复合生物反应器亚硝酸型同步硝化反硝化脱氮

Sequence hybrid biological reactor （SHBR） was proposed, and some key control parameters were investigated for nitrogen removal from wastewater by simultaneous nitrification and denitrification （SND） via nitrite. SND via nitrite was achieved in SHBR by controlling demand oxygen （DO） concentration. There was a programmed decrease of the DO from 2.50 mg·L^-1 to 0.30 mg·L^-1, and the average nitrite accumulation rate （NAR） was increased from 16.5% to 95.5% in 3 weeks. Subsequently, further increase in DO concentration to 1.50 mg·L^-1 did not destroy the partial nitrification to nitrite. The results showed that limited air flow rate to cause oxygen deficiency in the reactor would eventually induce only nitrification to nitrite and not further to nitrate. Nitrogen removal efficiency was increased with the increase in NAR, that is, NAR was increased from 60% to 90%, and total nitrogen removal efficiency was increased from 68% to 85%. The SHBR could tolerate high organic loading rate （OLR）, COD and ammonia-nitrogen removal efficiency were greater than 92% and 93.5%, respectively,, and it even operated under low DO concentration （0.5 mg·L^-1） and maintained high OLR （4.0 kg COD·m^-3·d^-1）. The presence of biofilm positively affected the activated sludge settling capability, and sludge volume index （SVI） of activated sludge in SHBR never hit more than 90 ml·L^-1 throughout the experiments.     

SBR法处理垃圾渗滤液的反硝化过程中NO~-_2积累的研究

The nitrite accumulation in the denitrification process is investigated with sequencing batch reactor (SBR) treating pre-treated landfill leachate in anoxic/anaerobic up-flow anaerobic sludge bed (UASB). Nitrite accumulates obviously at different initial nitrate concentrations (64.9,54.8,49.3 and 29.5 mg•L－1) and low temperatures, and the two break points on the oxidation-reduction potential (ORP) profile indicate the completion of nitrate and nitrite reduction. Usually, the nitrate reduction rate is used as the sole parameter to characterize the denitrification rate, and nitrite is not even measured. For accuracy, the total oxidized nitrogen (nitrate + nitrite) is used as a measure, though details characterizing the process may be overlooked. Additionally, batch tests are conducted to investigate the effects of C/N ratios and types of carbon sources on the nitrite accumulation during the denitrification. It is observed that carbon source is sufficient for the reduction of nitrate to nitrite, but for further reduction of nitrite to nitrogen gas, is deficient when C/N is below the theoretical critical level of 3.75 based on the stoichiometry of denitrification. Five carbon sources used in this work, except for glucose, may cause the nitrite accumulation. From experimental results and cited literature, it is concluded that Alcaligene species may be contained in the SBR activated-sludge system.     

水力停留时间对SBR工艺脱氮除磷效果的影响分析

以西安市第四污水处理厂初沉池实际出水为研究对象,研究了SBR试验装置中HRT对有机物、氮、磷的去除效果。结果表明,HRT对COD、PO43--P的去除效果影响较小,对TN和NH4+-N的去除影响较大。TN和NH4+-N的去除率随好氧停留时间、缺氧停留时间的增加而增大。试验装置在缺氧段、好氧段停留时间分别为5 h、3.5 h的运行条件下,对COD、NH4+-N和TN的平均去除率分别达到了86%、98%和74%,出水水质除TP之外,均达到了城镇污水处理厂污染物排放标准(GB 18918-2002)一级A排放标准要求,试验结果为SBR工艺污水厂升级改造提供了工艺运行参数,也可供同类型污水处理厂工艺升级改造设计时参考。     

