1、附件1：外文资料翻译译文城市污水常温处理中的新型改良EGSB（膨胀颗粒污泥床）反应器的发展近年来，厌氧处理技术已经成为一项有吸引力的可持续发展的污水处理技术，因为它耗能少而且产气量少。特别的，流式厌氧污泥床(UASB)和常规膨胀颗粒污泥床(EGSB)在城市污水处理中得到了广泛应运。通常，EGSB比UASB更能有效去除化学需氧量（COD），更能有效抵抗有机负荷率(OLR)、温度和pH的变化。然而，由于较高的上升流速和较多的甲烷气泡，使膨胀颗粒污泥床（EGSB）中的三相分离器中的水的流速很高，这就导致了大量生物质的流失,最终废水中的COD浓度就升高了。所以，有时候不能满足城市污水处理厂或生物处理系
2、统排放的标准，并导致生物处理系统崩溃。因此,对与EGSB系统来说，城市污水处理中的关键问题是如何控制在高上升流速下的生物量流失。在本文中,提出一种改进型的EGSB反应器模型，它结合了EGSB 和UASB两者的优势。在相同环境下通过比较，试验性地研究EGSBm和EGSBc两种反应器。在东区污水处理厂中有一个初级出水沉降池。在对膨胀颗粒污泥床（EGSBm）中水动力特征分析时，进行了停留时间分布(RTD)的实验和Polvmerase连锁反应实验，并且应用变性梯度凝胶电泳(PCR-DGGE)技术来探索颗粒污泥中微生物的多样性。1.材料和方法1.1影响生物量和养料的来源常温厌氧颗粒污泥取自中国无锡市的一
3、家污水处理厂，该厂主要利用全比例内循环生物反应器处理酸性废水。黑色的颗粒污泥有规则的形状（=0.8 - 2毫米）和良好的沉降性能。污泥中含有悬浮固体（TSS）73.6克/升和挥发性悬浮固体（VSS）59克/升。在EGSBm和EGSBc两种反应器中，最初的接种污泥量占有效总量的65%。污水样本取自上海东区城市污水处理厂的一个初级沉淀池中。其中包括60%生活污水和40%的工业废水。污水的主要指标如表1。表1 污水的主要指标1.2反应器的描述工业生产中EGSBm和EGSBc反应器的原理图如图1。两个反应器都是有机玻璃制成的,容量为300 升,采用连续流动模式。在EGSBc中,配水系统在反应器的底部，
4、进水和污水一起进入循环。在EGSBm中,其混合液体通过循环泵和进水一起进入循环。EGSBm配水系统包括一个5升的水箱和4根聚氯乙烯管（ PVC ）。水箱置于反应器的顶部,管子延伸到反应器的底部。在东区污水处理厂这两种类型反应器都有，它们表现可以相媲美。图1 EGSBc和EGSBm反应器的原理图在EGSBm反应器中，含颗粒污泥的混合液大约在反应器的中部通过循环泵进入循环，同位于反应器顶部的进水很好的混合。由于混合液受重力的影响，沿分布管道进而进入底部的反应堆。在底部的反应区域内,复合液进一步混合了局部液体，水中有机物在高浓度的颗粒污泥中被有效地分解。废水向上循环，达到中间的流动循环管,很大一部分
5、是被吸进管孔并通过水泵循环至反应器顶部的水箱中，同时一小部分继续向上流动达到进一步分解。然后，向上流动的部分会进入三相分离器，在这里气体、水、颗粒状污泥会被分开。在分离后,颗粒污泥经过处理还能循环利用到上层反应室中去。1.3实验条件在这两个试验性反应器成功开动起来，反应达到了稳定的状态后,它们还得在常温下连续运行165 天。基于稳态条件下，总的反应过程分为十个阶段。每个阶段具体实验数据在表2中有详细说明。表2 各反应阶段的实验数据R：循环比例1.4反应器的性能评价在每个反应阶段，通过去除COD，CODfilt和SS的效率来评价EGSBc和EGSBm两者的总体性能。CODfilt表示经过定性滤纸
6、后污水中的COD浓度。COD和CODfilt的浓度可以经重铬酸钾溶液检测出来，而SS的浓度是通过过滤，干燥，然后称水样本检测出来。1.5颗粒状污泥的分析在第4和第10个运行阶段结束后，从EGSBm反应器的四个不同反应区取颗粒污泥样本，并在图1中标明A、B、C、D。A、B、C、D四个反应区距离反应区底部分别为2.0,1.5,1.0,0.5米。从颗粒污泥中提取DNA后，16S核糖体RNA基因的特定区域经过聚合酶链反应（PCR）被放大，进而用来克隆和排序。然后，使用变形梯度凝胶电泳（EGGB）分离聚合酶链反应（PCR）的产物。已经分化的菌株再经过培养，使菌株数量达到所需的测量水平。在预选的反应时间中
7、，使用激光粒度仪（LS230，美国贝克曼库尔特）测得四个不同区域的颗粒污泥的直径分布在0.04-2000微米的范围内。1.6水动力特性有一种利用锂离子（Li+）的脉冲追踪仪，可以通过锂离子反应器中不同区域内停留的时间来分析水动力特性。在每一次试验中，通过脉冲注射器向进水中注入10mL浓度为10mg/L锂离子溶液，运用电感耦合等离子ICP/脂肪醇聚氧乙烯醚硫酸盐AES外加铂金埃尔默奥普玛2100等离子发射光谱仪对污水中锂离子的浓度进行周期性检测。2 结果和讨论2.1反应器的性能1）上升流速（Vup）的影响。对于EGSBc和EGSBm两种反应器，上升流速对污水中COD和CODfilt浓度的影响在图
8、2中有说明。结果表明在EGSBm和EGSBc两种污水中，当上升流速从5.0米/时(阶段3)到10.3米/时（阶段5），CODfilt浓度分别从94.1和97.1毫克/升（阶段1）下降为59.4和71.4毫克/升（阶段5）.两种反应器污水中COD浓度和CODfilt浓度变化趋势大致相同。在较高的上升流速下，通过比较两者污水中COD的浓度，显而易见，EGSBm比EGSBc具有更好的性能和恢复效果。当上升流速从2米/小时（阶段1）到10.3米/小时变化时，两种反应器中SS的浓度分别从18.5和22.2毫克/升上升为60.1和126.5毫克/升。从中我们看出在相同流速下，EGSBm比EGSBc更容易造
9、成生物量的流失。因此，EGSBm具有较好的恢复能力是因为其高污泥浓度的保持能力。图2 上升流速对EGSBc和EGSBm两种反应器中污水中COD和CODfilt浓度的影响2)水力停留时间的影响。水力停留时间对EGSBm和EGSBc两种反应器中污水中COD和CODfilt浓度的影响可以在图3中看出来。结果显示，在EGSBm反应器中，当水力停留时间从6降为2小时时，COD和CODfilt浓度分别从119.7毫克/升和94.1毫克/升（阶段1）下降为104和82.6毫克/升（阶段7）。当水力停留时间降为1小时后，EGSBm和EGSBc两者中COD和CODfilt浓度都有上升趋势。但是，EGSBm有更好
10、的基质清除效果，主要是因为它具有改进了的水循环结构。在EGSBm和EGSBc两种反应器中，挥发性脂肪酸的平均浓度分别从28和31克/升（阶段6，水力停留时间4小时）上升为42和65克/升（阶段7，水力停留时间2小时）。这就意味着在低水力停留时间内，EGSBm比EGSBc更能有效利用挥发性脂肪酸来产生甲烷气体。图3水力停留时间对EGSBm和EGSBc两种反应器中污水中COD和CODfilt浓度的影响3）有机负载率的影响。在两种反应器中，有机负载率对COD和CODfilt浓度的影响如图4。当有机负载率由7.2（阶段8）突然降为1.2千克COD/（立方米*天）（阶段9），EGSBm反应器能维持它的处
