MBBR用于南方某污水厂强化脱氮效果分析

浙江某污水厂设计规模为16×10^4m^3/d,采用Bardenpho—MBBR工艺进行升级改造后,生化池出水COD、NH4^+-N、TN、TP均值分别为17.2、0.37、7.72、0.168 mg/L,在不投加碳源的情况下即可达到准Ⅳ类水标准,生物脱氮除磷效果良好。对生化池各功能区沿程采样测定发现,好氧MBBR区对TN的去除率为28%~46%,受到泥浆水冲击后也能保持在15%~22%,系统高效去除TN得益于好氧MBBR区的同步硝化反硝化(SND)作用;由于好氧区的SND现象,平均可以节省0.23元/m^3的碳源费用,年节约碳源费用近1343.2万元;生物膜厚度和溶解氧的控制对于稳定表现SND有重要影响;系统中微生物的高通量测序结果显示,悬浮载体上硝化菌丰度为32.19%、反硝化菌丰度为4.86%,硝化菌和反硝化菌同时存在为SND现象的产生提供了微观保证;冬季低温时,悬浮载体实际承担了系统近90%的硝化负荷。     

MBBR工艺用于唐山某污水厂提标改造效能分析

唐山某污水厂进行一级A提标改造,采用MBBR工艺对氧化沟进行改造,在缺氧区及好氧区同时投加悬浮载体。改造后系统出水COD、BOD5、TN、氨氮、TP、SS分别为(30.5±5.2)、(3.4±0.6)、(13.0±1.4)、(1.6±1.0)、(0.42±0.05)、(7.55±1.18) mg/L,稳定达到一级A标准。污水厂全流程测定结果显示,好氧区存在稳定的同步硝化反硝化(SND)过程,对TN的去除率为8.9%,保障在不投加碳源的情况下出水TN稳定达标。小试结果表明,在10～12℃的低温环境下,悬浮载体的硝化速率为0.13 kgN/(m3·d),原水反硝化速率最大为0.039 kgN/(m3·d),悬浮载体的加入保障了系统低温下良好的处理效果。高通量测序结果表明:好氧区悬浮载体上硝化螺旋菌相对丰度为6.57%,是活性污泥的3倍,并且在好氧区悬浮载体上发现了相对丰度为1.85%的反硝化菌,为SND现象提供了微观解释。缺氧区悬浮载体上反硝化菌的相对丰度为7.72%,是活性污泥中的2.5倍。通过原池嵌入MBBR工艺,强化了系统的硝化反硝化效果。     

基于MBBR的AAO和Bardenpho工艺改造效果对比

移动床生物膜反应器(MBBR)是一种高效的生物脱氮工艺,是污水厂提标改造的主流工艺之一。通过北方某污水厂的持续升级改造工程,分析了基于MBBR的AAO和Bardenpho工艺(分别记作MBBR-AAO工艺、MBBR-Bardenpho工艺)的实际运行效果。MBBR-AAO工艺和MBBR-Bardenpho工艺的实际硝化能力分别为0.158、0.208 kg/(m~3·d),远高于活性污泥法,而且MBBR-Bardenpho工艺的抗冲击能力更强、出水水质更稳定;两种工艺的出水TN浓度分别为(20.9±3.8)、(7.4±2.3) mg/L,对TN的去除率分别为71.4%和88.8%。MBBR-Bardenpho工艺可使出水TN低于12 mg/L,达到地表准Ⅳ类水质标准,在TN去除方面优势突出。沿程测定结果显示,MBBR-Bardenpho工艺通过增加后置缺氧区,可使好氧区出水TN进一步降低,大大提高了生化池对TN的去除效果。悬浮载体和活性污泥的高通量测序结果显示,悬浮载体对硝化菌的富集能力较强,相对丰度超过10%,主要起硝化作用;而活性污泥中反硝化菌的相对丰度较高,主要起反硝化作用。两种工艺的生化池占地分别为0.162、0.136 m~2/(m~3·d~(-1)),基于MBBR的优势,均可再次提标提量,吨水占地将进一步降低。两种工艺均有良好的除污效果,其中,MBBR-AAO工艺主要适用于常规浓度进水的一级A达标污水厂,而MBBR-Bardenpho工艺适用于出水水质要求达到地表准Ⅳ类及以上标准的污水厂。     

