废水生物脱氮中N2O和NOx的产生和作用

废水生物脱氮中N2O和NOx来源于硝化、反硝化、厌氧氨氧化和化学反硝化等过程．电子受体和供体浓度、pH、缓冲剂类型、有机负荷、微生物种类及其相互作用等都会影响这些气态中间产物的产生．NO2能够氧化氨和强化好氧和厌氧氨氧化，NO能够阻止C2H2对好氧氨氧化活性的抑制，两者对好氧氨氧化活性的恢复至关重要．所有这些表明，废水生物脱氮的气态中问产物N2O和NOx在氮的生物转化中具有重要的正面作用，甚至必不可少．基于NO2曝气技术和Brocadia anammoxidans与Nitrosomonas协同作用的废水生物脱氮新技术开发是今后一段时间的重要研究方向．图4参35     

单级好氧和限氧污水处理系统中总氮损失的微生物学机理

近年来,单级好氧和限氧污水处理系统中总氮损失的现象引起了人们的普遍关注,本文对这种现象的微生物学机理及研究现状进行了阐述,主要是儿类细菌的单独脱氮或者它们之间的协同脱氮,包括自养(亚)硝化菌单独脱氮、好氧反硝化菌单独脱氮、(亚)硝化菌和好氧反硝化菌的协同脱氮以及(亚)硝化菌和厌氧氨氧化菌的协同脱氮.与传统的硝化-反硝化脱氮工艺相比,这些脱氮新途径具有不可比拟的优越性,对于强化污水生物脱氮具有重要意义.图8参53     

亚热带土壤氮素反硝化气态产物研究

亚热带可变电荷土壤化学性质与温带地区恒电荷土壤有诸多不同特点,使得反硝化具有一些与温带土壤不同的特性,进一步深入研究亚热带土壤反硝化气体产物的组成比例、主要影响因素和机理,将有助于加深对亚热带环境条件下土壤N循环的理解和认识,以及为正确评价亚热带土壤反硝化环境效应提高科学依据。因此,就亚热带土壤厌氧培养条件下反硝化的气态产物问题进行了探讨。土样采自江西典型亚热带红壤地区,在加入K15NO3（10 atom%15N,加入N量为200 mg·kg-1）条件下进行了7 d 30℃、密闭、淹水、充N2的严格厌氧培养试验。试验结果表明：随培养时间推移,15N回收率逐渐下降,土壤总残留的15NO3-质量分数和回收率之间存在显著正相关关系（p〈0.001）,表明反硝化作用越弱的土样回收率越高。总气态氮损失率的估计值和实测值都随培养时间延长呈上升趋势,两者之间存在显著正相关性（p〈0.001）。根据稳定性同位素15N示踪试验结果初步估计,厌氧培养7 d内反硝化作用产生的气态产物中N2O占总气态氮损失的17.1%,N2占8.7%,估计NO可能是主要的反硝化产物之一。以未能回收的氮计算,NO约占总气态氮损失的67.5%~78.6%,平均为74.1%。反硝化气态产物中NO和N2O总量占总气态氮损失的91.3%。NO、N2O和N2分别占总施入氮量的18.6%、4.4%、2.0%。因此,亚热带土壤氮素反硝化过程中主要气态产物可能为NO和N2O,而非对环境无害的N2。     

垃圾渗滤液生物脱氮新途径

介绍了垃圾渗滤液的传统脱氮技术，对短程硝化反硝化、同步硝化反硝化和厌氧氨氧化的研究作了综述和讨论，并分析了这些新技术的特点以及在垃圾渗滤液脱氮方面的研究和应用前景，指出了厌氧氨氧化是垃圾渗滤液生物脱氮可能的有效方法。     

碳氮比对晚期垃圾渗滤液自养脱氮的影响

采用缺氧/好氧(A/O)短程硝化与升流式厌氧污泥床(UASB)厌氧氨氧化组合的自养脱氮系统处理实际晚期渗滤液,重点考察了碳氮比(C/N)对该系统的综合影响.在较低C/N范围内(1.45到1.95),氨氮去除率变化不显著,当C/N达到2.46以上时,硝化和厌氧氨氧化活性恶化导致其去除率从97.7%降为83.3%.化学需氧量和总氮去除率整体随C/N的提高而呈现先增加后减少的趋势.适度反硝化补充的碱度不仅为硝化菌提供充足的无机碳源,且有利于保障较高的p H和游离氨以维持稳定的短程硝化,亚硝积累率随C/N的提升呈现小幅上升.种群结构分析表明高C/N与厌氧氨氧化菌群所占的比例呈反比关系,从1.65%降为0.31%,维持厌氧氨氧化菌和反硝化菌的动态平衡是保证系统正常运行的关键因素.C/N为1.95时系统整体性能最优.     

