初始5～10min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)=ΔH+Hb (19) vs=650/MLSSmax·SVI (20) 由式(18)代入式(17)并作相应变换改写为：
［650·A·Hmax／TS·SVI］(ts+td-10/60)=ΔＶ/Ａ+Hb (21) 式中 vs--污泥沉降速度，m/h
MLSSmax--当水深为Hmax时的MLSS，kg/m3 ts、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、ΔV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ΔH，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 Process
Sequencing 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 world's 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 \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, it's 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.
<1>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-η))] / [ln (1-η)] (1) Type η 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, μ Max), and the different substrates different growth rate constant is also different. Monod equation can be written as:
DX/Xdt = μ = μ Max [S / (KS + S)] (2) Type of ? X-biology concentration S-growth restrictive substrate concentration KS, saturated or half speed constant
μ μ Max-respectively, for practical and maximum growth rate than
According to Chudoba proposed theory, with low KS and μ 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 μ Max value is lower, and bacteria micelle bacteria KS and μ 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 improvement of water solution, make the SBR technology for use in a big central wastewater treatment plant.
3 Design method <1> Load method
The method and the continuous aeration pool similar volume of the design. The known SBR reaction pool capacity load NV or sludge load into Q0 NS, water and into water BOD5 concentration C0, can be obtained by next type quickly SBR ChiRong:
Volume load method V = nQ0C0 / Nv (3) Vmin = [SVI · MLSS / 106] · V
Sludge load method Vmin = nQ0C0 · SVI/Ns (4) V = Vmin + Q0
<2> Aeration time load method
In view of SBR intermittent aeration, a cycle effective aeration time for ta, is a total aeration time for days nta, to establish the following calculation formula:
Volume load method V = nQ0C0tc/Nv · ta (5) Sludge load method V = 24 QC0 / nta · MLSS · NS (6) <3>Dynamics design method
Due to different ways of operation of SBR, the calculation of the effective volume is not the same. According to the dynamic principle calculus (process slightly), SBR reaction ChiRong formula can be divided into the following three kinds of cases:
Limit aeration V = NQ (C0-Ce) tf / [MLSS · Ns · ta] (7)
Unrestricted aeration V = nQ (C0-Ce) tf / [MLSS · Ns (ta + tf)] (8) Half a limit aeration V = nQ (C0-Ce) / [LSS · Ns (ta + tf-prearcing)] (9) Type: tf-water filling time, generally take 1 ~ 4 h. Tr-the reaction time, be in commonly 2 to 8 h.
C0, Ce-respectively for water and reaction end of pollutant concentration. But in the actual application of the above methods that are the following questions: