低温投加短程硝化污泥下城市污水SPN/A工艺运行特性

王思萌,苗圆圆,彭永臻



低温投加短程硝化污泥下城市污水SPN/A工艺运行特性

王思萌,苗圆圆,彭永臻*

(北京工业大学,城镇污水深度处理与资源化利用技术国家工程实验室,北京市水质科学与水环境恢复工程重点实验室,北京 100124)

以城市污水为研究对象,考察低温条件下通过生物添加强化氨氧化菌(AOB)活性,并进一步提高短程硝化-厌氧氨氧化一体化(SPN/A)工艺脱氮效果的可行性.平行运行2个序批式反应器(SBR)SBR1与SBR2,在间歇曝气条件下运行,控制温度由30℃梯度下降至15℃(30,27,24,21,18,15℃),随后逐步回升至30℃.在降温与升温过程中,向SBR2中定期投加短程硝化污泥强化AOB活性,SBR1作为空白试验不进行投加.结果表明,30℃时SBR1与SBR2在不外加短程硝化污泥的条件下均可成功启动并稳定运行,脱氮效果均良好;温度降至15℃时,SBR1与SBR2出水NH4+-N分别为36.38,33.10mg/L,总氮去除率分别为30.72%与35.76%,2个反应器脱氮效果均变差,SBR2较SBR1抗低温能力较强;梯度升温至30℃时,SBR1与SBR2总氮去除率分别升至52.43%与63.60%.通过考察SBR1与SBR2菌群活性可知,2个反应器的菌群活性均随着温度降低而降低,但SBR2的AOB丰度活性均高于SBR1;温度回升阶段,2个反应器的菌群活性有所升高,其中SBR2亚硝酸盐氧化细菌(NOB)活性受到抑制持续降低,推测这是因为SBR2中的AOB活性得到强化后,产生更多的亚硝酸盐,厌氧氨氧化菌(Anammox)可获得基质增多,造成Anammox活性丰度较高,所以SBR2脱氮效果相对较好.因此,在低温条件下通过生物添加强化SPN/A系统中AOB活性,可提高系统抗温度冲击能力,利于系统脱氮效果的恢复.

短程硝化厌氧氨氧化一体化；城市污水；生物添加；温度；AOB活性

在短程硝化-厌氧氨氧化一体化(SPN/A)工艺中,AOB在好氧条件下,将生活污水中的部分氨氮(NH4+-N)转化为亚硝酸盐氮(NO2--N),Anammox在缺氧条件下,将生成的NO2--N与剩余NH4+-N转化为氮气[1-3].

SPNA工艺的反应方程式:

NH4++0.85O2®0.44N2+0.11NO3-+0.14H++1.43H2O (1)

SPN/A工艺中AOB、Anammox为自养菌,与传统硝化反硝化脱氮工艺相比,剩余污泥产量减少约90%,且无需外加碳源.反应过程中仅部分NH4+-N转化为NO2--N,可减少60%的曝气量[2],且具有节能降耗等优点.

目前,SPN/A工艺主要用于处理高温高NH4+-N和低C/N(低于0.5)废水[3-6],在反应器的启动与运行[7-8]、系统破坏和恢复[9]、污泥富集培养[10]等方面做了大量研究,在低NH4+-N废水的处理方面尚处于试验研究阶段.在低NH4+-N废水SPN/A工艺中,由于缺乏游离氨(FA)和游离亚硝酸(FNA)等抑制条件,NOB易富集,导致出水硝酸盐增加、脱氮效果变差[11-14],因此,NOB的抑制是低NH4+-N废水SPN/A系统稳定的一大难点.Miao等[15]发现采用间歇曝气(好氧7min/缺氧21min)的运行方式可有效抑制NOB活性,提高城市污水SPN/A脱氮效果.但是,由于间歇曝气中好氧时间较少,AOB活性会出现下降的现象[12,16-17],不利于SPN/A工艺长期稳定运行及脱氮效果的提高,因此强化AOB活性对于城市污水SPN/A工艺十分重要.Wett等[18]报道称通过向SPN/A工艺投加含有AOB和Anammox的污泥,实现了NOB活性的抑制和AOB活性的提高,且在该条件下,系统出水NO3--N浓度逐渐降低,脱氮效果有所改善.但城市污水季节性的水温变化较大[11-12,16],冬季温度较低[11,19-21].在低温条件下, SPN/A工艺内主要功能菌群受温度的影响程度不同,相比AOB和Anammox,NOB对温度变化更加敏感,因此低温下抑制NOB活性将更为困难[22].投加短程硝化污泥虽然强化AOB活性,但一定程度上也增加了系统内NOB的量,因此在低温条件下投加短程硝化污泥提高SPN/A工艺脱氮性能的可能性需要进一步验证.本文研究目的是考察在温度波动条件下,投加短程硝化污泥对SPN/A工艺的影响.本试验采用间歇曝气的运行方式,平行运行2个SBR反应器处理城市污水,向其中一个反应器定期投加短程硝化污泥,另一个不投加污泥作为空白试验.模拟城市污水水温波动的特点,考察温度波动条件下SPN/A工艺出水氮浓度变化规律,探究低温下强化AOB活性对系统中菌群活性的影响.

1 材料与方法

1.1 试验装置

短程硝化-厌氧氨氧化一体化工艺装置如图1所示.试验采用SBR反应器,直径13cm,高70cm,有效体积10L.通过加热及温控装置控制反应器温度;设置搅拌装置,通过微型曝气泵进行曝气,并通过转子流量计调节曝气量.

1.2 接种污泥和试验用水

试验接种的短程硝化污泥取自中试规模的短程硝化反硝化SBR[23],厌氧氨氧化污泥取自小试规模厌氧氨氧化UASB[23],SBR1与SBR2反应器分别接种4L短程硝化污泥和0.5L厌氧氨氧化污泥,接种后MLSS分别为4676与4594mg/L,MLVSS分别为3904与3896mg/L,试验用水取自9~12月某高校家属区化粪池的实际生活污水,经曝气预处理环节去除水中大部分可降解有机物,SPN/A工艺进水水质指标见表1.

图1 SBR反应器示意

1.加热棒;2.流量计;3.时间继电器;4.曝气泵;5.中间水箱;6.进水泵;7.温控仪;8.pH,DO,温度在线监测;9.搅拌桨;10.取样口; 11.曝气头

表1 SPN/A工艺进水水质

1.3 试验检测项目与方法

温度、pH值、DO采用德国WTW便携多功能检测仪(Multi340i)进行实时监测.水样经0.45μm滤膜过滤后检测各参数.NH4+-N采用纳氏试剂分光光度法检测;NO2--N采用N-(1-萘基)-乙二胺分光光度法检测;NO3--N采用麝香草酚分光光度法检测;COD采用5B-3型COD快速检测仪检测;MLSS采用滤纸称重法检测;MLVSS采用马弗炉灼烧重量法检测.在反应周期末期(第44,69,95与126d)从SBR1与SBR2取泥样,采用冷冻干燥机(LABCONCO Co., Free Zone,USA)冻干污泥;采用qPCR技术(SYBR Green法)对活性污泥系统中AOB、NOB(和)和Anammox进行检测.首先根据试剂盒(MP Biomedicals, OH, USA)说明对污泥样品进行DNA的提取,之后将DNA样品稀释100~1000倍待测(DNA浓度约1~ 10ng);采用MX3000P实时定量PCR仪(Stratagene, La Jolla,CA)检测,扩增PCR反应体系(20μL)包括: SYBR Green exTaq (Takara,大连,中国)10μL,去离子水7μL,ROX Reference Dye500.4μL,前引物(10mmol/L)后引物(10mmol/L)各0.3μL,DNA样品2μL.扩增程序为:95℃预变性3min,随后开始40个扩增循环(95℃变性30s,退火30s,72℃延伸45s).AOB所用引物amoA-1F(5’-GGGGTTTCTACTGGTGGT -3’)[24]、所用引物NSR 1113F(5’- CCTGCTTTCAGTTGCTACCG-3’)[25]、所用引物FGPS872f(5’-CTAAAACTCAAAGGA- ATTGA-3’)[26]、Anammox所用引物Amx368f(5’- TTCGCAATGCCCGAAAGG-3’)[27].当标线涵盖5~7个标准样,且标线相关系数(2)高于0.99,扩增效率在90%~110%范围内时,认为标线合格.

1.4 试验方法

本试验分为3个阶段(表2):第I阶段(1~48d)在30℃下平行启动SBR1与SBR2反应器,第II阶段(49~102d)温度梯度降低至15℃,第III阶段(103~ 126d)温度逐渐从15℃梯度回升至30℃;其中,第I阶段不进行污泥投加,第II、III阶段(49,71,92,114d)向SBR2投加短程硝化污泥,投加量为SBR2VSS的10%,分别约为380,340,400及340mg/L.SBR1作为空白试验不进行投加,分别在第8,44,69,95,126d测量污泥浓度.

SPN/A工艺运行方式如下:进水4min,缺氧/好氧交替共330min,其中缺氧21min,DO小于0.1mg/L,好氧7min,DO如表2所示.沉淀21min,排水4min.每天运行4个周期,运行周期为6h;通过控制温控仪及加热棒模拟城市污水在反应器中的温度变化,调节转子流量计对溶解氧进行控制,实时监测DO与pH值.进水通过投加KHCO3使反应器pH值维持在7.0~7.8之间.

表2 不同运行阶段温度的变化

2 结果与分析

2.1 强化AOB活性对SPN/A工艺脱氮特性的影响

2.1.1 系统启动与稳定运行 SBR1与SBR2启动与稳定运行阶段(1~48d)脱氮效果如图2第I阶段所示.反应器均在30℃下启动运行,通过对SBR1与SBR2的DO、pH值等运行条件的监控,保证2个反应器运行条件一致,且均不进行污泥投加.SBR1平均出水NH4+-N浓度为9.95mg/L,出水NO2--N及NO3--N浓度分别为0.13与6.02mg/L,平均总氮去除率为76.41%,DO约为0.81mg/L;SBR2平均出水NH4+-N浓度为14.70mg/L,出水NO2--N及出水NO3--N浓度分别为0.19与4.16mg/L,平均总氮去除率为71.83%,DO约为0.79mg/L.SBR1与SBR2总氮去除负荷(图3)分别为101.80和95.30gN/(m3·d).试验结果表明,成功启动SBR1与SBR2,脱氮效果较为稳定.

2.1.2 梯度降温条件下系统的脱氮效果 阶段II(49~102d),SBR1与SBR2温度由30℃梯度下降至15℃,试验过程中定期向SBR2投加短程硝化污泥,SBR1不进行投加.结果表明随着温度降低,2个反应器脱氮效果均下降(表3).当温度降至15℃时,2个反应器的DO分别调高约至1.20mg/L.SBR1与SBR2出水NH4+-N由9.95与14.70mg/L上升至36.38与33.10mg/L,说明温度降低,2个反应器中的AOB及Anammox活性受到影响,而SBR2的受影响程度小于SBR1.

图2 SBR1与SBR2氮浓度变化

图3 SBR1与SBR2氮负荷变化

SBR1与SBR2的出水NO3--N浓度随温度降低呈现先升高后降低的趋势,不同的是,SBR1出水NO3--N浓度迅速升高,在24℃时升至9.55mg/L,而SBR2出水NO3--N浓度缓慢升高,在24℃时升至6.32mg/L.温度由21℃继续降低的过程中,2个反应器出水NO3--N均下降,15℃时分别降至2.41与2.63mg/L.在整个梯度降温过程中,通过投加短程硝化污泥的SBR2出水NO3--N变化幅度小于SBR1.

由表3可知,当温度降低至15℃时,SBR1与SBR2总氮去除率分别由76.41%与71.83%降至30.72%与35.76%,总氮去除负荷分别由101.80, 95.30gN/(m3·d)降至36.00,40.89gN/(m3·d),说明SPN/A工艺的脱氮效果受温度影响较大.由表4可知,温度由21℃降至15℃过程中,SBR2出水总氮浓度变化幅度小于SBR1,且脱氮效果优于SBR1,证明向SPN/A工艺投加短程硝化污泥,可在一定程度上降低低温环境对SPN/A工艺脱氮性能的影响.