MBBR工艺用于污水厂提标改造的低温运行效果

天津市某污水处理厂进行提标改造,出水水质要求达到天津市《城镇污水处理厂污染物排放标准》(DB 12/599—2015)的A类标准,核心生化段采用移动床生物膜反应器(MBBR)工艺进行原位改造,将AAO工艺改为Bardenpho工艺,增设后缺氧区,增强生化系统的脱氮作用,好氧区投加悬浮载体,保障氨氮的稳定达标;深度处理工艺采用气浮、两级臭氧氧化、曝气活性炭滤池以及V型滤池,保障TP、SS、COD稳定达标。实际运行效果显示,在冬季9～11℃的低温条件下,污水厂出水COD、BOD5、氨氮、TN、TP、SS平均值分别为24.52、0.88、0.29、6.82、0.08、2.32 mg/L,稳定达到了提标改造目标。生化段沿程检测结果和硝化试验结果表明,悬浮载体在低温条件下优势突出,硝化速率是活性污泥的10倍,几乎承担了全部的硝化作用,Bardenpho工艺的设计破除了回流比对TN去除的限制,后置缺氧区的TN去除率为24.76%,强化了TN的去除,生化段出水氮素稳定达标。高通量测序结果显示,系统内主要的硝化菌属为Nitrospira,在MBBR区悬浮载体上的相对丰度达到13.14%,而在活性污泥中仅为0.68%。采用MBBR工艺对生化段进行原位改造,能够有效提高系统的硝化能力,是应对冬季低温、确保出水水质达标的有效措施。     

MBBR工艺在污水处理厂提量增效中的应用

采用MBBR对某污水厂扩容2×10~4m~3/d,改造后污水处理规模达到12×10~4m~3/d;改造时,保持厌缺氧区不变,好氧区采用两级MBBR、微动力混合池型,强化系统抗冲击能力;好氧区投加SPR-3型填料;同时将二沉池改建为高效沉淀池,新增转鼓过滤。改造后水量提升20%,出水水质稳定达到一级A标准,优化运行后可达到地表水准Ⅳ类水质;生化池出水TN均值为10. 40 mg/L,TN去除率为83. 50%,好氧段可去除TN 6～10 mg/L;生化池出水TP为0. 43 mg/L,TP去除率为93%,缺氧段发生显著的TP去除现象,在高效沉淀池投加铁盐絮凝剂后,出水TP可降到0. 30 mg/L以下;系统内同步硝化反硝化(SND)及反硝化除磷菌(DPB)的出现,实现了碳源限制下的同步强化脱氮除磷,未投加碳源情况下TN和TP稳定达标,通过SND途径去除TN贡献率为13. 20%,通过DPB途径去除TP贡献率为88%,实现了节能降耗。     

芜湖市某污水处理厂二期提标扩容工程设计

芜湖市某污水处理厂现状(一期)规模10×10⁴ m³/d,出水执行国家一级A排放标准。本次二期工程将污水厂总规模扩容至20×10⁴ m³/d,出水水质提标至地表水准Ⅳ类标准。二期扩建采用改良Bardenpho生物反应池+磁混凝高效沉淀池+反硝化深床滤池工艺;对一期厂区现状多模式AAO反应池进行内部挖潜,投加悬浮填料,以强化硝化反硝化效果。实际运行表明,出水水质可稳定达标。本工程总投资39 737.47万元,新增单位经营成本1.47元/m³。     

MBBR+磁混凝用于A2/O微曝氧化沟污水厂提标扩容

广东某污水厂处理工艺为A²/O微曝氧化沟，现要求同时扩容提标，处理规模由10×10⁴ m³/d提升至15×10⁴ m³/d，扩容50%，出水水质需满足广东省地方标准《水污染物排放限值》(DB44/26—2001)第二时段一级标准及《城镇污水处理厂污染物排放标准》(GB 18918—2002)一级A标准中的较严者。针对改造工程扩容体量大、可用土地少及排放标准严的问题，最终选择“MBBR原位强化生化处理能力+二沉池提高负荷+新建磁混凝沉淀保障固液分离”技术路线。通过生化段镶嵌MBBR工艺，使出水NH₃-N和TN分别稳定降至(1.28±0.91) mg/L和(5.78±1.33) mg/L；虽然改造后二沉池表面负荷提高致使出水SS略有升高，但磁混凝较高的固体通量承受能力，可确保SS由(17.45±4.18) mg/L稳定降至(3.59±0.71) mg/L，同时保障出水TP达到(0.09±0.09) mg/L。“MBBR+磁混凝沉淀”技术路线脱氮除磷效果好、占地...     

