城市污水连续流A/O系统富氧条件下脱氮特征

基于添加流离填料的连续流A/O生物膜反应器,研究城市污水生物脱氮特征。系统在富氧条件（溶解氧大于1.5 mg·L^-1）下连续运行113 d,氨氮和总氮去除率均稳定在50%。系统稳定运行阶段好氧区和出水均无亚硝酸盐或硝酸盐积累现象,表现出良好的同步硝化反硝化特征。16S rDNA分析表明,实现这一现象的主要功能细菌为好氧区存在的好氧反硝化菌;FISH分析表明,不同好氧区的好氧反硝化菌的活性和相对数量不同。结果证明系统内发生的同步硝化反硝化主要由好氧反硝化作用实现,硝化反应产生的硝酸盐类物质得到去除。根据试验结果与微生物学分析,提出了在富氧水环境中通过同步硝化反硝化途径脱氮的生物膜模型。     

Nitrogen Removal Characteristics of a Newly Isolated Indigenous Aerobic Denitrifier from Oligotrophic Drinking Water Reservoir,Zoogloea sp. N299

Nitrogen is considered to be one of the most widespread pollutants leading to eutrophication of freshwater ecosystems, especially in drinking water reservoirs. In this study, an oligotrophic aerobic denitrifier was isolated from drinking water reservoir sediment. Nitrogen removal performance was explored. The strain was identified by 16S rRNA gene sequence analysis as Zoogloea sp. N299. This species exhibits a periplasmic nitrate reductase gene (napA). Its specific growth rate was 0.22 h⁻¹. Obvious denitrification and perfect nitrogen removal performances occurred when cultured in nitrate and nitrite mediums, at rates of 75.53% ± 1.69% and 58.65% ± 0.61%, respectively. The ammonia removal rate reached 44.12% ± 1.61% in ammonia medium. Zoogloea sp. N299 was inoculated into sterilized and unsterilized reservoir source waters with a dissolved oxygen level of 5–9 mg/L, pH 8–9, and C/N 1.14:1. The total nitrogen removal rate reached 46.41% ± 3.17% (sterilized) and 44.88% ± 4.31% (unsterilized). The cell optical density suggested the strain could survive in oligotrophic drinking water reservoir water conditions and perform nitrogen removal. Sodium acetate was the most favorable carbon source for nitrogen removal by strain N299 (p < 0.05). High C/N was beneficial for nitrate reduction (p < 0.05). The nitrate removal efficiencies showed no significant differences among the tested inoculums dosage (p > 0.05). Furthermore, strain N299 could efficiently remove nitrate at neutral and slightly alkaline and low temperature conditions. These results, therefore, demonstrate that Zoogloea sp. N299 has high removal characteristics, and can be used as a nitrogen removal microbial inoculum with simultaneous aerobic nitrification and denitrification in a micro-polluted reservoir water ecosystem.     

悬浮填料床同步硝化反硝化脱氮试验研究

在好氧条件下,向反应器中装填悬浮填料进行脱氮试验,考察生物膜法对氨氮和总氮的去除效果.结果表明：DO为3.0 mg.L-1时,氨氮平均去除率达到89.52％、总氮平均去除率达到29.46％.在好氧条件下,生物膜脱氮效果明显,硝酸盐氮的积累使反硝化过程成为脱氮的制约因素之一.     

好氧反硝化脱氮技术研究进展

总结了近几年国内外研究者筛选鉴定的好氧反硝化菌,以及这些菌种的脱氮效果。从生物学和环境两方面对好氧反硝化作用机理进行了详细的探讨。介绍了好氧反硝化工艺因技术不成熟而尚未有实际工程应用的现状,对该领域的研究方向提出了建立数学模型,利用过程中条件的变化研究其控制系统等几点建议。     

Simultaneous removal of carbon,nitrogen and phosphorus from wastewater by coupling two-step anaerobic digestion with a sequencing batch reactor

