好氧微生物颗粒污泥脱氨机理

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.     

好氧颗粒污泥同步除磷脱氮研究的新进展

结合近年来国内外除磷脱氮的最新研究成果,对好氧颗粒污泥除磷脱氮的机理及工艺进行了探讨和研究。研究表明通过适当的SBR定向培养,可以在颗粒污泥中培养出不同的微生物菌群(硝化菌、反硝化菌、聚磷菌、反硝化聚磷菌等),使其能够实现同步除磷脱氮,从而为污水生物除磷脱氮工艺研究提供了一个新思路。     

好氧颗粒污泥的脱氮途径研究进展

好氧颗粒污泥(AGS)因具有独特的空间结构,可延径向形成氧传质梯度,为不同功能菌的分区定殖提供了必要场所,因而可实现单级脱氮。AGS内主要脱氮途径有同步硝化反硝化(SND)、厌氧氨氧化(Anammox)、异养反硝化、菌藻耦合脱氮等。综述了AGS各种途径的脱氮效果,总结了各途径的优缺点及适用范围,分析了现有研究存在的问题,并提出了相应的建议。     

好氧聚磷污泥反硝化除磷特性研究

以培养成功的好氧聚磷污泥为研究对象,考察其在硝酸盐或亚硝酸盐存在下的反硝化除磷特性。结果表明,好氧聚磷污泥在在未经厌氧/缺氧驯化条件下已具有良好反硝化聚磷特性。好氧聚磷污泥可利用硝酸盐作为电子受体进行脱氮除磷,在硝酸盐耗尽后停止聚磷,在一定的浓度范围内聚磷量与硝酸盐消耗量具有线性关系。在以亚硝酸盐作为电子受体的条件下,好氧聚磷污泥与反硝化聚磷污泥具有相似特点:在初始亚硝酸盐浓度较低情况下可少量聚磷,在其浓度较高时聚磷受到抑制。亚硝酸盐有可能为解偶联剂,在其还原的过程中并不耦合发生聚磷。反硝化速率随着其硝酸盐或亚硝酸盐初始浓度的升高而降低。     

连续流双污泥系统反硝化除磷实验研究

通过实验室小试,以生活污水为研究对象考察了厌氧/缺氧与淹没式好氧生物膜滤床相结合的连续流双污泥系统的除磷脱氮效果.长期试验结果表明,该工艺解决了传统脱氮除磷工艺中反硝化菌与聚磷菌竞争碳源这一主要矛盾,并可以分别控制硝化污泥与反硝化聚磷污泥的污泥龄,而且该系统适合处理C/N较低的生活污水,与传统除磷脱氮工艺相比,不用额外投加碳源,剩余污泥含磷量高,节省曝气量.系统对COD、总磷、总氮和氨氮的平均去除率分别为81.78%、92.51%、75.75%和84.47%.     

兼具脱氮和除磷性能菌株的优选

通过L9（34）正交试验和单因素实验优化培养条件,从七株不同菌属的异养硝化-好氧反硝化菌中优选兼具除磷性能菌株。结果表明：优选出的两株异养硝化-好氧反硝化菌分别为丛毛单胞菌WXZ-17和芽孢杆菌WXZ2-4,二者均具有厌氧除磷性能,磷化氢为重要除磷产物。优选的两株菌培养条件均为： T=32.0℃、 pH=6.50、氮源为蛋白胨＋氯化铵＋硝酸钠、总磷浓度为20.0 mg/L,相应的除磷率分别为25.6％和36.0％。在早期脱氮实验中已证实该两株菌脱氮效率分别为：89.7％和96.4％。筛选出的兼具脱氮和除磷性能的菌株使实现废水同步脱氮除磷成为可能。     

