The research of phosphorus of Xiangxi River nearby the Three Gorges, China

The Xiangxi River is the first middling tributary of the Changjiang River near the Three Gorges Dam. The River is subject to phosphorus pollution mainly from industrial wastewater. As the water quality of the Xiangxi River could directly influence the water quality of the Three Gorges Reservoir, the research on phosphorus levels and its change in the sediment profile of the Xiangxi River could provide useful information in the dynamic changes in the system, thereby offering options for mitigative measures. Water and sediment samples from lower reaches of Xiangxi River were collected and the different forms of phosphorus in sediments of the Xiangxi River were studied. The concentrations of total phosphorus in sediment ranged from 757.67 to 1438.54 mg/kg. Inorganic phosphorus concentrations ranged from 684.63 to 1055.58 mg/kg. Phosphorus contamination was serious in some parts of the Xiangxi River. With an average concentration of 635.17 mg/kg, calcium-bound phosphorus is the main form among different inorganic phosphorus forms. Labile phosphorus and iron/aluminum-bound phosphorus measured 3.40, 0.05and 35.28 mg/kg, respectively. The mobilization potential of phosphorus of sediments was studied through adsorption and release experiments. The equilibrium concentration of phosphorus adsorption and release was around 0.1 mg/L. The initial concentrations of phosphorus in the overlying water and the sediments have obvious effect on phosphorus mobilization potential. In addition, the release rate of phosphorus in sediment increased with water depth.

Discharges and sediments as sources of extracellular alkaline phosphatase in a shallow Chinese eutrophic lake

Total alkaline phosphatase activity (APA) and soluble reactive phosphorus (SRP) concentrations were measured in municipal wastewater, and a shallow Chinese freshwater lake receiving it. Activities of Dissolved alkaline phosphatase ( ADAP) in overlying and interstitial water were also analyzed monthly at three sites for several years. The lake was enriched with SRP and alkaline phosphatase by discharge of the wastewater, indicating that the inclusion of APA for estimating water pollution was reasonable. Annual data showed that APA in coarser fraction was significantly higher at the site receiving more wastewaters, both in surface and overlying water, suggesting that resuspension of enzyme most likely occurred in the basin heavily discharged. ADAP was an order of magnitude higher in the wastewater than those in lake waters, and was generally higher in interstitial water, a feature more striking at the site receiving more discharges. Besides, it was irrespectively inhibited by Na2WO4, L-cysteine and EDTA-Na, but stimulated by Cu2+, Zn2+, CTAB and Triton X-100 in interstitial, overlying and surface waters. This similarity of responding patterns to the stressors indicated an analogy between dissolved alkaline phosphatase in water column and that in interstitial water, supporting the hypothesis that the polluted sediments act as source of dissolved alkaline phosphatase in eutrophic lakes.

Root zone microbial populations, urease activities, and purification efficiency for a constructed wetland

In order to investigate the effects of microorganisms and their urease activities in macrophytic root zones on pollutant removal, four small-scale plots (SSPs) of vertical/reverse-vertical flow wetlands were set up to determine: a) the relationship between the abundance of microorganisms in the root zones and water purification efficiency; and b) the relationship between urease activities in the root zones and pollutant removal in a constructed wetland system. Total numbers of the microbial population (bacteria, fungi, and actinomyces) along with urease activities in the macrophytic root zones were determined. In addition, the relationships between microbial populations and urease activities as well as the wastewater purification efficiencies of total phosphorus (TP), total Kjeldahl nitrogen (TKN), biochemical oxygen demand in 5 days (BOD5), and chemical oxygen demand (COD) were also analyzed. The results showed that there was a highly significant positive correlation (r = 0.9772, P < 0.01) between the number of bacteria in the root zones and BOD5 removal efficiency and a significant negative correlation (r = -0.9092, P < 0.05) between the number of fungi and the removal efficiency of TKN. Meanwhile, there was a significant positive correlation (r = 0.8830, P < 0.05) between urease activities in the root zones and the removal efficiency of TKN. Thus, during wastewater treatment in a constructed wetland system, microorganism and urease activities in the root zones were very important factors.