2.1.3 梯度升温条件下系统的恢复效果 阶段III(103~126d),SBR1与SBR2温度从15℃梯度回升至30℃,2个反应器DO均约为0.8mg/L,脱氮效果明显提高,SBR1与SBR2出水NH4+-N分别降至21.45与15.57mg/L,出水NO2--N分别为0.22与0.33mg/L,氮去除负荷分别约为56.22与67.35gN/(m3·d),出水NO3--N分别约为3.49与3.38mg/L,平均总氮去除率分别升高至52.43%与63.60%.结果表明在梯度升温的过程中,SBR1和SBR2脱氮效果逐渐提高,其中SBR2好于SBR1.但是在短时间内SBR1和SBR2脱氮效果没有提高至第I阶段的水平,推测经过低温环境之后,系统中主要功能菌群AOB和Anammox活性降低,在短期内还没有完全恢复.

表3 梯度变温阶段出水水质指标

表4 梯度降温阶段出水指标变化幅度(%)

图4 SBR1与SBR2 NO3--N生成量与NH4+-N转化比值变化

2.1.4 强化AOB活性对NO3--N生成比的影响 由SPN/A工艺的反应方程式(1)可知,单个反应周期内NO3--N生成量占NH4+-N降解量的比值(ΔNO3--N/ΔNH4+-N)理论值为0.11.如图4所示,当温度为30℃,SBR1与SBR2的ΔNO3--N/ΔNH4+-N值分别为0.01与0.08,低于理论比值.尽管城市污水中大部分的可降解有机物在预处理反应器中被去除,SPN/A工艺进水中仍存在部分可降解有机物,因此反应器中可能存在反硝化现象,造成比值低于理论值. 温度由30℃降至24℃的过程中,SBR1与SBR2的ΔNO3--N/ΔNH4+-N均值分别升高至0.20与0.13;随着温度进一步降低至15℃,ΔNO3--N/ ΔNH4+-N比值开始降低.当温度回升至30℃,SBR1与SBR2比值近似理论值0.11,整个过程变化趋势与2个反应器脱氮效果一致,投加短程硝化污泥的SBR2在温度波动时ΔNO3--N/ΔNH4+-N低于SBR1.

2.2 强化AOB活性对菌群活性的影响

当温度从30℃梯度降至15℃时,SBR1与SBR2的AOB活性(图5)均随着温度的降低而降低,分别由4.10,4.01mgN/(h·gVSS)降至1.89,1.93mgN/(h·gVSS);对应PCR结果,SBR1与SBR2中的AOB丰度由1.33×109与1.89×109copies/g干污泥下降至2.87×108与9.31×108copies/g干污泥,相比而言,SBR2在温度降低时AOB活性下降较慢;此外,与脱氮效果对应,说明AOB受低温影响活性降低,导致SPN/A工艺脱氮效果变差.当温度回升至30℃,SBR1与SBR2的AOB活性分别升高至2.36与2.61mgN/(h·gVSS), AOB丰度分别回升至6.42×108与1.28×109copies/g干污泥,说明当温度升高,AOB活性提高,系统脱氮效果随之变好,其中SBR2的AOB活性升高较SBR1更快.但是,SBR1与SBR2在阶段III的AOB活性均没有升高至阶段I的水平,推测这是导致阶段III系统脱氮性能较差于阶段I的主要原因.由图5可知,SBR1在降温阶段的MLSS约为4500mg/L,升温阶段约为4200mg/L,污泥浓度整体变化不大;而SBR2在降温与升温阶段的MLSS一直约为4600mg/L,说明投加短程硝化污泥并没有使SBR2的MLSS明显增长,推测投加的污泥中存在异养菌,由于反应器中的有机物浓度较低,且缺氧时间较长,导致大量异养菌裂解衰亡,因而SBR2的MLSS较为稳定.此外,当温度从30℃梯度降至15℃时, SBR1与SBR2中的Anammox活性分别由2.14与2.01mgN/ (h·gVSS)降至0.69与0.77mgN/(h·gVSS), SBR1与SBR2中的Anammox丰度分别由2.5×109, 2.06× 109copies/g干污泥分别下降至4.33×108, 6.25× 108copies/g干污泥,SBR2中的Anammox活性与丰度在低温过程中下降幅度均小于SBR1,与AOB在低温过程中变化相似;当温度回升至30℃, SBR1与SBR2中的Anammox活性分别升至0.92, 1.04mgN/ (h·gVSS),Anammox丰度分别升至4.64×108,1.06× 109copies/g 干污泥.在升温过程中SBR2的Anammox活性与丰度恢复较快,这与升温阶段脱氮效果相符,说明投加短程硝化污泥也有利于Anammox活性的稳定与恢复.在降温与升温过程中, SBR2中AOB与Anammox活性之间的关系如图6所示,AOB与Anammox活性具有良好的相关性,2值为0.961,由此投加短程硝化污泥提高SPN/A工艺中AOB活性的过程中,AOB为Anammox提供了更多的NO2--N基质,从而Anammox活性得到提高.

随着温度的降低,2个反应器中NOB活性均出现下降现象.尽管向SBR2投加短程硝化污泥在一定程度上增加了系统NOB的量,但由于采用间歇曝气的运行方式,NOB活性并没有明显增高,且NOB活性的降低与2个反应器脱氮效果变化趋势一致.由表5可知,SBR1与SBR2中优势NOB菌种丰度均呈下降趋势,分别由2.12×1010,8.78× 109copies/g干污泥下降至5.49×109,6.33× 108copies/ g干污泥,这可能与反应器在间歇曝气条件下运行,利于抑制NOB活性有关.当温度回升, SBR1中的NOB活性回升,而SBR2中的NOB活性继续降低,推测经过投加短程硝化污泥的SBR2中的AOB得到强化成为优势菌群,在对DO的竞争中较NOB更占优势.此外,间歇曝气运行方式进一步利于NOB的抑制和Anammox的富集,与Miao等[16]的结论一致.Anammox对NO2--N的竞争也逐渐优于NOB,造成NOB活性逐渐降低.由此可通过强化AOB活性提高系统脱氮效果及稳定性,并且可有效抑制NOB活性,稳定Anammox活性,从而更有效的提高SPN/A工艺自养脱氮效果.

表5 不同温度下AOB、NOB和Anammox丰度变化情况(×108copies/g干污泥)

2.3 讨论

城市污水SPN/A工艺采用间歇曝气的运行方式,在30℃且不外加短程硝化污泥的条件下成功稳定运行,具有良好的脱氮效果.在温度波动阶段, SBR2的脱氮效果优于SBR1.其中,在梯度降温阶段,SBR1与SBR2脱氮效果均下降,SBR2中的AOB及Anammox活性相对较高于SBR1;温度升温阶段,SBR1与SBR2脱氮效果均提高,SBR2中的AOB及Anammox活性回升的更快,且NOB的抑制效果更好.因此通过本试验结论可知,低温使得SPN/A工艺脱氮效果下降;强化AOB活性利于SPN/A工艺Anammox活性的提高和NOB的抑制,并进一步降低低温对脱氮效果的影响.因此,可在低温下或温度降低前强化AOB活性,以提高SPN/A工艺在温度波动时的脱氮效果和稳定性.本试验选择的生物投加为短程硝化污泥强化AOB活性,选择不同种类的生物投加对城市污水SPN/A工艺菌群活性影响不同,可选择不同种类的污泥[28]、添加Fe(Ⅲ)[29]、NaCl盐度等[30]或者控制DO浓度[31-32]提高AOB活性,探究强化菌群过程对城市污水SPN/A工艺自养脱氮效果的影响.除此之外,在北方冬季城市污水厂处理污水的过程中,最低温度可能低于本试验采用的15℃[33],对自养脱氮效果是否有其他影响,值得继续探究.