11、理效率不变，而EGSBc则发生不同程度的变化。当有机负荷率从1.2（阶段9）又调整到7.2千克COD/（立方米*天）时，在阶段10的初期两种反应器中COD和CODfilt浓度都有明显提高。随后，EGSBm恢复到最初有机去除效率需用10天时间，而EGSBc反应器在20天后任然没能达到最初的有机物去除率水平。显而易见，EGSBm更能有效抵抗有机载荷的变化。图4有机负载率对EGSBm和EGSBc两种反应器中污水中COD和CODfilt浓度的影响总的来讲，当实验条件发生变化时，EGSBm反应器中COD，CODfilt和SS浓度比EGSBc中的浓度要低得多。即使SS浓度会随上升流速的升高而升高，但EGS
12、Bm比EGSBc的生物量流失少。而且在上升流速高达10.3米/小时时，EGSBm反应器中污水COD含量几乎不变。2.2颗粒污泥的分析这幅变形梯度凝胶电泳剖面图显示的是从EGSBm反应器中提取的75天和165天颗粒污泥样本中9-12DNA片段。相比之下，我们可以从处理酸性污水的最初的接种污泥中提取第15号DNA片段。这些DNA片段分布在16S核糖核酸RNA的V3区段内，每个基因片段代表一种微生物种类。图5颗粒污泥样本的变形梯度凝胶电泳（DGGE）剖面图比较了不同污泥样品的变形梯度凝胶电泳（DGGE）剖面图，结果表明,带1、2、3、4、9、10的接种污泥也存在于第75 天和第165 天 EGSBm
13、污泥样品中,而其他的9个频段内的接种污泥很少见。相反,在EGSBm颗粒污泥的样品中出现了一些新的频段。频段的强度随不同的运行阶段和反应区域而变化。然而,微生物物种的数量在整个反应阶段和反应区域内并没发生明显变化。由于环境的变化,譬如循环比率,水力停留时间（HRT），有机负载率（OLR）和进水质量，微生物会选择性地形成稳定的微生物群落，通过竞争来有效地降解有机污染物。在EGSBm反应器运行1,45,76和110天，分别检测A、B、C、D四个区域内颗粒污泥直径的变化。记录数据如图6。在第1天，接种污泥的直径均匀地分布在0.8-2毫米的范围内。在第45和76天，大部分颗粒污泥的直径分布在0.6-2毫
14、米范围内，而A和B区域也有一少部分颗粒污泥的直径分布在0.01-0.4毫米范围内。在第110天，颗粒污泥的直径逐渐地变大。从中我们看到颗粒污泥在EGSBm中最初是分散的,随着反应条件的变化逐步聚集为厌氧微生物菌落。图6不同反应阶段颗粒污泥直径的变化2.3 水动力特性当进水向上流动通过颗粒污泥床时，它将和该区域内污水混合（或分散到污水中）。因此，对于理想的塞式流动应分散考虑，如下面所表达的停留时间分布（RTD）模型：在公式中，D/UL表示无量纲的离散量，D表示扩散系数（平方米/小时），U表示上升流速Vup（米/小时），L代表反应器的长度（米）。对于理想的塞式流动反应器，D/UL的值是0。相反，对
15、于理想的连续搅拌釜式反应器（CSTR），D/UL的值趋近无穷大。通过脉冲示踪剂（例如，Li+）的方法，示踪剂浓度会随着试验时间在不同的水力停留时间发生变化，如图7。依据图7的结果，经过计算和总结得出了表3中的数据，记录了在三种不同的上升流速下无关量Vd和D/UL的值。图7 EGSBm和EGSBc两种反应器的水力停留时间（RTD）表3 EGSBm和EGSBc两种系统中Vd和D/UL的值对于EGSBc系统，在上升流速为5米/小时时，D/UL最大可取0.18对应的Vd的最小值取10.13。当上升流速降为2米/小时时，D/UL的值会随之降低，意味着局部流动增强了。这与先前得出的结论一致，在EGSBc系
16、统中，当上升流速超过5米/小时时，SS的浓度会随上升流速的升高而升高（如图2所示）。对于EGSBm系统，D/UL的值会随Vup的增大而增大（Vd下降）。在上升流速Vup为10.3米/小时，Vd取值为0.87%表明EGSBm系统能保持较好的水动力条件。这和前面在EGSBm污水中COD和CODfilt浓度数据结论一致（见图2）。当上升流速Vup上升时，EGSBm的综合水动力特性有所提高，同时污泥流失得到控制，所以它对有机污染物的去除效果更明显。这再次证明了改进型的EGSBm提高了污水处理效率。3总结这项研究表明，在常温条件下，EGSBm反应器通过混合液循环能更有效，更稳定地处理城市污水，相反，EG
17、SBc则采用污水回收的形式。EGSBm比EGSBc更能有效地处理污水中的COD、CODfilt和SS。在较高的上升流速情况下，EGSBc比EGSBm颗粒污泥流失情况严重。在EGSBm系统中，纵贯整个反应过程，不管污水水质的变化和流体力学特性，厌氧生物都保持一个稳定的生物群落，这样就能保证有效降解有机污染物。在EGSBm反应开始后，一小部分颗粒污泥通过分解，新的颗粒污泥厌氧微生物逐步聚集起来进而适应反应条件。运用流体停留时间模型对水力特性分析显示，在EGSBm系统中，D/UL的值会随上升流速Vup的增加而增加。Vd低至0.87%上升流速Vup是10.3米/小时对应的D/UL值为0.15。然而，在
18、EGSBc系统中，当上升流速Vup是5米/小时时，D/UL的最大值是0.18。在EGSBc系统中，无论Vup是增大还是减小，都会导致D/UL值的减小，主要是因为混合不充分进而增强了局部流动。在EGSBm系统中，良好的水动力条件确保了在较高流速情况下污水处理的效率。附件2：外文原文（摘自哈尔滨工业大学学报2009，4（16）development of a novel modified EGSB reactor for municipal sewage treatment at ambient temperatures In recent years，anaerobic treatment ha
19、s become an attractive sustainable wastewater treatment technology due to its low energy consumption and biogas production.In particular,the application of the upflow anaerobic sludge blanket(UASB)and the conventional expand granular sludge bed(EGSBc )in domestic wastewater treatment has gained much
20、 more attention.The EGSBc is generally more efficient in COD reduction,and more resistant to shock organic loading rates(OLR)as well as the changes of temperature and pH than the UASB.However,the very high water velocity in the three-phase separator of EGSBc ,which is caused by the high Vup and meth
