NO-2作为电子受体对反硝化吸磷影响动力学研究

在生物除磷系统中NO-2常被认为是反硝化吸收磷过程的抑制剂,而NO-2对反硝化吸磷抑制过程的抑制剂量的结果差别很大,缺乏动力学研究.本研究应用序批式反应器(SBR)在不同的NO-2浓度和pH梯度下进行了反硝化吸收磷试验,其接种活性污泥取自A2/O氧化沟中试反应器.SBR试验步骤为,取氧化沟好氧区活性污泥,先投加乙酸钠释放磷,然后投加NO-2吸收磷.大量试验发现NO-2和pH共同作用对反硝化吸磷产生了抑制.结果表明,[1]在恒定pH下,比反硝化速率和比吸磷速率与初始NO-2浓度均符合Andrews抑制动力学;[2]在6.5相似文献   

A2/O污水处理工艺中基质转化机理研究

以实际污水培养驯化污泥的小试规模A²/O工艺为研究对象,对系统中基质的转化机理及硝态氮对基质转化的影响进行了批式试验研究.结果表明,在无硝态氮存在于厌氧环境的系统中,厌氧段消耗的COD有51%可被聚磷菌吸收并合成为聚羟基链烷酸(PHAs);缺氧和好氧条件下的比吸磷速率为3.87和6.54 mg/(g·h),利用单位PHAs的吸磷量(r_P/PHA)分别为0.38和0.78.而在有硝态氮存在于厌氧环境的系统中,厌氧段消耗的COD仅有30.8%可被聚磷菌吸收并合成PHAs,61.5%用于还原硝态氮;缺氧和好氧条件下的比吸磷速率为2.24和4.58 mg/(g·h),r_P/PHA值分别为0.35和0.77.同时,在这2个系统中厌氧阶段释放的磷和消耗的COD成良好的线性关系.硝态氮存在于厌氧环境会降低聚磷菌的厌氧释磷速率和效率,使PHAs的合成量减少,从而降低聚磷菌的缺氧和好氧吸磷速率,但并不会影响其吸磷能力.     

模拟光伏曝气SBR除磷性能及其聚磷菌群落结构

基于村落生活污水排水、日光昼夜变化和SBR(序批式反应器)运行方式的特点及强化生物除磷所需的交替厌氧/好氧环境,采用模拟光伏曝气SBR处理生活污水,考察反应器的除磷效果及机理,并采用PCR(聚合酶链式反应)和TA克隆考察反应器内PAO(聚磷菌)的群落结构. 结果表明,反应器在12 d内成功启动,TP去除率从35.4%逐渐升至98.8%,此后TP去除率一直稳定在97%以上,出水ρ(TP)小于0.1 mg/L. 在反应段末期,反应器污泥中w(TP)达60 mg/g以上,其中w(complex-P)(complex-P为胞内聚合磷)达到55.0 mg/g,而w(EPS-P)(EPS-P为胞外聚合物结合磷)所占比例<10%,表明EPS吸附对除磷的贡献很小,除磷主要通过PAO的释磷/吸磷过程实现. 所有PAO均属于“Candidatus Accumulibacter”世系,Ⅱ型Candidatus Accumulibacter(包括Clade ⅡA-Clade ⅡD)是反应器内主要的PAO,其在3个克隆文库(d30、d60、d90)中所占比例分别为80.0%、80.0%和76.7%.      

聚烃基烷酸转化对强化生物除磷影响研究

通过丙酸和乙酸C-mol比为0.5和2的合成废水驯化微生物的SBR反应器(SBR1和SBR2)批式实验,研究了强化生物除磷系统中聚烃基丁酸(PHB)和聚烃基戊酸(PHV)的转化对磷吸收/释放及去除率的影响.结果显示,磷的释放/吸收和去除率与PHB和PHV的转化有很好的相关性(R²>0.90).回归系数表明,特定废水驯化的污泥,磷的吸收和释放主要受PHB转化的影响,但磷的去除率却主要依赖于PHV的合成与降解;对于不同比例丙酸/乙酸废水驯化污泥,SBR2比SBR1污泥的PHB合成和降解能力增强,PHV合成和降解能力减小,生物除磷效果平均增加16.69%.因此,进水丙酸/乙酸比例及驯化影响聚磷微生物的PHB/PHV转化量,进而影响对磷的吸收/释放和除磷效果,PHB与PHV的转化量应作为生物除磷系统的关键调控因素考虑.     

