异波折流板反应器水力特性试验研究

以Cl~-为示踪剂,采用停留时间分布法(RTD)研究在清水和有污泥稳定运行条件下,HRT对异波折流板反应器和平板折流板反应器水力特性的影响,并进行了对比分析.结果表明,进水为清水、HRT为2～8 h,HRT对平板折流板反应器的水力特性的影响比异波折板反应器更为显著,异波折板反应器的流动模式处于平推流和完全混合的"中间状态".相同HRT条件下异波折板反应器的死区率小于平板折板反应器,异波折板反应器内接种污泥后,死区比清水反应器时有所增加,生物死区成为死区大小的主要贡献者.     

影响循环移动载体生物膜反应器性能的因素分析

对循环移动栽体生物膜反应器进行了研究。通过改变循环移动栽体膜生物反应器的结构尺寸，研究了反应器内氧转移系数的变化。研究结果认为在反应器的升、降流区面积之比为2／3．挡板上方液面高度和底隙高度均为250mm，填料的填充比为50％时，氧转移效率最高。     

ABR处理油页岩干馏污水的试验研究

采用厌氧折流板反应器(ABR)处理油页岩干馏污水,结果表明:污水在ABR反应器中的水力停留时间为48 h、进水CODCr<5 000 mg/L时,具有良好的处理效果,CODCr去除率>43%,最大为65%;在ABR反应器中形成了分级厌氧菌落.     

分段组合式厌氧生物反应器流态特性

厌氧生物反应器高效性与稳定性取决于其流态特性的优良,采用示踪剂脉冲刺激响应技术研究了自主研发的分段组合式厌氧生物反应器的流态,以期揭示其高效机理,便于工程化开发与应用。试验结果表明:常负荷下该反应器的流态趋于平推流;以轴向扩散模型表征,不产气与产气工况下的Peclet数分别为7.94和5.66;以多釜串联模型表征,不产气与产气工况下的串联釜数分别为4.55与3.44。高负荷与超高负荷下该反应器的流态趋于全混流,以轴向扩散模型表征,不产气与产气工况下的Peclet数分别为4.02、2.57和3.93、3.77;以多釜串联模型表征,不产气与产气工况下的串联釜数分别为2.66、2.00与2.62、2.51。反应器总死区的平均值为33.58%,其中水力死区的平均值为13.58%。建立了水力死区V_h(%)与容积水力负荷L(m³·m^-3·d^-1)和容积产气速率G(m³·m^-3·d^-1)之间的关联式。值得注意的是,在分段组合式厌氧反应器中,容积产气速率对水力死区的影响小于容积水力负荷。     

内构件优化推动厌氧生物反应器的发展

厌氧生物反应器的更新换代与内构件的改造优化有着重要联系,其结构的不断优化改善了反应器内部流态。根据示踪实验和数值模拟方法,分析厌氧生物反应器内水动力学行为发现:一般情况下,高效厌氧生物反应器介于平推流反应器(PFR)和完全混合反应器(CSTR)之间。对国内外典型厌氧生物反应器的流态特性汇总分析认为:分散数D/(uL)、佩克莱数Pe和串联级数N值都可有效表现反应器内流态特性。当负荷、上升流速和转盘转速越大时,D/(uL)越大,Pe和N越小,流态越趋向完全混合流;隔室越多,水力停留时间(HRT)越大,D/(uL)越小,Pe和N越大,流态越趋向平推流。因此,基于增设内构件的流态变化研究可为高效厌氧生物反应器开发与应用提供理论基础。     

纤维素乙醇废水处理研究

采用微电解+厌氧折流板反应器(ABR)+上流式厌氧污泥床(UASB)+膜生物反应器(MBR)组合工艺对纤维乙醇滤液进行处理.结果表明,当滤液COD在12 000 mg·L-1左右,该组合工艺中厌氧停留时间(HRT)为48 h时,厌氧COD去除率达到72%,MBR停留时间(HRT)20 h时,COD的去除率在80.8%～87.5%之间,出水COD浓度稳定在301～537mg·L-1,且MBR抗冲击负荷能力较强.     

