A~2/O工艺反硝化除磷试验研究

在A2/O工艺中,通过调节混合液回流比,实现了反硝化除磷菌的富集。COD和氨氮的平均去除率分别为85%和95.6%,达到稳定除磷效果时,磷酸盐的平均去除率为82.9%。缺氧段吸磷量所占比例从27.4%增至65.7%,反应后期平均比值为62.6%。污泥特性实验表明最大缺氧吸磷速率为5.79 mgP/(gMLSS.h),最大好氧吸磷速率为9.29 mgP/(gMLSS.h),两者的比值为62.3%。     

A2O工艺处理低C/N比生活污水的试验研究

采用52.5 L的A²O试验装置处理实际生活污水,研究了A²O工艺在处理低C/N比生活污水时的脱氮除磷特性,并探讨了如何通过强化缺氧吸磷来提高系统的脱氮除磷效率。试验结果表明：在厌氧/缺氧/好氧体积比为1/1/2、HRT为8 h、污泥回流比为70%、内回流比为300%的工况下处理C/N为7.89的生活污水,TN和SOP去除率分别能够达到85.4%和93.3%,系统中存在反硝化除磷,缺氧吸磷占总吸磷量的25.3%。同样的运行条件下处理C/N为4.20的生活污水时,SOP去除几乎不受影响,但TN去除率降低至62.2%,平均出水TN浓度也超过20 mg•L^-1。维持厌氧区体积不变,增大缺氧区体积,使得缺氧/好氧体积比为5/8时,TN去除率可上升到70.7%,缺氧吸磷占总吸磷量的55.2%。同时改变内回流比的试验表明250%的内回流比能最大程度地强化反硝化除磷的作用,此时TN去除率可提高至77.3%。强化A²O工艺中的反硝化除磷,能克服碳源不足对脱氮除磷的影响,显著提高低C/N比污水的脱氮除磷效率。     

反硝化除磷菌富集试验研究

采用A2-SBR反应器对反硝化除磷菌进行富集研究,结果表明反硝化除磷菌存在于污水处理厂活性污泥中,通过厌氧／缺氧的强化交替运行,能使反硝化除磷菌得到富集。厌氧／好氧批实验结果表明,反硝化除磷菌能够利用氧气作为电子受体进行吸磷,其比吸磷速率高于缺氧比吸磷速率。     

分段进水脱氮除磷工艺中反硝化除磷的实现与维持

以实际城市生活污水为处理对象,应用改良UCT分段进水工艺研究反硝化除磷的实现途径与维持方法,探讨工艺运行参数对反硝化除磷性能的影响,并分析了强化缺氧吸磷对提高系统脱氮除磷效率的作用和稳定维持反硝化除磷的控制策略。结果表明,通过A/O分段进水工艺向改良UCT分段进水工艺运行方式的转变,可以成功富集反硝化聚磷菌,最高比例达39.2%,污泥缺氧吸磷速率为3.19～4.48 mg P·（g VSS）^-1·h^-1。缺氧/好氧吸磷速率和磷去除率随厌氧池体积的增加而增加,最佳体积分配为34/102/204 L（1/3/6）。控制污泥回流和内循环分别为100%相似文献   

强化生物除磷系统中聚磷菌菌群特性

为了研究强化除磷系统中聚磷菌(PAOs)菌群特性,通过批次试验分别考察了厌氧/好氧(A/O)污泥和厌氧/缺氧(A/A)污泥吸磷特性。试验结果表明:A/O污泥好氧吸磷速率(qPo)大于缺氧吸磷速率(qPa),而A/A污泥qPo却小于qPa。基于此试验结果可得出目前普遍应用qPa与qPo的比值表征反硝化聚磷菌(DPAOs)占PAOs的相对百分比的方法不合理。聚磷菌菌群构成与电子受体类型有关,根据电子受体类型可将PAOs分为三种,即:PON(既能以氧作为电子受体,也能以硝态氮作为电子受体)、PO(只能以氧作为电子受体)和PN(只能以硝态氮作为电子受体)。     

A2O工艺中反硝化除磷及过量曝气对生物除磷的影响

如何有效提高城市污水厂除磷效率一直是研究的热点,而反硝化除磷菌可以在碳源不足的条件下,通过“一碳两用”的方式同时实现反硝化脱氮和吸磷作用,是一种新型高效的技术.试验以啤酒废水为研究对象,验证了厌氧-缺氧-好氧（A²O）工艺中反硝化除磷现象的存在及其对系统脱氮除磷的影响.试验结果表明,A²O系统稳定运行时,反硝化聚磷菌在缺氧区可利用在厌氧段储存的PHB大量吸磷,同时氮也得到去除,计算表明缺氧除磷量可占厌氧总释磷量的71.3%,另外可节约曝气能耗25%.无论系统进水COD浓度从200 mg•L^-1变化为400 mg•L^-1,COD、总氮和总磷去除率总能保持较高水平,平均出水总氮和总磷浓度分别小于10 mg•L^-1和0.30 mg•L^-1.另外发现,过量曝气对系统除磷具有明显的影响,导致除磷效率降低,甚至会产生不吸磷现象,系统需要经过约一个污泥龄时间才能恢复其吸磷能力,所以应加强系统曝气的控制.     

