厌氧产氢ASBR对氮的脱除

在厌氧序批式人工有机污水生物产氢反应器（ASBR）中发现氮“丢失”现象，并对此产氢系统发生脱氮作用的机理和主要影响因素进行了研究。结果表明，在以葡萄糖为发酵底物的厌氧产氢系统中，微生物分别以铵和硫酸盐为电子供体和电子受体发生了硫酸盐型厌氧氨氧化；进水有机物负荷和pH主要通过影响不同种微生物的活性而影响脱氮性能，氨氮和硫酸盐的浓度直接与氮素去除率有关。在最大产氢能力为16m3／（m3·d）、氢气体积百分比为65％的生物制氢系统中，最大脱氮效率约为64％。产氢效率与氮脱除率呈现负相关关系。研究表明，在控制条件下，可以实现高有机物废水厌氧脱除氨态氮，为生活污水直接厌氧脱氮开辟一条新途径。     

厌氧产氢ASBR对氮的脱除

在厌氧序批式人工有机污水生物产氢反应器(ASBR)中发现氮"丢失"现象,并对此产氢系统发生脱氮作用的机理和主要影响因素进行了研究。结果表明,在以葡萄糖为发酵底物的厌氧产氢系统中,微生物分别以铵和硫酸盐为电子供体和电子受体发生了硫酸盐型厌氧氨氧化;进水有机物负荷和pH主要通过影响不同种微生物的活性而影响脱氮性能,氨氮和硫酸盐的浓度直接与氮素去除率有关。在最大产氢能力为16 m3/(m3·d)、氢气体积百分比为65%的生物制氢系统中,最大脱氮效率约为64%。产氢效率与氮脱除率呈现负相关关系。研究表明,在控制条件下,可以实现高有机物废水厌氧脱除氨态氮,为生活污水直接厌氧脱氮开辟一条新途径。     

低曝气下PAC强化SBR工艺同步脱氮除磷

采用序批式反应器(SBR)处理模拟生活污水,研究不同曝气量(30、24、18和12 L/h)下活性污泥同步脱氮除磷规律,并在最佳曝气量下,比较了粉末活性炭-序批式反应器(PAC-SBR)和SBR的脱氮除磷效率,分析了低曝气下PAC-SBR的运行特性和优越性。实验结果表明,当曝气量为24 L/h时,SBR内出水效果较好,其COD、TN和TP的平均去除率分别可以达到90.02%、81.13%和88.12%。在这个最佳曝气量下,PAC-SBR具有明显的优势,其COD、TN和TP的平均去除率均高于SBR,并且PAC-SBR具有较好的污泥沉降性能和较高的活性污泥浓度。在PAC-SBR中,活性污泥以PAC作为微生物载体强化了生物降解效果,并改善了低曝气下污泥絮体的结构,促使反应器内先后形成缺氧-厌氧-微氧/缺氧-缺氧的环境,利于同步硝化反硝化和反硝化聚磷,提高了PAC-SBR的同步脱氮除磷效率。     

低浓度废水厌氧处理的研究进展

本文展望了国内外厌氧处理低浓度废水的研究进展状况。着重介绍了厌氧滤池（AF）、厌氧流化床（AFB）、上流式厌氧污泥床（UASB）、厌氧颗粒污泥膨胀床（EGSB）、厌氧折流板反应器（ABR）和厌氧序批式活性污泥法（ASBR）等。     

Recovery potential of aerobic sludge biomass from Co (II) stress in sequencing batch reactors