OLAND生物脱氮系统运行及其硝化菌群的分子生物学检测

采用两阶段限氧自养硝化 -反硝化生物脱氮系统 (oxygen limitedautotrophicnitrificationanddenitrificationsystem ,以下简称OLAND)处理高氨氮、低COD的废水 .应用内浸式多聚醚砜中空膜 ,实现了污泥的完全截留 ,阻止了生物量的大量洗脱 ,并通过控制溶氧在 0 .1～ 0 .3mgL-1之间 ,实现了硝化阶段出水中氨氮与亚硝态氮浓度的比例达到最适值〔1 (1.2± 0 .2 )〕 ,从而为第二阶段的厌氧氨氧化提供理想的进水 ,进而获得较高的脱氮率 .同时应用荧光原位杂交技术对硝化阶段不同时期硝化菌群的变化进行分子生物学检测 ,揭示了随溶氧浓度的降低 ,氨氧化菌的数量基本保持恒定、亚硝酸氧化菌的数量略有减少的变化规律 ,并且发现 ,在两阶段限氧自养硝化 -反硝化生物脱氮系统中氨氮的氧化主要是由Nitrosomonassp .完成 ,亚硝酸的氧化主要由Nitrobactersp .完成 .图 4表 2参 2 2     

影响厌氧氨氧化与甲烷化反硝化耦合的因素

氨氮、氮氧化物对产甲烷菌有一定的抑制作用,但可以通过驯化去除毒性.亚硝酸盐在厌氧氨氧化菌作用下与氨发生厌氧氨氧化反应.虽然厌氧氨氧化菌是自养菌,但具有异养代谢能力,并且NO2可提高厌氧氨氧化菌的活性.因此,通过特殊的反应器技术,将厌氧氨氧化菌与甲烷菌、反硝化菌复合在一个有利的微生态环境中,充分发挥它们之间的协同耦合作用,把有机物转化为清洁能源又同时脱氮,是极有前景的废水厌氧(缺氧)处理研究新方向.表1参31     

生物电化学脱氮技术研究进展北大核心CSCD

生物电化学系统（BES）因兼有污染物去除与能量回收等优点,近年来已成为环境污染治理领域的关注热点. 对生物电化学技术在脱氮方面的基本原理、含氮污染物的转化途径进行综述,主要的生物脱氮过程包括阴极反硝化、阳极氨氧化以及阴极同步硝化反硝化等,而非生物脱氮过程包括NH3/NH4^＋的跨膜转移、氨气逃逸等. 总结已报道的BES中主要脱氮微生物及其脱氮机制,BES中多数反硝化菌属于变形菌门（Proteobacteria）;硝化细菌主要是亚硝化菌属（Nitrosomonas）和硝化杆菌属（Nitrobacter）;在同步硝化反硝化过程中,电极上的硝化、反硝化菌有明显的分层现象. 最后阐述了生物电化学脱氮技术在生活污水、渗滤液、地下水处理等领域的最新应用研究,通过改变反应器构型以及运行模式等条件构建不同BES处理各类污水,以达到去除污染物同时回收电能或资源的目的. 基于目前BES的优势,认为减少脱氮中间产物（NO2^- -N、N2O）的积累及扩大BES规模对电能输出和污染物去除效果的影响将是未来的研究方向. （图3 表2 参66）     

