稳定性的膨胀的颗粒状污泥床对涤纶人造丝印染废水的处理毕业设计外文翻译

《稳定性的膨胀的颗粒状污泥床对涤纶人造丝印染废水的处理毕业设计外文翻译》由会员分享，可在线阅读，更多相关《稳定性的膨胀的颗粒状污泥床对涤纶人造丝印染废水的处理毕业设计外文翻译（25页珍藏版）》请在装配图网上搜索。

1、目 录介绍：11实验性21.1污水和活性污泥21.2实验性设定和过程31.3测试和监视抽样采取从混杂的醇中过滤42.结果52.1泥浆化颗粒化52.2 EGSB操作流出物的稳定酸碱度63 .TPD污水的理论演算和讨论73.1酸平衡和中间转换能力酸碱度73.2 VFA在厌氧过程用二种主要方式的二个主要小组细菌介入降低有机基体.83.3 VFA和强碱性平衡强碱性的典型的变异.84.结论9命名原则10参考文献10Introduction121 Experimental142 Results163 Theoretical calculation and discussions194 Conclusion

2、s22recomference:23- 24 -稳定性的膨胀的颗粒状污泥床对涤纶人造丝印染废水的处理摘要涤纶人造丝印染污水(TPD污水)，包含平均7.0mg/L对苯二甲酸（技术援助）作为主要碳来源和特性污染物，从属于膨胀的颗粒状污泥床(EGSB)过程。EGSB过程的稳定由实验室实验首先研究了。TA电离是影响系统的酸基度平衡的优势的因素。废水的 TA 的高集中造成充份的缓冲能力使中立脂肪酸 (VFA) 从培养基降格产生而且提供了没有空气而能生活强的系统挥发性基础抵抗 pH 减少 到低于6.5 。挥发性脂肪和不饱和脂肪酸除每小时次于6.35和挥发性脂肪积极从事它的极大值以外几乎没有抑制上去沼气生产

3、。与颗粒化被激活的污泥一起,有机撤除效率和沼气的生产率逐渐增加了和变得更加稳定。在启动后,COD撤除效率增加到57%-64%,酸碱度被稳定在范围的7.996.04,和沼气的生产率是相对高。酸碱度污泥颗粒化的,适当的流入物和装载使EGSB过程稳定。EGSB反应器是稳定的为TPD废水处理。关键词:膨胀的颗粒状泥床;稳定;绝氧处理;印染污水介绍：为了获得柔韧的和优雅的如丝一样涤纶结构、涤纶本色布总是同碱分解过程被预先处理, NaOH以某一温度和压力涤纶纤维被水解在某种程度上。在这个过程期间,表面涤纶纤维从本色布料上被溶化,涤纶酸(TA)和1,2-亚乙基二醇被释放作为污水中主要污染物。获得的充满丝质皱

4、痕和软质感涤纶织品叫做人造丝织品。涤纶的碱分解可能由化工等式描述如下。污水碱分解过程与污水混合了从打印，洗染，漂洗和其他过程被命名为涤纶人造丝印染的污水(T/D污水)。只在中国东部绍兴县, ,那里每天释放超过300数以万计吨TPD污水。虽然缺氧的或好氧的生化处理已经作为通常的预先为处理的这种废水的方法。多样的曝气过程结构也是它们的一种用法。然而广泛应用的曝气过程已经妨害由缺乏了解到相关因素稳定性的生物进程包括去除系数的有机底质、沼气生产比率和另一些指标。那个包含于稳定性加工的、依靠酸碱平衡特征污染物在吨/日废水的TA是一种二重的有机酸、存在于进水形成分子或离子状态。酸碱平衡在厌氧的体系是静止的

5、大约是由于TA的效果。那展开粒状污泥床（egsb）处理发展从上流式厌氧污泥层处理、是一个有较高的比率和有害的阻力的厌氧控制处理方法。未来的egsb技术发展的由于吨/日废水处理依赖透处理的稳定性。处理的稳定性是论述、酸碱平衡是强调和实验室实验是传导。1实验性1.1污水和活性污泥因为3650吨/日TPD废水在绍兴县、浙江省、瓷器在最上级全年的调查以后废水在实验中是降低那中央的泵站处理率、主要的指标是废水中的污染物是TPD废水以每小时化学需氧量高、化学需氧量和色度为特征，与传统的印染废水COD从780mgL的到3116mgL的量不同；和生物需氧量因为（五日生化需氧量）从325mgL的到1436mgL