Removal of dibutyl phthalate by a staged, vertical-flow constructed wetland

Two sets of small scale systems of staged, vertical-flow constructed wetlands (VFCW) were operated in a greenhouse to study the purification of dibutyl phthalate (DBP) in admeasured water. Each system consisted of two chambers in which water flowed downward in chamber I and then upward in chamber 2. The systems were intermittently fed with wastewater under a hydraulic load of 420 mm(.)d(-1). The measured influent concentrations of DBP in the experimental system were 9.84 mg(.)l(-1), while the other system was used as a control and received no DBP. Effluent concentrations of the treated system averaged 5.82 mug(.)l(-1) and were far below the Chinese DBP discharge standard of less than or equal to0.2 mg(.)l(-1). These results indicate the potential purification capacity of this new kind of constructed wetland in removing DBP from a polluted water body.

Measurement of estrogen activity in two Chinese lakes

Estrogenic activities of samples from two Chinese lakes, Ya-Er Lake and Donghu Lake, were measured by in vitro recombinant yeast assay and found in both lakes polluted with industrial and domestic wastewater. In methanol extracts of lake water samples the estrogen-like activity was higher than in toluene extracts. These results have been inverted for solid samples. Furthermore, the EC50 value of the water samples was close to the original concentration in the lake.

Heavy metals in plants and phytoremediation - A state-of-the-art report with special reference to literature published in Chinese journals

Goal, Scope and Background. In some cases, soil, water and food are heavily polluted by heavy metals in China. To use plants to remediate heavy metal pollution would be an effective technique in pollution control. The accumulation of heavy metals in plants and the role of plants in removing pollutants should be understood in order to implement phytoremediation, which makes use of plants to extract, transfer and stabilize heavy metals from soil and water. Methods. The information has been compiled from Chinese publications stemming mostly from the last decade, to show the research results on heavy metals in plants and the role of plants in controlling heavy metal pollution, and to provide a general outlook of phytoremediation in China. Related references from scientific journals and university journals are searched and summarized in sections concerning the accumulation of heavy metals in plants, plants for heavy metal purification and phytoremediation techniques. Results and Discussion. Plants can take up heavy metals by their roots, or even via their stems and leaves, and accumulate them in their organs. Plants take up elements selectively. Accumulation and distribution of heavy metals in the plant depends on the plant species, element species, chemical and bioavailiability, redox, pH, cation exchange capacity, dissolved oxygen, temperature and secretion of roots. Plants are employed in the decontamination of heavy metals from polluted water and have demonstrated high performances in treating mineral tailing water and industrial effluents. The purification capacity of heavy metals by plants are affected by several factors, such as the concentration of the heavy metals, species of elements, plant species, exposure duration, temperature and pH. Conclusions. Phytoremediation, which makes use of vegetation to remove, detoxify, or stabilize persistent pollutants, is a green and environmentally-friendly tool for cleaning polluted soil and water. The advantage of high biomass productive and easy disposal makes plants most useful to remediate heavy metals on site. Recommendations and Outlook. Based on knowledge of the heavy metal accumulation in plants, it is possible to select those species of crops and pasturage herbs, which accumulate fewer heavy metals, for food cultivation and fodder for animals; and to select those hyperaccumulation species for extracting heavy metals from soil and water. Studies on the mechanisms and application of hyperaccumulation are necessary in China for developing phytoremediation.