Heavy metals in higher concentrations are often encountered in domestic sewage of developing and under-developed countries. High metallic concentrations can stress reactor sludge biomass morphology impeding its performance in organics reduction. However, the extent of damage and ability of sludge biomass to recover from the metallic stress is not fully understood. Also, there is no protocol to identify and prevent the sludge biomass from metallic stress in fully functional sewage treatment plants (STPs). This study investigates performance, metabolic activity, morphology, and settling characteristics of the sludge biomass under different Co(II) stress conditions. The extent of recovery in biomass, when the supply of Co(II) metal ion was discontinued in the inlet stream, was explored. The study also proposed a protocol based on simple settling characteristics of sludge biomass to get an early indication of metal infiltration to prevent potential damage to the biomass morphology. Four sequencing batch reactors (SBRs) with Co(II) ion concentrations of 0 (designated as RCo0), 5 (RCo5), 25 (RCo25), and 75 mg/L (RCo75) in the feed were operated with a cycle time of 12 h. Reactors were operated for 35 days with Co(II) in the feed (termed as stressed phase operation) followed by 24 days of operation without Co(II) in the feed (termed as recovery phase operation). Results show that COD removal in reactor RCo75 reduced to 48% on the 10th day of stressed phase operation, showing a lag in COD removal due to metallic stress. The activity of biomass in reactors RCo5, RCo25, and RCo75 was reduced by 39%, 45%, and 49%, respectively, in the stressed phase compared to the biomass in control reactor. Recovery in COD removal efficiency and specific biomass activity were observed in all the reactors after the removal of metallic stress. The settleability of sludge biomass in reactors RCo25 and RCo75 was significantly affected. Transformation in the shape of flocs in reactor RCo25 and RCo75 biomasses revealed the prolonged effect of metallic stress, which was observed to be irreversible even during the recovery phase operation.

     

降流式厌氧悬浮填料床工艺特性分析

厌氧生物技术能在无氧条件下,通过厌氧微生物的新陈代谢将废水中的有机物转化为无机物,同时产生具有能源回收价值的甲烷,并减少温室气体(CO2)的排放,符合节能环保的原则和发展趋势.在回顾厌氧技术以及厌氧反应器发展的基础上,从现代厌氧反应器的发展理念角度分析了新型厌氧反应器-降流式厌氧悬浮填料床(DASB)的工艺特性.降流式厌氧悬浮填料床在生物量的保持、微生物的多级多相和推流流态等方面较好地符合了新型现代厌氧反应器的发展要求,结构、运行简单,具有较好的处理效果,是中国农村污水处理或预处理的较佳选择.     

ASBBR-二级SBBR-化学除磷组合工艺处理榨菜腌制废水

针对榨菜腌制废水高盐高氮磷高有机物浓度的特征,提出"厌氧序批式生物膜反应器(ASBBR)-二级序批式生物膜反应器(SBBR)-化学除磷"组合处理工艺,在前期对组合工艺中单元工艺的关键工况参数研究的基础上,考察组合工艺的处理效能。实验结果表明,采用该组合工艺,可使进水COD、NH4+-N、TN及PO43--P分别为10 000、345、550和38.5mg/L的榨菜腌制废水,处理出水COD、NH4+-N、TN及PO43--P分别达到93.6、12.3、18和0.1 mg/L,去除率分别为99.1%、96.4%、96.7%和99.9%,出水达到污水综合排放一级标准。     

NaCl盐度对耐盐活性污泥沉降性能及脱氮的影响

针对海水冲厕工程的实施,采用序批式活性污泥反应器(SBR)处理实际含盐生活污水,考察了盐度对耐盐活性污泥沉降性能及脱氮效能的影响。研究发现,经过长期盐度驯化后的污泥系统也会出现丝状菌污泥膨胀。在经过10 g/L盐度长期驯化的污泥系统中,污泥容积指数(SVI)随着盐度的升高而降低,盐度升高使丝状菌减少,污泥絮体变小变密实。但是,盐度降低时会引发更严重的污泥膨胀,导致污泥流失。对脱氮性能的研究表明,硝化菌的耐盐能力较强。当盐度由10 g/L改变为0、5、15、20 g/L时,氨氮去除率依然可以维持在99%以上。但亚硝酸盐积累率无论是盐度升高或降低时都升高,这表明驯化后污泥中的亚硝酸氧化菌(NOB)对盐度变化的耐受能力比氨氧化菌(AOB)弱,无论盐度升高或降低都会对其产生较大的影响。     