SBR中生物除磷颗粒污泥的反硝化聚磷研究

反硝化聚磷菌(DNPAOs)可利用厌氧储存的聚.3.羟基丁酸(PHB)以硝酸盐和亚硝酸盐为电子受体进行过量吸磷和反硝化,从而达到在低碳源下脱氮除磷的双重目的.本试验在SBR反应器中,采用厌氧,缺氧/好氧(A/A/O)交替运行的方式.将富集聚磷菌(PAOs)的颗粒污泥成功地诱导为具有反硝化聚磷能力的颗粒污泥.诱导结束后P的去除率在90%以上,NOx-N的去除率在93%以上,厌氧段释磷量在25-33 mg/L,缺氧段每去除lg NOx-N吸收P约1.3 g;典型周期运行结果显示,厌氧段最大比释磷速率(SRPR)为18.39 mg/(g.h),缺氧段最大比吸磷速率(SUPR)为23.72 mg/(g·h),最大比反硝化速率(SDNR)为18.19mg/(g·h),好氧段最大SUPR为17.15 me,/(g·h):颗粒污泥中DNPAOs的数量由诱导前的14.9%增加到80.7%.与除磷颗粒污泥相比.反硝化聚磷颗粒污泥沉速提高0.16-0.7倍,比重提高0.003 1.     

Fe3+对反硝化系统除磷效果及微生物产物的影响

铁盐常作为化学药剂来辅助城市污水处理厂的生物除磷. 利用间歇试验考察投加不同ρ(FeCl₃)时反硝化除磷系统中污染物的去除效果以及EPS(胞外聚合物)、PHA(聚羟基脂肪酸酯)、糖原的形成与转化,并通过分析胞内Fe3+含量来解析Fe3+对反硝化除磷系统的影响. 结果表明:①Fe3+投加量(以ρ计)<10 mg/L时,系统中PO₄3-P的去除率由未投加时的88.4%升至100%;Fe3+投加量>10 mg/L时,PO₄3-P的去除率随Fe3+投加量的增加而缓慢降至84.4%(Fe3+投加量为25 mg/L时). ②Fe3+投加量(10 mg/L)较低时,会增加污泥中w(总EPS);但由于Fe3+会与EPS中的羟基、氨基等官能团发生络合反应,导致Fe3+投加量(>10 mg/L)较高时可检出的w(总EPS)降低. ③投加Fe3+对厌氧段内w(PHA)、w(糖原)的变化及生物释磷的抑制作用影响不大,但Fe3+投加量(>10 mg/L)较高时对缺氧段NO₃--N的生物利用、生物吸磷作用以及PHA和糖原的转化速率有明显的抑制作用. ④缺氧阶段末胞内Fe3+含量(以w计)增加144%(Fe3+投加量为25 mg/L时),说明抑制作用主要是因为缺氧段Fe3+随细胞吸磷作用一并进入胞内,直接影响生物酶活性.      

纳米ZnO浓度对EBPR系统除磷性能的影响

采用SBR工艺接种成熟的强化生物除磷(EBPR)絮状污泥,研究了不同浓度纳米ZnO(ZnO NPs)对颗粒化EBPR系统性能的影响。结果表明:低浓度(≤1 mg/L)ZnO NPs可促进厌氧释磷和好氧吸磷作用;随着ZnO NPs浓度的增加,磷酸盐及COD去除能力受到明显抑制;在厌氧释磷过程中,PAOs对ZnO NPs的毒性更为敏感;与未受ZnO NPs污染的系统相比,ZnO NPs浓度为15 mg/L条件下的释磷速率与吸磷速率分别下降了0.1 mg/(gVSS·min)和0.15 mg/(gVSS·min)。     

污水起始pH值对序批式反应器(SBR)中增强生物除磷过程的影响研究

通过序批式反应器（SBR）的连续运行,研究了污水不同起始pH值对增强生物除磷的影响（SBR1：pH=6.8;SBR2：pH=7.6）.结果表明,在厌氧阶段,SBR2释磷量高于SBR1;在好氧阶段,SBR2降解的聚羟基烷酸（PHA）量低于SBR1,并且糖原合成量/PHA降解量的比例要远远低于SBR1.但是,SBR2反而比SBR1吸收更多的磷.进一步的研究表明,由于SBR2比SBR1合成的糖原少,因此其低PHA降解量并没有导致低吸磷量.推测SBR2中的聚磷菌（PAO）量高于SBR1,从而导致SBR2有着更高的吸磷量以及PHA利用率.在好氧末,SBR2中的可溶解性正磷酸盐（SOP）浓度远远低于SBR1,SBR2的除磷效果达到93.67%,但SBR1仅为65.06%.因此,通过控制污水起始pH值的方法可以达到显著提高增强生物除磷效果的目的,比控制整个污水生物处理过程pH的方法要方便.     