苯酚对污水生物脱氮系统亚硝积累及污泥性能的影响

采用SBR缺氧/好氧反应工艺,研究了不同苯酚浓度对脱氮过程中亚硝积累与污泥性能的影响。结果表明,苯酚浓度在0~90 mg·L^-1变化时系统出现2次明显亚硝酸盐积累,最终稳定维持在70%±5%,低浓度(0~30 mg·L^-1)系统亚硝酸盐积累恢复是微生物改变自身结构及分泌胞外聚合物导致;高浓度(60~90 mg·L^-1)苯酚条件下亚硝积累是由于苯酚对AOB(ammonia-oxidizing bacteria,氨氮氧化细菌)和NOB(nitrite-oxidizing bacteria,亚硝酸氧化细菌)抑制作用引起的微生物种群改变形成。氨氮氧化速率和氮氧化物生成速率由10.85 mg N·(g MLSS)^-1·h^-1和10.12 mg N·(g MLSS)^-1·h^-1降低至2.79 mg N·(g MLSS)^-1·h^-1和2.32 mg N·(g MLSS)^-1·h^-1,亚硝酸盐积累率和氮氧化物生成速率呈现负相关性,与苯酚浓度呈正相关;荧光原位杂交表明苯酚的抑制使得硝化菌群结构发生了变化,AOB 相对数量由2.80%增加为9.30%。苯酚的可降解性使得系统污泥浓度由2500 mg·L^-1左右上升至5870 mg·L^-1。当EPS(extracellular polymeric substances,胞外聚合物)总量由67.20 mg·(g VSS)^-1减少至32.10 mg·(g VSS)^-1时,SVI从165 ml·g^-1降到50 ml·g^-1。亚硝酸盐积累、丝状菌和胞外聚合物是引起活性污泥系统SVI变化的原因,其中NAR影响最大,丝状菌次之。     

膜生物反应器中污泥膨胀对脱氮除磷的影响

膜生物反应器以其膜取代了常规活性污泥法中的二沉池的突出优点迅速成为污水处理的新的发展方向.试验研究了污泥膨胀时,膜生物反应器对脱氮除磷的影响.分别对比了在正常情况下和污泥膨胀时,膜生物反应器对CODCr、氨氮、TN、TP的去除率.试验结果表明:发生污泥膨胀后,对CODCr的去除率达到96.51%有所提高,对氨氮、TN、TP的去除率分别为75.9%、39.8%、19.7%均有不同程度的下降.     

水力停留时间对生物膜/颗粒污泥耦合工艺脱氮除磷的影响

采用自主设计的悬浮载体生物膜/颗粒污泥耦合装置,利用硝化菌载体生物膜和反硝化聚磷菌颗粒污泥,研究水力停留时间对生物膜/颗粒污泥耦合工艺脱氮除磷的影响,得出最佳工艺参数。试验考查水力停留时间分别为6 h、7 h、8.5 h和10.5 h,结果表明,当水力停留时间为8.5 h时,系统的COD去除率为91.26%,氨氮和总氮的去除率分别为80.68%和70.58%,厌氧释磷速率也较稳定,为0.47 mg P·（g SS）^-1·h^-1,厌氧释磷速率最高,其碳源利用率最大,反硝化除磷效率最稳定,PO₄^3--P去除率为76.50%,反硝化除磷效率为1.04 mg P·（mg NO₃^--N）^-1,所以当水力停留时间为8.5 h时,系统具有较高的脱氮除磷效率。当水力停留时间过短时,氮磷的去除不完全,过长时,系统不稳定,系统的最优水力停留时间为8.5 h。     

水力停留时间对生物膜/颗粒污泥耦合工艺脱氮除磷的影响

采用自主设计的悬浮载体生物膜/颗粒污泥耦合装置,利用硝化菌载体生物膜和反硝化聚磷菌颗粒污泥,研究水力停留时间对生物膜/颗粒污泥耦合工艺脱氮除磷的影响,得出最佳工艺参数。试验考查水力停留时间分别为6 h、7 h、8.5 h和10.5 h,结果表明,当水力停留时间为8.5 h时,系统的COD去除率为91.26%,氨氮和总氮的去除率分别为80.68%和70.58%,厌氧释磷速率也较稳定,为0.47 mg P·(g SS)-1·h-1,厌氧释磷速率最高,其碳源利用率最大,反硝化除磷效率最稳定,PO43--P去除率为76.50%,反硝化除磷效率为1.04 mg P·(mg NO-3-N)-1,所以当水力停留时间为8.5 h时,系统具有较高的脱氮除磷效率。当水力停留时间过短时,氮磷的去除不完全,过长时,系统不稳定,系统的最优水力停留时间为8.5 h。     

污泥膨胀对膜生物反应器脱氮除磷效果的影响

膜生物反应器以其用膜取代常规活性污泥法中二沉池的突出优点迅速成为污水处理的新发展方向.研究了污泥膨胀时,膜生物反应器脱氮除磷的效果.分别对比了在正常情况下和污泥膨胀时,膜生物反应器对CODCr氨氮、TN、TP的去除率.试验结果表明:发生污泥膨胀后,对CODCr的去除率提高到96.51%,而对氨氮、TN、TP的去除率分别为75.9%、39.8%、19.7%,均有不同程度的下降.     