厌氧序批式反应器中丝状颗粒污泥的形成

以葡萄糖为基质,研究浮动盖式ASBR中颗粒污泥的形成。实验结果表明,污泥在120 d时完全颗粒化,颗粒污泥具有良好的沉降性能(25 m/h)及良好的产甲烷活性,甲酸、乙酸、丙酸及丁酸最大代谢活性分别达到0.216、0.825、0.237和0.796 g COD/(g VSS.d)。电镜扫描(SEM)发现,整个污泥结构均一,均由丝状菌构成。     

营养限制对厌氧序批操作反应器的影响及其恢复重建过程

研究了在厌氧条件下以葡萄糖为基质的序批操作反应器(ASBR)中营养物浓度限制对基质吸收和储存的影响及其恢复重建过程。结果表明,营养物限制条件下,发酵细菌表现为过量吸收基质并储存为糖原,形成隐性增殖以维持其细胞的正常结构和代谢功能;而甲烷菌由于无储存能力,其表现为活性逐渐降低。短期营养限制条件下(1个周期),基质中无磷时,储存量增加29%;基质中无氮时,储存量增加90%;基质中既无氮也无磷时,储存量增加26%。长期(31个周期)营养限制(基质中氮磷含量减小50%)下,胞内储存糖原量可高达正常状态下的4.8倍,但甲烷活性减少为正常状态下的17.78%。营养物限制对发酵细菌影响较小,对甲烷菌影响较大。将氮磷浓度恢复正常后,反应器的产甲烷能力恢复较快,出水COD经31周期后恢复正常,而胞内糖原在85周期后恢复正常。     

Anammox enrichment from different conventional sludges

Three sets of sequencing batch reactor (SBR) were used for Anammox enrichment from conventional sludges including upflow anaerobic sludge blanket, activated sludge, and anaerobic digestion sludge. After four months of operation, the Anammox activity occurred in all reactors allowing continuous removal of ammonium and nitrite. The morphology of the cultivated Anammox sludge was observed using scanning electron microscope. The photographs showed that the obtained culture was mostly spherical in shape, presumably Anammox culture. There were also filamentous-like bacteria co-existing in the system. Fluorescence in situ hybridization (FISH) analysis using 16S rRNA targeting oligonucleotide probes PLA46 and Amx820 showed that the dominant population developed in all SBRs was hybridized with both PLA46 and Amx820 gene probes. It means that the cultivated biomass in all SBRs was classified in the group of Planctomycetales bacteria with respect to the anaerobic ammonium-oxidizing bacteria, Candidatus Brocadia anammoxidans and Candidatus Kuenenia stuttgartiensis. Numerous time sequences were tested in this experiment. The shortest workable reaction time was found in the range from 5 to 7 h. Good quiescence of sludge was obtained at 30 min of settle period followed by a discharge period of 15 min. A long-term performance showed a near perfect removal of nitrite based on the influent NO2(-)-N concentration of 50-70 mg l(-1). The maximum ammonia removal efficiency was 80% with the influent NH4(+)-N concentration of 40-60 mg l(-1). It is, therefore, concluded that Anammox cultivation from conventional sludges was highly possible under control environment within four months.     

2种反应器中好氧颗粒污泥培养的比较研究

以絮状活性污泥为接种污泥,采用人工配制的模拟生活污水,分别在气提式序批反应器(SBAR)和序批式活性污泥反应器(SBR)中成功地培养出了成熟的好氧颗粒污泥.SBAR和SBR中的好氧颗粒污泥都具有稳定的基本形态结构,其微生物主要由杆菌和球菌组成,对COD的去除率可达到93%左右.对NH+4-N的去除率可达到98%以上.SBAR中好氧颗粒污泥的粒径主要分布、污泥体积指数(SVI)、比耗氧速率(SOUR)、TN去除率和TP去除率分别为0.45～2.00 mm、19.97 mL/g、47.68 g/(kg·h)、82%和65%;而SBR中好氧颗粒污泥的粒径主要分布、SVI、SOUR、TN去除率和TP去除率分别为0.18～1.00 mm、29.12 mL/g、43.21 g/(kg·h)、58%和50%.相对而言,SBAR更有利于好氧颗粒污泥的培养和运行.     