碳源对短程反硝化-厌氧氨氧化工艺效能的影响

为探究大分子有机碳源对短程反硝化-厌氧氨氧化(PD/A)系统脱氮效能的影响,通过在厌氧氨氧化(Anammox)连续流反应器中投加葡萄糖和新型组合填料快速启动生物膜-活性污泥PD/A工艺,研究了不同碳源条件(单一碳源和混合碳源)和不同COD/NO₃^--N下该工艺的脱氮性能。结果表明,以葡萄糖为唯一碳源,控制COD/NO₃^--N为4.5,在第90天成功启动PD/A系统,TN去除率达到93.89%,出水TN为6.17 mg/L,此时Anammox过程对去除TN的贡献率高达95.83%,反硝化过程的贡献率仅为4.17%;而由于短程反硝化菌对淀粉和葡萄糖混合碳源的利用率下降,在混合碳源驱动下PD/A系统的TN去除率降至90.53%(COD/NO₃^--N=5),出水TN为9.19 mg/L,且反硝化过程对去除TN的贡献率升至8.48%。微生物高通量测序结果表明,在两种碳源条件下,变形菌门均为绝对优势菌门,其相对丰度均大于50%;Candidatus＿Brocadia和...     

基于A~2O—MBBR工艺的污水厂提标改造中试研究

针对某污水厂进水碳源不足、负荷冲击性强以及占地受限等问题,拟采用A~2O—MBBR工艺进行提标改造,并开展中试研究。中试结果表明,在进水平均C/N值3的条件下,生化池出水COD、NH_3-N、TN、TP平均值分别为14.4、0.24、5.93、0.25 mg/L,TN去除率相比现状污水厂提高了27.2%;在1.4倍水量冲击下,出水COD、NH_3-N、TN、TP平均值分别为9.9、0.56、6.17、0.2 mg/L;当垃圾渗滤液投加比为0.1%～0.4%时,出水COD、NH_3-N、TN、TP平均浓度分别为18.1、0.57、8.05、0.2 mg/L;悬浮载体上硝化菌群相对丰度为13.32%,反硝化菌群相对丰度为14.29%,硝化菌和反硝化菌同时存在,为同步硝化反硝化的发生提供了微观保证。可见,MBBR工艺可以强化中试系统的脱氮除磷能力,大幅提高系统的抗冲击负荷能力。     

后置生物膜三级反硝化工艺特性及其应用

为了改善日益严峻的水环境问题,不但要提高现有污水处理系统N、P去除效率,同时应在局部敏感水域实现出水的深度脱氮除磷。三级生物膜反硝化是极具发展前景的深度脱氮工艺,在分析单级悬浮活性污泥工艺技术缺欠的基础上,综述了反硝化滤池及反硝化MBBR两种三级生物膜反硝化工艺特性,并对参与实施的生物膜反硝化脱氮工程案例进行了介绍。     

节地型HBR生物膜技术在贵阳金百再生水厂的应用

贵阳金百再生水厂设计规模为3.0×10⁴m³/d,出水水质执行《城镇污水处理厂污染物排放标准》(GB 18918—2002)一级A标准,就近作为麦架河河道生态补水。生化处理采用节地型生物膜技术,通过悬浮填料和高填充率的固定床结构,实现生物膜处理和生物过滤的双重作用,高效去除污染物,省去二沉池,节省占地面积。介绍了该厂的工艺流程、构筑物设计及设备配置情况,并对运行效果进行总结。自运行以来,出水水质稳定达标,COD、SS、氨氮、总氮、总磷去除率分别为89.4%、92.8%、96.3%、48.4%、90.9%;节地效果明显,吨水占地仅为0.36 m²/(m³·d^-1);运行成本为0.56元/m³,与同等规模的传统活性污泥法污水厂的运行成本相近。     

Suspended biofilm carrier and activated sludge removal of acidic pharmaceuticals

Removal of seven active pharmaceutical substances (ibuprofen, ketoprofen, naproxen, diclofenac, clofibric acid, mefenamic acid, and gemfibrozil) was assessed by batch experiments, with suspended biofilm carriers and activated sludge from several full-scale wastewater treatment plants. A distinct difference between nitrifying activated sludge and suspended biofilm carrier removal of several pharmaceuticals was demonstrated. Biofilm carriers from full-scale nitrifying wastewater treatment plants, demonstrated considerably higher removal rates per unit biomass (i.e. suspended solids for the sludges and attached solids for the carriers) of diclofenac, ketoprofen, gemfibrozil, clofibric acid and mefenamic acid compared to the sludges. Among the target pharmaceuticals, only ibuprofen and naproxen showed similar removal rates per unit biomass for the sludges and biofilm carriers. In contrast to the pharmaceutical removal, the nitrification capacity per unit biomass was lower for the carriers than the sludges, which suggests that neither the nitrite nor the ammonia oxidizing bacteria are primarily responsible for the observed differences in pharmaceutical removal. The low ability of ammonia oxidizing bacteria to degrade or transform the target pharmaceuticals was further demonstrated by the limited pharmaceutical removal in an experiment with continuous nitritation and biofilm carriers from a partial nitritation/anammox sludge liquor treatment process.     

