【作者】 马春华；

【导师】 韩柏平；

【作者基本信息】 同济大学 ， 环境工程， 2008， 硕士

【摘要】 常规A²/O工艺是目前最常见的一种脱氮除磷工艺,其特点是厌氧区和缺氧区串联布置,在脱氮过程中污水进入无意义的厌氧区,在除磷过程中污水进入无意义的缺氧区,均使得反应池的有效停留时间大大浪费了,造成反应池的设计池容较大,投资及运行成本均较高。并联式A²/O工艺是将常规A²/O工艺的厌氧区和缺氧区并联,后接好氧区的一种新型脱氮除磷工艺。理论上这种新工艺能够改进常规A²/O工艺的缺点,在相同体积条件下,能够提高厌氧和缺氧时间。为考察并联式A²/O工艺和常规A²/O工艺实际脱氮除磷效果的异同,本研究对上海城市污水进行了为期一年的小试试验,为工程应用和理论研究提供经验数据。本研究采用两套平行装置,通过调节进水中COD和氮磷浓度,对于每个工况稳定运行半个月,分别考察了在一般条件下、碳源充足条件下和碳源不足条件下并联式A²/O工艺和常规A²/O工艺的氮磷去除效果。在水力停留时间13个小时的条件下,当进水COD为150～450mg/L时,两系统的COD去除效果都很好,出水COD均低于50mg/L,达到《城镇污水处理厂污染物排放标准》（GB18918-2002）中一级A标准。通过在COD浓度为170,250,330,450mg/L的浓度梯度下,对两系统的脱氮除磷效果进行研究,结果表明:一、两系统的脱氮效果随着COD浓度升高先上升后下降,在330mg/L时,TN去除率最高,常规系统达到58.5%,并联式系统达到66.7%,二者的TN出水均达到《城镇污水处理厂污染物排放标准》（GB18918-2002）中一级标准。并联式系统的脱氮效果略优于常规系统,这说明,在碳源相对充足条件下,并联式系统较长的缺氧时间,使得反硝化程度比常规充分,因此脱氮效果优于常规。二、两系统的除磷效果随着COD（有机负荷）的升高而逐渐升高,在COD浓度为450mg/L（负荷为0.49～0.62kgCOD/kgMLSS.d）时,TP去除效果最好,并联式可达到75.6%,常规可达到75.5%,出水均达到一级排放标准。总氮增加到50mg/L时,两系统氨氮去除率都小于75%,出水氨氮浓度均大于5mg/L,常规系统出水NO₃^--N浓度为15.1mg/L,并联式系统出水NO₃^--N浓度为14.9mg/L。这说明50mg/L进水氨氮浓度超过了系统的硝化容量。在0.18～0.24kgCOD/kgMLSS.d的负荷下,两系统的反硝化效果较差。增加氮磷对并联式系统的影响远大于对常规系统的影响,即碳源严重不足对并联式系统的影响更大,这是因为并联式系统对碳源利用率高,将原本不足的碳源平分到厌氧和缺氧区使得二者所能利用的碳源都不足以进行有效的释磷和反硝化反应,因此氮磷脱除效果反而不如常规系统。实验表明:在有机负荷为0.30～0.48kgCOD/kgMLSS.d时,由于并联式系统厌氧和缺氧时间是常规系统的两倍,反硝化和释磷都相对充分,因此并联式系统的脱氮除磷效果相对常规系统有一定的优势;而在0.49～0.62kgCOD/kgMLSS.d的负荷下,由于碳源充足,两者的脱氮除磷效果相差不大;在0.18～0.24kgCOD/kgMLSS.d的负荷下,由于碳源严重不足,而并联式系统将原本不足的碳源分两股进入厌氧区和缺氧区,既不能保证充分释磷,又不能保证充分反硝化,此时常规系统相对并联式系统的脱氮除磷效果有相对的优势。实验表明,在0.38～0.48kgCOD/kgMLSS.d的负荷下,无论常规还是并联式系统,两者的氮磷脱除效果都较好。因此,并联式系统适合在碳源充足的条件下使用。更多还原