Heavy metal pollution in China: Origin, pattern and control

Goal, Scope and Background. Heavy metal is among one of the pollutants, which cause severe threats to humans and the environment in China. The aim of the present review is to make information on the source of heavy metal pollution, distribution of heavy metals in the environment, and measures of pollution control accessible internationally, which are mostly published in Chinese. Methods. Information from scientific journals, university journals and governmental releases are compiled focusing mainly on Cd, Cu, Pb and Zn. Partly Al, As, Cr, Fe, Hg, Mn and Ni are included also in part as well. Results and Discussion. In soil, the average contents of Cd, Cu, Pb and Zn are 0.097, 22.6, 26.0 and 74.2 mg/kg, respectively. In the water of. the Yangtze River Basin, the concentrations of Cd, Cu, Pb and Zn are 0.080, 7.91, 15.7 and 18.7 pg/L, respectively. In reference to human activities, the heavy metal pollution comes from three sources: industrial emission, wastewater and solid waste. The environment such as soil, water and air were polluted by heavy metals in some cases. The contents of Cd, Cu, Pb and Zn even reach 3.16, 99.3, 84.1 and 147 mg/kg, respectively, in the soils of a wastewater irrigation zone. These contaminants pollute drinking water and food, and threaten human health. Some diseases resulting from pollution of geological and environmental origin, were observed with long-term and non-reversible effects. Conclusions. In China, the geological background level of heavy metal is low, but with the activity of humans, soil, water, air, and plants are polluted by heavy metals in some cases and even affect human health through the food chain. Recommendations and Outlook. To remediate and improve environmental quality is a long strategy for the polluted area to keep humans and animals healthy. Phytoremediation would be an effective technique to remediate the heavy metal pollutions.

Efficiency of constructed wetlands in decontamination of water polluted by heavy metals

A twin-shaped constructed wetland (CW) comprising a vertical flow (inflow) chamber with Cyperus alternifolius followed by a reverse-vertical flow (outflow) chamber with Villarsia exaltata was assessed for decontamination of artificial wastewater polluted by heavy metals. After application of Cd, Cu, Pb, Zn over 150 days, together with Al and Mn during the final 114 days, no heavy metals with the exception of Mn could be detected in either the drainage zone at the bottom, shared by both chambers, or in the effluent. The inflow chamber was, therefore, seen to be predominantly responsible for the decontamination process of more toxic metal species with final concentrations far below WHO drinking-water standards. About one-third of the applied Cu and Mn was absorbed, predominantly by lateral roots of C. alternifolius. Lower accumulation levels were observed for Zn (5%), Cd (6%), Al (13%). and Pb (14%). Contents of Cd, Cu, Mn, and Zn in soil were highest in top layer, while Al and Pb were evenly distributed through the whole soil column. Metal species accumulating mainly in the top layer can be removed mechanically. A vertical flow CW with C. alternifolius is an effective tool in phytoremediation for treatment of water polluted with heavy metals. (C) 2002 Elsevier Science B.V. All rights reserved.

STUDIES ON THE PURIFICATION AND RECLAMATION OF WASTE-WATER FROM A MEDIUM-SIZED CITY BY AN INTEGRATED BIOLOGICAL POND SYSTEM

The feasibility of an inexpensive wastewater treatment system is evaluated in this study. An integrated biological pond system was operated for more than 3 years to purify the wastewater from a medium-sized city, Central China. The experiment was conducted in 3 phases with different treatment combinations for testing their purification efficiencies. The pond system was divided into 3 functional regions: influent purification, effluent upgrading and multi-utilization. These regions were further divided into several zones and subzones. Various kinds of aquatic organisms, including macrophytes, algae, microorganisms and zooplankton, were effectively cooperating in the wastewater treatment in this system. The system attained high reductions of BOD5, COD, TSS, TN, TP and other pollutants. The purification efficiencies of this system were higher than those of most traditional oxidation ponds or ordinary macrophyte ponds. The mutagenic effect and numbers of bacteria and viruses declined significantly during the process of purification. After the wastewater flowed through the upgrading zone, the concentrations of pollutants and algae evidently decreased. Plant harvesting did not yield dramatic effects on reductions of the main pollutants, though it did significantly affect the biomass productivity of the macrophytes. The effluent from this system could be utilized in irrigation and aquaculture. Some aquatic products were harvested from this system and some biomass was utilized for food, fertilizer, fodder and some other uses. The wastewater was reclaimed for various purposes.