EGSB反应器的流态模拟研究

用自来水加葡萄糖配成10000mg/L的溶液模拟废水,用强碱性阴离子树脂模拟生物颗粒污泥,用注入空气的方式模拟反应器中产生的沼气的方法,研究了颗粒污泥膨胀床反应器中的流态情况。结果表明:上升流速vup是影响EGSB反应器膨胀性能的主要参数,vup小于10m/h时,模拟的颗粒污泥不会流失;vup为3,4和6m/h时,通过示踪剂浓度计算出的试验平均停留时间分别为54.2,46.2,28.3min,均小于各自的理论平均停留时间,说明反应器中存在死区。在理论停留时间为30,45,60min时,反应器中的死区百分比分别为5.6%,5.3%,9.7%,离散数分别为0.134,0.105,0.092。     

泥水自循环反应器的水力流态特性及生活污水处理效能

以Na Cl为示踪剂进行示踪脉冲响应试验,研究了同一水力停留时间(HRT)下泥水自循环反应器(AMTR)与AAO反应器水力特性的区别,以及泥水自循环反应器在不同HRT下的停留时间分布曲线和水力特性参数。试验结果表明:当HRT=9. 7 h时,AMTR比起AAO具有较强的水力混合程度以及较低的死区容积率;当HRT在9. 7～13. 75 h变化时,AMTR死区容积率Vd/V为0. 169～0. 124;随着HRT的增大,串联级数N由2. 87减小到2. 27,轴向扩散数D/UL由0. 223增大到0. 317,AMTR推流效果减小,混合程度增大,流态处在完全混合与平推流之间,具有较强的抗冲击负荷能力。此外,通过污泥接种培养,当AMTR稳定运行时,其处理城市生活污水效能较高,COD、TN、TP的去除率分别为85%、70%和85%。     

折流式厌氧反应器启动的关键因素探讨

厌氧折流板反应器(ABR)是一种具有分阶段多相厌氧反应器工艺思想(SMPA)的新型高效厌氧反应器,ABR反应器前面隔室中以产酸菌为优势菌群,后面隔室中以产甲烷为优势菌群,使消化反应的产酸相和产甲烷相沿程得到分离,参与厌氧消化过程的微生物能够生长于各自最佳的生长环境中,使厌氧消化过程的效率大大提高。厌氧折流板反应器的启动跟多因素有关,研究证明低有机负荷,长停留时间是反应器启动的关键,直接接种厌氧颗粒污泥有助于反应器的快速启动。在合适的条件下,反应器内可形成良好的按沿程分布优势菌属的颗粒污泥。     

生物膜法处理2,3-二甲基苯胺废水试验研究

采用缺氧折流板生物膜和循环移动载体生物膜反应器处理2，3－二甲基苯胺废水，结果表明，缺氧折流板反应器具有厌氧滤池和厌氧折流板反应器的优点，当水力停留时间为10．5h(缺氧5．5h，好氧5h)时，系统去除率可达89．7％。     

新型外循环厌氧反应器污泥沉降的数值模拟

结合EGSB及其它厌氧高效反应器的结构特征而开发的新型外循环厌氧反应器,在高上升流速下能有效控制污泥的流失,处理城市污水时获得了良好的效果。为了对新型外循环反应器的污泥沉降性能进行准确模拟和有效控制,利用质量平衡方程与颗粒污泥自由沉降理论,考虑沉降速率与浓度的关系,确定污泥沉降速率,从而建立了该反应器污泥沉降的弥散模型。对不同上升流速下的污泥浓度分布情况进行了模拟,其模拟结果与实测值吻合良好。然后纳入三相分离器分离效率（SE）的概念,实现了对出水SS的模拟,模拟数据的标准偏差小于6%。在确定污泥相对浓度的前提下,利用二次插值预测污泥层高度,结果表明不同上升流速的污泥层高度基本一致,但是同一高度不同上升流速的污泥浓度各不相同。     

Modelling the effects of imperfect mixing on the performance of anaerobic reactors for sewage sludge treatment