好氧颗粒污泥工艺强化脱氮研究进展

好氧颗粒污泥是微生物通过自凝聚作用形成的一种特殊的生物聚集体,具有结构致密、沉降性能优异、抗冲击负荷能力强、多功能微生物分区定殖等特点,其在废水强化脱氮除磷与难降解有机物去除方面具有明显的技术优势.针对目前工业和养殖废水及城镇生活污水等碳氮比低、处理出水总氮达标压力大等突出问题,综述基于好氧颗粒污泥的全自养、同步硝化反硝化、短程硝化反硝化、短程硝化-厌氧氨氧化、异养硝化-好氧反硝化等强化脱氮工艺,介绍其脱氮机制及技术优势,阐明不同好氧颗粒污泥脱氮工艺的特点与颗粒污泥特性,同时总结各种工艺的启动条件及富集相应功能菌的好氧颗粒污泥的形成因素,评估不同工艺应用于实际废水生物处理的可行性.在此基础上进一步分析进水基质组成(不同碳氮比)、运行模式(连续曝气和间歇曝气)、运行条件(溶解氧浓度、温度和pH)等对好氧颗粒污泥工艺强化脱氮性能与稳定运行的影响.最后提出应进一步优化好氧颗粒污泥强化脱氮工艺的运行参数,解析好氧颗粒污泥微生物菌群功能,揭示好氧颗粒污泥形成与结构稳定的微生物学机理.     

新型废水生物脱氮的微生物学研究进展

生物脱氮是含氮废水处理公认的最佳处理方式,随着对生物脱氮微生物学原理研究的不断深入,许多新的生物脱氮特殊菌株或菌群及微生物转化机制不断被发现.本文在传统生物脱氮过程机理上,结合最近国内外生物脱氮的新发现,就短程硝化反硝化、同时硝化反硝化、厌氧氨氧化的微生物学原理进行了阐述.图1表2参23     

微生物菌剂对不同废水的适配试验

采用15种不同的微生物菌剂,以葡萄糖配水、中药提取废水、啤酒废水、氨氮配水等为基质,分别测定了微生物菌剂的耗氧速率和厌氧比产甲烷速率,以单位菌剂对不同基质的耗氧速率和厌氧比产甲烷活性为指标,比较了各菌剂对废水的适配性.根据测定结果选择活性高的菌剂,在试验室进行了菌剂对废水的连续处理试验.结果表明,不同菌剂对同一种废水的好氧或厌氧活性不同,同种菌剂对不同废水的好氧和厌氧活性不同.废水的连续处理试验取得良好的处理效果.No.8菌剂处理葡萄糖配水,系统有机负荷最高可达(COD)10.8 g L-1d-1,COD去除率可达90%以上;采用No.10菌剂处理氨氮配水,好氧氨氮负荷可达(NH4-N )1.42 g L-1d-1,厌氧氨氮负荷可达(NH4-N )0.3 gL-1d-1,系统NH4-N 去除率可达90%以上.图2表3参8     

Treatment of swine wastewater in aerobic granular reactors: comparison of different seed granules as factors

The granulation process, physic-chemical properties, pollution removal ability and bacterial communities of aerobic granules with different feed-wastewater (synthetic wastewater, R1; swine wastewater, R2), and the change trend of some parameters of two types of granules in long-term operated reactors treating swine wastewater were investigated in this experiment. The result indicated that aerobic granulation with the synthetic wastewater had a faster rate compared with swine wastewater and that full granulation in R1 and R2 was reached on the 30th day and 39th day, respectively. However, although the feed wastewater also had an obvious effect on the biomass fraction and extracellular polymeric substances of the aerobic granules during the granulation process, these properties remained at a similar level after long-term operation. Moreover, a similar increasing trend could also be observed in terms of the nitrogen removal efficiencies of the aerobic granules in both reactors, and the average specific removal rates of the organics and ammonia nitrogen at the steady-state stage were 35.33 mg·g⁻¹ VSS and 51.46 mg·g⁻¹ VSS for R1, and 35.47 mg·g⁻¹ VSS and 51.72 mg·g⁻¹ VSS for R2, respectively. In addition, a shift in the bacterial diversity occurred in the granulation process, whereas bacterial communities in the aerobic granular reactor were not affected by the seed granules after long-term operation.     

