不同固态碳源用于反硝化去除污水处理厂尾水中硝态氮的研究

针对污水处理厂尾水氮素高度硝化的现状,研究了不同固体碳源在不同条件下的反硝化速率及对硝态氮的去除率。结果表明:麦秆、PBS和PHAs较其他固态碳源具有更好的脱氮效果,25℃为最适宜反应温度;进水硝态氮浓度与硝态氮去除率之间有很好的相关性;随着反应时间的延长,各碳源脱氮效率也在不断加速,至24 h时,PBS、PHAs和麦秆对应的去除率分别为98.53%、93.41%和73.26%。对三种碳源反应前后的表面进行扫描电镜分析,证实了三种碳源作为反硝化固体碳源的可行性。COD反弹和硝态氮积累试验表明,麦秆更适用于污水处理厂尾水的生态净化工艺。     

潜流湿地短程硝化反硝化强化脱氮研究

为探索人工湿地系统短程硝化反硝化脱氮作用对微污染水体脱氮性能的提升效果及影响因素,构建两级垂直流潜流湿地系统,对比分析了间歇进水、同步回流、预曝气等运行方式下的净水效果及含氮污染物的转化规律,结果表明:进水低碳氮比条件下,系统对COD_Cr和NH■-N的去除率稳定在60.5%～64.3%和90%以上;通过水位/水量调节方式强化湿地内部自然富氧作用,实现TN去除效果增长8%～10%,亚硝化率呈升高趋势,NO■-N的累积现象有所改善;氨氧化细菌（AOB）和氨氧化古菌（AOA）群落分布一致性和优势群菌丰度显著提升,反硝化细菌（nirS）优势种群分布同时得到改善,水位/水量调控的运行方式可以提升短程硝化效率,为反硝化反应提供更充足的底质和溶解氧条件,强化湿地系统对微污染水体的短程硝化反硝化脱氮作用。     

好氧颗粒污泥用于垃圾渗滤液脱氮的研究

利用好氧颗粒污泥处理垃圾渗滤液,试验结果表明,好氧颗粒污泥对垃圾渗滤液具有较好的脱氮效果,经10 h处理,氨氮去除率可达95%以上,亚硝态氮转化率在60%以上,总氮去除率在15%以上,为后续的脱氮反硝化工艺提供了便利条件。     

溶解氧对A~2/O工艺脱氮除磷效果的影响及解决方法

溶解氧对微生物生长的影响很大,通过溶解氧对硝化、反硝化、除磷的影响试验,详细论述了溶解氧对A2/O工艺脱氮除磷的效果影响.试验结果表明,在保证足够好氧泥龄的前提下,提高曝气池的溶解氧,可以改善硝化效果.在好氧段末端设置20～30 min的非曝气区,可以使内回流中的DO降低2～3 mg/L,当内回流比为400%时可节约碳源28～41 mg/L.曝气段中过度曝气会造成生物除磷能力下降.因此,必须通过自动控制维持好氧段的溶解氧在合理水平,并通过设立非曝气区和预缺氧区,消除内外回流中溶解氧过高造成的缺氧区和厌氧区氧化还原电位的提高,从而保证进水中碳源有效用于脱氮除磷.     

纯氧预曝气-生物过滤组合工艺处理微污染水中试研究

采用中试规模设备研究纯氧预曝气和生物过滤组合工艺对微污染水源水中多种污染物的处理效果。在沉淀池末端进行纯氧预曝气,能够提高溶解氧浓度至9.43~13.05mg/L,比较了活性无烟煤和活性炭两种滤料生物过滤工艺。原水氨氮为3mg/L时,出水氨氮平均值为0.07mg/L,且无亚硝态氮积累,CODMn平均去除率为71.72%,出水CODMn浓度均值为0.94mg/L,铁离子平均去除率为98.29%,出水铁离子浓度均值为0.011 mg/L,对典型臭味物质二甲硫醚的去除率为95.24%。结果表明活性无烟煤和活性炭两种滤料的性能类似。纯氧预曝气-生物过滤组合工艺适用于水厂常规处理工艺改造,对传统水厂技术升级具有重要的价值。     

氨氮废水处理过程中的好氧反硝化研究

采用序批式反应器处理氨氮废水 ,试验结果验证了好氧反硝化的存在 ,好氧反硝化脱氮能力随混合液溶解氧浓度的提高而降低 ,当溶解氧浓度为 0 5mg/L时 ,总氮去除率可达到 6 6 0 %。并结合理论分析 ,对好氧反硝化的机理进行了探讨     

内源电子受体产生及其在强化脱氮工艺中的研究

将城市污水生物脱氮除磷工艺中剩余活性污泥(EAS)与生产废水(RW)按不同比例混合并进行曝气,利用EAS中所含的硝化细菌转化生产废水中的氨氮,并同步获得内源电子受体(硝酸盐);随后加入一定量的EAS,利用其胞内碳源进行反硝化脱氮。结果表明:采用EAS处理生产废水并用于产生内源电子受体时,生产废水中氨氮浓度由119.94~171.31 mg/L下降为0.24~0.37mg/L,氨氮去除率可达87.65%~99.72%,最佳硝化时间为8h或12h。当硝化生产废水与不同比例EAS进行混合,采用好氧硝化(12h)、重力浓缩(24h)工艺时,最佳混合比为55%(EAS)∶15%(RW)∶30%(EAS),总氮去除率最高可达68%;采用硝化(12h)、反硝化(24h)、重力浓缩(24h)工艺时,最佳混合比为65%(EAS)∶15%(RW)∶20%(EAS),总氮去除率最高达75.16%。     

数学模型在污水处理厂优化控制过程中的应用

通过小试结合模拟计算,分析了某污水处理厂现有运行存在的不足.试验表明,内回流比对提高脱氮率的作用是有限制条件的;对于溶解氧的控制,要根据系统硝化反应的需要来确定;缺氧区/总体积的比例是影响脱氮效果的一个关键因素,在保证硝化不受影响的前提下,增大缺氧区使反硝化进行得更充分,有助于提高系统的脱氮能力.通过模拟计算,对其工艺参数进行了优化组合,在不改变池容、不增加其他处理设施的情况下提出了优化方案,确定其最佳工艺控制参数为:缺氧区/总体积的比例为0.45,混合液内回流比为200%,好氧区溶解氧2 mg/L.调整后的出水总氮为21.77 mg/L,去除率较改造前提高了4%,出水氨氮浓度为1.16 mg/L,去除率提高了7.2 %.     

达坂城区第二污水处理厂改良Carrousel氧化沟启动运行调试的研究

乌鲁木齐市达坂城区第二污水处理厂进水量较少,水质波动比较大,加之结合改良Calcareous氧化沟工艺的设备安装和进水情况,污泥培养方式是以接种培养和间歇培养为主。随着污泥浓度的升高,出水系统的化学耗氧量、氨氮渐渐达到一级A的排放标准,但对总磷、总氮的去除效果不佳。结合氧化沟系统的运行情况对SRT、曝气模式进行调试,结果表明：当SRT=16 d时,系统对总磷、总氮的去除效果最佳,对化学耗氧量、氨氮的去除效果与SRT=20 d时相差无几;当选用“氧化沟进水曝气时,停止进水就会停止曝气”的曝气模式在系统稳定性以及污染物去除效果方面优于连续曝气与“曝气2 h+停曝2 h”的曝气模式,试运行期间进水量仅为设计值的30%左右,且总磷、氨氮远高于设计值,但出水总磷、总氮、氨氮、化学耗氧量平均去除率分别为97.75%、89.64%、98.93%、96.40%,表明该改良Carrousel氧化沟工艺的脱氮除磷及有机物的去除效果显著。     

固定化细胞去除废水中硝态氮的试验研究

通过对常用的聚乙烯醇-硼酸固定化方法优化改进,有效解决了固定化细胞技术在废水处理领域推广应用中所面临的机械强度小、易破碎、发胀粘连和带气上浮等问题。对包埋固定化反硝化菌与未包埋反硝化菌处理含硝态氮的废水进行比较,结果表明:固定化反硝化菌在不适宜的pH值、温度和有氧条件下均比未包埋菌具有明显的耐受性,表现出良好的反硝化特性,并且能和硝化细菌在同一反应器中进行单级生物脱氮,总氮去除率达到52%,因而在处理含氮废水中具有一定的实际应用价值。     

Biological phosphorus and nitrogen removal with biological aerated filter using denitrifying phosphorus accumulating organism.

In order to accomplish the biological nutrient removal with a weak sewage at low temperature, a hybrid process consisted of anoxic denitrifying phosphorus accumulating organism (dPAO) and nitrifying biological aerated filter (BAF) was studied in both lab and field pilot plants with weak sewage. The biofilm BAF was used as a post-nitrification process that provided sufficient nitrate to suspended growth dPAO. The anoxic/BAF configuration could remove nitrogen and phosphorus appreciably compared to other BNR systems. The enhanced biological phosphorus removal (EBPR) was mainly occurred in anoxic zone of suspended growth reactor. It has been found that P removal efficiency of dPAO was enhanced with an addition of a short oxic zone in suspended reactors compared to that of without oxic zone. However, the degree of aerobic P uptake in oxic zone was far lower than anoxic P uptake. The operating results of field plant indicated that dPAO/BAF configuration successfully reduced the adverse temperature effects at lower than 15 degrees C.     