The objective of this study was to develop an integrated process for simultaneous removal of carbon, nitrogen and phosphorus from industrial wastewaters. The process consisted of a-two step anaerobic digestion reactor, for carbon removal, coupled with a sequencing batch reactor (SBR) for nutrient removal. In the proposed process, carbon is eliminated into biogas by anaerobic digestion: acidogenesis and methanogenesis. The volatile fatty acids (VFA) produced during the first step of anaerobic digestion can be used as electron donors for both dephosphatation and denitrification. In the third reactor (SBR) dephosphatation and nitrification are induced through the application of an anaerobic–aerobic cycle. This paper describes the first trials and experiments on the SBR and a period of 210 days during which the SBR was connected to the acidogenic and methanogenic reactors. It was shown that nitrification of ammonia took place in the SBR reactor, during the aerobic phase. Furthermore, denitrification and VFA production were achieved together in the acidogenic reactor, when the efflux of nitrates from the SBR reactor was added to the first reactor influx. The proposed process was fed with a synthetic industrial wastewater, the composition of which was: total organic carbon (TOC)=2200 mg dm⁻³, total Kjeldahl nitrogen (TKN)=86 mg dm⁻³, phosphorus under phosphate form (P-PO₄)=20 mg dm⁻³. In these conditions, removals of carbon, nitrogen and phosphorus were 98%, 78% and 95% respectively. The results show that the combination of the two-step anaerobic digestion reactor and an SBR reactor is effective for simultaneous carbon, nitrogen and phosphorus removal. Reactor arrangements enabled zones of bacterial populations to exist. Complete denitrification occurred in the acidogenic reactor and hence the anaerobic activity was not reduced or inhibited by the presence of nitrate, thus allowing high TOC removal. Stable phosphorus release and phosphorus uptake took place in the SBR after coupling of the three reactors. A fast-settling compact sludge was generated in the SBR with the operational conditions applied, thus giving good separation of supernatant fluid. The benefits from this process are the saving of (i) an external carbon source for denitrification and phosphorus removal, (ii) a reactor for the denitrification step. © 1998 Society of Chemical Industry     

Simultaneous nitrification and denitrification with electricity generation in dual‐cathode microbial fuel cells

BACKGROUND: Nitrogen removal using microbial fuel cells (MFCs) is of great interest owing to the potential benefits of bioenergy production. In this study, simultaneous nitrification and denitrification in dual‐cathode MFCs was investigated. RESULTS: The dual‐cathode MFCs investigated were capable of generating electricity and removing nitrogen, influenced by operating methods, nitrogen loading rates and external resistance. Depending on the ammonium concentration in the anode chamber, 84–97% of the ammonium nitrogen was removed via nitrification in the aerobic cathode. The removals of nitrate and total nitrogen were relatively low (～50%) at the influent ammonium concentration of 80 mg NH₄⁺‐N L^?1, but were significantly improved to more than 90% at a lower ammonium input (40 and 20 mg NH₄⁺‐N L^?1). When the electrode couples were electrically connected for different purposes, with high power output from the anode/aerobic cathode and high current generation from the anode/anoxic cathode, nitrogen removal was also improved. An investigation of aeration suggested that factors other than carbon supply, possibly inefficient reactor configuration, also limited the performance of the developed MFC. CONCLUSION: The experimental results demonstrated that the proposed pathway was feasible with effective nitrogen and organic removal. This study provided valuable information for the further development of a continuously operated dual‐cathode MFC system. Copyright © 2011 Society of Chemical Industry     

Process Control of an Alternating Aerobic‐Anoxic Sequencing Batch Reactor for Nitrogen Removal via Nitrite