生物质煤气废水氨氮脱除的研究

生物质煤气废水是一种新出现的高浓度氨氮有机废水。作者采用化学沉淀法去除该废水中的氨氮，研究了不同沉淀剂、pH、温度和搅拌时间对氨氮去除效果的影响。结果表明，MgCl2＋Na3PO4·12H2O明显优于其他沉淀剂组合。当n（Mg^2＋）：n（NH4^＋）：n（PO4^3-）=1：1：1、pH10．0、温度30℃、搅拌时间30min时，废水中的氨氮质量浓度从处理前的222mg/L降到17mg／L，去除率为92.3％。

Design and Operation of A 5.5 MWe Biomass Integrated Gasification Combined Cycle Demonstration Plant

The design and operation of a 5.5 MWe biomass integrated gasification combined cycle (IGCC) demonstration plant, which is located in Xinghua, Jiangsu Province of China, are introduced. It is the largest complete biomass gasification power plant that uses rice husk and other agricultural wastes as fuel in Asia. It mainly consists of a 20 MWt atmospheric circulating fluidized-bed gasifier, a gas-purifying system, 10 sets of 450 kW(e) gas engines, a waste heat boiler, a 1.5 MWe steam turbine, a wastewater treatment system, etc. The demonstration plant has been operating since the end of 2005, and its overall efficiency reaches 26-28%. Its capital cost is less than 1200 USD/kW, and its running cost is about 0.079 USD/kWh based on the biomass price of 35.7 USD/ton. There is a 20% increment on capital cost and 35% decrease on the fuel consumption compared to that of a 1 MW system without a combined cycle. Because only part of the project has been performed, many of the tests still remain and, accordingly, must be reported at a later opportunity.

Establishment and characterization of dual-species biofilms formed between a 3,5-dinitrobenzoic-degrading strain and bacteria with high biofilm-forming capabilities

In this study, the possibility of establishing a dual-species biofilm from a bacterium with a high biofilm-forming capability and a 3,5-dinitrobenzoic acid (3,5-DNBA)-degrading bacterium, Comamonas testosteroni A3, was investigated. Our results showed that the combinations of strain A3 with each of five strains with a high biofilm-forming capability (Pseudomonas sp. M8, Pseudomonas putida M9, Bacillus cereus M19, Pseudomonas plecoglossicida M21 and Aeromonas hydrophila M22) presented different levels of enhancement regarding biofilm-forming capability. Among these culture combinations, the 24-h dual-species biofilms established by C. testosteroni A3 with P. putida M9 and A. hydrophila M22 showed the strongest resistance to 3,5-DNBA shock loading, as demonstrated by six successive replacements with DMM2 synthetic wastewater. The degradation rates of 3,5-DNBA by these two culture combinations reached 63.3-91.6% and 70.7-89.4%, respectively, within 6 h of every replacement. Using the gfp-tagged strain M22 and confocal laser scanning microscopy, the immobilization of A3 cells in the dual-species biofilm was confirmed. We thus demonstrated that, during wastewater treatment processes, it is possible to immobilize degrader bacteria with bacteria with a high biofilm-forming capability and to enable them to develop into the mixed microbial flora. This may be a simple and economical method that represents a novel strategy for effective bioaugmentation.