Total nitrogen removal in a hybrid, membrane-aerated activated sludge process

The hybrid (suspended and attached growth) membrane biofilm process (HMBP) is a novel method to achieve total nitrogen removal from wastewater. Air-filled hollow-fiber membranes are incorporated into an activated sludge tank, and a nitrifying biofilm develops on the membranes, producing nitrite and nitrate. By suppressing bulk aeration, the bulk liquid becomes anoxic, and the nitrate/nitrite can be reduced with influent BOD. The key feature that distinguishes the HMBP from other membrane-aerated processes is that it is hybrid; heterotrophic bacteria are kept mainly in suspension by maintaining low bulk liquid BOD concentrations. We investigated the HMBP's performance under a variety of BOD and ammonium loadings, and determined the dominant mechanisms of nitrogen removal. Suspended solids increased with the BOD loadings, maintaining low bulk liquid BOD concentrations. As a result, nitrification rates were insensitive to the BOD loadings, remaining at 1gNm(-2)day(-1) for BOD loadings ranging from 4 to 17gBODm(-2)day(-1). Nitrification rates decreased during short-term spikes in bulk liquid BOD concentrations. Shortcut nitrogen removal was confirmed using microsensor measurements, showing that nitrite was the dominant form of oxidized nitrogen produced by the biofilm. Fluorescence in situ hybridization (FISH) showed that ammonia oxidizing bacteria (AOB) were dominant throughout the biofilm, while nitrite oxidizing bacteria (NOB) were only present in the deeper regions of the biofilm, where the oxygen concentration was above 2mg/L. Denitrification occurred mainly in the suspended phase, instead of in the biofilm, decreasing the potential for biofouling. When influent BOD concentrations were sufficiently high, full denitrification occurred, with total nitrogen (TN) removal approaching 100%. These results suggest that the process is well-suited for achieving concurrent BOD and TN removal in activated sludge.     

MBBR+磁混凝用于CAST工艺升级改造的效果分析

浙江省某市政污水处理厂设计规模为10×10^4m^3/d,出水水质执行《城镇污水处理厂污染物排放标准》(GB 18918-2002)的一级B标准,采用MBBR+磁混凝工艺对其进行一级A升级改造,改造完成至今已运行1年多,在冬季低温条件下仍具有较好的运行效果。改造后,出水COD、BOD5、氨氮、TN、TP和SS平均浓度分别为13.87、2.10、0.75、10.83、0.10和5.3 mg/L,稳定达到了GB 18918-2002的一级A标准。不改变原有CAST工艺的运行方式和池容,在主反应区镶嵌MBBR,安装搅拌器,增加反硝化时序,有效提高了系统的脱氮效果;深度处理采用磁混凝+纤维转盘滤池工艺,以微小磁粉作为晶核,强化混凝效果,确保出水SS和TP稳定达标。生化系统内主要的硝化菌群为Nitrosomonas和Nitrospira,硝化菌群在悬浮载体上的相对丰度达到8.71%,高于活性污泥中的4.85%;主要的反硝化菌群为Azoarcus和Zoogloea,反硝化菌群在悬浮载体上的相对丰度达到11.58%,在活性污泥中为9.78%。     

硫自养波形潜流人工湿地的脱氮机理及工况优化

将硫自养反硝化工艺与潜流人工湿地相结合,考察了其对低碳氮比污水中氮的去除效果。结果表明,增加曝气装置后硫自养波形潜流人工湿地的脱氮效果可以得到保障,在气水比为8∶1、水力负荷为0.8 m³/(m²·d)时,TN去除率为(70±5)%,出水TN浓度低于8 mg/L;NH4+-N去除率在90%以上,出水NH4+-N浓度低于3 mg/L;COD去除率为(50±2)%,出水COD浓度低于40 mg/L;p H值可维持在7~9。同时,石灰石填料具有同步除磷的效果。该工艺具有脱氮效率高、效果好、运行费用低的特点。     

Characterization of nitrifying granules produced in an aerobic upflow fluidized bed reactor