6、不同，TA从286mgL的到1279mgL不同。特征污染物控制在4068COD的3650吨/日废水活性污泥实验是从杀虫剂废水、印染废水和石炭酸废水污泥处获得。处理设备在实验室厌氧的反应器和egsb反应器到保持高浓度的生物资源的情况一样。1.2实验性设定和过程圆柱状的EGSB反应器被划分了成四隔间(图2):(1)粒状污泥积聚区；（）液化区；（）三相分离器（）粒状污泥床。在那粒状污泥床上、由于废水在粒状污泥的再循环床和液化区，所以液化区发展主要是生物降解发生和沼气生产的地方。当做混合溶液穿过气体液体固体分离器、那污泥穿过分离器的孔到那液化区和污泥场、在一些絮凝和分散污泥泥沉淀反应器同流出的的时候、

7、那表面水流变成存储器从堰流出，并且沼气流入一湿式气体流量计反应器。反应器(图2)是1.5米高的与流化的区域和污泥床f7.0升有效的容积和2.0升的设置隔间。实验性设定的一张概要图被显示在图31为了从消除高酸碱度和短缺N和P,培养的污水中第一次集中调整了COD:N:P=200:5:1。在污水水库被增加氢磷酸盐和氨硫酸盐和增加稀释盐酸在中立化反应器由滴定器控酸碱度=10.0。泵被连续使用提供污水给EGSB反应器中混杂的积累污泥有能力在碳上退化。反应温度被加热器和温度调解器控制了。酸碱度被定器(DL55,MettlerToledo,德国)监测了和调整了。而滴温度一根热探针连接到一台红外光芒加热器所确

8、定。其它项目的根据标准方法(中国1997环境保护局编辑委员会) 进行了测试。在EGSB反应器的起动期间,磷酸盐和碳酸盐包含Fe、Al,Ni等增加入混杂的矾花提高被激活的污泥颗粒化。TPD流入物使污水比率逐渐增加到100%。过程稳定被重视当起动由逐步增加举办了污泥负荷和水力负荷。在EGSB反应器起动期间,它被管理在流入物酸碱度6.36.8和水力装载0.00264m3/(m3d)和往上流动线性速度0-2.0m/h,与温度被控制在336(Table2)。通常,开始阶段为厌氧过程能被定义作为过渡阶段在反应器之前平稳地运转。参量表明反应器表现在起动期间包括污染物撤除效率,沼气生产率,酸碱度,集中的变异V

9、FA等等。在EGSB反应器起动以后,它被管理在流速大约7.5LPd和HRT32h在EGSB,1h在中立化反应器里,当水力负荷22609m3/(m3d)和往上流动线性速度1.06.0m/h和温度受控在336(表2)。厌氧反应器的稳定是以COD撤除效率、沼气生产率和PH值来评价的。所有这些参量取决于酸基地平衡在反应器稳定性。如此总强碱性,VFA和TA集中并且被测试了。1.3测试和监视抽样采取从混杂的酒立刻被过滤了对TA的分析是用一台高性能液体色谱分析仪(HPLC,Gilson,法国)测定的。运行以流动相(v/v)在58/42,和加法26被集中的H3PO4每公升。分离进行在1.5ml/min流速和专

10、栏温度256使用ODS218反回阶段column(Alltech,美国)。一台紫外探测器以波长在254毫微米被使用了。测量出来,TA保留时间是在4.576.63分钟。2.结果2.1泥浆化颗粒化泥浆化颗粒化并且EGSB反应器起动起动是EGSB反应器烂泥的过程颗粒化(Hulshoff1986) 的根本。起动经常采取26几个月,长期的有一年(Juragen1990)。流入物COD和TA是各自地受控在125061943mg/L和5636.41mg/L,。水力负荷对对污泥稳定进行了调整。图4显示污泥在反应器起动期间在30天和60天特征。被激活的污泥看来分明是异种的反应器,能被划分成污泥床,污泥暂停的区域