低碳氮比下曝气对反硝化过程中亚硝酸盐积累特性的影响

采用SBR反应器内的活性污泥,模拟污水厂AAO运行方式中活性污泥外回流经厌氧池至缺氧池、内回流至缺氧池和在缺氧池与好氧池循环的3种条件以及3种条件下的污泥按不同比例混合后的活性污泥状态,研究不同状态活性污泥反硝化过程中亚硝酸盐积累特性,考察在低碳氮比(C/N)时不同初始COD浓度条件下的亚硝酸盐积累特性。试验结果表明:通过活性污泥间歇曝气与未曝气反应的最高亚硝酸盐氮(NO~-_2-N)积累量与亚硝酸盐积累率(NAR)的对比可以看出,曝气有利于活性污泥反硝化过程中NO~-_2-N积累,可通过调节不同状态污泥的混合比例来提高NO~-_2-N积累量,反复经过缺氧-好氧的活性污泥的NO~-_2-N积累效果最好,最高NO~-_2-N积累量和NAR为15 mg/L、37.5%;适当降低C/N有利于NO~-_2-N积累,且NO~-_2-N积累量维持在较高浓度的持续时间长,但碳源严重不足会导致硝酸盐氮(NO~-_3-N)不能被充分还原,导致NO~-_2-N积累效果差。     

污泥运行指标对A/A/O氧化沟生物脱氮的影响研究

采用实际城市污水,研究污泥回流比、污泥龄和污泥浓度(MLSS)对中试A/A/O氧化沟脱氮的影响。结果表明:系统脱氮能力随污泥回流比增大而增强,大于90%时,NH4+-N和TN去除率没有明显提高,还会增加能耗。污泥回流比为60%~90%,泥龄为15~20 d时脱氮效果较好,还需根据进水负荷和脱氮效果进行调节。MLSS对工艺同时硝化反硝化(SND)有显著影响,当MLSS从3 000 mg/L增至6 000 mg/L时,NH4+-N去除率从81.7%增至98.8%,TN去除率从47.2%增至66%,SND/TN从19.8%增至37.4%。     

Denitrifying phosphorus removal with nitrite by a real‐time step feed sequencing batch reactor

BACKGROUND: Nitrite is toxic to anoxic phosphorus uptake when it exceeds a threshold concentration. In this study, denitrifying phosphorus removal with nitrite as electron acceptor was investigated in a sequencing batch reactor (SBR) operated using a real‐time step feed strategy. RESULTS: The nitrite pulse concentration was initially determined by batch experiments. pH increased with use of nitrite for phosphate uptake, and decreased when the nitrite was used up. Nitrite was added promptly after the pH reached the peak value, and phosphate uptake continued, driven by the nitrite addition. The pH was adjusted to 7.50 using HCl with each pulse of nitrite addition. ORP could be used to determine the endpoint of denitrifiying phosphorus removal. However, the variation of second derivative of ORP with time was much more sensitive and should be a more suitable control parameter than ORP itself to determine the endpoint of denitrifying phosphorus removal. CONCLUSION: Compared with denitrifying phosphorus removal with nitrate as electron acceptor, denitrifying phosphorus removal with nitrite using real‐time step feed can save 22.3% of polyhydroxyalkanoate (PHA) for phosphorus removal and 49.4% of PHA for nitrogen removal. In addition, the reaction time could be shortened. Copyright © 2010 Society of Chemical Industry     

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。     

厌氧序批式反应器快速形成颗粒污泥技术研究

厌氧序批式反应器(ASBR)初次启动用厌氧消化污泥接种,比较了投加聚季铵盐(A柱)与空白对照(B柱)2个反应器的颗粒污泥形成过程。启动后以每隔2 d投加1次的投加方式向反应器中不断补充聚季铵盐,聚季铵盐投加质量与污泥质量之比取1.6 mg/g。结果表明,A柱颗粒污泥平均粒径达到0.72 mm仅需73 d,比B柱提前了25 d。A柱在启动56 d后COD负荷达到10 g/(L.d),形成的颗粒污泥平均粒径大于B柱(0.55 mm),产甲烷活性也较高。所以投加聚季铵盐能有效促进污泥颗粒化进程。     