进水方式及水质对厌氧/缺氧系统反硝化聚磷的影响研究

采用厌氧/缺氧(A/A)SBR和人工废水,研究了不同硝酸盐投加方式下反硝化除磷的效果,探讨了进水方式以及水质对反硝化除磷的影响.结果表明,在厌氧段进水,反应器内初期形成的较高浓度磷会对聚磷菌释磷及其吸收碳源产生抑制作用.控制投加的COD量,使反应器内在厌氧段存在充足的碳源而在缺氧段时基本不残留碳源,则有利于提高除磷效果.厌氧/缺氧交替的环境,若厌氧段初始进水后反应器内初期磷浓度较高则有利于反硝化而非反硝化聚磷.     

反硝化除磷技术分析及展望

目前水体富营养化情况相当严重,其主要原因是磷含量的增加,因此废水的除磷技术十分重要.反硝化除磷技术利用厌氧、缺氧交替的环境,通过反硝化聚磷菌的作用,同时完成过量吸磷和反硝化过程,应用前景广阔.简述了反硝化除磷技术的机理,介绍了单污泥系统反硝化除磷工艺(BCFS工艺)及双污泥系统反硝化除磷工艺(A2N工艺、DEPHANO...     

强化生物除磷系统除磷性能分析

采用厌氧/好氧和厌氧/缺氧两阶段方法培养反硝化聚磷菌,研究了第一阶段系统的除磷性能。结果表明,稳定运行的强化生物除磷系统,具有良好的除磷性能,出水磷的质量浓度小于0.5 mg/L,除磷率大于93%。通过厌氧/好氧交替方式运行,反硝化聚磷菌占聚磷菌的比例约为21.2%。缺氧段硝酸盐的消耗量与磷的摄取量成线性关系,缺氧吸磷速率约为好氧吸磷速率的49.3%。     

厌氧段HRT对A2N工艺反硝化除磷脱氮效果的影响

为了考察厌氧段水力停留时间（HRT）对A2N工艺反硝化除磷脱氮效果的影响，采用连续流双污泥反硝化除磷脱氮装置以生活污水为处理对象，研究了厌氧段在不同HRT时系统的除磷脱氮效果，以及厌氧段不同HRT对系统处理过程的影响。结果表明，厌氧段是A2N工艺实现反硝化除磷脱氮的关键阶段。当厌氧段的HRT过长时，虽然溶解性PO4^3-的总释放量增加，但是后续的缺氧吸磷量和总氮的去除量并没有相应地增加。厌氧段的HRT时间过短，反硝化聚磷菌（DPB）在此对进水中易降解COD（CODRB）吸收不完全，导致后续缺氧吸磷量下降，同时影响了系统的除磷和脱氮效果。在处理实际生活污水水质时，厌氧段的HRT为2h即可满足除磷和脱氮要求。     

AOA-SBR工艺用于城市污水同步脱氮除磷

以城市污水为研究对象，考察了不同COD／N／P对厌氧／好氧／兼氧（AOA）．SBR工艺脱氮除磷效果的影响。经过3个月稳定运行，当COD：N：P-800：24：11时，AOA．SBR工艺对污水中有机物、氨氮和磷的去除率分别为100％、84％和93％。实验通过提高有机物浓度削弱聚磷菌（PAOs）与聚糖菌（GAOs）竞争底物的能力，抑制了PAOs好氧放磷速率。当COD=800mg／L时，GAOs和PAOs厌氧乙酸摄取量之比为l：9。此外，实验采用兼氧／好氧吸磷速率比，对反硝化聚磷菌数量（DNPAOs）进行估算，结果表明AOA-SBR工艺比值明显高于A20和AO工艺。因此，通过调节进水有机物浓度，可使DNPAOs在AOA-SBR同步脱氮除磷过程中发挥重要作用。     