11、并且设置区域在天60.Granular烂泥直径是1.0毫米占领超过在EGSB反应器里60天的总烂泥的10%。反应器中基体含量被显示在图5。在0.4m高度之上,COD集中在设置区域。从底部对0.4反应器的m轴向高度,COD集中退出了。COL出现同COD一样。COD撤除效率增加了从23.6%在30天到49.1%在60,天和COL撤除效率被增加从60%在30天到75.0%在60天。反应器表现改变了污泥颗粒化。EGSB反应器为TPD废水处理通常起动器。生物降解首要发生了在污泥床,并且外部圈导致密集混合污水在EGSB反应器里。2.2 EGSB操作流出物的稳定酸碱度使用表明EGSB反应器COD去除效率(6

12、COD)并且沼气生产率(Vg,相当数量沼气从1公斤COD去除在标准状态之下)。图6显示EGSB的表现变异在起始的期间。从10天到28天,TPD污水在流入物成比例地增加。6COD的第一高峰价值被提出了在15天和20天之间,与Vg0.116.18m3/(kgCOD)。COD去除效率和沼气生产率是不稳定的,和TPD污水流入物在过量地增加了。从28天,流入物是所有TPD污水。在30天和45天之间,流出物酸碱度是7.456.056COD是36%69%并且Vg是0.0156.20m3/(kgCOD)。流出物酸碱度、6COD和Vg的变异是在45天之前卓越的。这是一个分化期间为被激活的污泥。在45天以后,流出

13、物酸碱度被稳定在7.996.046。COD的范围增加到57%64%,Vg并且保留了0.126.17m3(的稳定的价值kgCOD)。实际上,从45天,粒子污泥从污泥中被区分,EGSB反应器提出了它的更好的稳定。颗粒状污泥被测量,弥补了总污泥的在60天10%。当只采取了反应器cubage的25%污泥床被填满以总污泥的65%。EGSB反应器6表现改善了和变得稳定与污泥一起颗粒化。它是显著的,COD去除效率总是在75%以下。因为TA依然是作为在厌氧条件下以转交在31.4%和56.0%(Guan之间,2003)慢慢地生物可分解的基体。EGSB反应器在温度2065三个月，操作保留在停滞的状态为45d。图7

14、说明反应器再开始，沼气生产率逐步被增加。COD去除以40%60%的效率是相对地稳定。反应器再开始只采取12d。在COD的最大转交率平均为60%之后,系统被交换了对负荷冲击以更高的水力负荷。尽管在16天内200%是正常负荷。沼气生产消沉是由于可怕的负荷。COD去除效率在厌氧系统接受了过量的负荷之后减少了几天滞后。结果说明,EGSB反应器表现能当操作参量很大地改变了不稳定的。在一个星期恢复了对55%62%的一个正常水平,沼气生产在10d恢复了对0.1160.15m3/(kgCOD)的正常水平。3 .TPD污水的理论演算和讨论3.1酸平衡和中间转换能力酸碱度酸平衡和中间转换能力酸碱度是最重要的参量。

15、当中一个表明厌氧系统的稳定。细菌的最佳的酸碱度为从6.5到7.5(Souza1986)。当VFA积累导致酸碱度减退,厌氧处理的效率明显已经下降(顾1993)。所以,它在厌氧系统对控制VFA是比对控制酸碱度重要。强碱性被看成如同抵抗VFA储积一个重要角色以便增加一个厌氧系统酸碱度 (Kroeker1979年;顾,1993)。污水的强碱性被定义作为可能适合与强的酸的起反应总物质。强碱性包括许多碱组分譬如碳酸盐、重碳酸盐、含水物和有机基物。它们在污水中(叫作为总强碱性中国1997环境保护局编辑委员会)。TPD污水有复杂组分并且碳酸盐、重碳酸盐和含水物的集中无法适当被获得。如此总强碱性在污水被使用来作

16、为重大显示为基本的组分。共同地,混杂的酸2基点平衡在厌氧反应器里由电离平衡氨、VFA和碳酸盐控制(KroekerEJ1979年;张,1997)。氨电离平衡作为等式(2):NH3H2.O=NH+OH-。(2)当H+增加,酸碱度减少并且平衡转移在右边。在356,电离常数是1.8560-5VFA通常由乙酸和酸组成。因为二VFA有接近的电离常数,电离平衡可能被简化作为乙酸电离被说明在等式(3):CH3COOH=CH3COO-+H+。(3)当H+增量,平衡转移到左边并且使成为挥发性酸(UVA)集中增加。在356,电离常数是1.7360-5。当UVA集中增加在10mg/L之上,作试验者趋向失败(Kroek