Overlooked nitrogen-cycling microorganisms in biological wastewater treatment

• AOA and comammox bacteria can be more abundant and active than AOB/NOB at WWTPs. • Coupled DNRA/anammox and NO_x-DAMO/anammox/comammox processes are demonstrated. • Substrate level, SRT and stressors determine the niches of overlooked microbes. • Applications of overlooked microbes in enhancing nitrogen removal are promising. Nitrogen-cycling microorganisms play key roles at the intersection of microbiology and wastewater engineering. In addition to the well-studied ammonia oxidizing bacteria, nitrite oxidizing bacteria, heterotrophic denitrifiers, and anammox bacteria, there are some other N-cycling microorganisms that are less abundant but functionally important in wastewater nitrogen removal. These microbes include, but not limited to ammonia oxidizing archaea (AOA), complete ammonia oxidation (comammox) bacteria, dissimilatory nitrate reduction to ammonia (DNRA) bacteria, and nitrate/nitrite-dependent anaerobic methane oxidizing (NO_x-DAMO) microorganisms. In the past decade, the development of high-throughput molecular technologies has enabled the detection, quantification, and characterization of these minor populations. The aim of this review is therefore to synthesize the current knowledge on the distribution, ecological niche, and kinetic properties of these “overlooked” N-cycling microbes at wastewater treatment plants. Their potential applications in novel wastewater nitrogen removal processes are also discussed. A comprehensive understanding of these overlooked N-cycling microbes from microbiology, ecology, and engineering perspectives will facilitate the design and operation of more efficient and sustainable biological nitrogen removal processes.     

城市污水二级硝化出水的离子交换脱氮除磷

以城市污水二级硝化出水为原水,对比研究了3种强碱性阴离子交换树脂(201×4、D296、D301T)动态脱氮除磷情况,并以201×4树脂为模式树脂考察了树脂活化方式(常规酸碱交替活化与NaCl再生液活化)、腐殖酸(HA)浓度(1.1,2.8和9.4 mg·l~(-1))对树脂动态脱氮除磷的影响.结果表明,3种树脂都具有较好的脱氮除磷效果,达到TP穿透点(0.1 mg·l~(-1),去除率92%)时,201×4树脂具有最大的穿透体积(418 BV),但其对NO_3~--N的去除率(69%)明显低于其它树脂(97%-98%);3种树脂对SO_4~(2-)和HA的去除率分别为97%-99%,71%-80%;常规酸碱活化使树脂穿透体积较再生液活化仅提高了12%;超滤膜法和臭氧氧化法预处理对原水HA的去除率分别为27%和68%;原水HA浓度增加使树脂穿透体积从28lBV降至239BV,同时NO_3~-去除率从80%上升至92%.     

低碳氮比废水好氧颗粒污泥系统稳定性及微生物种群多样性研究

低碳氮比(C/N)废水处理是含氮废水处理中的难题之一.本实验在C/N为4:1和2:1(COD和NH₄⁺-N浓度分别为400 mg·L^-1和100 mg·L^-1,400 mg·L^-1和200 mg·L^-1)条件下,考察好氧颗粒污泥系统对低碳氮比废水的处理效果、长期运行稳定性,研究C/N对好氧颗粒微生物结构变化的影响.研究结果表明,在C/N为4:1的废水中接种活性污泥培养好氧颗粒污泥,形成的颗粒沉降性能良好,MLSS为4.94 g·L^-1,SVI30为40 mL·g^-1,COD去除率90%以上,氨氮去除率接近100%.降低碳氮比,即C/N为2:1后,好氧颗粒的物理及硝化性能无明显变化,MLSS为11.38 g·L^-1,SVI₃₀/SVI₅维持在1左右,COD去除率大于85%,氨氮去除率98%.碳氮比降低使颗粒微生物多样性减少,其中陶厄氏菌受影响较小,而硝化功能菌出现更替:噬氢菌、食酸菌、里德拜特氏菌消失,鞘氨醇单胞菌、束缚杆菌等成为优势菌种.实验表明,该低碳氮比条件下好氧颗粒污泥系统能够稳定运行,且具有优良的处理性能.     

