A2O工艺处理低C/N比生活污水的试验研究

采用52.5 L的A²O试验装置处理实际生活污水,研究了A²O工艺在处理低C/N比生活污水时的脱氮除磷特性,并探讨了如何通过强化缺氧吸磷来提高系统的脱氮除磷效率。试验结果表明：在厌氧/缺氧/好氧体积比为1/1/2、HRT为8 h、污泥回流比为70%、内回流比为300%的工况下处理C/N为7.89的生活污水,TN和SOP去除率分别能够达到85.4%和93.3%,系统中存在反硝化除磷,缺氧吸磷占总吸磷量的25.3%。同样的运行条件下处理C/N为4.20的生活污水时,SOP去除几乎不受影响,但TN去除率降低至62.2%,平均出水TN浓度也超过20 mg•L^-1。维持厌氧区体积不变,增大缺氧区体积,使得缺氧/好氧体积比为5/8时,TN去除率可上升到70.7%,缺氧吸磷占总吸磷量的55.2%。同时改变内回流比的试验表明250%的内回流比能最大程度地强化反硝化除磷的作用,此时TN去除率可提高至77.3%。强化A²O工艺中的反硝化除磷,能克服碳源不足对脱氮除磷的影响,显著提高低C/N比污水的脱氮除磷效率。     

混合液回流比对A/A/O工艺反硝化除磷的影响

以生活污水培养驯化污泥的小试规模A/A/O工艺为研究对象,进行了混合液回流比为100%、200%和300%时对反硝化除磷的影响研究,并利用厌氧/缺氧批式试验方法对污泥特性进行单独考察。结果表明,随着混合液回流比的增大,缺氧除磷在系统除磷所起的作用、反硝化聚磷菌缺氧利用单位聚羟基链烷酸（PHAs）的吸磷量和反硝化数量出现先升高后下降,厌氧合成单位PHAs的释磷量和好氧利用单位PHAs的吸磷量并没有受到影响,以200%时反硝化除磷和系统脱氮除磷效果为最好,过高或过低NO₃-N浓度均会影响反硝化聚磷菌的缺氧吸磷速率和PHAs降解速率,但并没有影响其本身所固有的特性。     

电子受体和MLSS对反硝化除磷的影响

采用序批式活性污泥法进行污水处理试验,考察电子受体的浓度和种类、MLSS对反硝化聚磷污泥脱氮除磷效果的影响。结果表明硝酸盐浓度的提高有利于除磷,但过高的硝酸盐浓度（40 mg/L）,会导致脱氮效果降低,进而影响下一周期的厌氧释磷效果;在较低的亚硝酸盐浓度下（5 mg/L）,有少量摄磷;当亚硝酸盐浓度大于20 mg/L时,对反硝化除磷有明显的抑制作用;随着MLSS增加,厌氧释磷量和缺氧摄磷量均增加;单位MLSS释磷量和单位MLSS摄磷量均与MLSS变化趋势相反;当MLSS大于11．3 g/L时,MLSS的增加对厌氧释磷量和缺氧摄磷量影响不大。     

AOA-SBR工艺用于城市污水同步脱氮除磷

以城市污水为研究对象，考察了不同COD／N／P对厌氧／好氧／兼氧（AOA）．SBR工艺脱氮除磷效果的影响。经过3个月稳定运行，当COD：N：P-800：24：11时，AOA．SBR工艺对污水中有机物、氨氮和磷的去除率分别为100％、84％和93％。实验通过提高有机物浓度削弱聚磷菌（PAOs）与聚糖菌（GAOs）竞争底物的能力，抑制了PAOs好氧放磷速率。当COD=800mg／L时，GAOs和PAOs厌氧乙酸摄取量之比为l：9。此外，实验采用兼氧／好氧吸磷速率比，对反硝化聚磷菌数量（DNPAOs）进行估算，结果表明AOA-SBR工艺比值明显高于A20和AO工艺。因此，通过调节进水有机物浓度，可使DNPAOs在AOA-SBR同步脱氮除磷过程中发挥重要作用。     

人工配水和实际污水(AO)2SBR同步脱氮除磷比较研究

在污泥停留时间为15d、HRT为1.5h和DO的质量浓度约为2.5 mg·L-1条件下,分别对人工配水和实际生活污水进行了(AO)2SBR法同步脱氮除磷试验,并对处理效果进行了对比.结果表明,人工配水和实际污水的(AO)2SBR工艺好氧和缺氧脱氮除磷过程几乎全部以厌氧阶段合成的胞内聚羟基烷酸为碳源,说明反硝化脱氮除磷确实可实现“一碳两用”;人工配水和实际污水的好氧吸磷率分别为67.49％和93.42％、缺氧除氮率分别为58.22％和77.98％,实际污水驯化得到的反硝化聚磷菌和聚磷菌具有更强的反硝化能力和好氧吸磷能力.     