An approach to the modelling of suspended-growth anaerobic digestion systems based on the assumption of an incompletely mixed reactor is presented. The mathematical model developed describes the dynamic behaviour of anaerobic sludge digesters under non-ideal mixing conditions. The microbial kinetic model for the anaerobic digestion of waste-activated sludge distinguishes the processes of death and lysis of activated sludge cells, hydrolysis of particulate material, fermentation of soluble substrates, volatile fatty acids utilisation and methane formation. The interaction of two microbial groups is considered, i.e. acid-formers and methanogens. Their growth is assumed to depend on Monod kinetics for the substrates. Death and lysis, hydrolysis and biomass decay are described by first order reactions. The biokinetic expressions were linked to a simple mixing model which considered the reactor volume split into two sections: the flow-through and the retention regions. The transfer of material between regions was assumed to be limited. Deviations from an ideal completely mixed regime were represented by changing the relative volume of the flow-through region (α) and the turnover time of material in the vessel (τ). The dynamic model described the effects of the retention time and reactants' distribution, resulting from the mixing condition, on process performance. Computer simulations under different conditions showed a considerable decline in methane production and treatment efficiency due to incomplete mixing. The COD removal efficiency increased by extending the retention time and the degree of mixing. The evaluation of the impact of the mixing parameters showed that α has a far more significant effect on the performance of anaerobic digestion than τ does. Nevertheless, both are important and the overall efficiency is a complex function of both parameters. The results obtained confirm and emphasise the importance of considering mixing when simulating anaerobic digestion, calculating process conversion efficiency, and during anaerobic reactor design. © 1998 SCI.     

印染废水驯化的厌氧颗粒污泥微生物的动态变化

针对厌氧系统中功能菌群的多样性及其在代谢过程中的协同作用机制,以升流式厌氧污泥床(UASB)反应器内颗粒污泥微生物为研究对象,通过增量为20％阶段式提高实际印染废水进水比例的方法对其进行驯化,监测各阶段颗粒污泥微生物生态结构的变化.结果表明,随着进液印染废水比例的增加,毒性增强,COD去除率由92％降至约70％,比产甲...     

Hydrodynamics of upflow anaerobic sludge blanket reactors

The hydrodynamic characteristics of upflow anaerobic sludge blanket (UASB) reactors were investigated in this study. A UASB reactor was visualized as being set‐up of a number of continuously stirred tank reactors (CSTRs) in series. An increasing‐sized CSTRs (ISC) model was developed to describe the hydrodynamics of such a bioreactor. The gradually increasing tank size in the ISC model implies that the dispersion coefficient decreased along the axial of the UASB reactor and that its hydrodynamic behavior was basically dispersion‐controlled. Experimental results from both laboratory‐scale H₂‐producing and full‐scale CH₄‐producing UASB reactors were used to validate this model. Simulation results demonstrate that the ISC model was better than the other models in describing the hydrodynamics of the UASB reactors. Moreover, a three‐dimensional computational fluid dynamics (CFD) simulation was performed with an Eulerian‐Eulerian three‐phase‐fluid approach to visualize the phase holdup and to explore the flow patterns in UASB reactors. The results from the CFD simulation were comparable with those of the ISC model predictions in terms of the flow patterns and dead zone fractions. The simulation results about the flow field further confirm the discontinuity in the mixing behaviors throughout a UASB reactor. © 2008 American Institute of Chemical Engineers AIChE J, 2009     

A study of A2/O process in El-Berka WWTP by replacing the anaerobic selector with UASB and adopting a hybrid system in the oxic zone

ABSTRACT

A multistage system comprising an upflow anaerobic sludge blanket (UASB) followed by anoxic unit and then oxic activated sludge (AS) with biofilm is studied in El-Berka WWTP, Egypt. Different organic loading wastewaters of chemical oxygen demand (COD) less than 500 mg/L till 3000 mg/L are tested during the study. The hydraulic retention time (HRT) varies for each loading from 7.5 to 10 to 15 h. The UASB reactor accomplishes the removal efficiency of 50%–70% of influent COD. The overall system performs the removal efficiency of 95% of influent COD and NH₄-N. Also, the results are verified by a modified mathematical model.     