UASB反应器处理维生素C生产废水研究

维生素C生产废水有机物浓度高、成分复杂、排放量大，是一种亟待处理的典型工业废水。本研究分别采用实验室规模和中试规模的升流式厌氧颗粒污泥床反应器（UASB）对该制药工业废水的厌氧生物处理工艺进行了较为深入的研究。同时采用两种不依赖于纯培养的分子生物学手段—变性梯度凝胶电泳（DGGE）和扩增核糖体DNA限制性分析（ARDRA）技术揭示了UASB反应器不同运行阶段污泥中微生物群落多样性组成及变化。此外，首次研究了零价铁（Fe0）在厌氧消化过程中对反应器运行及微生物群落结构的影响。 采用城市污水处理厂厌氧消化池絮状污泥和处理啤酒废水的颗粒污泥混合接种，小试中温（35±1℃）UASB反应器在其运行的第65天启动成功。反应器稳定运行阶段，在进水COD浓度为9000mg/L、水力停留时间为12h、容积负荷为13.6 kgCOD/m3.d条件下，其COD去除率稳定在85~90%之间，沼气产率达到4.5 m3/m3.d，沼气甲烷含量平均为72%。中试UASB反应器的接种污泥为厌氧消化污泥，其启动时间相对较长，为90天。在稳定运行期，反应器的进水COD浓度为8000~10000mg/L，水力停留时间和容积负荷分别保持在12~16h和10.6~14.2 kgCOD/m3.d范围，该阶段反应器的平均COD去除率稳定在85%左右，沼气产率平均为5.2m3/m3.d，沼气中甲烷含量为69%。上述结果表明中温UASB工艺用于维生素C生产废水处理是高效、可行的。 与对照反应器相比，添加Fe0的小试UASB反应器的COD去除率和沼气产量分别提高了6.5%和10.2%。同时，磷酸盐平均去除率为79%，比对照提高了64%，目前尚未见类似研究报道。在中试规模的UASB反应器中补充一定量的Fe0可缩短反应器启动时间，促进颗粒污泥的形成，该结果可能具有重要的应用价值。培养试验进一步表明，Fe0可以作为产甲烷菌还原CO2生成甲烷的电子供体。培养实验还表明，当系统中存在硝酸盐（0.40 mM）和硫酸盐（0.26 mM）时，Fe0促产甲烷过程受到一定程度的抑制。 采用细菌通用引物968F/1401R和341F/907R获得的PCR-DGGE指纹图谱均表明UASB反应器不同运行阶段细菌种群结构变化明显。小试和中试稳定期污泥的微生物多样性均高于各自初始接种污泥。产甲烷菌通用引物340F/519R的PCR-DGGE结果显示，虽然接种污泥中产甲烷菌的丰富度系数略低于稳定期，但总体而言，反应器运行期间产甲烷菌的种群组成相对稳定。 通过构建不同处理和不同运行阶段污泥样品的16S rRNA基因文库并对克隆基因进行限制性内切酶消化、测序分析。结果表明，稳定期两个反应器微生物群落结构相似，但与各自接种污泥差异明显。小试UASB反应器接种污泥中细菌的优势菌群分别为变形菌纲的δ亚纲（28.7%）和β亚纲（17.4%），至稳定运行期则演替为革兰氏阳性低GC菌群（21.9%）和变形菌纲的δ亚纲（14.0%）。中试反应器接种污泥Green non-sulfer bacteria（25.9%）和变形菌纲的δ亚纲（16.4%）类群占优势，而稳定期Green non-sulfer bacteria类群（17.9%）、革兰氏阳性低GC菌群（16.2%）和变形菌纲的δ亚纲（15.4%）为优势菌群。 产甲烷菌的优势克隆为SRJ 230、SRJ 26和SRJ 583，前两者分别与Methanosaeta concilii和未培养的Methanobacteria-like克隆Gran7M4的同源性达到97%和98%，后者与Methanomethylovorans. sp同源性为99%。接种污泥中上述类群占总克隆数量的比例较低。小试、中试接种污泥中产甲烷菌分别占7.8%和3.0%，但稳定运行期，该比例明显增加，分别达到21.9%和18.8%。上述结果表明启动期与稳定期污泥产甲烷菌种群组成相对稳定，但各类群数量明显增加。 添加Fe0的UASB反应器稳定运行期污泥中产甲烷菌比例（31.2%）高于对照反应器（24.2%）, 革兰氏阳性低GC类群、变形菌纲的δ亚纲比例差异不明显，而变形菌纲β亚纲（6.0%）和Green non-sulfer bacteria（9.2%）的比例均分别低于对照反应器（13.1%和17.1%）。该结果表明，添加Fe0使反应器内微生物群落多样性发生了显著变化。 此外，在添加Fe0的UASB反应器中检测到特异性的克隆SRJ 341和SRJ 320，两者分别同磷酸盐去除和铁氧化有关的克隆子Orbal D41和Clone195的序列相似性达95%和96%。这两个类群可能分别与磷酸盐去除及铁促产甲烷作用密切相关。这一结果尚未见报道。