Enhancement on the ammonia oxidation capacity of ammonia-oxidizing archaeon originated from wastewater: Utilizing low-density static magnetic field

• AOA’s ammonia oxidizing capacity was enhanced under moderate magnetic field. • AOA possessed a certain magnetotaxis under uneven magnetic field. • Enhanced ammonia oxidizing capacity was lost once magnetic field was removed. Ammonia-oxidizing archaeon (AOA) could play important roles for nitrogen removal in the bioreactors under conditions such as low pH and low dissolved oxygen. Therefore, enhancing ammonia oxidation capability of AOA has great significance for water and wastewater treatment, especially under conditions like low dissolved oxygen concentration. Utilizing a novel AOA strain SAT1, which was enriched from a wastewater treatment plant by our group, the effect of magnetic field on AOA’s ammonia oxidation capability, its magnetotaxis and heredity were investigated in this study. Compared with control experiment, AOA’s maximum nitrite-N formation rate during the cultivation increased by 56.8% (0.65 mgN/(L·d)) with 20 mT magnetic field. Also, it was testified that AOA possessed a certain magnetotaxis. However, results manifested that the enhancement of AOA’s ammonia oxidation capability was not heritable, that is, lost once the magnetic field was removed. Additionally, the possible mechanism of improving AOA’s ammonia oxidation capability by magnetic field was owing to the promotion of AOA single cells’ growth and fission, rather than the enhancement of their ammonia oxidation rates. The results shed light on the application of AOA and methods to enhance AOA’s ammonia oxidation capability, especially in wastewater treatment processes under certain conditions.     

提高常规净水工艺除氮能力的试验

介绍了一种微污染源水中去除氨氮的小型动态试验的结果,以凹凸棒粘土为启动期的生物载体替代生物陶粘或软性填料,采用脱氮反应池串联或并联于常规净水工艺两种工艺流程,取得了类似其他生物氧化法的除氮效果,并且具有无明显生物培养期及启动快的特点,考了影响因素和含氮化合物在净化过程中的举动。     

A review on anammox process for the treatment of antibiotic-containing wastewater: Linking effects with corresponding mechanisms

• Anammox is promising for nitrogen removal from antibiotic-containing wastewater. • Most antibiotics could inhibit the anammox performance and activity. • Antibiotic pressure promoted the increase in antibiotic resistance genes (ARGs). • Antibiotic-resistance mechanisms of anammox bacteria are speculated. Antibiotic is widely present in the effluent from livestock husbandry and the pharmaceutical industry. Antibiotics in wastewater usually have high biological toxicity and even promote the occurrence and transmission of antibiotic resistant bacteria and antibiotic resistance genes. Moreover, most antibiotic-containing wastewater contains high concentration of ammonia nitrogen. Improper treatment will lead to high risk to the surrounding environment and even human health. The anaerobic ammonium oxidation (anammox) with great economic benefit and good treatment effect is a promising process to remove nitrogen from antibiotic-containing wastewater. However, antibiotic inhibition has been observed in anammox applications. Therefore, a comprehensive overview of the single and combined effects of various antibiotics on the anammox system is conducted in this review with a focus on nitrogen removal performance, sludge properties, microbial community, antibiotic resistance genes and anammox-involved functional genes. Additionally, the influencing mechanism of antibiotics on anammox consortia is summarized. Remaining problems and future research needs are also proposed based on the presented summary. This review provides a better understanding of the influences of antibiotics on anammox and offers a direction to remove nitrogen from antibiotic-containing wastewater by the anammox process.     

The combined effects of biomass and temperature on maximum specific ammonia oxidation rate in domestic wastewater treatment

• Actual SAORs was determined using MLVSS and temperature. • Measured SAOR decreased with increasing MLVSS 1.1‒8.7 g/L. • Temperature coefficient (θ) decreased with increasing MLVSS. • Nitrification process was dynamically simulated based on laboratory-scale SBR tests. • A modified model was successfully validated in pilot-scale SBR systems. Measurement and predicted variations of ammonia oxidation rate (AOR) are critical for the optimization of biological nitrogen removal, however, it is difficult to predict accurate AOR based on current models. In this study, a modified model was developed to predict AOR based on laboratory-scale tests and verified through pilot-scale tests. In biological nitrogen removal reactors, the specific ammonia oxidation rate (SAOR) was affected by both mixed liquor volatile suspended solids (MLVSS) concentration and temperature. When MLVSS increased 1.6, 4.2, and 7.1-fold (1.3‒8.9 g/L, at 20°C), the measured SAOR decreased by 21%, 49%, and 56%, respectively. Thereby, the estimated SAOR was suggested to modify when MLVSS changed through a power equation fitting. In addition, temperature coefficient (θ) was modified based on MLVSS concentration. These results suggested that the prediction of variations ammonia oxidation rate in real wastewater treatment system could be more accurate when considering the effect of MLVSS variations on SAOR.