SBR双颗粒污泥系统脱氮除磷性能研究

以模拟废水为研究对象,对SBR双颗粒污泥系统的脱氮除磷性能进行了考察.试验结果表明,A₂N双颗粒污泥系统能使硝化菌和聚磷菌分别在各自最佳的环境中生长,有利于系统脱氮除磷的稳定和高效运行,可控制性也得到了提高.在COD为300 mg·L^-1条件下,系统对COD的平均去除率达到78.8%,大部分COD被聚磷菌用来合成PHA;当溶解氧控制在3.55~4.90 mg·L^-1和5.60~6.60 mg·L^-1之间时,硝化SBR对氨氮的去除率分别为87.0%和94.5%.除磷SBR仅设置缺氧段时,磷去除率为72%;增设后曝气段后,磷去除率增至85%.NO_x^--N(NO₂^--N+ NO₃^--N)的去除主要发生在缺氧段,在反硝化除磷时作为电子受体被去除,平均去除率为90.6%.     

不同碳源对EBPR启动期聚磷菌的影响研究

以实验室序批式反应器(SBR)为强化生物除磷工艺(EBPR)载体,接种具有初步除磷功能的污泥后,以乙酸∶丙酸=1∶1(按各自折算的COD计)为混合碳源(以下简称混酸),厌氧初始pH 7.6±0.1,富集聚磷菌(PAO)。启动30 d后,EBPR反应器中为PAO和聚糖菌(GAO)的混合菌属,此时从反应器中取泥样进行批式试验,分别考察乙酸、丙酸及混酸对聚磷菌的富集和厌氧释磷的影响。结果表明:在EBPR启动期内,乙酸作为单一碳源时释磷量最大,但混酸碳源释磷效率最高,最有利于PAO富集;丙酸作为单一碳源时降解率最大而释磷量最小,不适合EBPR启动期的PAO富集。     

基于磷回收的低温微氧EBPR系统的表观与微观特性

在低溶解氧(DO=1mg/L)条件下启动2个厌氧/好氧交替运行的SBR(A/O-SBR),中温(22±1)℃SBR1和低温(14±1)℃SBR2,考察侧流磷回收工艺对低耗主流强化生物除磷(EBPR)系统污染物去除性能?微生物种群结构和磷回收潜能的影响.结果表明,SBR1和SBR2的脱氮及COD去除性能未受磷回收操作的影...     

厌氧推流进水对反硝化除磷好氧颗粒污泥系统的影响

实际生活污水成分复杂,且碳氮比较低,而厌氧推流进水可以通过提供局部高底物浓度来加强好氧颗粒污泥对进水中COD的利用.实验采用间歇曝气的方式在序批式反应器（SBR）中培养好氧颗粒污泥,以实际生活污水为进水,接种污水厂污泥.R1采用厌氧快速进水,R2采用厌氧推流进水,探究不同进水模式对生活污水好氧颗粒污泥系统的影响.结果表明,快速厌氧进水条件下,R1中更早出现颗粒结构,但在运行71 d时出现颗粒破裂的现象;应用厌氧推流进水模式的R2生成的颗粒结构较R1的更为致密,颗粒表面更加光滑,且反硝化聚磷菌（DPAO）的富集效果更好.最终R1和R2反应器内DPAO占聚磷菌（PAO）的比例分别为14.17%和22.07%.结果表明,厌氧推流进水模式能够加强颗粒污泥对进水中COD的利用,有利于富集DPAO,生成结构更加致密稳定的颗粒,实现"一碳两用",获得更好的脱氮除磷效果.     

厌氧、缺氧、好氧环境下富磷剩余污泥的释磷机制

以采用A/O生物强化除磷工艺水质净化厂排出的富磷剩余污泥为研究对象,利用棕色消化瓶设计3组释磷试验,讨论厌氧、缺氧、好氧环境下富磷剩余污泥消化释磷的机制. 结果表明:富磷剩余污泥在厌氧和缺氧环境下均有明显的释磷现象,平均释磷速率分别为1.614和0.998 mg/(L·d);厌氧和缺氧环境下释磷量与聚β-羟基丁酸(PHB)之间的计量关系比较表明,释磷过程中包含有明显的微生物释磷机制,同时还存在着物理化学方面引起的释磷机制,硝酸盐抑制剩余污泥中磷的释放主要是通过影响其微生物学机制完成的.      

低表观气速间歇曝气AGS-SBR系统处理实际生活污水

实验选用3个SBR反应器接种污水厂活性污泥,R1采用高表观气速（SGV）连续曝气,R2采用低SGV连续曝气,R3采用低SGV间歇曝气,在低碳氮比的实际生活污水中培养好氧颗粒污泥,探究不同SGV曝气条件对好氧颗粒污泥的形成及系统处理效果的影响.经过120d的培养,R1、R2和R3中颗粒粒径分别为（754±78）,（812±86）,（1183±93）μm,R3的脱氮除磷效果优于R1和R2.结果表明,应用低SGV间歇曝气策略在低碳氮比实际生活污水中培养的好氧颗粒污泥脱氮除磷性能良好,且系统中反硝化聚磷菌（DPAO）占聚磷菌（PAO）比例为24.75%.     

Characteristics of anoxic phosphors removal in sequence batch reactor

The characteristics of anaerobic phosphorus release and anoxic phosphorus uptake were investigated in sequencing batch reactors using denitrifying phosphorus removing bacteria （DPB） sludge. The lab-scale experiments were accomplished under conditions of various nitrite concentrations （5.5, 9.5, and 15 mg/L） and mixed liquor suspended solids （MLSS） （1844, 3231, and 6730 mg/L）. The results obtained confirmed that nitrite, MLSS, and pH were key factors, which had a significant impact on anaerobic phosphorus release and anoxic phosphorus uptake in the biological phosphorous removal process. The nitrites were able to successfully act as electron acceptors for phosphorous uptake at a limited concentration between 5.5 and 9.5 mg/L. The denitrification and dephosphorous were inhibited when the nitrite concentration reached 15 mg/L. This observation indicated that the nitrite would not inhibit phosphorus uptake before it exceeded a threshold concentration. It was assumed that an increase of MLSS concentration from 1844 mg/L to 6730 mg/L led to the increase of denitrification and anoxic P-uptake rate. On the contrary, the average P-uptake/N denitrifying reduced from 2.10 to 1.57 mg PO4^3--P/mg NO3^--N. Therefore, it could be concluded that increasing MLSS of the DEPHANOX system might shorten the reaction time of phosphorus release and anoxic phosphorus uptake. However, excessive MLSS might reduce the specific denitrifying rate. Meanwhile, a rapid pH increase occurred at the beginning of the anoxic conditions as a result of denitrification and anoxic phosphate uptake. Anaerobic P release rate increased with an increase in pH. Moreover, when pH exceeded a relatively high value of 8.0, the dissolved P concentration decreased in the liquid phase, because of chemical precipitation. This observation suggested that pH should be strictly controlled below 8.0 to avoid chemical precipitation if the biological denitrifying phosphorus removal capability is to be studied accurately.     

厌氧-缺氧下反硝化除磷对低碳污水的处理性能研究

采用厌氧-缺氧条件运行的序批式移动床生物膜反应器,考察了NO3--N进水浓度及其投加方式对低碳废水(COD=200mg/L)反硝化除磷的影响.经驯化后,反硝化聚磷菌(DPB)在总聚磷菌的份额从15.7%增长到71.3%,富集了DPB.NO3--N的浓度对处理有较大影响.在NO3--N为30mg/L(即C/N=6.7:1)时,COD、PO43--P和NO3--N的去除率分别为97.8%、82.0%和81.2%,实现低碳污水的高效处理.NO3--N较低或较高浓度(20mg/L和40mg/L)时,缺氧段吸磷不充分,PHB由厌氧开始时的2.2mg/g左右分别积累至5.1mg/g和3.5mg/g,影响下一周期磷的释放.1次投加、2次投加和连续流加NO3--N,除对缺氧初期的反硝化吸磷速率有影响外,对反硝化除磷的效率影响不明显.     

不同曝气强度下SBMBBR和SBR脱氮除磷性能对比研究

对比考察了不同曝气强度下序批式活性污泥反应器(SBR)和序批式移动床生物膜反应器(SBMBBR)的脱氮除磷效果,并分析了反应器单个周期内有机物、氮和磷的转化过程.实验结果表明,SBMBBR和SBR脱氮主要是基于好氧段发生的同步硝化反硝化(SND)及进水、搅拌阶段发生的缺氧反硝化途径实现的,而除磷是基于常规生物除磷和反硝化除磷过程而完成.曝气强度会影响SBR和SBMBBR好氧阶段SND发生的程度,最佳曝气强度下两者通过SND作用去除的TN量分别达到去除总量的47.7%和79.0%.在采用先行厌氧的运行方式,保持系统内高浓度微生物,使反应器在进水C/N比只有2.2～3.5的条件下均取得了良好的脱氮除磷效果.两者相比,SBMBBR和SBR在COD和NH4-N去+除方面没有差异,而SBMBBR的反硝化、除磷效果更优,TN、TP去除率分别达到95.4%和93.5%,较SBR分别高出10.9%和4.1%.     