污灌和农药对农田土壤假单胞菌种群的影响

随着环境污染问题的日益严重，微生物修复起到越来越重要的作用。假单胞菌是土壤微生物中最重要、研究最多的细菌之一，能降解简单和复杂的有机物，它们因此而广泛的存在于土壤和水体。但有关于石油、重金属及农药污染物对农田土壤假单胞菌多样性及种群结构的影响却缺乏全面和系统的认识。 本论文首次采用传统微生物培养方法与PCR-DGGE等现代微生物分子生态学研究方法相结合的手段，系统评价了长期含石油和重金属污水灌溉对中国最大的石油、重金属污灌区——沈抚、张士灌区农田土壤中的假单胞菌多样性及其种群结构的影响。同时，本论文也研究了乙草胺、甲胺磷对黑土假单胞菌多样性及种群结构的影响。得出以下结果： 石油污灌区土壤中总的假单胞菌多样性显著高于重金属污灌区；石油污灌区旱田土壤假单胞菌多样性接近于对照清洁土壤,同时低于相似污染程度的石油污灌区水田土壤。进一步测序发现，Pseudomonas mendocina、Pseudomonas stutzeri、Pseudomonas aeruginosa是所分析石油和重金属污灌区土壤中的优势类群，说明在长期污染胁迫下这3种假单胞菌分别得到了不同程度的富集。DGGE 结果显示石油和重金属污染土壤样品的可培养假单胞菌多样性没有显著差异，但均低于对照清洁土壤样品。对各个土壤样品可培养假单胞菌菌株进行REP-PCR基因分型，结果表明这些假单胞菌之间有显著的遗传差异。进一步测序表明，土壤样品中可培养假单胞菌优势类群中含有Pseudomonas. fluorescens 和Pseudomonas. Putida两种。 黑土农田土壤中使用乙草胺会严重降低总的及可培养假单胞菌群落的多样性，而且在5周内不能恢复。而甲胺磷处理土壤与对照相比则差异不显著，并且经过一段时间的适应，土壤中的总的及可培养假单胞菌种群不仅得到恢复而且超过对照。对各处理土壤总的及可培养假单胞菌DGGE谱带类型聚类分析，发现乙草胺、甲胺磷处理土壤样品均各自聚为一簇，说明农药污染类型是影响土壤中假单胞菌种群结构的重要因素。