Nitrogen removal via nitrite is a novel technology and is becoming popular for engineering applications since it results in a saving of the aeration energy required for nitritation and external carbon sources for denitritation. An alternating aerobic‐anoxic (AAA) operational pattern was applied in a sequencing batch reactor (SBR) process to improve the nitrogen removal efficiency and achieve partial nitrification via nitrite from industrial wastewater with influent alkalinity deficiencies. The results showed that the online monitoring of the pH‐time variations during nitrification could indicate if the alkalinity was sufficient and when the ammonia nitrogen was completely oxidized. Under conditions of deficient influent alkalinity, the AAA process reduced the external alkalinity and the carbon sources addition and improved the effluent quality with ammonia nitrogen concentration below the detection limits. Half of the alkalinity previously consumed during aerobic nitrification could be recovered during the subsequent anoxic denitrification period. If the cycles of alternating aerobic/anoxic were repeated more than twice, the first nitrification cycle was stopped when the pH decreased by 0.4–0.5. The middle nitrification was terminated when the pH decreased by 0.8–1.0, and the final nitrification duration was controlled by the dissolved oxygen (DO) breakpoint and ammonia valley on the pH profile. Each anoxic time‐scale for denitrification was determined by the nitrate knee on the oxidation‐reduction potential (ORP) profile and the nitrate apex on the pH profiles. In comparison to the conventional SBR process, the AAA process with a real‐time control strategy resulted in an improved nitrogen removal efficiency of greater than 97 % under conditions of deficient influent alkalinity. Moreover, nitrogen removal via nitrite was achieved with a nitrite accumulation rate above 95 %.     

碳源类型和温度对BAF脱氮性能影响研究

以某钢铁厂的二级出水为研究对象,研究了曝气生物滤池(BAF)系统的挂膜,不同碳源类型和温度对该系统脱氮的影响。结果表明:利用含有硝化菌与好氧反硝化菌的富集菌液进行挂膜,16d基本完成挂膜,氨氮、硝态氮的去除率分别高达90.2%和92.2%。不同碳源类型对系统的脱氮性能影响存在差异,以葡萄糖和乙醇作为碳源时效果最佳,氨氮和硝态氮的去除率均超过85%,总无机氮去除率分别是93.4%、95.6%。乙酸钠为碳源时亚硝态氮的质量浓度积累最高达5.79mg/L,采用其它碳源时亚硝态氮几乎没有积累;当不投加外部碳源时,通过内源呼吸代谢作用进行硝化反硝化效果最差,总无机氮的去除率仅有20.4%。随着温度的上升,硝化和反硝化效果逐渐升高,其中硝化的最适温度是在27.3℃左右,氨氮的去除率高达91.1%,好氧反硝化过程对温度的耐受性比较好,在17.5～33.1℃时,平均去除率大于90%。     

新型生物脱氮除磷技术的研究进展

对同时硝化反硝化、短程硝化反硝化、好氧反硝化、厌氧氨氧化及反硝化除磷脱氮等生物脱氮除磷新技术的研究和开发进行综述和讨论,分析了新技术的机理、特点和开发应用的前景.通过与现有的传统生物脱氮除磷工艺进行比较,认为今后应加强对生物脱氮除磷,尤其是反硝化除磷机理更深入的研究,大力开发技术成熟、高效经济又符合我国国情的新工艺.     

高效嗜碱好氧反硝化细菌的筛选及其脱硝特性

从碱厂污泥中筛选出一株高效嗜碱好氧反硝化细菌BMEN1,通过生理生化鉴定和16S rDNA序列分析,鉴定为Pseudomonas stutzeri,命名为Pseudomonas stutzeri BMEN1,其具有napA, nirK, norB和nosZ等好氧反硝化相关基因. 通过条件实验确定该菌最适脱硝条件为：pH 9.0, 37℃, 有效碳源依次为丁二酸钠、乙酸钠和葡萄糖等. 在最适条件下,以菌体浓度计脱硝(NO3--N)速率高达52.92 mg/(h×OD),且无NO2-累积. 将其用于模拟烟道气吸收液脱硝,能在16 h内完全脱除NO3--N和NO2--N 140 mg/L,表明该菌是有应用潜力的好氧反硝化脱硝细菌.     

好氧微生物颗粒污泥脱氮机理

好氧颗粒污泥应用于生物脱氮，机理为如下几种。第一种为常规硝化-反硝化途径。第二种为亚硝化-反硝化途径，颗粒污泥的外部为好氧的硝化区．通过适当的控制．使硝化过程停留在亚硝化阶段．直接进入内层进行反硝化。第三种为硝化-厌氧氨氧化途径．通过外层的硝化和内层的厌氧氨氧化作用实现脱氮。第四种为硝化-反硝化聚磷方式．颗粒污泥内部在反硝化的同时聚磷，实现好氧颗粒污泥同步脱氮除磷。第五种脱氮的途径为好氧反硝化。在不同的条件下．某一种脱氮的途径可能占主导地位。     