曝气条件对侧流活性污泥水解工艺脱氮性能和微生物的影响

通过改变传统厌氧/缺氧/好氧（A²/O）反应器和侧流活性污泥水解（SSH）反应器的曝气强度和溶解氧（DO）浓度,考察了曝气条件对脱氮性能的影响,并对比研究了微生物群落结构的变化规律。结果表明：相较于高DO阶段,两组反应器在中低DO阶段有更好的脱氮效果。在相同进水条件下,SSH反应器的脱氮性能优于A²/O反应器,且出水满足一级A标准。高通量测序结果表明,中低DO浓度更有利于脱氮微生物的生长。相对于A²/O反应器,SSH反应器中反硝化微生物的相对丰度更高。因此,合理控制曝气条件维持中低DO浓度有利于SSH工艺达到良好的脱氮性能及脱氮微生物的生长。     

Performance and microbial ecology of the hybrid membrane biofilm process for concurrent nitrification and denitrification of wastewater.

We report on a novel process for total nitrogen (TN) removal, the hybrid membrane biofilm process (HMBP). The HMBP uses air-supplying hollow-fibre membranes inside an activated sludge tank, with suppressed aeration, to allow concurrent nitrification and denitrification. We hypothesised that a nitrifying biofilm would form on the membranes, and that the low bulk-liquid BOD concentrations would encourage heterotrophic denitrifying bacteria to grow in suspension. A nitrifying biofilm was initially established by supplying an influent ammonia concentration of 20 mgN/L. Subsequently, 120 mg/L acetate was added to the influent as BOD. With a bulk-liquid SRT of only 5 days, nitrification rates were 0.85 gN/m(2) per day and the TN removal reached 75%. The biofilm thickness was approximately 500 lim. We used DGGE to obtain a microbial community fingerprint of suspended and attached growth, and prepared a clone library. The DGGE results, along with the clone library and operating data, suggest that nitrifying bacteria were primarily attached to the membranes, while heterotrophic bacteria were predominant in the bulk liquid. Our results demonstrate that the HMBP is effective for TN removal, achieving high levels of nitrification with a low bulk-liquid SRT and concurrently denitrifying with BOD as the sole electron donor.     

泥龄对反硝化除磷脱氮系统效率的影响分析

反硝化除磷脱氮系统中,生物脱氮与生物除磷是两个相互独立、相互竞争又相互交叉的生理反应过程,存在着硝化菌与聚磷菌的不同泥龄之争。应用数学模式分析了泥龄对氮、磷去除效率的影响,并就反硝化除磷脱氮工艺的单、双级污泥系统的泥龄进行了探讨。推导出以下结论:缩短泥龄可以提高系统的同化除磷能力;长泥龄的生物除磷系统单靠生物作用以期达到完全除磷是几乎不可能的。     

水生经济植物根际氮循环细菌及其作用的研究

利用生态浮床系统,在室内研究了浮床植物单作和混作对氮的去除效果及其根际周围硝化与反硝化菌种群数量以及硝化与反硝化作用速率的变化规律.结果表明,浮床植物混作系统对氮的去除效果优于植物单作和无植物系统,而植物系统又优于无植物系统;植物单作与混作根际硝化细菌种群数量和硝化作用速率、反硝化细菌种群数量和反硝化作用速率均具有明显的差异;处理15 d后,硝化细菌种群数量在水芹系统中的减少较比豆瓣菜和混作系统多,硝化作用速率在水芹系统中的降低较豆瓣菜和混作系统明显(P <0.05);反硝化细菌种群数量由多到少的顺序分别为水芹系统,豆瓣菜系统,混作系统,无植物系统;且反硝化作用速率由高到低的顺序分别为水芹系统,豆瓣菜系统,混作系统,无植物系统.     

Development and optimisation of VFA driven DEAMOX process for treatment of strong nitrogenous anaerobic effluents.

