污水处理 毕业论文 文献翻译 中英文

SBR 法工艺简介序批式活性污泥法（SBR-Sequencing Batch Reactor）是早在1914年英国学者 Ardern和 Lockett发明活性污泥法之时，首先采用的水处理工艺。70年代初，美国 Natre Dame大学的 R.Irvine教授采用实验室规模对 SBR工艺进行了系统深入的研究,并于1980年在美国环保局(EPA)的资助下，在印地安那州的Culver城改建并投产了世界上第一个 SBR法污水处理厂。80年代前后，由于自动化、计算机等高新技术的迅速发展以及在污水处理领域的普及与应用，此项技术获得重大进展，使得间歇活性污泥法（也称“间歇式活性污泥法” ）的运行管理也逐渐实现了自动化。SBR工艺的过程是按时序来运行的，一个操作过程分五个阶段：进水、曝气、沉淀、滗水、闲置。由于 SBR在运行过程中，各阶段的运行时间、反应器内混合液体积的变化以及运行状态都可以根据具体污水的性质、出水水质、出水质量与运行功能要求等灵活变化。对于 SBR反应器来说，只是时序控制，无空间控制障碍，所以可以灵活控制。因此，SBR 工艺发展速度极快，并衍生出许多新型 SBR处理工艺。90 年代比利时的 SEGHERS公司又开发了 UNITANK系统，把经典 SBR的时间推流与连续的空间推流结合了起来 SBR工艺主要有以下变形。一、SBR 工艺特点及分析SBR工艺是通过时间上的交替来实现传统活性污泥法的整个运行过程，它在流程上只有一个基本单元，将调节池、曝气池和二沉池的功能集于一池，进行水质水量调节、微生物降解有机物和固、液分离等。经典 SBR反应器的运行过程为：进水曝气沉淀滗水待机。1、理论分析SBR 反应池充分利用了生物反应过程和单元操作过程的基本原理。（1）流态理论由于 SBR在时间上的不可逆性，根本不存在返混现象，所以属于理想推流式反应器。（2）理想沉淀理论其沉淀效果好是因为充分利用了静态沉淀原理。经典的 SBR反应器在沉淀过程中没有进水的扰动，属于理想沉淀状态。（3）推流反应器理论假设在推流式和完全混合式反应器中有机物降解服从一级反应，那么在相同的污泥浓度下，两种反应器达到相同的去除率时所需反应器容积比为：V 完全混合/V 推流=（1-（1/1-） ）/ ln(1-) （1）式中 -去除率从数学上可以证明当去除率趋于零时 V完全混合/V 推流等于1，其他情况下（V 完全混合/V 推流）1，就是说达到相同的去除率时推流式反应器要比完全混合式反应器所需的体积小，表明推流式的处理效果要比完全混合式好。（4）选择性准则1973年 Chudoba等人提出了在活性污泥混合培养中的动力学选择性准则5，这个理论是基于不同种属的微生物在 Monod方程中的参数（KS、max）不同，并且不同基质的生长速度常数也不同。Monod 方程可以写成：dX/Xdt=max S/(KS+S) （2）式中 X- 生物体浓度S-生长限制性基质浓度KS-饱和或半速度常数、max-分别为实际和最大比增长速率按照 Chudoba所提出的理论，具有低 KS和 max 值的微生物在混合培养的曝气池中，当基质浓度很低时其生长速率高并占有优势，而基质浓度高时则恰好相反。Chudoba 认为大多数丝状菌的 KS和 max 值比较低，而菌胶团细菌的KS和 max 值比较高，这也解释了完全混合曝气池容易发生污泥膨胀的原因。有机物浓度在推流式曝气池的整个池长上具有一定的浓度梯度，使得大部分情况下絮状菌的生长速率都大于丝状菌，只有在反应末期絮状菌的生长没有丝状菌快，但丝状菌短时间内的优势生长并不会引起污泥膨胀。因此，SBR 系统具有防止污泥膨胀的功能。（5）微生物环境的多样性SBR 反应器对有机物去除效果好，而对难降解有机物降解效果好是因为其在生态环境上具有多样性，具体讲可以形成厌氧、缺氧等多种生态条件，从而有利于有机物的降解。2、传统 SBR工艺的缺点（1）连续进水时，对于单一 SBR反应器需要较大的调节池。（2）对于多个 SBR反应器，其进水和排水的阀门自动切换频繁。（3）无法达到大型污水处理项目之连续进水、出水的要求。（4）设备的闲置率较高。（5）污水提升水头损失较大。（6）如果需要后处理，则需要较大容积的调节池。3、 SBR 的适用范围SBR 系统进一步拓宽了活性污泥的使用范围。就近期的技术条件，SBR 系统更适合以下情况：（1）中小城镇生活污水和厂矿企业的工业废水，尤其是间歇排放和流量变化较大的地方。（2）需要较高出水水质的地方，如风景游览区、湖泊和港湾等，不但要去除有机物，还要求出水中除磷脱氮，防止河湖富营养化。（3）水资源紧缺的地方。SBR 系统可在生物处理后进行物化处理，不需要增加设施，便于水的回收利用。（4）用地紧张的地方。（5）对已建连续流污水处理厂的改造等。（6）非常适合处理小水量，间歇排放的工业废水与分散点源污染的治理。近期来随着 SBR工艺的发展，特别是连续进水、连续出水方案的改进，使 SBR工艺以应用于大中心污水处理厂。二、设计方法1、负荷法该法与连续式曝气池容积的设计相仿。已知 SBR反应池的容积负荷 NV或污泥负荷 NS、进水量 Q0及进水中 BOD5浓度 C0，即可由下式迅速求得 SBR池容：容积负荷法 V=nQ0C0Nv (3)Vmin=SVIMLSS106V污泥负荷法 Vmin=nQ0C0SVINs (4)V=Vmin+Q02、曝气时间内负荷法鉴于 SBR法属间歇曝气，一个周期内有效曝气时间为 ta，则一日内总曝气时间为 nta，以此建立如下计算式：容积负荷法 V=nQ0C0tcNvta (5)污泥负荷法 V=24QC0ntaMLSSNS (6)3、 动力学设计法由于 SBR的运行操作方式不同，其有效容积的计算也不尽相同。根据动力学原理演算(过程略)，SBR 反应池容计算公式可分为下列三种情况：限制曝气 V=NQ(C-Ce)tfMLSSNsta (7)非限制曝气 V=nQ(C-Ce)tfMLSSNs(ta+tf) (8)半限制曝气 V=nQ(C0-Ce)LSSNs(ta+tf-t0) (9)式中： tf-充水时间，一般取14h。tr-反应时间，一般在28h。C、Ce-分别为进水和反应结束时的污染物浓度。但在实际应用中发现上述方法存有以下问题：（1）对负荷参数的选用依据不足，提供选用参数的范围过大例如文献推荐 Nv=0.11.3kgBOD5/(m3d)等 ，而未考虑水温、进水水质、污泥龄、活性污泥量以及 SBR池几何尺寸等要素对负荷及池容的影响；（2）负荷法将连续式曝气池容计算方法移用于具有二沉池功能的 SBR池容计算，存有理论上的差异，使所得结果偏小；（3）在计算公式中均出现了 SVI、MLSS、Nv、Ns 等敏感的变化参数，难于全部同时根据经验假定，忽略了底物的明显影响，并将导致各参数间不一致甚至矛盾的现象；（4）曝气时间内负荷法与动力学设计法中试图引入有效曝气时间 ta对SBR池容所产生的影响，但因其由动力学原理演算而得，假定的边界条件不完全适应于实际各个阶段的反应过程，将有机碳的去除仅限制在好氧阶段的曝气作用，而忽略了其他非曝气阶段对有机碳去除的影响，使得在同一负荷条件下所得 SBR池容惊人地偏大。