21、ane bubble production,ofen leads to a significant washout of biomass and thus a high COD concentration in the effluent.As a result,the efiuent quality sometimes can not meet the discharge standards for municipal wastewater treatment plants or the biological treatment system eventually collapses .The
22、refore,the key problem for EGSBc in municipal sewage treatment is to control the loss of biomass under a high up-flow velocity In this paper,a modified EGSB reactor was developed by combining the advantages of the UASB and EGSBc reactors.Pilot-scale study was carried out for both EGSBm and EGSBc rea
23、ctors under ambient conditions for the purpose of comparison.The effluent of a primary sedimentation tank in the Dongqu municipal sewage treatment plant was used as influent.The hydrodynamic characteristics in EGSBm were analyzed by Retention Time Distribution(RTD)experiments and the Polvmerase Chai
24、n Reaction.Denaturing Gradient Gel Electrophoresis ( PCR-DGGE) technique was used to explore the microbial diversity in the granular sludge 1 Materials and Methods 1.1 Sources of Biomass and Feed Influent Mesophilic anaerobic granular sludge was obtained from a ful1-scale internal circulation biorea
25、ctor treating citric acid production wastewater located in Wuxi City,China.The black granular sludge had a regular form(=0.8-2 mm)and good settleability.The sludge contained 736 gL total suspended solids(TSS)and 590 gL volatile suspended solids(VSS)The initial inoculated sludge volume occupied 65 of
26、 the effective volume of the EGSBm and EGSBc reactors.The efluent from a primary sedimentation tank of Dongqu municipal sewage treatment plant located Shanghai was used as influent.The raw sewage consisted of 60of domestic wastewater and 40 of industrial wastewater.The major characteristics of the i
27、nfluent were summarized in Tab.1 .1.2 Reactor Description The schematic diagram of the pilot-scale EGSBc and EGSBm reactors was shown in Fig.1.Both reactors were made of plexiglass with a total volume of 300 L and adopted a continuous flow mode.In the EGSBc ,the distribution system was placed at the
28、 bottom of the reactor，and its effluent was recirculated to mix with the influent.In the EGSBm ,its mixed liquid was recirculated to mix with the influent using a pump.The distribution system of EGSBm consisted of a tank of 5 L and 4 PVC tubesThe tank was placed above the top of the reactor,and the
29、tubes extended from the tank to the bottom of the reactor.The two reactors were run in parallel at Dongqu municipal sewage treatment plant and their performances were comparatively evaluated. In the EGSBm ,the mixed liquid containing granular sludge was recirculated approximately at the middle of th
30、e reactor to the top tank where it was mixed well with the influent.The composite influent then flowed downward gravitationally along the distribution tubes to come into the bottom of the reactor.In the lower reaction chamber,the composite influent was further mixed with local liquid and got degrade