A calibration methodology and model‐based systems analysis for SBRs removing nutrients under limited aeration conditions

A methodology is proposed for the model calibration of nutrient‐removing laboratory‐scale SBRs under limited aeration. Based on in‐process measurements and influent wastewater characterization, the ASM2d model was modified by adding an organic nitrogen module incorporating a hydrolysis mechanism. After calibration, the simulation results showed that enhanced biological nutrient removal occurred during the fill period and under reduced aeration achieving so‐called ‘simultaneous nutrient removal’. A model‐based systems analysis was performed in terms of the contributions of different processes to overall oxygen, nitrogen and phosphate utilization. In each phase, simultaneously occurring biological reactions were compared using the calibrated model. According to the calibrated model, 61% of all denitrified nitrate is denitrified during the mixing/filling phase. On the other hand, 17% of all denitrified nitrate is consumed by simultaneous nitrification–denitrification during the first aerobic period. The aerobic and anoxic P‐removals were quantified as 73% and 12%, respectively. Copyright © 2006 Society of Chemical Industry     

Bioaugmentation of two-stage aerobic sequencing batch reactor with mixed strains for high nitrate nitrogen wastewater treatment

Mixed strains Delftia sp.YH01 and Acidovorax sp.YH02, with capability of heterotrophic nitrification-aerobic denitrification, were introduced into a two-stage aerobic sequencing batch reactor to enhance NO₃⁻-N removal. With optimal C/N of 8, efficient NO₃⁻-N removal was achieved at initial NO₃⁻-N concentration of 2000 mg·L⁻¹. Meanwhile, the massive accumulation of NO₂⁻-N was avoided during the long operation. Compared to the one-stage aerobic sequencing batch reactor, the removal efficiency of NO₃⁻-N and TN in the two-stage aerobic sequencing batch reactor was increased by 36.5% and 42.7%, which respectively was 93.8% and 88.4%. Microbial community study showed that the mixed strains have the stronger viability and can synergistically denitrify with the indigenous microorganisms in system, such as Azoarcus, Uncultured Saprospiraceae, Thauera, Paracocccus, which could be major contributors for aerobic denitrification. The proposed technology was shown to achieve high-efficiency treatment of high NO₃⁻-N wastewater through aerobic denitrification.     

好氧反硝化生物脱氮机理分析及研究进展

传统生物脱氮包括好氧硝化和缺氧反硝化两个过程。针对传统生物脱氮工艺存在的不足,提出好氧反硝化技术优点,初步探讨了好氧反硝化的机理,并从不同角度做了理论分析。同时阐述了有关好氧反硝化脱氮的研究进展,对好氧反硝化的应用前景作了展望,提出了好氧反硝化今后的研究方向应重点放在对好氧反硝化菌的筛选和驯化上,并深入了解其反硝化特性,以对好氧反硝化生物脱氮提供有力的技术支持。(哈尔滨工业大学市政环境工程学院,哈尔滨150090)     

Biodegradation of monoethanolamine in aerobic and anoxic conditions

Monoethanolamine (MEA) is widely used in many industries and its proper treatment is important for protecting the water environment. As MEA contains an amine group, nitrogen removal by nitrification/denitrification as well as biodegradation of MEA is necessary for wastewater treatment. In this study the effects of adaptation and inhibition of MEA on biological degradation, and the removal of amine were investigated in a laboratory scale sequencing batch reactor (SBR). In addition, the denitrification characteristics of nitrate, and nitrite with MEA as the electron donor, were compared to the other electron donor (acetate). In the aerobic SBR, the removal efficiency of 9,000 mg/L MEA reached 92% at the hydraulic retention time (HRT) of 10.5 days. Ammonium hydrolyzed from the MEA was nitrified after 8 weeks from the start-up showing that adaptation time is needed for nitrification. Non-linear curve fitting of the specific MEA biodegradation gave the maximum specific activity (V _max ), the half saturation constant (K _s ), and the inhibition constant (K _i ) of 2.81 g/(g VSS·d), 102.1 mg/L, and 1149.6 mg/L, respectively. Batch denitrification showed that MEA is a competitive electron donor to acetate.     