碳源浓度和污泥龄对反硝化聚磷脱氮影响研究

利用间歇试验研究了反硝化除磷过程中有机碳源和污泥龄对脱氮除磷的影响。试验结果表明:(1)厌氧段碳源COD浓度越高(150～250mg/L),放磷越充分,则缺氧段反硝化和吸磷速率越大;但当碳源COD浓度超过200mg/L时,未反应完全的有机物残留于后续缺氧段对缺氧吸磷产生抑制作用。(2)在水温为15℃～25℃,污泥负荷为0.12kgCOD(/kgMLSS·d),SRT为15d,HRT为7h时,利用人工配水作为碳源,在保持较高的COD去除率的同时,总氮和总磷的去除率最高,分别在80%和88%以上。     

Kinetic analysis of anaerobic phosphorus release during biological phosphorus removal process

Enhanced biological phosphorus removal (EBPR) is a commonly used and sustainable method for phosphorus removal from wastewater. Poly-β-hydroxybutyrate (PHB), polyphosphate, and glycogen are three kinds of intracellular storage polymers in phosphorus accumulation organisms. The variation of these polymers under different conditions has an apparent influence on anaerobic phosphorus release, which is very important for controlling the performance of EBPR. To obtain the mechanism and kinetic character of anaerobic phosphorus release, a series of batch experiments were performed using the excessively aerated sludge from the aerobic unit of the biological phosphorus removal system in this study. The results showed that the volatile suspended solid (VSS) had an increasing trend, while the mixed liquid suspended sludge (MLSS) and ashes were reduced during the anaerobic phosphorus release process. The interruption of anaerobic HAc-uptake and phosphorus-release occurs when the glycogen in the phosphorus-accumulating-organisms is exhausted. Under the condition of lower initial HAc-COD, HAc became the limiting factor after some time for anaerobic HAc uptake. Under the condition of higher initial HAc-COD, HAc uptake was stopped because of the depletion of glycogen in the microorganisms. The mean ratio of Δρ _P/Δρ _PHB, Δρ _GLY/Δρ _PHB, Δρ _P/ΔCOD, was 0.48, 0.50, 0.44, and 0.92, respectively, which was nearly the same as the theoretical value. The calibrated kinetic parameters of the HAc-uptake and phosphorus-release model were evaluated as follows: Q _HAc,max was 164 mg/(g · h), Q _P,max was 69.9 mg/(g · h), K _gly was 0.005, and KCOD was 3 mg/L. An apparently linear correlation was observed between the ratio of Δρ _P/ΔCOD and pH of the solution, and the equation between them was obtained in this study. Translated from Acta Scientiae Circumstantiae, 2005, 25(9), 1164–1169 [译自: 环境科学学报]     

Anoxic gas recirculation system for fouling control in anoxic membrane reactor

Anoxic gas recirculation system was applied to control the membrane fouling in pilot-scale 4-stage anoxic membrane bioreactor(MBR). In the anaerobic-anoxic-anoxic-aerobic flow scheme,hydrophilic polytetrafluoroethylene(PTFE) membrane(0.2 μm, 7.2 m2/module) was submerged in the second anoxic zone. During 8 months operation, the average flux of the membrane was 21.3L/(m2·hr). Chemical cleaning of the membrane was conducted only once with sodium hydroxide and sodium hypochlorite. Dissolved oxygen(DO) concentration in the second anoxic zone was maintained with an average of 0.19 ± 0.05 mg/L. Gas chromatography analysis showed that the headspace gas in the second anoxic reactor was mainly consisted of N2(93.0% ± 2.5%), O2(3.8% ± 0.6%), and CO2(3.0% ± 0.5%), where the saturation DO concentration in liquid phase was 1.57 mg/L. Atmospheric O2 content(20.5% ± 0.8%) was significantly reduced in the anoxic gas. The average pH in the reactor was 7.2 ± 0.4. As a result, the recirculation of the anoxic gas was successfully applied to control the membrane fouling in the anoxic MBR.