图6 SBR2中AOB与Anammox活性的相关性

3 结论

3.1 在30℃条件下启动SPN/A工艺,2个反应器总氮去除率分别约为76%与72%,不外加短程硝化污泥可成功启动城市污水短程硝化-厌氧氨氧化一体化系统并具有良好的脱氮效果.

3.2 在低温条件下,SPN/A工艺受温度影响,2个反应器脱氮效果下降,NH4+-N去除率分别降至35%与40%,向SBR2定期投加短程硝化污泥可在一定程度上增强系统的抗低温能力;在温度梯度回升过程中,SBR1与SBR2的NH4+-N去除率分别约为59%与71%,投加短程硝化污泥利于SPN/A系统脱氮效果较快较好的回升.

3.3 向SPN/A工艺定期投加短程硝化污泥,可增强AOB丰度与活性,AOB活性得到强化后,更利于抑制NOB活性.此外,AOB活性与Anammox活性之间具有良好的相关性,利于Anammox活性的稳定与提高.

[1] Sliekers A O, Derwort N, Campos-Gomez J L, et al. Completely autotrophic nitrogen removal over nitrite in one single reactor [J]. Water Research, 2002,36(10):2475–2482.

[2] Qiao S, Tian T, Duan X M, et al. Novel single-stage autotrophic nitrogen removal via co-immobilizing partial nitrifying and anammox biomass [J]. Chemical Engineering Journal, 2013,230:19–26.

[3] Joss A, Salzgeber D, Eugster J, et al. Full-scale nitrogen removal from digester liquid with partial nitritation and anammox in one SBR [J]. Environmental Science & Technology, 2009,43(14):5301–5306.

[4] van der Star W R L, Abma W R, Blommers D, et al. Startup of reactors for anoxic ammonium oxidation: experiences from the first full-scale anammox reactor in Rotterdam [J]. Water Research, 2007,41(18): 4149–4163.

[5] Lv Y T, Chen X, Wang L, et al. Microprofiles of activated sludge aggregates using microelectrodes in completely autotrophic nitrogen removal over nitrite (CANON) reactor [J]. Frontiers of Environmental Science & Engeering, 2016,10(2):390–398.

[6] Abma W R., Driessen W, Haarhuis R, et al. Upgrading of sewage treatment plant by sustainable and cost-effective separate treatment of industrial wastewater [J]. Water Science and Technology, 2010,61(7): 1715-1722.

[7] Ali M, Okabe S. Anammox-based technologies for nitrogen removal: Advances in process start-up and remaining issues [J]. Chemosphere, 2015,141:144-153.

[8] Regmi P, Miller M W, Holgate B, et al. Control of aeration, aerobic SRT and COD input for mainstream nitritation/denitritation [J]. Water Research, 2014,57:162-171.

[9] Ma B, Wang S Y, Cao S B, et al. Biological nitrogen removal from sewage via anammox: Recent advances [J]. Bioresource Technology, 2016,200:981-990.

[10] Wang T, Zhang H, Gao D, et al. Enrichment of Anammox bacteria in seed sludges from different wastewater treating processes and start-up of Anammox process [J]. Desalination, 2011,271(1-3):193-198.

[11] Cao Y S, van Loosdrecht M C, Daigger G T, Mainstream partial nitritation-anammox in municipal wastewater treatment: status, bottlenecks, and further studies [J]. Applied Microbiology and Biotechnology, 2017,101(4):1365–1383.

[12] Ma B, Bao P, Wei Y, et al. Suppressing nitrite-oxidizing bacteria growth to achieve nitrogen removal from domestic wastewater via anammox using intermittent aeration with low dissolved oxygen [J]. Scientific Reports, 2015,5:13048.

[13] Yang Q, Peng Y Z, Liu X H, et al. Nitrogen removal via nitrite from municipal wastewater at low temperatures using real-time control to optimize nitrifying communities [J]. Environmental Science & Technology, 2007,41(23):8159–8164.

[14] Xu G J, Zhou Y, Yang Q, et al. The challenges of mainstream deammonification process for municipal used water treatment [J]. Applied Microbiology and Biotechnology, 2015,99(6):2485-2490.