兼具脱氮和除磷性能菌株的优选

通过L9(34)正交试验和单因素实验优化培养条件,从七株不同菌属的异养硝化-好氧反硝化菌中优选兼具除磷性能菌株。结果表明:优选出的两株异养硝化-好氧反硝化菌分别为丛毛单胞菌WXZ-17和芽孢杆菌WXZ2-4,二者均具有厌氧除磷性能,磷化氢为重要除磷产物。优选的两株菌培养条件均为:T=32.0℃、pH=6.50、氮源为蛋白胨+氯化铵+硝酸钠、总磷浓度为20.0 mg/L,相应的除磷率分别为25.6%和36.0%。在早期脱氮实验中已证实该两株菌脱氮效率分别为:89.7%和96.4%。筛选出的兼具脱氮和除磷性能的菌株使实现废水同步脱氮除磷成为可能。     

碳源对SBR系统短程硝化/反硝化除磷影响的比较研究

2个实验室规模的序批式反应器在厌氧/好氧/缺氧交替条件下运行,以比较表面活性剂SDBS促进剩余污泥发酵产生的发酵液(S-SBR)与乙酸(A-SBR)分别作碳源对同时生物除磷脱氮系统的影响.结果表明,2个SBR反应器中均发生部分短程硝化反硝化,好氧段,S-SBR中亚硝态氮累积的VSS最高浓度为3.5mg·g-1,累积率达到70.0%,分别为A-SBR的2.3倍和1.7倍;A-SBR中的磷主要通过好氧聚磷去除,而S-SBR中除了好氧聚磷外,另有13.0%的磷通过反硝化除磷去除,使得S-SBR中总氮和磷的去除率(分别为94.7%和100.0%)比A-SBR(分别为79.2%和73.4%)高,因此,以剩余污泥发酵液作碳源与乙酸相比有助于生物脱氮除磷系统保持较好的脱氮、除磷效果.     

异养硝化-好氧反硝化菌的研究进展

近年来发现了一类具有异养硝化-好氧反硝化功能的细菌,其能够实现同步硝化反硝化(SND)的特性引起了人们广泛的关注。研究表明,异养硝化-好氧反硝化菌具有良好的脱氮性能,并且与传统脱氮过程相比,其N2O释放量占总脱氮量的比例可低至0.04%,COD的去除率有所提高。综述了影响异养硝化-好氧反硝化菌脱氮性能的因素,以及该菌在N2O生物控逸方面的应用,并提出了未来对异养硝化-好氧反硝化应用研究的方向。     

好氧脱氮过程中脱氮途径的初探

采用SBR工艺处理氨氮废水，试验结果验证了好氧反硝化的存在，在好氧脱氮总量中按照氨氮→硝态氮(包括硝基氮和亚硝基氮，以NOx-N表示)→含氮气态物这一传统生物脱氮途径进行的仅占46．5％，在扣除生化合成反应所需氮素以及游离氨解析吹脱之外，尚有半数左右的氮在硝化过程中尚未形成NOx-N之前便已转化为不明物质而丢失。     

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.     

序批式反应器中反硝化除磷脱氮的研究

为了提高污水脱氮除磷的效率,研究采用序批式反应器(SBR工艺)厌氧、好氧和缺氧(AOA)的运行方式富集反硝化聚磷菌(DPB),实现同步脱氮除磷。结果表明:在好氧段投加甲醇作为碳源(25—40 mg/L)可有效抑制好氧吸磷,对硝化反应影响较小,能够在缺氧段实现同时反硝化脱氮除磷。SBR反应器稳定运行10个月,当进水NH4+-N、PO43--P分别为30,15 mg/L时,总氮(TN)和PO43--P的平均去除率分别为82.5%和92.1%。聚磷菌能够利用硝酸盐作为电子受体,DPB占总聚磷菌的比例达到44.8%。与A2O运行方式相比,AOA运行方式更有利于实现DPB的富集。     