Influence of gas flow-induced shear stress on the operation of the Anammox process in a SBR

The start up and performance of the Anammox process were tested in sequencing batch reactors with two different configurations: a bubble column (SBR-B) and a gas-lift reactor (SBR-G). Different off-gas upflow velocities were tested (3.53-12.3 cm min(-1)) in order to expose the biomass to different shear conditions and to study their effects on both efficiency and physical properties of the Anammox granular biomass. For the SBR-B the minimum gas upflow velocity needed to achieve biomass suspension inside the reactor was 12.3 cm min(-1). Such velocity made impossible the stable operation of the process. The fluidization of biomass for the SBR-G was reached at a gas upflow velocity of 3.52 cm min(-1). This system maintained an efficiency of nitrite removal around 98% at values up to 5.29 cm min(-1) but when the gas upflow velocity was increased from 5.29 to 9.70 cm min(-1) a significant decrease of the specific Anammox activity of the biomass from 0.35 to 0.05 g Ng(-1) VSS d(-1) was measured. The system lost 85% of its nitrogen removal efficiency which was not restored in spite of returning the gas upflow velocity to its initial value.     

Production of polyhydroxyalkanoate during treatment of low-phosphorus-content wastewater.

To evaluate whether poly-beta-hydroxyalkanoate (PHA) production and wastewater treatment could be combined in a single biological process, a bench-scale sequencing batch reactor was operated with sequential anaerobic and aerobic stages and removal of excess sludge at different stages of treatment. The reactor treated synthetic wastewater with a high organic and low nutrient content, simulating industrial wastewater. Chemical oxygen demand removal efficiency was more than 90% in all cases. Poly-beta-hydroxyalkanoate accumulation was significant, although it did not appear to be induced by oxygen limitations during the anaerobic stage. Sphaerotilus natans was apparently the dominant PHA-accumulating organism at the end of each reactor run and corresponded to a PHA accumulation of 16 to 20% of the total dry cell mass. Before S. natans dominated the reactors, PHA accumulation was approximately 17% when biomass was removed at the end of the aerobic stage and 6.6% when sludge removal also occurred during the anaerobic stage.     

Influence of nutrients on biomass evolution in an upflow anaerobic sludge blanket reactor degrading sulfate-laden organics.

This paper describes the effect of the nutrients iron (Fe), nickel (Ni), zinc (Zn), cobalt (Co), and molybdenum (Mo) on biomass evolution in an upflow anaerobic sludge blanket (UASB) reactor metabolizing synthetic sulfate-laden organics at varying operating conditions during a period of 540 days. A bench-scale model of a UASB reactor was operated at a temperature of 35 degrees C for a chemical oxygen demand-to-sulfate (COD/SO4(2-)) ratio of 8.59 to 2.0, a sulfate loading rate of 0.54 to 1.88 kg SO4(2-)/m3 x d, and an organic loading rate of 1.9 to 5.75 kg COD/m3 x d. Biomass was characterized in terms of total methanogenic activity, acetate-utilizing methanogenic activity, total sulfidogenic activity, acetate-utilizing sulfidogenic activity, and scanning electron microscopy (SEM). Nickel and cobalt limitation appears to affect the activity of hydrogen-utilizing methane-producing bacteria (HMPB) significantly without having an appreciable effect on the activity of acetate-utilizing methane-producing bacteria (AMPB). Nickel and cobalt supplementation resulted in increased availability and, consequently, restoration of biomass activity and process performance. Iron limitation and sulfidogenic conditions resulted in the growth of low-density, hollow, fragile granules that washed out, causing process instability and performance deterioration. Iron and cobalt supplementation indicated significant stimulation of AMPB with slight inhibition of HMPB. Examination of biomass through SEM indicated a population shift with dominance of sarcina-type organisms and the formation of hollow granules. Granule disintegration was observed toward the end of the study.     