SBR工艺研究进展

近年来，间歇式活性污泥法由于其工艺简单、运行灵活、基建和运行费用低，已成为国内外竞相研究和开发的热门污水生物处理工艺。在阐述了SBR反应器的工艺特点及计算的基础上，对近年来其主要的变形丁艺(ICEAS，CAST，IDEA，DAT—IAT，UNITANK等)和其他新型SBR工艺的发展进行了综述。同时指出随着对该工艺的研究和开发，它必将成为一种很有竞争力的污水处理工艺，拥有良好的发展前景。     

SBR反应器结构对好氧颗粒污泥形态的影响及其动力学分析

采用屠宰废水酸化池出水,在高径比分别为11.1和1.2的SBR反应器(编号分别为R1和R2)中培养好氧颗粒污泥(AGS),考察了AGS的形成过程及其对COD的去除效果.结果表明,R1反应器运行29d形成了圆形AGS,R2反应器运行44d形成了圆柱状AGS,并且形成过程具有反复性.当圆形AGS粒径为2mm,纵横比接近1,...     

温度对AOA-SBR工艺同步脱氮除磷的影响

为了提高脱氮除磷的效率,采用序批式生物反应器（SBR）工艺处理模拟生活污水,考察了不同温度下N/P、污泥龄（SRT）对厌氧/好氧/缺氧序批式生物反应器（AOA-SBR）工艺同步脱氮除磷效能的影响。结果表明：当温度为10 ℃、N/P为2～3、SRT为20 d时,NH4+-N、TN和TP去除率分别为78%、69%和56%,污泥产率YS为0.339 kgSS/(kgBOD5),污泥含磷率PC为4.68%。当温度为25 ℃、N/P为3～5、SRT为15 d时,NH4+-N、TN和TP的去除率分别为88%、83%和91%,污泥产率YS为0.253 kgSS/(kgBOD5),污泥含磷率PC为6.35%。当温度为35 ℃、N/P为5～7、SRT为10 d时,NH4+-N、TN和TP去除率分别为80%、66%和73%,污泥产率YS为0.225 kgSS/(kgBOD5),污泥含磷率PC为7.42%。污泥产率YS随着温度和污泥龄的增加而降低,通过调节温度和污泥龄能够实现污泥减量。     

Biological nutrient removal in a sequencing batch reactor using ethanol as carbon source

BACKGROUND: When organic matter is limiting for biological nutrient removal (BNR) from wastewater, external organic carbon can be added to a wastewater treatment plant (WWTP). This increases the overall treatment cost, so the choice of substrate is critical. The effect of using ethanol as the carbon source for BNR is investigated. RESULTS: The results clearly showed that using ethanol as a carbon source is a promising strategy for removing nutrients from wastewater. Effluent concentrations of 3.0 mg total nitrogen (TN) L^?1 (96% N removal efficiency) and 0.05 mg phosphate (P‐PO₄) L^?1 (99.9% P removal efficiency) were obtained. Furthermore, tests performed in order to identify the carbon source used by polyphosphate‐accumulating organisms (PAOs) showed that the phosphorus release/carbon uptake ratio using ethanol (0.41 mmol P mmol^?1 C) was slightly lower than that with acetate (0.50 mmol P mmol^?1 C) but close to that with propionate (0.42 mmol P mmol^?1 C). CONCLUSION: Therefore, taking into account the results presented for ethanol‐acclimatised biomass and the fact that the cost of ethanol is lower than that of acetate or propionate, ethanol can be considered as an alternative carbon source if one is needed in a WWTP. Copyright © 2007 Society of Chemical Industry     

Sensitivity analysis on a sequencing batch reactor model I. Effect of kinetic parameters

A structured model for sequencing batch reactors, which was developed earlier and tested successfully against a number of experimental data sets, is used in this study to investigate the sensitivity of model predictions to some of the system kinetic parameters for a wide range of parameter values. The results obtained reveal the relative importance of the various parameters. The parameter K_s has insignificant effects on the effluent COD concentration; although its effect on the intermediate COD concentration is appreciable. The parameters α₁, μ_m, K_p, K_x, K_h and B_h have been shown to affect considerably both the intermediate and effluent COD concentrations. Since the effluent COD concentration is one of the prime state variables in the design of wastewater treatment reactors, special attention should be given to these parameters when such a model is used for design and control purposes. ©1997 SCI