应用16S rRNA基因文库技术分析3种生物填料上生物膜的细菌群落组成

为研究生物填料上生物膜的细菌群落组成及其在循环水养殖系统中的应用,选择3种生物填料构建生物滤池,采用细菌16S rRNA基因片段扩增和Illumina高通量测序法,分析了循环水养殖系统中填料上生物膜和对应生物滤池水体中的细菌群落种类组成。结果表明:3种生物填料均有富集微生物生长的作用,生物填料上生物膜的细菌种类和多样性大于对应的生物滤池水体;在门分类水平,3个生物滤池水体中的优势菌相同,均为厚壁菌门,3种生物填料上生物膜的优势菌不尽相同,聚乙烯小球生物膜的优势菌为厚壁菌门,陶瓷环和弹性毛刷生物膜的优势菌为变形菌门;弹性毛刷生物膜的细菌种类最多、多样性指数最高,由变形菌门的26个属细菌组成,聚乙烯小球生物膜的细菌种类组成最少、多样性指数最低,由厚壁菌门的23个属组成,细菌丰度指数最低。     

应用16S rRNA基因文库技术分析3种生物填料上生物膜的细菌群落组成

为研究生物填料上生物膜的细菌群落组成及其在循环水养殖系统中的应用,选择3种生物填料构建生物滤池,采用细菌16S rRNA基因片段扩增和Illumina高通量测序法,分析了循环水养殖系统中填料上生物膜和对应生物滤池水体中的细菌群落种类组成。结果表明:3种生物填料均有富集微生物生长的作用,生物填料上生物膜的细菌种类和多样性大于对应的生物滤池水体;在门分类水平,3个生物滤池水体中的优势菌相同,均为厚壁菌门,3种生物填料上生物膜的优势菌不尽相同,聚乙烯小球生物膜的优势菌为厚壁菌门,陶瓷环和弹性毛刷生物膜的优势菌为变形菌门;弹性毛刷生物膜的细菌种类最多、多样性指数最高,由变形菌门的26个属细菌组成,聚乙烯小球生物膜的细菌种类组成最少、多样性指数最低,由厚壁菌门的23个属组成,细菌丰度指数最低。     

BAF工艺深度处理四环素类制药废水研究

针对市政污水处理厂、制药厂和医院污水处理厂出水中的抗生素残留,采用曝气生物滤池（BAF）工艺进行深度处理。分别建立了两组曝气生物滤池实验装置,研究不同抗生素残留浓度、不同水力停留时间条件下对污染物降解及微生物菌群变化规律。长期实验结果表明,在进水抗生素浓度低于1 mg/L的情况下,COD、氨氮的去除效果稳定,在水力停留时间为10 h时,四环素类抗生素的去除率均在82.5%以上。对BAF中微生物群落的分析表明：投加抗生素后,BAF中微生物种群多样性明显降低。Proteobacteria（变形菌门）是主要的菌群,且丰度变化最大;Alphaproteobacteria（α-变形杆菌纲）、Flavobacteriia（黄杆菌纲）和Betaproteobacteria（β-变形杆菌纲）丰度增加,该菌属可以适应抗生素废水;Acidovorax（嗜酸菌属）和Flavobacterium（黄杆菌属）丰度增加,具有反硝化作用的菌属可优势生长。     

油藏内源微生物演替规律及其对驱油效果的影响

利用长岩心连续动态驱替实验模拟现场微生物驱油过程,通过高通量测序及荧光定量PCR技术定量描述物模驱出液菌群结构、多样性指数及驱油功能细菌浓度的动态变化规律,并分析生物特征动态变化规律与含水率变化之间的对应关系。结果表明:激活剂多轮次段塞注入方式下,内源菌群呈现连续动态演替变化,菌群结构趋于简单化,多样性指数逐渐降低,不动杆菌、厌氧小杆菌及甲烷嗜热杆菌逐渐成为群落中的优势菌属;内源总细菌浓度及驱油功能细菌浓度随激活剂的注入逐渐升高,在时间尺度上存在明显的好氧、兼性及厌氧驱油功能菌级联激活规律,厌氧产甲烷古菌激活时整个代谢链被启动,驱油效率最高;在兼性及厌氧驱油功能细菌浓度提高2个数量级后,产出液细菌群落多样性指数与含水率变化之间存在明显的相关性,可以作为内源微生物驱油生物特征指标,指导内源微生物驱油现场效果的分析及方案的针对性调整。     

不同处理方式对大豆耕地土壤微生物多样性的影响

对不同肥料及农药处理的大豆耕地土壤微生物进行传统分离、纯化及鉴定,最终分离得到细菌73株,分属于12个不同菌属;分离出放线菌49株,分属于7个不同菌属;分离出真菌41株,属于4个不同菌属和不产孢真菌。对其土壤微生物多样性进行比较分析,结果表明施用除草剂、杀虫剂和NPK复合肥对微生物多样性影响较大,几个处理组的多样性指数均较高。虽然除草剂和杀虫剂对微生物的生长有抑制作用,但是多样性不受影响。     

不同温度下UASB反应器对苯酚的降解及微生物分析

利用上流式厌氧污泥床(UASB)反应器对以苯酚作为惟一底物的合成废水进行处理,比较在不同温度下苯酚的去除效果,并利用DNA克隆技术对不同温度下UASB污泥中的微生物种群进行鉴别.利用变性梯度凝胶电泳(DGGE)对微生物种群进行分析,结果表明温度变化对微生物群落的影响不大;而较高的苯酚负荷(或较少的HRT)会抑制消失的谱带所代表的细菌种类,使微生物的多样性减少.利用UASB反应器降解含苯酚废水时,建议选择室温,最佳的HRT取12～16 h,相应的有机负荷率取6.0～4.5 gCOD/(L·d-1).根据DNA克隆分析,试验污泥由五种类型的微生物组成脱硫黄斑菌、羧状芽孢杆菌、互营共生菌、产甲烷菌及Z形蛋白质分解菌.     

城市污水脱氮除磷系统的活性污泥菌群结构特征

为表征我国城市污水处理厂活性污泥微生物的群落结构特征,并了解污水处理工艺、进水水质和地域环境等因素对其分布的影响,采用Miseq高通量测序技术对9座城市污水处理厂生物脱氮除磷系统的活性污泥群落结构进行了分析。结果表明,这些活性污泥系统中的优势微生物种群均以变形菌门(Proteobacteria)和拟杆菌门(Bacteroidetes)为主,而且变形菌主要分布在β-Proteobacter纲,最大比例达到了约24%;脱氮除磷菌属主要为亚硝化单胞菌属(Nitrosomonas)和Accumulibacter Phosphatis,最大比例分别为4.69%和7.51%;活性污泥微生物的多样性和丰度指数受进水水质的影响较为明显,而不同样品的相似度则受到工艺类型和地理位置等因素的影响。     

集中式空调机组系统微生物污染的实测分析

对陕西历史博物馆集中通风空调机组设备的积尘伴生微生物和空气微生物进行了实测。分析结果表明,机组粗效过滤器对微生物的去除效果,细菌优于真菌;空气处理机组内部本身有真菌滋生,真菌浓度最大时达到200.3cfu/皿,系统微生物污染可导致送风空气质量的下降;微生物浓度与相对湿度具有显著的正相关性;空调机组的真菌优势菌属是青霉属、曲霉属和枝孢霉属。     

长庆油田石油污染土壤微生物种群多样性研究

以姬塬油田井场石油污染土壤为研究对象,通过高通量测序,分析了细菌群落的类型和结构,结果显示3份土壤样品中共检测到包括变形菌门、放线菌门、厚壁菌门、拟杆菌门、酸杆菌门和疣微菌门等24个门的细菌,土壤微生物结构多样性丰富,揭示了原油污染土壤的微生物种群多样性情况,对石油污染微生物治理技术具有重要的意义。     

691例化妆品微生物检测结果分析

目的检测化妆品的微生物指标,分析污染微生物的种群分布,了解化妆品的卫生情况及其中存在的潜在危害。方法按照《化妆品卫生规范》(2007版)第四部分—微生物检验方法检测化妆品中微生物指标,并将检出的细菌分离,利用VITEK2全自动微生物鉴定仪进行鉴定。结果 691例化妆品的合格率为99.13%,菌落总数合格率为99.42%,霉菌和酵母菌合格率为100%,检出粪大肠菌群1例,铜绿假单胞菌1例、未检出金黄色葡萄球菌。菌属分布主要为假单胞菌属、埃希菌属、泛菌属、气单胞菌属、葡萄球菌属等,分离出的细菌多数为条件致病菌,对使用者的健康可能造成危害。结论化妆品的微生物指标超标率较低,但是有致病菌和条件致病菌检出,说明化妆品的卫生安全问题仍不容忽视。     

超稠油废水中COD和氨氮等的降解试验研究

分析了超稠油废水处理现状与趋势,针对超稠油废水特性提出处理方案,通过试验证明以增强型CAST与生物接触氧化法作为主体工艺,并附以油、气浮等预处理工艺路线,对特征污染指标COD、油类等都具有较高的去除率。     

沉降/旋流分离/气浮工艺预处理稠油废水

针对稠油废水油含量大、乳化程度高等特点,采用沉降除油/旋流油水分离/气浮工艺进行预处理。在旋流油水分离器中投加LT1#破乳剂20～30 mg/L,对油和COD的去除率分别达到83%～90%和81%～86%,整个系统对油和COD的总去除率分别达到99%和90%以上,对油的回收率80%。实际运行表明,该工艺具有处理效率高、设备运行稳定、耐冲击性能好和维护简单等特点,出水水质可以满足对稠油废水预处理的要求。     

泡沫分离—Fenton氧化处理炼油废水

针对炼油厂废水处理工程,分析了表面活性剂成分及运行中产生泡沫的原因。采用泡沫分离—Fenton氧化技术进行处理,实践证明其出水水质优于国家排放标准,解决了废水排放过程中产生泡沫的问题。     

ABR-BAF工艺处理采油废水的中试研究

进行了利用折流板厌氧反应器（ABR）-曝气生物滤池（BAF）工艺处理江汉油田马-25污水处理站采油废水的中试研究，主要考察了ABR的除油效果、提高废水可生化性的作用以及BAF的运行参数、处理效果等。研究结果表明：当废水流量为0．3m^3／h时，ABR反应器对油的去除率平均为83．5％，对COD的去除率平均为40．8％，出水BOD，／COD值提高了24．8％。ABR一方面去除了采油废水中的大部分油，另一方面提高了采油废水的可生化性。当BAF的水力负荷为0．6m／h、进水COD平均为203．5mg／L时，出水COD平均为85．7mg／L，平均去除率为57．9％；对SS的去除率为82．7％。组合工艺对油、COD、BOD，和SS的总去除率分别为96．1％-96．9％、58．2％～75．1％、80．0％-93．1％和80．7％～87．1％。扫描电镜（SEM）观察结果显示：生物膜结构紧密，并且观察到裂口虫，生物相非常丰富。ABR-BAF工艺能够很好地处理采油废水，出水水质满足污水二级排放标准。     

Stability of the bacterial communities supported by a seven-stage biological process treating pharmaceutical wastewater as revealed by PCR-DGGE