污水处理体系中的微生物群落特征研究

污水生物处理系统本质上是一种人工强化的工程化微生态系统。污水处理过程往往由多个功能互补的反应单元协同完成，例如因对污水中有机碳、氮和磷兼具良好的去除功能而在城市污水处理中被广泛应用的Anoxic / Oxic（A/O）生物处理工艺。不同反应单元特有的微生物群落之间的相互关系和相互作用与处理系统的稳定性和处理效率密切相关。所以对污水处理系统中微生物群落进行系统分析非常重要。研究系统中微生物群落的时空演替对于优化处理系统的设计和操作具有重要意义。但是，以往对于污水处理系统中微生态系统的解析多数针对实验室规模的其中个别反应器独立进行，还缺乏从系统水平对实际大规模运行的整个污水处理过程中所有反应单元群落进行分析的研究。 悬挂链移动曝气系统是对A / O工艺的完善和发展。悬挂链曝气工艺的实现是依靠悬挂链移动曝气设备和完善的自动控制系统来完成的。可以在系统中实现类似多级A/O的可能性，水力停留时间较长，污泥龄达到15天以上，能够完全实现A / O 工艺。 目前正被广泛应用在各种行业的污水处理项目中。 本文应用基于细菌16S rRNA中的PCR扩增方法（Polymerase Chain Reactor），结合变性梯度凝胶电泳指纹分离技术（Denaturing Gradient Gel Electrophoresis, DGGE），对实际规模的运用Anoxic / Oxic（A/O）工艺并采用悬挂链式移动曝气技术的污水生物处理系统中微生物群落特征，主要对细菌组成结构和群落动态，细菌优势菌群的多样性以及与系统功能稳定性的关系进行了研究，拟为更全面了解活性污泥处理系统中的优势菌群特征，以及细菌群落结构和功能动态变化关系，实现对活性污泥处理的优化操作，对污染物降解功能菌群的筛选，为运用现代培养技术实现分离培养并运用于环境修复实践奠定方法和理论基础。 首先，对影响PCR-DGGE分析的重要前操作步骤进行了优化和筛选，包括两个方面：细菌基因组DNA的高效提取和纯化；不同16S rRNA靶序列对PCR-DGGE分析的影响。从中选出适合于活性污泥样品的细菌基因组DNA提取方法和PCR-DGGE分析的最优靶序列组合。 其次，运用PCR-DGGE指纹图谱技术分析了该污水处理系统中不同功能反应单元中活性污泥的细菌种群结构特征，探讨了系统运行过程中细菌种群时间和空间上的动态特征。并将图谱中所显示的优势条带进行切割回收，重复扩增，电泳检测，序列测定并与GenaBank数据库中的微生物类群进行同源性比对，探讨活性污泥中细菌种群多样性，了解污泥中可能含有的主要具有污染物降解功能的类群信息。 在整个处理过程中，同一功能反应单元中不同位置的活性污泥微生物菌群结构不同。执行不同功能的处理单元活性污泥细菌多样性和组成结构各有不同。 在系统稳定运行的状态下，细菌组成结构的时间变化动态不显著。但是在系统的不同操作条件下，主要处理池的微生物群落的DGGE遗传指纹图谱较独特。 对该处理系统污泥中优势菌群的序列测定和同源性比对表明，优势菌群所对应的细菌的16S rDNA序列可以被归属于以下四个主要的细菌系：α, β, γ- Proteobacteria 以及厚壁菌门 phylum Firmicutes （low G+C Gram-positive）。 该处理系统的优势菌群的DGGE条带拥有潜在的具有异养硝化/好氧反硝化的除 N / P 类群。该类菌群中的大多数属于Pseudomonas spp.。另外，回收到两个与已鉴定的具有异养硝化和好氧反硝化能力的Pseudomonas stutzeri 和 Pseudomonas borbori 最相似的菌株的条带。γ-变形菌纲门（γ- Proteobacteria）的微生物类群在该缺氧-好氧处理厂中分布较广泛，尤其是和 N / P 去除紧密相关的具有脱氮除磷能力的Pseudomonas 类群，而且在好氧曝气处理池中分布较广，这可能和系统中表现的好氧反硝化现象相关。 不同的操作状况下微生物群落结构有差异。增加污泥回流比，增加DO（Dissolved oxygen）浓度，COD去除率和NH4+-N去除率显著增加，总N和总P的去除率改变不显著。 最后，对整个处理过程中微生物群落结构在系统正常调控改变范围内的长期动态和稳定性进行了探讨。整个处理系统的长期稳定性与体系中的每个处理环节相关，而不是仅与其中的单个主要反应池相关。污水处理体系的功能稳定性与其中的微生物群落稳定性相关，微生物群落结构决定了生态功能，群落结构变化能反应系统的运行状况及其降解效率。