[15] Miao L, Wang S Y, Li B K, et al. Effect of carbon source type on intracellular stored polymers during endogenous denitritation (ED) treating landfill leachate [J]. Water research, 2016,100:405-412.

[16] Miao Y Y, Zhang L, Yang Y D, et al. Start-up of single-stage partial nitrification-anammox process treating low-strength swage and its restoration from nitrate [J]. Bioresource Technology, 2016,218:771- 779.

[17] Regmi P, Bunce R, Miller M W, et al. Ammonia-based intermittent aeration control optimized for efficient nitrogen removal [J]. Biotechnology and Bioengineering, 2015,112(10):2060-2067.

[18] Wett B, Omari A, Podmirseg S M, et al. Going for mainstream deammonification from bench to full scale for maximized resource efficiency [J]. Water Science and Technology, 2013,68(2):283-289.

[19] Perez J, Lotti T, Kleerebezem R, et al. Outcompeting nitrite-oxidizing bacteria in single-stage nitrogen removal in sewage treatment plants: a model-based study [J]. Water Research, 2014,66:208-218.

[20] Lotti T, Kleerebezem R, Hu Z, et al. Pilot-scale evaluation of anammox-based mainstream nitrogen removal from municipal wastewater [J]. Environmental Technology, 2015,36(9-12):1167- 1177.

[21] Cema G, Plaza E, Trela J, et al. Dissolved oxygen as a factor influencing nitrogen removal rates in a one-stage system with partial nitritation and Anammox process [J]. Water Science and Technology, 2011,64(5):1009-1015.

[22] Trojanowicz K, Plaza E, Trela J. Pilot scale studies on nitritation- anammox process for mainstream wastewater at low temperature [J]. Water Science and Technology, 2016,73(4):761-768.

[23] 唐晓雪.生活污水厌氧氨氧化组合处理工艺及过程控制 [D]. 北京: 北京工业大学, 2014. Tang X X, Autotrophic nitrogen removal process treating domestic wastewater based on real-time control [D]. Beijing:Beijing University of Technology, 2014.

[24] Schmid M C, Maas B, Dapena A, et al. Biomarkers for in situ detection of anaerobic ammonium-oxidizing (anammox) bacteria. Applied and Environmental Microbiology, 2005,71(4):1677–1684.

[25] Geets J, de Cooman M, Wittebolle L, et al. Real-time PCR assay for the simultaneous quantification of nitrifying and denitrifying bacteria in activated sludge [J]. Applied Microbiology and Biotechnology, 2007,75(1):211–221.

[26] Degrange V, Bardin R, Detection and counting of nitrobacter populations in soil by PCR [J]. Applied and Environmental Microbiology, 1995,61(6):2093–2098.

[27] Wang S Y, Wang Y, Feng X J, et al. Quantitative analyses of ammonia-oxidizing Archaea and bacteria in the sediments of four nitrogen-rich wetlands in China [J]. Applied Microbiology and Biotechnology, 2011,90(2):779–787.

[28] Miao Y Y, Zhang L, Li B K, et al. Enhancing ammonium oxidizing bacteria activity was key to single-stage partial nitrification-anammox system treating low-strength sewage under intermittent aeration condition [J]. Bioresource Technology, 2017,231:36-44.

[29] 王亚娥,冯娟娟,李杰,等.不同Fe(III)对活性污泥异化铁还原耦合脱氮的影响及机理初探 [J]. 环境科学学报, 2014,34(2):377-384 Wang Y E, Feng J J, Li J, et al. Effect and mechanism of nitrogen removal by dissimilatory reduction of different Fe(Ⅲ) in activated sludge [J]. Acta Scientiae Circumstantiae, 2014,34(2):377-384.

[30] 张宇坤,王淑莹,董怡君,等.NaCl盐度对氨氧化细菌活性的影响及动力学特性 [J]. 中国环境科学, 2014,35(2):465-470 Zhang Y K, Wang S Y, Dong Y J, et al. Effect of NaCl salinity on activity of ammonia-oxidizing bacteria and kinetic characterization [J]. China Environmental Science, 2015,35(2):465-470.