The stabilities of the bacterial community structures supported by seven full-scale biological reactors treating pharmaceutical wastewater were investigated by denaturing gradient gel electrophoresis (DGGE) of polymerase chain reaction (PCR) amplified 16S rRNA gene fragments. Effluent quality from this treatment process was consistently high with respect to BOD5 (<30 mgl(-1)), soluble COD (<500 mgl(-1)), and total ammonia (< 5 mgl(-1) as N) concentrations. Long-term community structure stability was studied by comparing the similarity of PCR-DGGE fingerprints from samples collected 87 days apart between which the influent wastewater characteristics were relatively stable. The Dice index (Cs) of similarity was moderately high for the first four reactors (Cs = 0.61-0.77) and very high for the last three reactors (Cs = 0.89-0.91). Short-term community structure stability was studied by comparing PCR-DGGE fingerprints from samples collected 15 days apart between which the influent wastewater characteristics changed significantly, while the effluent quality remained consistently high. The bacterial community composition of each of the seven bioreactors showed a moderate community shift (Cs = 0.70-0.76). Short-term variability in influent wastewater composition, therefore, affected a greater community shift than did long-term operation treating a wastewater of relatively consistent composition. These results indicate that functionally stable wastewater treatment bioreactors have stable microbial community structures under normal operating conditions but are able to adapt in response to perturbations to sustain high effluent quality.     

Size distribution of wastewater COD fractions as an index for biodegradability

The study proposes direct particle size measurement by sequential filtration and ultrafiltration as a convenient method for wastewater characterization for appropriate treatment technology. It also explores the correlation between particle size distribution (PSD) and chemical oxygen demand (COD) fractionation, as an index for biological treatability. Profiles obtained through PSD-based COD fractionation serve as the fingerprints for wastewaters, and as demonstrated in this study, reflect different pictures for textile wastewater and domestic sewage. PSD-based COD fractionation profiles identify the soluble range below 2 nm as the size interval housing both the soluble inert COD initially present in the wastewater and soluble inert microbial products generated during biological treatment, as also supported by the metabolic fractionation attained through respirometric analyses. Moreover, PSD-based color profiling offers a good index for the fate of biologically resistant chemicals passing through biological treatment. Compatible results obtained from comparative evaluation of PSD-based COD and color profiles provide useful information on the biodegradability of the textile wastewater studied.     

Bacterial community structures in MBRs treating municipal wastewater: relationship between community stability and reactor performance

Bacterial community structures in pilot-scale conventional membrane bioreactors (CMBRs) and hybrid MBRs (HMBRs) which were combined with pre-coagulation/sedimentation were analyzed by polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) and fluorescence in situ hybridization (FISH) techniques. The results were compared with the community structure in a full-scale activated sludge (AS) process treating the same municipal wastewater. The Dice index (Cs) of similarity analysis of DGGE banding patterns demonstrated that the microbial community in AS was more similar to those in CMBR1 and CMBR2 than HMBR1 and HMBR2. This suggested that influent wastewater composition had a larger impact on bacterial community structures. Long-term community structure changes in the HMBRs and CMBRs were monitored and analyzed over 240 days by Non-metric multidimensional scaling (NMDS) analysis of DGGE banding patterns. The NMDS analysis revealed that both HMBRs and CMBRs had marked changes in community structures during the first about 100 days. Thereafter the perpetual fluctuations of bacterial community structures were observed in both HMBRs and CMBRs, even though the stable MBR performances (the performance was measured as membrane permeability and removal of dissolved organic carbon, DOC) were achieved. These results suggest that not only the stability, but also the adequate dynamics ("flexibility") of the bacterial community structure are important for the stable performance of the MBRs treating complex municipal wastewater.     

Metal supplementation to UASB bioreactors: from cell-metal interactions to full-scale application

Upflow anaerobic sludge bed (UASB) bioreactors are commonly used for anaerobic wastewater treatment. Trace metals need to be dosed to these bioreactors to maintain microbial metabolism and growth. The dosing needs to balance the supply of a minimum amount of micronutrients to support a desired microbial activity or growth rate with a maximum level of micronutrient supply above which the trace metals become inhibitory or toxic. In studies on granular sludge reactors, the required micronutrients are undefined and different metal formulations with differences in composition, concentration and species are used. Moreover, an appropriate quantification of the required nutrient dosing and suitable ranges during the entire operational period has been given little attention. This review summarizes the state-of-the-art knowledge of the interactions between trace metals and cells growing in anaerobic granules, which is the main type of biomass retention in anaerobic wastewater treatment reactors. The impact of trace metal limitation as well as overdosing (toxicity) on the biomass is overviewed and the consequences for reactor performance are detailed. Special attention is given to the influence of metal speciation in the liquid and solid phase on bioavailability. The currently used methods for trace metal dosing into wastewater treatment reactors are overviewed and ways of optimization are suggested.     