上述问题的存在不仅不利于 SBR法对污水的有效处理，而且进行多方案比较时也不可能全面反映 SBR法的工程量，会得出投资偏高或偏低的结果。针对以上问题，提出了一套以总污泥量为主要参数的 SBR池容综合设计方法4、总污泥量综合设计法该法是以提供 SBR反应池一定的活性污泥量为前提，并满足适合的 SVI条件，保证在沉降阶段历时和排水阶段历时内的沉降距离和沉淀面积，据此推算出最低水深下的最小污泥沉降所需的体积，然后根据最大周期进水量求算贮水容积，两者之和即为所求 SBR池容。并由此验算曝气时间内的活性污泥浓度及最低水深下的污泥浓度，以判别计算结果的合理性。其计算公式为：TS=naQ0(C0-Cr)tTS (10)Vmin=AHminTSSVI10-3 (11)Hmin=Hmax-H (12)V=Vmin+V (13)式中TS- 单个 SBR池内干污泥总量，kgtTS-总污泥龄，dA-SBR 池几何平面积，m2Hmax、Hmin-分别为曝气时最高水位和沉淀终了时最低水位，mH-最高水位与最低水位差，mCr-出水 BOD5浓度与出水悬浮物浓度中溶解性 BOD5浓度之差。其值为：Cr=Ce-ZCse1.42(1-ek1t) (14)式中Cse- 出水中悬浮物浓度，kg/m3k1-耗氧速率，d-1t-BOD 实验时间，dZ-活性污泥中异养菌所占比例，其值为：Z=B-（B2-8.33s1.072(15-T)）0.5 (15)B=0.555+4.167(1+TS0/BOD5)Ns1.072(15-T) (16)Ns=1/atTS (17)式中a- 产泥系数，即单位 BOD5所产生的剩余污泥量，kgMLSS/kgBOD5，其值为：a=0.6(TS0/BOD5+1)-0.60.0721.072(T-15)1/tTS+0.081.072(T-15) (18)式中 TS、BOD5-分别为进水中悬浮固体浓度及 BOD 5浓度，kg/m3T-污水水温，由式(9)计算之 Vmin系为同时满足活性污泥沉降几何面积以及既定沉淀历时条件下的沉降距离，此值将大于现行方法中所推算的 Vmin。必须指出的是，实际的污泥沉降距离应考虑排水历时内的沉降作用，该作用距离称之为保护高度 Hb。同时，SBR 池内混合液从完全动态混合变为静止沉淀的初始510min 内污泥 仍处于紊动状态，之后才逐渐变为压缩沉降直至排水历时结束。它们之间的关系可由下式表示：vs(ts+td-10/60)=H+Hb (19)vs=650/MLSSmaxSVI (20)由式(18)代入式(17)并作相应变换改写为：650AHmaxTSSVI(ts+td-10/60)=/+Hb (21)式中 vs-污泥沉降速度，m/hMLSSmax-当水深为 Hmax时的 MLSS，kg/m3ts、td-分别为污泥沉淀历时和排水历时，h式(19)中 SVI、Hb、ts、td 均可据经验假定，Ts、V 均为已知，Hmax 可依据鼓风机风压或曝气机有效水深设置，A 为可求，同时求得 H，使其在许可的排水变幅范围内保证允许的保护高度。因而，由式(10)、(11)可分别求得Hmin、Vmin 和反应池容。三、SBR 在发展中的问题相对于传统连续流活性污泥法，SBR 工艺是一种尚处于发展、完善阶段的技术，许多研究工作刚刚起步，缺乏科学的设计依据和方法以及成熟的运行管理经验，另外，SBR 自身的特点更加深了解决问题的难度。SBR在现阶段的发展过程中，主要存在以下方面的问题：1、 基础研究方面（1）关于污水在非稳定状态下活性污泥微生物代谢理论的研究；（2）关于厌氧、好氧状态的反复交替对微生物活性和种群分布的影响；（3）可同时除磷、脱氮的微生物机理的研究。2、工程设计方面（1）缺乏科学、可靠的设计模式；（2）运行模式的选择与设计方法脱节。The Description of SBR ProcessSequencing Batch type of activated sludge (SBR-Sequencing Batch Reactor) is as early as 1914 British scholar Ardern and Lockett invention of activated sludge, first of all the water treatment technology. 70 s, the United States Natre Dame university professor R.I rvine using laboratory scale of SBR process system of further research, and in 1980 in the United States the environmental protection agency (EPA) by in indiana Culver city rebuilt and put the worlds first SBR sewage treatment plants 1. Before and after the 80 s, as a result of automation, computers and other the rapid development of high-technology and in the waste water treatment field application and popularization of the technique, get great progress, and makes the intermittent activated sludge method (also called “sequencing batch reactor“) of the operation management also gradually realized the automation.The process of SBR technology is run by the time sequence, a process is divided into five stages: water, aeration, precipitation, Bi water, idle. Because of SBR during operation, each phase of the running time, within reactor volume