Inhibition of sulfide on the simultaneous removal of nitrate and p‐cresol by a denitrifying sludge

BACKGROUND: Many industrial discharges, such as those generated from petrochemical refineries, contain large amounts of sulfurous, nitrogenous and organic contaminants. Denitrification has emerged as a suitable technology for the simultaneous removal of these pollutants in a single reactor unit; however, more evidence is demanded to clarify the limitations of denitrification on the simultaneous removal of sulfide and phenolic contaminants and to optimize the biological process. The aim of this study was to evaluate the capacity of a denitrifying sludge to simultaneously convert sulfide and p‐cresol via denitrification. RESULTS: Sulfide was the preferred electron donor over p‐cresol, imposing a 5 h lag phase (required for complete sulfide removal) on organotrophic denitrification. Addition of sulfide (20 mg S^2? L^?1) to p‐cresol‐amended denitrifying cultures also decreased the reduction rate of nitrate and nitrite, as well as the production rate of nitrogen gas. Nitrite reduction rate was the most affected step by sulfide, decreasing from 35 to 21 mg N (g VSS d)^?1. A synergistic inhibitory effect of nitrate and sulfide was also observed on nitrite reduction. Despite the effects of sulfide on the respiratory rates monitored, complete removal of nitrate, sulfide and p‐cresol could be achieved after 48 h of incubation. CONCLUSION: Our results suggest that simultaneous removal of sulfide and p‐cresol could be achieved in denitrifying reactors, but a large hydraulic residence time may be required to sustain an efficient process due to inhibitory effects of sulfide. Copyright © 2008 Society of Chemical Industry     

生活污水不同生物脱氮过程中N_2O产量及控制

利用好氧-缺氧SBR反应器和全程曝气SBBR反应器处理生活污水,分别实现了全程、短程和同步硝化反硝化脱氮过程,研究了不同脱氮过程中N2O的产生及释放情况,同时考察了不同DO条件下同步脱氮效率及N2O产生量。结果表明,全程、短程生物脱氮过程中N2O主要产生于硝化过程,反硝化过程有利于降低系统N2O产量。全程、短程、同步硝化反硝化脱氮过程中N2O产量分别为4.67、6.48和0.35mg.L-1。硝化过程中NO2-N的积累是导致系统N2O产生的主要原因。部分AOB在限氧条件下以NH4+-N作为电子供体,NO2-N作为电子受体进行反硝化,最终产物是N2O。不同DO条件下同步硝化反硝化过程中N2O的产生表明:控制SBBR系统中DO浓度达到稳定的同步脱氮效率可使系统N2O产量最低。     

炼油废水中好氧反硝化菌的筛选及降解特性

为了提高炼油废水生物处理装置的反硝化性能,从武汉石化污水处理厂的活性污泥中筛选出一株好氧反硝化菌AD10,经生理生化及16SrDNA序列分析,将其鉴定为假单胞菌属。通过单因素实验研究了该菌的最适培养条件:以丁二酸钠为碳源,C/N=14,温度30℃,初始pH=6.0,摇床转速200r/min。在此条件下,ρ(NO₃^--N)=556.81mg/L时72h的去除率为97.2%,且耐受的硝酸盐氮质量浓度达到654.00mg/L。菌株AD10培养11.5h,对ρ(NO₃^--N)=140.31mg/L和ρ(TN)=141.62mg/L的去除率分别为95.8%和93.9%,其反硝化速率高于大部分已发现的好氧反硝化菌,检测到的ρ(NO₂^–-N)≤2.30mg/L,未出现明显的积累,菌株AD10能够进行完全反硝化。     

SA-CMC固定反硝化细菌好氧反硝化性能探究

为扩大反硝化菌应用和抗逆性,以海藻酸钠(SA)和羧甲基纤维素钠(CMC)为载体、用CaCl2交联,联合包埋脱氮副球菌,制作反硝化菌剂,探究有氧条件下,菌剂的好氧反硝化性能.结果表明,有氧条件下,所得菌剂对硝态氮的还原能力显著高于游离态菌(总氮氧化物去除率分别为95.6％和9.6％).CMC含量升高能显著提高菌剂好氧反硝...