Impact of nitrate addition on biofilm properties and activities in rising main sewers

Anaerobic sewer biofilm is a composite of many different microbial populations, including sulfate reducing bacteria (SRB), methanogens and heterotrophic bacteria. Nitrate addition to sewers in an attempt to control hydrogen sulfide concentrations affects the behaviour of these populations, which in turn impacts on wastewater characteristics. Experiments were carried out on a laboratory reactor system simulating a rising main to determine the impact of nitrate addition on the microbial activities of anaerobic sewer biofilm. Nitrate was added to the start of the rising main during sewage pump cycles at a concentration of 30 mg-N L⁻¹ for over 5 months. While it reduced sulfide levels at the outlet of the system by 66%, nitrate was not toxic or inhibitory to SRB activity and did not affect the dominant SRB populations in the biofilm. Long-term nitrate addition in fact stimulated additional SRB activity in downstream biofilm. Nitrate addition also stimulated the activity of nitrate reducing, sulfide oxidizing bacteria that appeared to be primarily responsible for the prevention of sulfide build up in the wastewater in the presence of nitrate. A short adaptation period of three to four nitrate exposure events (approximately 10 h) was required to stimulate biological sulfide oxidation, beyond which no sulfide accumulation was observed under anoxic conditions. Nitrate addition effectively controlled methane concentrations in the wastewater. The nitrate uptake rate of the biofilm increased with repeated exposure to nitrate, which in turn increased the consumption of biodegradable COD in the wastewater. These results provide a comprehensive understanding of the impact of nitrate addition on wastewater composition and sewer biofilm microbial activities, which will facilitate optimization of nitrate dosing for effective sulfide control in rising main sewers.     

Influence of irrigation with lagooned urban wastewater on chemical and microbiological soil parameters in a citrus orchard under Mediterranean condition

The reduced availability of water resources in semi-arid Mediterranean regions requires an efficient use of supply sources. Urban wastewater, after treatment to minimise health hazards, may constitute an important resource for irrigation in areas characterised by intensive agriculture. These considerations have motivated an investigation (during the irrigation season 1996) of the dynamics of microbial biomass in the soil of a citrus orchard in eastern Sicily, which has been irrigated for 15 years with lagooned urban wastewater, to evaluate the effects of this practice on soil fertility. The analyses of parameters regarding soil microbial biomass (microbial carbon and microbial nitrogen, soluble carbon and nitrogen, cumulative respiration, respiratory quotient and enzymatic activity in the soil) have confirmed that the evolution of soil microflora is directly conditioned by the type of water used for irrigation and climatic conditions. Just before the beginning of the irrigation season (May), microbial biomass carbon (MBC), soluble C, cumulative respiration and enzymatic activity were significantly higher in the soil irrigated with wastewater with respect to the same soil irrigated with 'clear' water; the qCO2 was significantly lower. In June, after 1 month of irrigation, both soils showed an increase of all microbial parameters except for enzymatic activity and qCO2 which showed a significant reduction. In September, at the end of the irrigation period, there was a decrease of almost all investigated parameters in both plots, which was more evident in the soil irrigated with 'clear' water. The microbial biomass of the soil irrigated with wastewater, during the irrigation period, did not undergo any negative effects, having an evolution analogous to the plot irrigated with 'clear' water. The use of lagooned wastewater after three lustrums has shown, particularly in the dry season, an increase in quantity of easily available nutrients, with an improvement of the metabolic efficiency of soil microflora coupled with a more marked activity of total hydrolase and phosphatases. The variations of the parameters related to the soil microflora were strongly influenced by the seasonal climatic trend.