changes, and run the mixture state can be based on the nature of the concrete sewage effluent water, water quality, and operation of the functional requirements, and so flexible and change. For SBR reactor, its just sequential control, no space control disorders, so can the flexible control. Therefore, the development of SBR very fast, and derive a lot of new SBR process. In the 90 s SEGHERS Belgium company have developed UNITANK system, the classic of SBR and continuous flow of time pushing space push flow is a combination of 2 SBR technology mainly in the following deformation. 1 SBR process features and analysis By the time of SBR alternate traditional activated sludge method to realize the whole operation process, it is only in the process a basic unit, will adjust pool, aeration pool and the second pond set of features in a pool, the water quality of water regulation, microbial degradation organic matter and solid, liquid separation etc. The operation of the reactor classic SBR process for: feed water-aeration and precipitation-Bi water-standby. The theoretical analysis SBR reaction pool make full use of the biological reaction process and unit operation process basic principle. (1) Flow pattern theory Because in time of SBR irreversible, has no return to mix phenomenon, so belongs to the ideal push streaming the reactor. (2) The ideal precipitation theory The precipitation effect is good because make full use of the static precipitation principle. Classic SBR reactors in precipitation process of water without disturbance, belongs to the ideal state of precipitation. (3) Push flow reactor theory Assume that the push streaming and completely hybrid reactors organic matter degradation in response to level, so in the same sludge concentration, the two kinds of reactor achieve the same for the reactor volume ratio removal rate for: V/V push completely mixed flow = (1-(1/1-) / ln (1-) (1) Type in-removal Mathematics can be proved from the removal rate tends to zero when mixing/V V completely push flow is equal to 1, other cases (V/V push completely mixed flow) 1, that is to say the same removal rate than pushing streaming reactor completely hybrid reactors needed small volume, show that push the treatment effect of streaming than completely hybrid. (4) The selective criteria In 1973, Chudoba people put forward in the active sludge in the mixed cultivating dynamics selective criteria 5, this theory is based on the different species of microbes in the Monod of the parameters of the equation (KS, Max), and the different substrates different growth rate constant is also different. Monod equation can be written as: DX/Xdt = = Max S / (KS + S) (2) Type of X-biology concentration S-growth restrictive substrate concentration KS, saturated or half speed constant Max-respectively, for practical and maximum growth rate than According