改进型分段进水厌氧/缺氧/好氧工艺强化营养物去除

In order to enhance phosphorus removal in traditional step-feed anoxic/oxic nitrogen removal process,a modified pilot-scale step-feed anaerobic/anoxic/oxic (SFA²/O) system was developed,which combined a reactor similar to UCT-type configuration and two-stage anoxic/oxic process.The simultaneous nitrogen and phosphorus removal capacities and the potential of denitrifying phosphorus removal,in particular,were investigated with four different feeding patterns using real municipal wastewater.The results showed that the feeding ratios(Q₁)in the first stage determined the nutrient removal performance in the SFA²/O system.The average phosphorus removal efficiency increased from 19.17% to 96.25% as Q₁ was gradually increased from run 1 to run 4,but the nitrogen removal efficiency exhibited a different tendency,which attained a maximum 73.61% in run 3 and then decreased to 59.62% in run 4.As a compromise between nitrogen and phosphorus removal,run 3 (Q₁=0.45Q_total) was identified as the optimal and stable case with the maximum anoxic phosphorus uptake rate of 1.58mg·(g MLSS)^-1·h^-1.The results of batch tests showed that ratio of the anoxic phosphate uptake capacity to the aerobic phosphate uptake capacity increased from 11.96% to 36.85% with the optimal influent feeding ratio to the system in run 3,which demonstrated that the denitrifying polyP accumulating organisms could be accumulated and contributed more to the total phosphorus removal by optimizing the inflow ratio distribution.However,the nitrate recirculation to anoxic zone and influent feeding ratios should be carefully controlled for carbon source saving.     

A2O工艺缺氧生物磷去除

A lab-scale anaerobic-anoxic-oxic (A2O) process used to treat a synthetic brewage wastewater was investigated. The objectives of the study were to identify the existence of denitrifying phosphorus removing bacteria (DPB), evaluate the contribution of DPB to biological nutrient removal and enhance the denitrifying phosphorus removal in A2O bioreactors. Sludge analysis confirmed that the average anoxic P uptake accounted for approximately 70% the total amount of P uptake, and the ratio of anoxic P uptake rate to aerobic P uptake rate was 69%. In addition, nitrate concentration in the anoxic phase and different organic substrate introduced into the anaerobic phase had significant effect on the anoxic P uptake. Compared with conventional A2O processes, good removal efficiencies of COD, phosphorus, ammonia and total nitrogen (92.3%, 95.5%, 96% and 79.5%, respectively) could be achieved in the anoxic P uptake system, and aeration energy consumption was saved 25%. By controlling the nitrate recirculation flow in the anoxic zone, anoxic P uptake could be enhanced, which solved the competition for organic substrates among poly-P organisms and denitrifiers successfully under the COD limiting conditions. Therefore, in wastewater treatment plants the control system should be applied according to the practical situation to optimize the operation.     

厌氧／缺氧SBR反硝化除磷过程的研究

Removal of denitrifying phosphorus was verified in a laboratory anaerobic/anoxic sequencing batch reactor (A/A SBR). The results obtained demonstrated that the anaerobic/anoxic strategy can enrich the growth of denitrifying phosphorus removing bacteria (DPB) and take up phosphate under anoxic condition by using nitrate as the electron acceptor. The phosphorus removal efficiency was higher than 90% and the effluent phosphate concentration was lower than 1mg·L^-1 after the A/A SBR was operated in a steady-state. When the chemical oxygen demand(COD) of influent was lower than 180mg·L^-1, the more COD in the influent was, the higher efficiency of phosphorus removal could be attained under anoxic condition. However, simultaneous presence of carbon and nitrate would be detrimental to denitrifying phosphorus removal. Result of influence of sludge retention time (SRT) on denitrifying phosphorus removal suggested that the decrease of SRT caused a washout of DPB and consequently the enhanced biological phosphorus removal decreased with 8 days SRT. When the SRT was restored to 16 days, however, the efficiency of phosphorus removal was higher than 90%.     

Optimisation of anaerobic/anoxic/oxic process to improve performance and reduce operating costs

A laboratory‐scale anaerobic/anoxic/oxic reactor system was used to treat synthetic brewery wastewater for 1 year. The objectives were to enhance denitrifying phosphorus removal, improve biological nutrient removal and reduce operating costs. Three operational strategies were tested: (1) controlling nitrate recirculation to stimulate the growth of denitrifying phosphate‐accumulating organisms; (2) adjusting the volume ratio of the anaerobic/anoxic/oxic zones to enhance anoxic P uptake; (3) bypassing a part of the influent flow into the anoxic zone to maximise anoxic P uptake and denitrification. The results showed that not only was anoxic P uptake enhanced but also energy consumption for aeration could be reduced when the anoxic effluent NO₃^?‐N concentration was controlled between 1 and 3 mg L^?1. The optimal volume ratio of the anaerobic/anoxic/aerobic zones in this system was found to be 1:1:2. The optimal bypass flow ratio was 0.32. The results indicated that the optimal strategies could improve treatment performance and reduce operational costs, but there was still a challenge to treat wastewater with low C/N ratio. Copyright © 2006 Society of Chemical Industry     