【Abstract】 Normal A²/O process is the most common nutrient removal technology at present,with connected anaerobic zone and anoxic zone.It means that the wastewater has to enter meaningless anaerobic zone in the nitrogen removal process and the same disadvantage exits in the phosphorus removal process to enter meaningless anoxic zone.This results in long retention time,large tank volume and high investment and operation cost.Parallel Connected A²/O process is a new technology with parallel connected anaerobic zone and anoxic zone,followed by aerobic zone.In theory,this new technology can modify the disadvantage of Normal A²/O process by improving anaerobic and anoxic time in the same volume and influent.To investigate the difference between Normal A²/O process and Parallel Connected A²/O process,a lab-scale experiment was conducted for one year to obtain the optimized running parameter of the new process.This study uses two parallel equipments to study on the the nutrients removal effect of the two technologies in three conditions（respectively the common condition, the condition of abundant carbon source and the condition of deficient carbon source）, through regulating COD,TN and TP of the influent from municiple wastewater of Shanghai,with 15 days of each test condition.In the condition of 150～450mg/L COD influent with 13 hours’ waterpower retention time,both the two systems perform good removal effect of COD.The outlet water absolutely meets the requirement of the first rank A of <Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant>（GB18918-2002）,which is less than 50 mg/L.In the concentration gradient of 170,250,330 and 450mg/L,comparing the nitrogen removal effect,two outcomes can be concluded:First,the nitrogen removal effect of the two systems are growing first and then lowing with the growing of COD concentration.The nitrogen removal rate reaches the highest when the influent COD is 330 mg/L,the Normal A²/O is 58.5%and the Parallel Connected A²/O is 66.7%. Both of them can meet the requirement of the first rank of <Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant>（GB18918-2002）.The nitrogen removal effect of Parallel Connected A²/O system is better than Normal A²/O system,because the anoxic time of Parallel Connected A²/O is two times of Normal A²/O.When the carbon source is relavent abundant,the denitrification of Parallel Connected A²/O is more sufficient than Normal A²/O.Second,as the influent COD（organic load）grows,phosphorus removal effect becomes better,when the influent COD is 330 mg/L,the Normal A²/O is 75.5%and the Parallel Connected A²/O is 75.6%.Both of them can meet the requirement of the first rank of <Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant>（GB18918-2002）. So it reflects that the growth of influent COD is good for phosphorus release.When influent TN is up to 50mg/L,Both the two systems perform bad removal rate of NH₄⁺-N,less than 75%.And the outlet concentration of NH₄⁺-N is more than 5mg/L in both the two systems,which are about 15mg/L.This reflect that the influent NH₄⁺-N concentration of 50mg/L beyond the nitrification ability.In the load of 0.18～0.24mg/L kgCOD/kgMLSS.d,the detrification of the two systems are bad.The increase of nitrogen and phophorus affects parallel A²/O much more than A²/O,it is to say,serious unsufficiency of carbon source affects parallel A²/O much more than A²/O.That is because the carbon source using efficiency of parallel A²/O is higher than A²/O,when unsufficient carbon source sivided into anaerobic zone and anoxic zone,none of the two zone can perform efficient phosphorus release and denitrification,which lead to worse nutrients removal effect of parallel A²/O system.Three outcomes can be abttained from the experiment:at the organic load of 0.30～0.48kgCOD/kgMLSS.d,the phosphorus release and denitrification of parallel A²/O is relovent sufficient for its anaerobic time and anoxic time is twice than Normal A²/O system,so Parallel Connected A²/O system possesses advantage to Normal A²/O system.At the organic load of 0.49～0.62kgCOD/kgMLSS.d,the nutrients removal rates of both systems are the same for sufficient carbon source.At the organic load of 0.18～0.24kgCOD/kgMLSS.d,none of phosphorus releases and denitrification can be good for seriously unsufficient carbon source divided into two influents.In this condition,the phosphorus removal of Parallel Connected A²/O system is worse than Normal A²/O system.The experiment reflects that the organic load of 0.18～0.24kgCOD/kgMLSS.d is fit for both the two systems.Therefore,Parallel Connected A²/O system is fit for abundant carbon source condition.更多还原