污水脱氮除磷新工艺研究进展

随着人们对污水生物脱氮除磷过程认识的不断深入,产生了一些新的处理工艺。本文重点介绍了耦合好氧-缺氧N2O分解工艺（CANDO）、同时去除含碳有机物及氮磷营养物质新工艺（BioCAST）、上流式厌氧-缺氧污泥床工艺（UAASB）、厌氧循环流化床工艺（A-CFBBR）、双循环流化床生物反应工艺（TCFBBR）、双污泥反硝化诱导结晶工艺（A2N-IC）等6种新工艺的原理、影响因素和工艺流程特点。通过与传统工艺的相比较,对新工艺的特性进行了探讨。最后展望了污水脱氮除磷技术的发展趋势,指出经济、高效、低能耗的可持续脱氮除磷工艺是污水处理未来的发展方向。     

A~2/O工艺强化反硝化除磷控制策略研究

在传统A2/O工艺的基础上,通过设立预缺氧区(即建立A-A2/O工艺)、外加碳源等手段,强化A2/O工艺处理低C/N生活污水的脱氮除磷能力。试验结果表明,经过强化后的A2/O反应器对COD、TN及TP去除效果良好,COD、TN及TP的去除率分别为92%、98%、85%。系统表现出明显的反硝化除磷现象,缺氧区除磷量占总除磷量的17.18%。反硝化除磷现象的产生降低了碳源缺乏对A2/O工艺脱氮除磷性能的影响,提高碳源的利用效率。为采用A2/O工艺处理低C/N生活污水的污水处理厂提供理论依据。     

A2N反硝化除磷脱氮工艺的影响因素分析

A2N(厌氧/缺氧和硝化)反硝化除磷脱氮工艺是基于反硝化聚磷菌缺氧吸磷理论开发的新工艺。介绍了A2N工艺的原理和特点,对其影响因素诸如水力停留时间、溶解氧、NO3-和NO2-的浓度、原水中COD与TN的质量比、容积交换比及出水SS等进行讨论和分析,并综合国内外的研究结果给出工艺关键影响参数的设定范围。     

改良A~2/O对低C/N城市污水的脱氮除磷研究

针对牡丹江城市污水低C/N水质特点,依据现有污水处理厂广泛应用的A~2/O工艺,提出一种改良A~2/O工艺,并投加填料以期解决脱氮除磷过程中存在的碳源竞争、污泥龄矛盾等问题。通过控制回流至预缺氧段的污泥量,回流体积比为15%时,获得最释磷效果,并探讨了其对除磷效果的影响作用,考察至好氧段的污泥回流量与好氧段NH_3-N去除的关系,并分析了缺氧段硝化液回流量对TN去除的影响,污泥回流体积比为50%时,达到最佳效果,硝化液回流体积比为2.5时,获得最佳处理效果;同时研究了投加填料后污泥龄的调整对工艺脱氮除磷的影响。改良A~2/O工艺能够有效地解决反硝化细菌和厌氧释磷菌对有机物的竞争,通过投加填料可有效缓解脱氮与除磷之间存在的污泥龄矛盾。     

污水生物脱氮除磷新技术

首先简单阐述了生物脱氮除磷机理,然后重点介绍了目前几种污水生物处理新技术:厌氧/缺氧/好氧MBR工艺、短程硝化反硝化工艺和倒置A2/O工艺等,最后对污水生物脱氮除磷技术的发展进行了展望,并提出了一些建议。     