17、er1979)。碳酸盐电离平衡被阐明作为等式(4)H2CO3=HCO-+H+=CO-+2H+。(4) 在一个厌氧系统酸基点平衡并且包括在液体气体阶段之间二氧化碳溶化平衡, 在液体坚实阶段之间碳酸盐平衡和磷酸盐,其它盐电离平衡。它被解释为由于低集中硫氢化物和正磷酸的酸共同地只提供有限的缓冲能力 (Capri1975)。氨和VFA缓冲能力当酸碱度从6.0到7.7变化了可能被忽略,并且厌氧系统的缓冲能力起因于碳酸的电离。如此酸碱度和酸基本的平衡由碳酸和碱电离控制。后者由VFA、氨和另一强的酸和碱合成。NH3-N被测试。PO3-4的集中的范围-P和硫化物是1.8164.45mg/L,1.7860.20

18、Mg/L并且0.766.21mg/L相应地, 各自的平均值是10.23,4.26和2.12mg/L,。根据以前的工作以上提到,氨缓冲能力,磷酸盐和氢硫酸在TPD污水可能被忽略。然后,哪个负责对酸2base平衡的中间转换？当EGSB过程向被应用的TPD污水6在这样一个碳酸系统怎么获得稳定的酸碱度。以6.56.5的范围6TA是双重有机酸,存在在水中以分子或离子状态二个状态。进一步来说,它的可溶性与酸碱度密切相关。电离平衡被显示得如下(百科全书编辑委员会化工业1990):3.2 VFA在厌氧过程用二种主要方式的二个主要小组细菌介入降低有机基体在第一阶段对挥发性脂肪酸(VFA)水解和降低复杂有机基体。

19、在第二阶段,VFAs由细菌运用并且导致甲烷气产生。二个过程同时发生并且过程稳定取决于在二个主要阶段之间有机基体细微生物化学的平衡。厌氧处理不稳定通常以由VFAs的集中的迅速增量而甲烷气生产的随后减退表明。有许多因素与相关不稳定或过程破坏。例如,甲烷的不足的生理适应对新基体、迅速温度或酸碱度波动。从结果由Kroeker等。(Andrews1969年;Kroeker,1979),厌氧消化毒力与挥发性酸的过份集中关系了(UFAs)更加直接,虽然它们与过份游离氨含量大概间接地关系了。而且,以由于膜法酸碱度比其它化合物容易击穿通过细胞膜毒力有一种接近的交互作用。当微生物同化污泥，酸碱度使细胞迅速地下降并

20、且微生物的新陈代谢率减少。它是可接受的,作试验者毒力由膜法造成在集中在30到60mg/L之上作为乙酸。3.3 VFA和强碱性平衡强碱性的典型的变异VFA和强碱性平衡强碱性的典型的变异和VFA在EGSB反应器里被显示在图11。缺氧流出物的强碱性集中与TPD污水在9006000mg/L的范围近似地相等的。反弹范围是大约100mg/L。在EGSB的处理以后总强碱性集中增加了大约250mg/L到11506250mg/L。流入物(TPD污水)VFA90633mg/L增加到197636mg/L在缺氧处理以后,当流出物VFA以去除效率79.1%62.1%从EGSB反应器是19.863.2mg/L。总强碱性增

21、量在EGSB反应器里能被假定与VFA的消耗量相关。强碱性是在厌氧系统缓冲抵抗VFA能力。污水的VFA几乎抑制不了厌氧过程。强碱性的集中是缓冲VFA足够高的混杂的醇。Lesilie(Lesilie1989)采取为VFA比与总强碱性评估缓冲厌氧能力system(Leslie,1989)。总强碱性轻微只下降了在缺氧治处理期间和在EGSB反应器里轻微登升高。VFA的定量对total2.alkalinity比0141VFA比和总强碱性与相关厌氧系统的稳定被显示在表3 (Leslie1989)。明显地, 当TPD污水在EGSB反应器里处理时VFA集中的变异只导致了酸碱度的少量变化。混杂的醇的缓冲能力在EG

