系统性能的影响,采用序批式反应器(SBR),在低温条件下考察了SRT对Cas aa为碳源的EPBR中微生物菌群的变化及其污染物去除性能的影响。结果表明,SRT为15 d时,系统除磷性能最佳,除磷率可达95%以上,显著高于其他SRT条件。系统运行典型周期分析表明:当SRT为15 d时,系统的厌氧释磷质量浓度最大,为34.03 mg/L,好氧吸磷质量浓度最大,为48.45 mg/L,除磷效果最优。高通量测序分析结果表明,系统内聚磷菌(PAOs)的组成和结构会随着SRT的变化而变化,SRT为15 d时,系统内全体PAOs相对丰度最高。

Temporal Dynamics and Performance Association of the Tetrasphaera-Enriched Microbiome for Enhanced Biological Phosphorus Removal

Tetrasphaera have been recently identified based on the 16S ribosomal RNA(rRNA)gene as among the most abundant polyphosphate-accumulating organisms(PAOs)in global full-scale wastewater treatment plants(WWTPs)with enhanced biological phosphorus removal(EBPR).However,it is unclear how Tetrasphaera PAOs are selectively enriched in the context of the EBPR microbiome.In this study,an EBPR microbiome enriched with Tetrasphaera(accounting for 40%of 16S sequences on day 113)was built using a top-down design approach featuring multicarbon sources and a low dosage of allylthiourea.The microbiome showed enhanced nutrient removal(phosphorus removal~85%and nitrogen removal~80%)and increased phosphorus recovery(up to 23.2 times)compared with the seeding activated sludge from a local full-scale WWTP.The supply of 1 mg·L^(-1)allylthiourea promoted the coselection of Tetrasphaera PAOs and Microlunatus PAOs and sharply reduced the relative abundance of both ammonia oxidizer Nitrosomonas and putative competitors Brevundimonas and Paracoccus,facilitating the establishment of the EBPR microbiome.Based on 16S rRNA gene analysis,a putative novel PAO species,EBPR-ASV0001,was identified with Tetrasphaera japonica as its closest relative.This study provides new knowledge on the establishment of a Tetrasphaera-enriched microbiome facilitated by allylthiourea,which can be further exploited to guide future process upgrading and optimization to achieve and/or enhance simultaneous biological phosphorus and nitrogen removal from high-strength wastewater.

短程硝化-强化生物除磷序批式反应器处理畜禽养殖废水

畜禽养殖废水有机物水质水量变化大,有机物、氨氮与磷的浓度较高,直接排放会严重危害环境。通过构建厌氧-好氧序批式反应器(SBR)处理预酸化畜禽养殖废水,分析了不同进水负荷条件下反应器对污染物的去除性能和微生物群落结构的变化规律。结果表明:SBR反应器对高负荷进水中TN、PO_(4)^(3-)—P和COD的平均去除率可分别达到64.5%、97.5%和94.5%。反应器出现NH_(4)^(+)—N和NO_(2)^(—)-N亚硝酸同时积累的短程硝化现象,这可能与高进水负荷对氨氧化菌和亚硝酸盐氧化菌的活性和种群的影响有关。与乙酸盐相比,以丙酸盐作碳源时污泥的强化生物除磷活性更高。随着进水负荷的增大,聚糖菌(GAOs)的相对丰度明显升高。四联球状菌(Tetrasphaera)为反应器中始终占优势的聚磷菌(PAOs),对反应器除磷性能有重要贡献。在高有机负荷条件下,SBR内PAOs与GAOs之间不存在明显的底物竞争关系,系统脱氮除磷性能未受影响。

第八届远东运动会的筹办研究——基于《申报》的分析

第八届远东运动会是由中国人在1927年完全自主筹办的国际性赛事。在中华全国体育协进会的统筹安排下,主办方通过筹集经费、准备运动场所、进行人员选拔以及全面的赛事准备,最终成功地举办了一场在中国体育史上意义重大的赛事。《申报》对第八届远东运动会全程进行了跟踪报道,通过纸面新闻报道,不仅为各地群众立体地展示了这次盛会,而且对增强中国人的自信心也有着重大意义。

Comparing results of cultured and uncultured biological methods used in biological phosphorus removal

Increasing attention has been paid to phosphate-accumulating organisms （PAOs） for their important role in biological phosphorus removal. In this study, microbial communities of PAOs cultivated under different carbon sources （sewage, glucose, and sodium acetate） were investigated and compared through culture-dependent and culture-independent methods, respectively. The results obtained using denaturing gradient gel electrophoresis （DGGE） of polymerase chain reaction-amplified 16S rDNA fragments revealed that the diversity of bacteria in a sewage-fed reactor （1#） was much higher than in a glucose-fed one （2#） and a sodium acetate-fed one （3#）; there were common PAOs in three reactors fed by different carbon sources. Five strains were separated from three systems by using a phosphaterich medium; they were from common bacteria isolated and three isolates could not be found in DGGE profile at all. Two isolates had good phosphorus removal ability. When the microbial diversity was studied, the molecular biological method was better than the culture-dependent one. When phosphorus removal characteristics were investigated, culture-dependent approach was more effective. Thus a combination of two methods is necessary to have a comprehensive view of PAOs.