The recently proposed DEAMOX (DEnitrifying AMmonium OXidation) process combines the anammox reaction with autotrophic denitrifying conditions using sulphide as an electron donor for the production of nitrite from nitrate within an anaerobic biofilm. This paper firstly presents a feasibility study of the DEAMOX process using synthetic (ammonia + nitrate) wastewater where sulphide is replaced by volatile fatty acids (VFA) as a more widespread electron donor for partial denitrification. Under the influent N-NH+4/N-NO3(-) and COD/N-NO3(-) ratios of 1 and 2.3, respectively, the typical efficiencies of ammonia removal were around 40% (no matter whether a VFA mixture or only acetate were used) for nitrogen loading rates (NLR) up to 1236 mg N/l/d. This parameter increased to 80% by increasing the influent COD/N-NO3(-) ratio to 3.48 and decreasing the influent N-NH4 +/N-NO3(-) ratio to 0.29. As a result, the total nitrogen removal increased to 95%. The proposed process was further tested with typical strong nitrogenous effluent such as reject water (total N, 530-566 mg N/l; total COD, 1530-1780 mg/l) after thermophilic sludge anaerobic digestion. For this, the raw wastewater was split and partially ( approximately 50%) fed to a nitrifying reactor (to generate nitrate) and the remaining part ( approximately 50%) was directed to the DEAMOX reactor where this stream was mixed with the nitrified effluent. Stable process performance up to NLR of 1,243 mg N/l/d in the DEAMOX reactor was achieved resulting in 40, 100, and 66% removal of ammonia, NOx(-), and total nitrogen, respectively.     

影响反硝化除磷与厌氧氨氧化耦合的因素

氧对厌氧氨氧化菌有毒,但在颗粒污泥和生物膜中的厌氧氨氧化菌对氧有较高的耐受能力,并且聚磷菌能消耗影响氧氨氧化菌生长的氧。厌氧氨氧化菌的生长无需有机物的参与,聚磷菌释磷需要吸收有机物,少量有机物的加入对厌氧氨氧化菌的活性影响不大。亚硝酸盐是厌氧氨氧化菌氧化氨的电子受体,较高浓度的亚硝酸盐对反硝化聚磷有抑制作用,但合适浓度的亚硝酸盐(该浓度可以通过驯化来提高)可以作为反硝化聚磷菌吸磷的电子受体。厌氧氨氧化过程中有硝酸盐生成,反硝化聚磷菌能利用这部分硝酸盐。另外,两类菌都适宜于中温略偏碱性的环境。因此,通过创造同时对厌氧氨氧化菌和反硝化聚磷菌有利的微生态环境,发挥两者在脱氮除磷方面的协同耦合作用,达到高度脱氮除磷,是极有前景的废水厌氧(缺氧)处理研究方向。     

A two-sludge system for simultaneous biological C, N and P removal via the nitrite pathway

Nitrogen removal via the nitrite pathway results in significant savings in both aeration costs and COD requirements for denitrification when compared to the conventional biological nitrogen removal process. Implementation of the nitrite pathway for simultaneous C/N/P removal in a single sludge system has a major drawback: the aeration phase disfavours denitrifying phosphorus removal. A possible configuration to overcome this issue is the utilisation of a two-sludge system where autotrophic and heterotrophic populations are physically separated. This paper experimentally demonstrates the feasibility of a nitrite-based two-sludge system with sequencing batch reactors (SBR) for the treatment of urban wastewater: a heterotrophic SBR with denitrifying PAOs for P removal and an aerobic SBR for N removal. Partial nitrification was attained in the autotrophic SBR so that shortcut biological nitrogen removal was achieved by using the anoxic dephosphatation activity of DPAOs. Finally, the effect of operating this system without pH control was studied using different influent pH values (pH = 6.8, 7.5 and 8.2) and, despite some efficiency lost due to the pH fluctuations, the system was able to remove most of the C, N and P present in the wastewater.     

BICT biological process for nitrogen and phosphorus removal.

An updated biological nitrogen and phosphorus removal process--BICT (Bi-Cyclic Two-Phase) biological process--is proposed and investigated. It is aimed to provide a process configuration and operation mode that has facility and good potential for optimizing operation conditions, especially for enhancing the stability and reliability of the biological nutrient removal process. The proposed system consists of an attached-growth reactor for growing autotrophic nitrifying bacteria, a set of suspended-growth sequencing batch reactors for growing heterotrophic organisms, an anaerobic biological selector and a clarifier. In this paper, the fundamental concept and operation principles of BICT process are described, and the overall performances, major operation parameters and the factors influencing COD, nitrogen and phosphorus removal in the process are also discussed based on the results of extensive laboratory experiments. According to the experimental results with municipal sewage and synthetic wastewater, the process has strong and stable capability for COD removal. Under well controlled conditions, the removal rate of TN can reach over 80% and TP over 90% respectively, and the effluent concentrations of TN and TP can be controlled below 15 mg/L and 1.0 mg/L respectively for municipal wastewater. The improved phosphorus removal has been reached at short SRT, and the recycling flow rate of supernatant between the main reactors and attached-growth reactor is one of the key factors controlling the effect of nitrogen removal.