22、SB过程是充足的。4.结论TA,二重的有机酸因为酸碱平衡对那碱度的那废水供应充分的缓冲量，当EGSB加工被用于处置TPD废水，与污泥颗粒一起作用，EGSB反应器性能改善和变成更稳定。命名原则BOD5:五日生化需氧量,mg/L;SS:悬浮固体;COD:化学氧需求,mg/L;VFA:挥发性脂肪酸;COL:颜色;UFA:不饱和脂肪酸;EGSB:膨胀的颗粒状烂泥床;Vg:沼气生产率,m3/(公斤COD);HRT:水力保留时间,h;T:温度6;K:电离常数;TA;MLSS,g/L;COD:化学需氧量除去;PVA:聚乙烯醇。参考文献1 Andrews J F , 19691 Dynamic model o

23、f the anaerobic digestion process J .Sanitary Engineering Division ASCE , 95 (SA1) : 95 6161.2 Capri M G, Marais G V R , 19751 pH adjustment in anaerobic digestion J .Water Research , 9(3) : 307 6131.3 Editorial Board of Encyclopedia of Chemical Industry , 19901 Encyclopedia ofchemical industryM . V

24、ol 11 Beijing.4 Chemical Industry Press. Editorial Board of Environment Protection Bureau of China , 1997.1.5 Monitoring and determination methods for water and wastewater M . 3rd. ed. Beijing : China Environmental Science Press.Guan B H , Wu ZB , Wu Z C et al . , 2003.1 .6 Gu X S , 19931 Mathematic

25、al model for wastewater bio-treatment M . 2nd ed. Beijing : Tsinghua University Press. Hulshoff P L , Lettinga G, 1986.1 .7 New technologies for anaerobic treatment J . Water Science and Technology , 18 (2) : 41 631 Juragen H T , Wu WM, Mahendra KJ , 1990.1 .8 Ecoengineering high rate anaerobic dige

26、stion systems : Analysis of improved syntrophic biomethanation catalysts J . Biotechnology and Bioengineering , 35 (10) : 990 6991 Kroeker E J , Schulte D D , Sparling A B et al . , 1979.1. 9 Anaerobic treatment process stabilityJ . J Water Pollution Control Federation , 51 (4) : 718 67271 Leslie G

27、C P , Henry C L , 1989.1 .10 Biological wastewater treatment : Theory and application(Li , X.W. , Yang , X. K. , Zhang , Y. G. ed. ) M . Beijing : China Architecture and Building Press. Souza M E , 1986.1. 11 Criteria for the utilization , design and operation of UASB reactorsJ . Water Science and T

28、echnology , 18 (12) : 55 661 Zhang X, Wang B Z , Zhu H , 1997.1. 12 The Acid2alkaline equilibrium and buffer capacity of anaerobic digestion systemJ . China Environmental Science , 17 (6) : 492 6951.13 Biodegradability of terephthalic acid in terylene artificial silk printing and dyeing wastewater J

29、 . Journal of Environmental Sciences , 15(3) : 296 6011.Stability of expanded granular sludge bed process for terylene artificial silk printing and dyeing wastewater treatmentAbstractTerylene artificial silk printing and dyeing wastewater (TPD wastewater), containing averaged 7.0 mg/L terephthalic a

30、cid (TA) as the main carbon source and the character pollutant, was subjected to expanded granular sludge bed (EGSB) process. The stability of the EGSB process was firstly conducted by laboratory experiment. TA ionization was the predominated factor influencing the acid-base balance of the system. H

31、igh concentration of TA in wastewater resulted in sufficient buffering capacity to neutralize the volatile fatty acids (VFA) generated from substrate degradation and provided strong base for anaerobic system to resist the pH decrease below6.5. VFA and UFA caused almost no inhibition on the anaerobic

32、 process and biogas production except that pH was below 6.35 and VFA was at its maximum value. Along with the granulating of the activated sludge, the efficiency of organic removal and production rate of biogas increased gradually and became more stable. After start-up, the efficiency of COD removal

33、 increased to 57 %64 %, pH stabilized in a range of 7.99 6.04, and production rate of biogas was relatively high and stable. Sludge granulating, suitable influent of pH and loading were responsible for the EGSB stability. The variation of VFA concentration only resulted inneglectable rebound of pH,

34、and the inhibition from VFA could be ignored in EGSB. The EGSB reactor was stable for TPD wastewater treatment.Keywords: expanded granular sludge bed; stability; anaerobic treatment; dyeing and printing wastewaterIntroduction：In order to obtain pliable and elegant terylene fabric just like silk, ter