[31] 杨 庆,杨玉兵,杨忠启,等.溶解氧对短程硝化稳定性及功能菌群的影响 [J]. 中国环境科学, 2018,38(9):3328-3334. Yang Q, Yang Y B, Yang Z Q, et al. Effect of dissolved oxygen on the stability and functional microbial communities of the partial nitrification [J]. China Environmental Science, 2018,38(9):3328-3334.

[32] 张功良,李 冬,张肖静,等.低温低氨氮SBR短程硝化稳定性试验研究 [J]. 中国环境科学, 2014,34(3):610-616. Zhang G L, Li D, Zhang X J, et al. Stability for shortcut nitrification in SBR under low ammonia atlow temperature [J]. China Environmental Science, 2014,34(3):610-616.

[33] 赵昕燕,卞 伟,侯爱月,等.季节性温度对短程硝化系统微生物群落的影响 [J]. 中国环境科学, 2017,37(4):1366-1374. Zhao X Y, Bian W, Hou A Y, et al. Characteristics of microbial community structure in the stable operation of the partial cut nitrification system with seasonal temperature [J]. China Environmental Science, 2017,37(4):1366-1374.

Operation characteristics of the SPN/A process for municipal wastewater under low temperature shortcut nitrification sludge.

WANG Si-meng, MIAO Yuan-yuan, PENG Yong-zhen*

(1.Key Laboratory of Beijing for Water Quality Science and Water Environment Recovery Engineering, National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Beijing University of Technology, Beijing 100124, China)., 2019,39(4)：1456~1463

In this study, feasibility of enhancing ammonia-oxidizing bacteria (AOB) activity by biological addition under the condition of temperature fluctuation and further improving the denitrification effect of Single-stage Partial Nitrification and Anammox (SPN/A) process in municipal wastewater treatment was investigated. Two sequencing batch reactors (SBR) SBR1 and SBR2 were operated in intermittent aeration. The controlled temperature was reduced from 30℃ gradient to 15℃ (30, 27, 24, 21, 18, 15℃), and then gradually increased to 30℃.Shortcut nitrification sludge was regularly added to SBR2 to enhance AOB activity during the cooling and heatingprocess, and SBR1was used as the control process. The results showed that SBR1 and SBR2 started successfully and run stably without shortcut nitrification sludge, and the nitrogen removal efficiency of SBR1 and SBR2 was good at 30℃. When the temperature was dropped to 15℃, the concentration of the ammonia nitrogen in effluents of of SBR1 and SBR2 were 36.38mg/L and 33.10mg/L, and the total nitrogen removal efficiency was 30.72% and 35.76%, respectively. Both rectors’ efficiency become worse in low temperature settings, SBR2 shown a better cold resistance performance. When temperature were increased gradient back to 30℃,the total nitrogen removal rates of SBR1 and SBR2 increased back to 52.43% and 63.60% respectively. The activity of bacteria in SBR1 and SBR2 decreased with the decrease of temperature, but the AOB activity of SBR2 was higher than that of SBR1. During the temperature rising stage, the activity of bacteria in SBR1 and SBR2 both increased, and the inhibition of nitrite-oxidizing bacteria (NOB) activity in SBR2 was continuously decreasing. The better denitrification performance of SBR2 was suspected because when the AOB activity of SBR2 was enhanced, more nitrite was produced, and the substrate of Anammox was increased, which resulted in the higher activity abundance of Anammox. Therefore, it was conclude that the AOB activity in SPN/A system can be enhanced by biological addition at low temperature, which can improve the resistance performance of the system to the temperature shocks and facilitate the recovery of denitrification capacity.

single-stage partial nitrification and anammox；municipal wastewater；biological addition；temperature；AOB activity

X703

A

1000-6923(2019)04-1456-08

2018-09-28

北京市科技计划(D171100001017001);水体污染控制与治理科技重大专项(2017ZX07102-003)

*责任作者, 教授, pyz@bjut.edu.cn

王思萌(1993-),女,北京人,北京工业大学硕士研究生,主要从事城市污水短程硝化-厌氧氨氧化一体化自养脱氮的应用研究.发表论文2篇