31、d efficiently since a high concentration of granular sludge was available.As the wastewater flowed upward and reached the middle recirculation pipe,a large portion was sucked into the pipe orifices and recirculated to the top tank again by the pump,while a small portion continued to flow upward to a
32、chieve further degradation.The upflowing portion then entered the three-phase separator where its gas,water and granular sludge were well separated.After separation，the granular sludge was settled and recycled to the upper reaction chamber. 1.3 Experimental Conditions After the two pilot-scale react
33、ors had been successfully started up and reached a steady state condition,they were continuously run for a total period of 165 d at ambient temperatures.Based on the steady state conditions,the total operation period was divided into ten operation phasesThe specific experimental conditions of each o
34、peration phase are detailed in Tab.2. 1.4 Reactor Performance Evaluation In each operation phase,the overall performance of EGSBc and EGSBm was evaluated by the removal efficiencies of COD,CODfilt and SS.The CODfiltrepresented the COD concentration of the effluent after passing through a qualitative
35、 filter paper.The concentrations of COD and CODfilt were measured by the standard potassium dichromate method,and the concentration of SS was measured by filtering,drying and weighing water samples.1.5 Granular Sludge Analysis At the end of the operation phases 4 and 10, granular sludge samples were
36、 taken from four different regions in the EGSBm which were denoted as A,B,C and D in Fig.1.The distances of A,B,C and D from the reactor bottom were 2.0,1.5,1.0 and 0.5 m,respectively.After DNA was extracted from the granular sludge samples,the 16SrRNA genes were amplified for cloning and sequencing
37、 by polymerase chain reactions (PCR)on specific regions.The PCR product was then differentiated by the use of DGGE. The differentiated strains were amplified again to make the strain quantity reach the needed measurement level.At pre-selected reaction times,the diameters of the granular sludge colle
38、cted from the above four regions were analyzed by a laser granularity instrument (Model LS230,Beckman Coulter of America)with a detection range of 0.04-2000 m. 1.6 Hydrodynamic Characteristics A pulse tracer,Li+ was used to analyze the retention time distribution in the reactor.In each analysis,10 m
39、L of 10 mg/L Li+ was introduced into the influent through pulse injection and its concentration in the effluent was determined periodically by ICP/AES coupled with a PerkinElmer Optima 2100 DV plasma emission spectrometer. 2 Results and Discussions 2.1 Reactor Performance 1)Effect of VupThe effect o