35、ylene greige cloth is always pretreated with alkali-decomposition process, wherein terylene fiber is hydrolyzed to some extent in NaOH solution at certain temperature and pressure. During this process, the superficial terylene fibred is peeled off from the greige cloth and dissolved into solution, i

36、n which terylene acid (TA) and ethylene glycol are discharged as the main pollutants in wastewater. The obtained terylene fabric with silken wrinkle and soft feeling is called artificial silk fabric. The alkali-decomposition of terylene can be described by the chemical equation below.The wastewater

37、from the alkali-decomposition process mixed with wastewater from printing, dyeing, potch and the other processes is named terylene artificial silk printing and dyeing wastewater ( T/D-wastewater ) . Only in Shaoxing County, East China, are there more than 300 thousands tons TPD-wastewater discharged

38、 each day.Although the anoxic or aerobic bio-process has been the usual approach for the treatment of such kind of wastewater, various anaerobic process configurations were also found their usage in this field. However, the widespread application of anaerobic process has been hampered by the lack of

39、 understanding of factors associated with stability of the biological processes involved. The removal efficiency of organic substrates , the biogas production rate and the other items , which are involved in the stability of the process , depends on the acid-base balance. The characteristic pollutan

40、t TA in the TPD-wastewater is a kind of dual-organic acid , which exists in water in the form of molecule or ion state. It is still vague about the effect of TA to the acid-base balance in anaerobic system.The expanded granular sludge bed ( EGSB) process developed from UASB process , is one of the c

41、ontrolled anaerobic treatment processes with advantages of higher rate and better toxic resistance. Although EGSB process has the efficiency of 27.1 % 68.0 % for chemical oxygen demand ( COD) removal and 31.4 % 66.0 % for TA removal(Guan , 2003) , further development of EGSB technology for TPD-waste

42、water treatment depends upon a better understanding of the process stability. In this paper , the stability of the process was discussed , the acid-base balance was emphasized and lab scale experiments were conducted.1 Experimental1.1 Wastewater and activated sludgeThe wastewater in the experiment w

43、as taken from the central pump station for 3 605 t/d TPD wastewater in Shaoxing County , Zhejiang Province , China. After a one-year round survey , the main pollutants in the wastewater are given in Table 11 TPD wastewater characterized by high pH , COD value and color (COL) is different from tradit

44、ional printing and dyeing wastewater. The value of COD varies from 780 mg/L to 3116 mg/L ; and biological oxygen demand for 5 d (BOD5 ) from 325 mg/L to 1436 mg/L. TA ranging from 286 Mg/L to 1279 mg/L is the characteristic pollutant controlling40 % 68 % of the total COD in TPD wastewater. Activated

45、 sludge for the experiment was obtained from the treatment facility for pesticide wastewater , printing and dyeing wastewater and phenol wastewater. Sludge was acclimated firstly in a laboratory anaerobic reactor running in a fill and drawn mode under the same conditions as EGSB reactor to retain hi

46、gh concentration of biomass.1.2 Experimental set-up and processThe columned EGSB reactor was divided into four compartments (Fig. 2) : (1) the granular sludge bed in which the granulated sludge was accumulated ; ( 2) the fluidized zone in which sludge was suspended ; (3) the gas-liquid- sludge separ

47、ator ; and (4) the setting zone. The influent and reflux from the recycle pump was pumped into the bottom of the reactor and passed through the granular sludge bed.Above the granular sludge bed , a fluidized zone developed mainly due to wastewater recycle. In the granular sludge bed and fluidized zo

48、ne , the biological degradation took place and the biogas was produced. As mixed liquor passed through the gas-liquid-solid separator , the sludge with good setting abilities settled back through the apertures of the separator to the fluidized zone and sludge bed , while some flocculated and dispers

49、ed sludge was washed out of the reactor with effluent , the effluent flowed into the storage vessel from the weir , and biogas flowed into a wet gas flow meter. The reactor ( Fig. 2) is 1.5 meter high with fluidized zone and sludge bed f100 6 , effective cubage of 7.0 L and a setting compartment of

50、2.0 L.A schematic drawing of the experimental setup is shown in Fig. 31 In order to eliminate the inhibition from high pH and shortage of N and P , the feeding wastewater was first adjusted to the concentration of COD:N:P = 200:5:1 in wastewater reservoir by adding dipotassium hydrogen phosphate and