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。     

序批式移动床生物膜反应器脱氮除磷影响因素及特性

考察了曝气量、进水C/N比（COD/TN）及进水氮、磷浓度对序批式移动床生物膜反应器（SBMBBR）脱氮除磷效果的影响,分析了该复合生物系统的污染物去除特性。实验结果表明,反应器脱氮主要是基于好氧段发生的同时硝化反硝化（SND）作用实现的,而除磷是基于常规生物除磷和反硝化除磷过程而完成;在保持载体良好流化状态的前提下,反应器硝化效果和TP去除受曝气量变化影响不大,反硝化效果随曝气量的减小而改善;采用厌氧/好氧序批式运行方式,能够使进水中的有机物被反硝化聚磷菌优先利用,实现一碳两用,节省了脱氮对外部碳源的需要,在进水C/N为2.8～4.0时能获得良好的硝化、反硝化和TP去除效果;随着进水氮、磷浓度的提高,反应器除磷效果相对稳定,脱氮效果变差,最大氮、磷去除负荷分别达到0.17 kg TN·m^-3·d^-1和0.06 kg TP·m^-3·d^-1。     

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 removal of organic substances and nitrogen using amembrane bioreactor seeded with anaerobic granular sludge under oxygen-limited conditions

An innovative process, the oxygen-limited membrane bioreactor seeded with anaerobic granular sludge, wasproposed and its performance investigated for concurrent removal of organic substances and nitrogen from synthetic domestic wastewaters. An air diffuser was installed just above the granular sludge bed to supply air to the reactor at an intermittent mode. The internal recycle from the upper part of the reactor to the bottom was introduced to provide the granular sludge bed under the oxygen-limited conditions. The oxygen addition rates were controlled at 3-4 g O₂ 1⁻¹d⁻¹. The total COD removal efficiency of more than 94% was achieved throughout the whole operation period. N was removed through the simultaneous nitrification and denitrification process that took place in the granular sludge bed. TN levels decreased with the decrease of ammonium levels, indicating that nitrification was the rate-limiting step. The TN removal efficiency reached 80-91% at an hydraulic retention time of 15 h. Nitrate was scarcely detected and nitrite was the main NO_x-N species in the effluent, indicating that nitrite oxidizers were inhibited in the system.     

SBR好氧污泥颗粒的脱氮性能研究

The sequencing batch reactor （SBR） was started up by seeding the anaerobic granular sludge and the aerobic granular sludge was successfully cultivated. The performance characteristic of the aerobic granules for nitrogen removal was investigated in detail. The experimental results demonstrated the relationship between operational parameters [dissolved oxygen （DO） and pH] and variation of chemical oxygen demand （COD）, ammonium （NH4^＋-N） and total nitrogen （TN）. In continuous flow pattern, COD was too low in the reactor at the later stage of a cycle, which restrained denitrification and decreased the removal of nitrogen, while in discontinuous flow pattern, the carbon source could be supplemented in time, which improved denitrification and increased the removal of TN from 66% to 81%.     

焦化废水的亚硝化反硝化研究

为了确证脱酚焦化废水亚硝化型硝化及以焦化废水中的氨酚为电子供体实现亚硝酸盐的反硝化的可行性，以模拟SBR法的好氧与厌氧过程，对脱酚后的焦化废水实现了亚硝化型硝化，产生的亚硝酸盐浓度达到117.6mg/L，以未脱酚的焦化废水中的酚，氨为电子供体，实现了亚硝酸盐的反硝化。     

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 %.     

高溶解氧环境下好氧亚硝化颗粒污泥短程硝化特性研究

研究好氧亚硝化颗粒污泥的快速形成及在高溶解氧环境下好氧亚硝化颗粒污泥的短程硝化特性。采用SBR反应器,在偏碱性、高溶解氧条件下,以好氧颗粒污泥和具有硝化功能的活性污泥为种泥驯化培养,分析好氧亚硝化颗粒污泥形成机理及对亚硝酸盐的积累能力。研究结果表明:12d可形成具有氨氮平均去除率97%、最高亚硝化率70%的好氧亚硝化颗粒污泥,反应器能持续稳定运行;溶解氧高低对好氧亚硝化颗粒污泥的亚硝化率影响不大。说明此方法能够快速形成具有高亚硝酸盐积累率的好氧亚硝化颗粒污泥。