EGSB反应器运行中的床层流态行为及其控制

生物量流失是EGSB反应器在高负荷状态下稳定运行面临的主要问题。利用实验室EGSB反应器在中温条件下处理高浓度葡萄糖废水,研究EGSB反应器在高负荷状态下的床层流态行为及其受影响因素。结果表明,在该反应器结构形式下,当有机负荷达到23-26 kg COD/（m3·d）,水力上升流速在约3.0 m/h,气体上升流速在约1.3 m/h状态下运行时,床层易发生剧烈流化现象,并导致颗粒污泥的解体和流失。降低反应器回流比、减小反应器内水力上升流速,控制床层在悬浮状态时可以有效降低高负荷状态下生物量的流失,并取得了有机负荷46 kg COD/（m3·d）,COD去除率97%以上的处理效果。     

污泥转移SBR工艺处理低浓度生活污水

污泥转移SBR工艺是一种通过内部污泥回流实现污泥在不同SBR隔室间转移,从而增加污泥利用效率,提高系统除污效能的新工艺。以设计规模为240 m3/d、处理低浓度生活污水的工艺系统为对象,研究了新工艺在不同泥转移量(污泥回流比)下的除污性能,并与系统以传统SBR方式运行的情况进行了对比。结果表明,新工艺可以有效提高SBR反应器的容积利用率;采用30%的污泥回流比进行污泥转移,新工艺的处理能力比传统SBR工艺提高近1/2,除磷效率从46%提升至85%。出水各项水质指标均能达到国家排放标准的要求。     

好氧颗粒污泥的培养及处理味精废水

以厌氧颗粒污泥为接种污泥,在模拟废水条件下利用SBR 35 d成功培养出了具有同步硝化反硝化作用的好氧颗粒污泥,反应器对COD和NH4+-N去除率分别高于95%和99%。将该反应器用于处理味精废水,当COD、NH4+-N的容积负荷分别为2.4 kg/(m3.d)、0.24 kg/(m3.d)时,COD、NH4+-N和TN去除率分别高于90%、99%和85%。处理味精废水后的颗粒污泥粒径由之前的0.8～2.5 mm减小至0.6～1.8 mm,颗粒结构较之前更加密实。     

序批式反应器用于牛场污水的处理

对序批式反应器 (SBR)用于牛场污水的处理进行了试验研究 ,主要研究了三个水力停留时间 (HRT)和有机负荷率对污染物去除率、出水水质和污泥特性的影响。试验结果表明 ,对 10 0 0 0mg/LCOD牛场污水 ,使用 1dHRT ,相应有机负荷率为 10gCOD/L·d时 ,混合出水COD、TS、VS、TKN和TN的去除率分别为 45 %、2 1.4%、34 .2 %、5 3.2 %和 2 2 .2 % ,上清液出水的分别为 80 .2 %、6 3.4%、6 6 .2 %、75 %和 38.3% ;两种出水的SCOD和NH3 N去除率相同 ,分别为 5 0 .0 %和 76 .5 %。经SBR处理后 ,污泥的沉降浓缩性能也有了比较明显的改善。     

pH-gradient real-time aeration control for nitritation community selection in a non-porous hollow fiber membrane biofilm reactor (MBfR) with dilute wastewater

Nitritation (ammonium to nitrite) as a pre-treatment of Anammox (anaerobic ammonium oxidation) is a key step for an energy-efficient nitrogen-removal alternative from dilute wastewaters, e.g. anaerobically-treated sewage, with which limited study has achieved sustainable nitritation at ambient temperature and short hydraulic retention times. To this end, pH-gradient real-time aeration control in an oxygen-based membrane biofilm reactor was observed at 20 °C in the sequencing batch mode. An optimum oxygen supply via diffusion for ammonium-oxidizing bacteria (AOB) was established, but nitrite-oxidizing bacteria (NOB) could be inhibited. The system achieved nitrite accumulation efficiencies varying from 88% to 94% with the aeration control. Mass balance and rate performance analyses indicate that this aeration control is able to supply an oxygen rate of 1.5 mol O₂ mol^?1 ammonium fed, the benchmark oxygenation rate based on stoichiometry for nitritation community selection. Microbial analyses confirmed AOB prevalence with NOB inhibition under this aeration control.