51、 ammonia sulfate and pH =10.0 by adding dilute hydrochloric acid in a neutralization reactor controlled by titrator. A pump was used to supply wastewater continuously to EGSB reactor charged with mixed accumulated sludge capable of carbon degradation. Reaction temperature was controlled with a heate

52、r and a temperature controller.The pH was monitored and adjusted with a titrator (DL55 , Mettler Toledo , Germany ) . Temperature was determined with a thermo probe connected to an infrared ray heater. Test of the other items was conducted according to the standard methods ( Editorial Board of Envir

53、onment Protection Bureau of China , 1997) . During the start-up of the EGSB reactor , phosphate and carbonate containing Ca , Fe , Al , Ni etc. were added into mixed liquor to enhance the granulating of the activatedsludge. The ratio of TPD wastewater in the influent was gradually increased to 100 %

54、. The stability of the process was valued while start-up was conducted by increasing sludgeloading and hydraulic loading step by step. During the EGSB reactor start-up , it was operated at influent pH 6.3 6.8 and hydraulic load 0.002 64 m3/(m3d ) and up-flow linear velocity 0 2.0 m/h , with temperat

55、ure controlled at 33 (Table 2) . Generally , start-up stage for anaerobic process could be defined as the transitional stage before the reactor working steadily. The parameters indicating reactor performance during start-up include removal efficiencies of pollutants , biogas production rate , variat

56、ion of pH , concentration of VFA and so on. After the EGSB reactor start-up , it was operated at a Flow-rate about 7.5 LPd and HRT 32 h in EGSB , 1 h inneutralization reactor , while the hydraulic loading 22 609 m3/(m3 d) and up-flow linear velocity 1.0 6.0 m/h and temperature was controlled at 33 (

57、 Table 2) . Stability of anaerobic reactor was valuated with COD removal efficiency , biogas production rate and pH value. All of these parameters involved in the stability depended on the acid-base balance in the reactor. So total-alkalinity , VFA and TA concentration were also tested.1.3 Test and

58、monitoringSamples taken from mixed liquor were filtered immediately. Analysis of TA was carried on a high performance liquid chromatograph (HPLC , Gilson , France) . Aliquots of 25 were injected to the HPLC , running with mobile phase of acetonitrile/water ( v/v) at 58/42 , and an addition of 2祃 of

59、concentrated H3 PO4 per liter of solution. The separation was performed using an ODS218 reversed phase column(Alltech , USA) at the flow-rate of 1.5 ml/min and column temperature of 25 . An UV detector was used with the wavelength at 254 nm. It is measured that TA retention time was at 4.57 6.63 min

60、.2 Results2.1 Sludge granulating and EGSB reactor start-upThe start-up is a process of sludge granulating that is essential for EGSB reactor (Hulshoff , 1986) . Start-up often takes 2 6 months , even as long as one year (Juragen , 1990) . The influent COD and TA were controlled at 1250 61943 mg/L an

61、d 563 6.41 mg/L , respectively. The hydraulic loading was adjusted to suit for sludge settlingback. Fig. 4 shows the sludge characteristics along the axis at the day 30 and the day 60 during reactor start-up. Activated sludge appeared to be heterogeneous distinctly along the axis of reactor , in whi

62、ch could be divided into sludge bed , sludge suspended zone and setting zone at the day 60.Granular sludge which diameter is over 1.0 mm occupied more than 10 % of total sludge in EGSB reactor at the day 60.The substrate concentration along reactor axis is shown in Fig. 5. Above 0.4 m height , COD c

63、oncentration at different height closed extremely to each other except in setting zone. From the bottom to 0.4 m axial height of the reactor , COD concentration stepped down extremely. The COL appeared the same as the COD. Removal efficiency ofCOD increased from 23.6 % at the day 30 to 49.1 % at the

64、 day 60 , and the removal efficiency of COL increased from 60 % at the day 30 to 75.0 % at the day 60. The reactor performance changed with the sludge granulating. The EGSB reactor for TPD wastewater treatment started up normally. The biodegradation occurred chiefly in sludge bed , and the outside l

65、oop resulted in intensive mixing of wastewater in EGSB reactor.2.2 Stability of the EGSB operationEffluent pH , COD removal efficiency (COD) and biogas production rate ( Vg , amount of biogas from 1 kg COD removal under standard state) were used to indicate the EGSBreactors performance. Fig. 6 shows the performance variation of EGS