交替式厌/缺氧-好氧双膜反硝化除磷工艺

采用某污水处理厂A²/O工艺中的活性污泥为种泥,以模拟生活污水为对象,考察了交替式厌/缺氧-好氧双膜反硝化除磷工艺的启动与运行特性,并采用高通量测试技术分析系统除磷污泥的菌群结构。通过60天的启动试验,系统内反硝化聚磷菌占聚磷菌总数的比例由21.3%提高到94.4%,出水磷在0.6mg/L左右。通过逐步增加进水氨氮的方法运行2个月,系统的脱氮除磷效果稳定。在进水P浓度为6.4mg/L,保持进水N/P比为8.8,交替厌/缺氧-好氧双膜反硝化除磷工艺效能最优,可达0.12kgN/(m³?d)和0.018kgP/(m³?d),出水总磷(TP)0.8mg/L,总氮(TN)12mg/L,出水COD、NH₃-N和TN达到国家综合排放标准GB18918-2002一级A排放标准。周期试验中,pH值、氧化还原电位(oxidation-reduction potential,ORP值)均可作为厌氧释磷的控制参数,ORP也可指示缺氧吸磷的终点。典型周期内硝酸盐、亚硝酸盐的消耗量与磷的吸收量基本呈线性关系。系统内污泥多样性约为种泥的0.5倍,在“门”、“属”分类级别上分别以Proteobacteria、Xanthomonadales-nobank为主。     

两级MBfR工艺处理高强度生活废水能力研究

针对受控生态生保系统（CELSS）中生活废水（含卫生废水和尿液废水）的水质特点,采用厌氧、好氧两级MBfR工艺,完成CELSS特征性生活废水的微生物转化处理,以达到循环回用作植物营养液的水质要求。本文研究了水力停留时间（HRT）、尿液强度对该工艺有机物去除及氮素转换效率的影响。试验结果表明,当HRT≥1 d时,HRT对该系统TOC的去除效率无明显影响,其去除效率大于90%,出水TOC的浓度低于15 mg/L; HRT=1 d时,好氧反应器全程硝化能力达到最高,其容积负荷为0.418 kg N/(m³·d);而HRT≥2 d时,能获得相对更为稳定的氮素转换效率。工艺系统最高能处理1/5尿液强度的生活废水,该条件下,系统TOC的去除率达94.3%,出水TOC浓度低于20 mg/L;系统氮素的全程硝化效率为90.6%,且反应器容积负荷较高为0.409 kg N/(m³·d)。本文构建的两级MBfR工艺能较好地实现CELSS中特征性生活废水的有机物去除和氮素的有效转换,研究结果可为CELSS中生活废水微生物处理系统的设计和运行提供参考。     

改进型分段进水厌氧/缺氧/好氧工艺强化营养物去除

In order to enhance phosphorus removal in traditional step-feed anoxic/oxic nitrogen removal process,a modified pilot-scale step-feed anaerobic/anoxic/oxic (SFA²/O) system was developed,which combined a reactor similar to UCT-type configuration and two-stage anoxic/oxic process.The simultaneous nitrogen and phosphorus removal capacities and the potential of denitrifying phosphorus removal,in particular,were investigated with four different feeding patterns using real municipal wastewater.The results showed that the feeding ratios(Q₁)in the first stage determined the nutrient removal performance in the SFA²/O system.The average phosphorus removal efficiency increased from 19.17% to 96.25% as Q₁ was gradually increased from run 1 to run 4,but the nitrogen removal efficiency exhibited a different tendency,which attained a maximum 73.61% in run 3 and then decreased to 59.62% in run 4.As a compromise between nitrogen and phosphorus removal,run 3 (Q₁=0.45Q_total) was identified as the optimal and stable case with the maximum anoxic phosphorus uptake rate of 1.58mg·(g MLSS)^-1·h^-1.The results of batch tests showed that ratio of the anoxic phosphate uptake capacity to the aerobic phosphate uptake capacity increased from 11.96% to 36.85% with the optimal influent feeding ratio to the system in run 3,which demonstrated that the denitrifying polyP accumulating organisms could be accumulated and contributed more to the total phosphorus removal by optimizing the inflow ratio distribution.However,the nitrate recirculation to anoxic zone and influent feeding ratios should be carefully controlled for carbon source saving.     

水力停留时间对改良型AAO-MBR工艺处理夏季农村生活污水的影响

水力停留时间(HRT)是影响AAO工艺脱氮除磷效率的重要因素.采用改良型AAO-MBR工艺处理某农村生活污水,考察了夏季时HRT对处理装置出水效果的影响.试验结果表明,该工艺对低浓度农村生活污水中CODCr、氨氮的去除效果较稳定,平均去除率分别为69.50％、98.90％.TN去除率为26.50％～56.60％,随厌氧...     