Since nitrification is the rate-determining step in the biological nitrogen removal from wastewater, many research studies have been conducted on the immobilization of nitrifying bacteria. In this research, granulation of nitrifying bacteria in an aerobic upflow fluidized bed (AUFB) reactor in a nitrification process for inorganic wastewater containing 500 g/m³ of NH₄⁺-N was investigated. It was observed that spherical, pseudocubic and elliptical granules with a diameter of 346 μm were produced at the bottom of the reactor after 300 days. Denaturing gradient gel electrophoresis analysis revealed that Nitrosomonas-like bacteria were the dominant ammonia-oxidizing species in the granules. Many colonies of Nitrosomonas-like bacteria were found in the outer part of the granules based on the spatial distribution analysis by fluorescence in situ hybridization. By stepwise reduction of the hydraulic retention time, the ammonia removal rate of the AUFB reactor containing these nitrifying granules finally reached 1.5 kg-N/m³/day. Results suggested that the use of granules realizes the retention of a large amount of nitrifying bacteria in the reactor, which guarantees a highly efficient nitrification.     

高盐度冲击后厌氧氨氧化工艺恢复及运行特性

通过逐步增加UASB反应器进水氮负荷[1.06~1.42 kg/(m³·d)]方式,考察了厌氧氨氧化(Anammox)工艺受到高盐度冲击后的恢复及运行特性。结果表明,经过156 d的运行,NH4+-N、NO2--N、TN去除率及总氮去除负荷(NRR)分别达到97.57%、96.40%、83.90%和1.19kg/(m³·d),这主要归功于Anammox污泥的活性得到了有效恢复[TN的比降解速率由0.131mg/(mgVSS·d)提高到0.302 mg/(mgVSS·d)];随着工艺运行效能的恢复,颗粒污泥的颜色由深褐色变为红褐色,平均粒径也随之增大,粒径>1.5 mm的占比最高,达到了68.25%;此外,胞外聚合物(EPS)含量由96.66 mg/g增大至147.98 mg/g,并且PN/PS值由4.86增大至13.34,厌氧氨氧化工艺可恢复到高效运行状态。     

Influence of detachment on substrate removal and microbial ecology in a heterotrophic/autotrophic biofilm

Competition between heterotrophic bacteria oxidizing organic substrate and autotrophic nitrifying bacteria in a biofilm was evaluated. The biofilm was grown in a tubular reactor under different shear and organic substrate loading conditions. The reactor was initially operated without organic substrate in the influent until stable ammonia oxidation rates of 2.1 g N/(m² d) were achieved. A rapid increase of fluid shear in the tubular reactor on day 156 resulted in biofilm sloughing, reducing the biofilm thickness from 330 to 190 μm. This sloughing event did not have a significant effect on ammonia oxidation rates. The addition of acetate to the influent of the reactor resulted in decreased ammonia oxidation rates (1.8 g N/(m² d)) for low influent acetate concentrations (17 mg COD/L) and the breakdown of nitrification at high influent acetate concentrations (55 mg COD/L). Rapidly increasing fluid shear triggered biofilm sloughing in some cases—but maintaining constant shear did not prevent sloughing events from occurring. With the addition of acetate to the influent of the reactor, the biofilm thickness increased up to 1350 μm and individual sloughing events removed up to 50% of the biofilm. Biofilm sloughing had no significant influence on organic substrate removal or ammonia oxidation. During 325 days of reactor operation, ammonia was oxidized only to nitrite; no nitrate production was observed. This lack of nitrite oxidation was confirmed by fluorescent in situ hybridization (FISH) analysis, which detected betaproteobacterial ammonia oxidizers but not nitrite oxidizers. Mathematical modeling correctly predicted breakdown of nitrification at high influent acetate concentrations. Model predictions deviated systematically from experimental results, however, for the case of low influent acetate concentrations.     

淹没式复合型MBR处理城市生活污水的效能研究

为了缓解缺水压力，在传统膜生物反应器（CMBR）的基础上开发出了一种新型城市污水处理回用工艺——淹没式复合型膜生物反应器（SHMBR），并考察了对城市生活污水的处理效果。试验结果表明，SHMBR可以在CMBR的基础上进一步提高生物量，并明显改善了对有机物和NH4^＋-N的去除效果。试验中对TN、TP的去除效果没有提高，原因可能是生物膜的厚度不够，没有在生物膜内部形成厌氧微环境。另外，SHMBR的除磷效果没有增强还可能与生物膜的SRT较长以及聚磷菌主要生活在活性污泥中有关。