UASB反应器处理高浓度蛋白质废水启动特性的研究

采用上流式厌氧污泥床(UASB)反应器,以高浓度蛋白质废水为处理对象,研究了中温条件下UASB反应器的启动、颗粒污泥特性和废水处理效果。结果表明：采用接种颗粒污泥与消化污泥的混合泥进行培养,并逐步提高进水浓度,运行88 d后,可实现UASB反应器的启动。当进水COD值达到7000 mg/L左右,容积负荷2.00 kg ...     

A novel combination of methane fermentation and MBR — Kubota Submerged Anaerobic Membrane Bioreactor process

Methane fermentation is considered one of the best placed biological processes to reduce volume of organic waste while keeping small sludge production and recovering energy. One of the disadvantages of early anaerobic digestion technologies was the long hydraulic retention time thus large capacity tanks were required to hold slow growing methanogenic bacteria. New technological attempts such as upflow anaerobic sludge blanket (UASB), fixed or fluidised bed and membrane bioreactor (MBR) appeared as countermeasures.Kubota’s submerged anaerobic membrane biological reactor (KSAMBR) process has been developed in the last decade and successfully applied in a number of full-scale food and beverage industries. It consists of a solubilization tank and a thermophilic digestion tank, the latter incorporating submerged membranes. The biogas generated can be utilized for water heating via boilers. Both permeate and waste anaerobic sludge are further treated in wastewater treatment facilities.One of the main advantages of KSAMBR is that membranes retain the methanogenic bacteria while dissolved methane fermentation inhibitors such as ammonia are filtered out with the permeate. This makes the KSAMBR process very stable. Furthermore, the digester volumes can be scaled down to 1/3 to 1/5 of the conventional digesters provided that biomass is 3 to 5 times as concentrated.Applications include stillage treatment plants for Shouchu (Japanese spirits made from sweet potato, rice or other grains), potato processing sites, sludge liquor and food factory treatment plants.In summary, it is believed that KSAMBR offers the best possible solution combining the benefits of methane fermentation process with the performance of membrane technology. More details will be presented in the proceedings paper and in the presentation.     

Dry anaerobic batch digestion of the organic fraction of municipal solid waste

Anaerobic digestion at high solid concentrations (dry anaerobic digestion) is an attractive method for the stabilization of solid organic wastes. A new concept for dry anaerobic batch digestion (BIOCEL) of the organic fraction of municipal solid waste is presented. The start up of a BIOCEL reactor was studied with several methods of process set up and operation. Dry anaerobic digestion of the pure undiluted organic fraction obtained from a shredding/separation process was not accelerated by partial spatial separation of substrate and methanogenic inoculum (granular sludge) or leachate recycle, or both. With these three methods after 30 days the high organic acids concentration and low pH in the reactor indicated a sour reactor, unable to establish significant methane production. When the organic fraction was digested in combination with compost addition (40% (w/w) of the initial solids) and leachate recycle, the stabilization rate increased significantly. Leachate recycling in combination with partial spatial separation of the substrate/compost mixture and the inoculum showed the shortest lag phase in the methane production and the shortest digestion time. When the digested residue of a completed digestion was applied as the methanogenic inoculum (40% (w/w) of the initial total solids) the digestion time was slightly shorter. It is concluded that dilution with compost had a positive effect on the start up of the dry anaerobic digestion and compensated for a suboptimal amount of initial methanogenic biomass. During the start up of dry anaerobic batch digestion of municipal solid waste the rapid recovery of methane formation from an initial overloading was observed and was found to be the result of a population shift in the methanogenic biomass and the existence of zones in the reactor with more optimal conditions (higher p H, lower organic acids concentration). The observed digestion time was 36 days. Recommendations are given to shorten the period needed, for complete digestion.     

厌氧生物法处理皂素废水的试验研究

采用UASB厌氧反应器处理高浓度皂素废水,试验结果表明,当温度控制在35～40℃、pH在6.8～7.5之间、COD容积负荷保持在6.0kg/(m3.d)时,COD去除率可达到90%以上。