40、f Vup on the COD and CODfilt concentrations of the EGSBc and EGSBm effluents is shown in Fig.2.Results indicate that the mean concentrations of CODfilt of the EGSBm and EGSBc effluents decreased from 94.1 and 97.1 mg/L(P1)to 59.4 and 71.4 mg/L(P5),respectively,when the Vup increased from 5.0 m/h(P3)
41、to 10.3 m/h(P5). Effluent COD concentration of the two reactors had the same trend as CODfilt concentration.The EGSBm exhibited a much better performance and restorability at a high Vup than the EGSBc ,as reflected by the COD dataThe SS concentrations of the EGSBm and EGSBc .effluents increased sign
42、ificantly from 18.5 and 22.2 mg/L to 60.1 and 126.5 mg/L,respectively,as the Vup increased from 2 m/h(P1)to 10.3 m/h(P5).It is seen that much less biomass was washed out of EGSBm than EGSBc under identical conditions.Therefore, the better restorability of the EGSBm ，could be ascribed to its high slu
43、dge concentration maintained. 2)Effect of HRT.The effect of HRT on the COD and CODfilt concentrations of EGSBcand EGSBm effluents is shown in Fig.3.Results indicate that the mean concentrations of COD and CODfilt of the EGSBm effluent decreased from 119.7 and 94.1 mg/L(P1)to 104 and 82.6 mg/L(P7),re
44、spectively,when the HRT significantly decreased from 6to 2h.Similarly,the meanconcentrations of COD and CODfilt of the EGSBc effluent decreased from l22.7 and 97.1 mg/L(P1) to 113.3 and 91.5 mg/L(P7),respectively.As the HRT further decreased to 1 h,the COD and CODfilt concentrations of both EGSBm an
45、d EGSBc effluents increased rapidly.However,the EGSBm always achieved higher substrate removal efficiencies than the EGSBc due to its modified recirculation mode. The mean concentrations of VFA of both EGSBm and EGSBc effluents increased rapidly from 28 and 31 g/L(P6，HRT 4 h)to 42 and 65 g/L(P7，HRT
46、2 h),respectively.This implies that the VFA was used more rapidly for methane generation in EGSBmthan EGSBc at low HRT values. 3）Effect of OLR.The effect of OLR on the COD and CODfilt concentrations of the EGSBm and EGSBc effluents is shown in Fig.4.When the OLR suddenly decreased from 7.2(P8)to 1.2
47、 kgCOD/(m3d)(P9), the EGSBm almost maintained its treatment efficiency, while the treatment efficiency of the EGSBc was improved to some extent.When the OLR was adjusted from 1.2(P9) back to 7.2 kgCOD/(m3d)(P10),a rapid increase of the COD and CODfilt concentrations of both EGSBm and EGSBc effluents
48、 was observed during the initial period of P10.Thereafter,the EGSBm approximately restored its organic removal efficiency within 10 d,but the EGSBc failed to regain its removal efficiency even after 20 d.This clearly indicates that the EGSBm is more resistant to shock organic loadings.In general,the
49、 COD,CODfilt and SS concentrations of the EGSBm effluent was notably lower than those of the ECSBc effluent when the experimental condition(e.g.,Vup , HRT,and OLR)was changed.Although the SS concentrations of both EGSBm and EGSBc effluents increased with the increasing Vup,the EGSBm always washed out much less biomass than the EGSBc .The COD concentratio
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