to Chudoba proposed theory, with low KS and Max value of the microorganisms in the mixed cultivating aeration pool, when the very low concentrations to its growth rate and high when the advantage, and the matrix when high concentration, the opposite is true. Chudoba think that most of the filamentous fungi KS and Max value is lower, and bacteria micelle bacteria KS and Max value is higher, it also explain completely mixed aeration pool prone to the cause of the expansion of sludge. Organic matter concentration in the push streaming of aeration the whole pool ChangShang has certain concentration gradient, making the most of the time the growth rate of the floe bacteria are greater than filamentous fungi, only in the end the growth of bacteria reaction floe no filamentous fungi fast, but filamentous fungi a short time advantage of growth does not lead sludge inflation. Therefore, SBR system has the function of preventing sludge inflation. (5)The diversity of the microbial environment headscarf SBR reactor on the organic remove effect is good, and to the difficult degradable organic matter degradation effect is good because it has a diversity in ecological environment, specific tell can form anaerobic, lack of oxygen and so on many kinds of ecological condition, so as to facilitate the degradation of organic matter. 2The disadvantages of traditional SBR technology (1) Water for, for a single SBR reactor need larger regulation ponds. (2) For multiple SBR reactor, the feed water and drainage of the valve to be automatic switching frequency. (3) Is unable to achieve the large wastewater treatment projects for water, the water requirements. (4) The idle equipment rate is higher. (5) Sewage ascension head loss is bigger. (6)If need post-processing, need to be larger volume of the regulation ponds. 3 SBR range SBR system to expand the scope of application of activated sludge. To the recent technical conditions, more suitable for the SBR system: (1) Medium and small urban sewage and industrial waste water of corporations, especially intermittent discharge and great changing flow place. (2)Need more water quality higher places, such as the scenic area, lakes and harbor, not only should the removing of organic matter, also requires a water phosphorus removal denitrification, prevent the eutrophication of the rivers. (3) The place of water resources. SBR system can be in biological treatment after the physico-chemical treatment, do not need to increase the facilities, facilitate water recycling. (4)Land of nervous place. (5)Has built for the continuous flow of reform of the wastewater treatment plant. (6)Is very suitable for processing small water, intermittent discharge of industry wastewater and scattered non-point source pollution control. Recently with the development of SBR technology, especially the continuous water, continuous impro