两株好氧反硝化聚磷菌的筛选、鉴定及水质净化研究

旨在从环境样品中筛选对富营养化水体具有良好脱氮除磷效果的好氧反硝化菌。采集福州某养猪场污水处理池中的水样。通过反硝化细菌培养基培养、BTB培养基平板分离、硝酸盐还原试验和蓝白斑筛选法、异染颗粒以及聚-β-羟基丁酸(PHB)颗粒染色试验,筛选获得两株具有脱氮除磷特性的菌株,命名为N1和N2。经16S r RNA基因序列分析,N1和N2分别属于无色杆菌属(Achromobacter.sp)和短波单胞菌属(Brevundimonas.sp)。将菌株N1和N2复配,获得脱氮除磷复合菌FIM-1。考察了菌株对人工合成污水和富营养化水体脱氮除磷的效果。结果表明,两株菌在含磷量较低的水体中,对磷的去除率较高,相对于单菌,复合菌表现出更佳的脱氮除磷效果。

污水处理反硝化除磷-诱导结晶磷回收工艺中除磷微生物特性

为探究反硝化除磷-诱导结晶磷回收工艺中缺氧池污泥释磷、吸磷以及微生物特征,利用荧光原位杂交(fluorescence in situ hybridization,FISH)技术、电子扫描显微镜(scanning electron microscope,SEM)观察了微生物的数量、分布和形态;通过批次试验考察了污泥在厌氧/好氧和厌氧/缺氧2种模式下的释磷和吸磷特征。结果表明:该双污泥系统缺氧池中聚磷菌占总细菌比例的69.7%,明显高于单污泥系统中富集的聚磷菌比例,污泥中的微生物多呈杆状;厌氧/好氧、厌氧/缺氧模式下单位污泥浓度(mixed liquor suspended solids,MLSS)总吸磷量(以PO43--P计)分别为22.84、18.60 mg/g,反硝化聚磷菌(denitrifying polyphosphate-accumulating organisms,DPAO)占聚磷菌(polyphosphate-accumulating organisms,PAO)的比例为81.44%,表明在长期的厌氧/缺氧运行条件下可以富集到以硝酸盐为电子受体的反硝化聚磷菌,同时还存在着仅以氧气为电子受体的聚磷菌;通过pH值和氧化还原电位(oxidation reduction potential,ORP)的实时监测可以快速地了解污水生物处理系统中各类反应的进程,对调控工艺参数有着重要的意义。综上所述,为保证污水生物处理工艺的正常稳定运行,将微生物分析与常规的化学参数分析结合起来考察将是未来发展的必然趋势。

生物除磷系统聚糖菌的代谢机理及菌群结构

针对聚糖菌的富集引起强化生物除磷系统(EBPR)运行不稳定问题,开展聚糖菌代谢机理、微生物形态和菌群结构研究,以了解EBPR工艺的微生物原理.聚糖菌在厌氧环境中分解体内的糖原以获得能量来摄取外界环境中的短链脂肪酸,因而在厌氧反应阶段与聚磷菌形成对有机底物的竞争矛盾.尤其当聚糖菌在某些未明确因素下取得竞争优势后,系统中的聚磷菌将逐渐被淘汰替换或成为非优势菌种,从而导致EBPR除磷功能的完全丧失.研究表明,进水基质类型、进水P/C比、pH、温度以及亚硝酸盐等因素决定着聚糖菌和聚磷菌的竞争优势,并在特定阈值内引起EBPR系统聚糖菌的富集而使除磷功能丧失.

市政污水处理厂生物除磷运行效能与机理分析

选取浙江北部10个污水处理厂,调研污水厂生物除磷的运行效能并开展污泥活性以及微生物分布特征及其除磷机理的研究.通过活性污泥批试验表明,厌氧释磷率和好氧聚磷率(以P计)平均为2.4mg/(g·h)和2.2mg/(g·h);反硝化聚磷菌(DPAOs)占聚磷菌(PAOs)的比例为0.0%～80.1%.荧光原位杂交法(FISH)对活性污泥微生物群落结构分析表明,聚磷菌(PAOs)比例为2.0%～8.7%,聚糖菌(GAOs)比例为1.3%～22.4%.根据调查结果和生物除磷性能研究,可通过调整污水营养成分和设置独立前置反硝化池等方法改善除磷效果.

序批式膜生物反应器中反硝化聚磷菌的富集

采用序批式膜生物反应器(SBMBR)对以硝酸盐作为电子受体的反硝化聚磷菌的富集进行了研究.结果表明,经过厌氧-好氧和厌氧-缺氧-好氧2个阶段的富集,反硝化聚磷菌占全部聚磷菌的比例从19.4%上升到69.6%,每周期缺氧段投加硝酸盐氮120mg时,SBMBR系统运行最为稳定.稳定运行的SBMBR反硝化强化除磷体系具有良好的强化除磷和反硝化脱氮性能,缺氧段脱氮和除磷效率分别达到100%和84%,膜出水总磷浓度平均低于0.5mg/L,系统除磷率达到96.1%.此外,氨氮去除率保持在92.2%,氨氮被去除的同时并没有发现亚硝酸盐氮和硝酸盐氮的明显积累.