A2O工艺缺氧生物磷去除

A lab-scale anaerobic-anoxic-oxic （A^2O） process used to treat a synthetic brewage wastewater was investigated. The objectives of the study were to identify the existence of denitrifying phosphorus removing bacteria （DPB）, evaluate the contribution of DPB to biological nutrient removal and enhance the denitrifying phosphorus removal in A^2O bioreactors. Sludge analysis confirmed that the average anoxic P uptake accounted for approximately 70% the total amount of P uptake, and the ratio of anoxic P uptake rate to aerobic P uptake rate was 69%. In addition, nitrate concentration in the anoxic phase and different organic substrate introduced into the anaerobic phase had significant effect on the anoxic P uptake. Compared with conventional A^2O processes, good removal efficiencies of COD, phosphorus, ammonia and total nitrogen （92.3%, 95.5%, 96% and 79.5%, respectively） could be achieved in the anoxic P uptake system, and aeration energy consumption was saved 25%. By controlling the nitrate recirculation flow in the anoxic zone, anoxic P uptake could be enhanced, which solved the competition for organic substrates among poly-P organisms and denitrifiers successfully under the COD limiting conditions. Therefore, in wastewater treatment plants the control system should be applied according to the practical situation to optimize the operation.     

序批式反应器中反硝化除磷脱氮的研究

为了提高污水脱氮除磷的效率,研究采用序批式反应器(SBR工艺)厌氧、好氧和缺氧(AOA)的运行方式富集反硝化聚磷菌(DPB),实现同步脱氮除磷。结果表明:在好氧段投加甲醇作为碳源(25—40 mg/L)可有效抑制好氧吸磷,对硝化反应影响较小,能够在缺氧段实现同时反硝化脱氮除磷。SBR反应器稳定运行10个月,当进水NH4+-N、PO43--P分别为30,15 mg/L时,总氮(TN)和PO43--P的平均去除率分别为82.5%和92.1%。聚磷菌能够利用硝酸盐作为电子受体,DPB占总聚磷菌的比例达到44.8%。与A2O运行方式相比,AOA运行方式更有利于实现DPB的富集。     

耦合内置缺氧区的氧化沟系统强化脱氮除磷的研究(英文)

A novel modified pilot scale anaerobic oxidation ditch with additional internal anoxic zones was operated experimentally, aiming to study the improvement of biological nitrogen and phosphorus removal and the effect of enhanced denitrifying phosphorus removal in the process. Under all experimental conditions, the anaerobic-oxidation ditch with additional internal anoxic zones and an internal recycle ratio of 200% had the highest nutrient removal efficiency. The effluent NH4+-N, total nitrogen (TN), PO43-P and total phosphorus (TP) contents were 1.2mg·L-1 , 13mg·L-1, 0.3mg·L-1 and 0.4mg·L-1, respectively, all met the discharge standards in China. The TN and TP removal efficiencies were remarkably improved from 37% and 50% to 65% and 88% with the presence of additional internal anoxic zones and internal recycle ratio of 200%. The results indicated that additional internal anoxic zones can optimize the utilization of available carbon source from the anaerobic outflow for denitrification. It was also found that phosphorus removal via the denitrification process was stimulated in the additional internal anoxic zones, which was beneficial for biological nitrogen and phosphorus removal when treating wastewater with a limited carbon source. However, an excess internal recycle would cause nitrite to accumulate in the system. This seems to be harmful to biological phosphorus removal.     

Performance and microbial population variation in a plug‐flow A2O process treating domestic wastewater with low C/N ratio

BACKGROUND: In this study, a plug‐flow A²O (anaerobic/anoxic/oxic) reactor, with a working volume of 52.5 L, was employed to investigate the performance of biological nutrients removal and microbial population variations when treating low C/N ratio domestic wastewater. RESULTS: Results showed that TN removal was significantly affected by the shortage of carbon source while phosphorus removal was only slightly affected. The effluent soluble orthophosphate‐phosphorus (SOP) concentration was lower than 0.50 mg L^?1 but the TN concentration was over 20 mg L^?1 when the C/N ratio was 4.43. There was denitrifying phosphorus removal in the anoxic reactor and this was enhanced by increasing the volume ratio of anoxic reactor and maintaining appropriate mixed liquor recycle rate. More than 60% of the SOP were removed in anoxic reactors by denitrifying phosphorus removal when the volume ratio of anaerobic/anoxic/oxic was 1/1.4/1.6 and the mixed liquor recycle rate was 250%. The TN concentration of effluent decreased to 11.34 mg L^?1 and SOP concentration was still lower than 0.5 mg L^?1 in this condition. The main microorganisms found in the process by polymerase chain reaction‐denaturing gradient gel electrophoresis (PCR‐DGGE) and the functional biodiversity are discussed. CONCLUSION: Traditional design and operating parameters of A²O are not appropriate for treating low C/N wastewater. Enhancing the denitrifying phosphorus removal ratio in an A²O process is an effective way to increase the removal rate of N and P from low C/N wastewater. Copyright © 2010 Society of Chemical Industry