Optimisation of anaerobic/anoxic/oxic process to improve performance and reduce operating costs

A laboratory‐scale anaerobic/anoxic/oxic reactor system was used to treat synthetic brewery wastewater for 1 year. The objectives were to enhance denitrifying phosphorus removal, improve biological nutrient removal and reduce operating costs. Three operational strategies were tested: (1) controlling nitrate recirculation to stimulate the growth of denitrifying phosphate‐accumulating organisms; (2) adjusting the volume ratio of the anaerobic/anoxic/oxic zones to enhance anoxic P uptake; (3) bypassing a part of the influent flow into the anoxic zone to maximise anoxic P uptake and denitrification. The results showed that not only was anoxic P uptake enhanced but also energy consumption for aeration could be reduced when the anoxic effluent NO₃^?‐N concentration was controlled between 1 and 3 mg L^?1. The optimal volume ratio of the anaerobic/anoxic/aerobic zones in this system was found to be 1:1:2. The optimal bypass flow ratio was 0.32. The results indicated that the optimal strategies could improve treatment performance and reduce operational costs, but there was still a challenge to treat wastewater with low C/N ratio. Copyright © 2006 Society of Chemical Industry     

The beneficial role of intermediate clarification in a novel MBR based process for biological nitrogen and phosphorus removal

BACKGROUND: A novel membrane bioreactor (MBR) is described, employing an intermediate clarifier. Unlike the established function of a final clarifier in a conventional biological nutrient removal system, the role of an intermediate clarifier has rarely been studied. Thus, this work focused on explaining the fate of nutrients in the intermediate clarifier, as influenced by the hydraulic retention time (HRT) of the preceding anaerobic bioreactor. RESULTS: The system was tested with two different anaerobic/anoxic/aerobic biomass fractions of 0.25/0.25/0.5 (run 1) and 0.15/0.35/0.45 (run 2) using synthetic wastewater. The major findings of the study were that phosphorus (P) removal was affected by the role of the intermediate clarifier. In run 1, P was removed at a rate 0.16 g d⁻¹ in the intermediate clarifier while in run 2, additional P was released at 0.49 g d⁻¹. The nitrogen (N) removal efficiencies were 74 and 75% for runs 1 and 2 respectively, while P removal was 91 and 96%. P uptake by denitrifying phosphate accumulating organisms (DPAOs) accounted for 41–52% of the total uptake in the MBR. CONCLUSIONS: This study found that the intermediate clarifier assisted chemical oxygen demand (COD), N, and P removal. With respect to the fate of P, the intermediate clarifier functioned as an extended anaerobic zone when the HRT of the preceding anaerobic zone was insufficient for P release, and as a pre‐anoxic zone when the anaerobic HRT was adequate for P release. Copyright © 2008 Society of Chemical Industry     

序批式活性污泥法反硝化聚磷菌的培养驯化研究

以某污水处理厂活性污泥作为种泥,采用序批式活性污泥法(SBR)进行反硝化聚磷菌(DPB)培养驯化研究。结果表明,经过厌氧-好氧,厌氧-换水-缺氧,厌氧-缺氧,厌氧-缺氧-短时曝气4个阶段培养驯化,系统出水效果良好:出水PO43--P的质量浓度稳定在0.5 mg.L-1以下,平均除磷率达96%;出水COD稳定在50 mg.L-1以下,平均去除率达77%。DPB占聚磷菌的比例约为65.02%。当投加不同含量的NO3--N时,硝酸盐的含量只影响吸磷速率而不影响吸磷量。当缺氧段DPB体内的PHB为限制因素时,缺氧吸磷过程在不同NO3--N含量下基本相同。     

A2N2双污泥系统反硝化除磷工艺的启动与稳定

采用低C/N比实际生活污水,以A₂N₂-SBR（厌氧/硝化/缺氧/硝化）双污泥系统为研究对象,重点考察了A₂N₂系统启动过程中的脱氮除磷特性。试验结果表明：采用在A²/O-SBR和N-SBR单元分别接种种泥,分开培养驯化聚磷菌污泥和硝化菌生物膜,并利用A²/O-SBR单元的出水作为N-SBR单元的进水,25 d好氧硝化菌生物膜挂膜成功,氨氮去除率稳定在93%以上;A²/O-SBR单元采用先厌氧/好氧（A/O）后厌氧/缺氧（A/A）的运行方式,43 d成功培养富集了反硝化聚磷菌（DPAOs）,DPAOs占PAOs的67.81%,反硝化除磷率在77.9%以上;启动成功后原水中约73%和13%的COD分别在A²/O-SBR单元的厌氧段和N-SBR单元曝气过程中被去除,系统出水COD、NH⁺₄-N、PO₄^3--P、TN浓度分别为40.6、0、0.4、13.5 mg·L^-1,达到国家《城镇污水处理厂污染物排放标准》（GB 18918-2002）一级A排放标准。     

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。