任志強(qiáng),李 冬*,王文強(qiáng),張 杰,2

側(cè)流FNA抑制的CANON顆粒-絮體復(fù)合系統(tǒng)參數(shù)優(yōu)化

任志強(qiáng)1,李 冬1*,王文強(qiáng)1,張 杰1,2

(1.北京工業(yè)大學(xué),水質(zhì)科學(xué)與水環(huán)境恢復(fù)工程北京市重點(diǎn)實(shí)驗(yàn)室,北京 100124；2.哈爾濱工業(yè)大學(xué),城市水資源與水環(huán)境國(guó)家重點(diǎn)實(shí)驗(yàn)室,黑龍江 哈爾濱 150090)

為探究側(cè)流游離亞硝酸(FNA)處理抑制亞硝酸鹽氧化菌(NOB)策略相關(guān)工藝參數(shù)的最佳組合,在顆粒-絮體復(fù)合系統(tǒng)的全程自養(yǎng)脫氮(CANON)工藝中,采用批次試驗(yàn)探討污泥沉降時(shí)間、FNA處理濃度及處理時(shí)間對(duì)相關(guān)功能菌活性的影響,針對(duì)性抑制NOB活性,降低FNA對(duì)功能菌活性影響.結(jié)果顯示,沉降時(shí)間影響處理污泥中功能菌群活性,隨著沉降時(shí)間的延長(zhǎng),排出污泥中厭氧氨氧化菌(AnAOB)活性逐漸減弱.沉降1min后進(jìn)行排泥排出了大部分NOB并且反應(yīng)器內(nèi)保留了盡可能多的AnAOB,此時(shí)排出的污泥中AnAOB、氨氧化菌(AOB)和NOB的相對(duì)活性分別為15.79%、54.55%和68.63%.綜合FNA對(duì)NOB和AOB活性的影響,采用0.6mg/L的FNA抑制12h后AOB活性為38.71%,而NOB活性僅為12.5%.響應(yīng)曲面分析結(jié)果顯示,FNA處理時(shí)間、處理濃度是影響NOB、AOB活性的關(guān)鍵因素.

顆粒-絮體；CANON；FNA；NOB；響應(yīng)曲面

全程自養(yǎng)脫氮(CANON)工藝相比其他傳統(tǒng)生物脫氮工藝,具有節(jié)省曝氣量、污泥產(chǎn)量低、無(wú)需外加碳源等諸多優(yōu)點(diǎn)[1-2].亞硝酸鹽氧化菌(NOB)是CANON工藝的限制因素,阻礙了該工藝的規(guī)?；瘧?yīng)用[3].有研究表明NOB傾向于生長(zhǎng)在直徑2.5～ 22.5μm的微生物聚集體中,NOB在相對(duì)較小的顆粒中更容易生長(zhǎng)[4-5].利用這一特性可以達(dá)到針對(duì)性篩分顆粒-絮體復(fù)合系統(tǒng)反應(yīng)器內(nèi)NOB附著的絮體污泥進(jìn)行處理的目的.一定濃度的游離亞硝酸(FNA)對(duì)NOB有強(qiáng)烈的抑制作用[6],與顆粒-絮體污泥系統(tǒng)結(jié)合應(yīng)用能夠彌補(bǔ)FNA無(wú)法直接在CANON工藝中使用的難題.目前關(guān)于FNA對(duì)AOB、NOB活性的影響已經(jīng)有大量研究,Jiang等[7]和Miao等[8]分別使用1.2mg/L和0.118mg/L的FNA處理后發(fā)現(xiàn)對(duì)AOB和NOB活性均產(chǎn)生了影響,但對(duì)NOB的抑制作用明顯比AOB更強(qiáng),甚至導(dǎo)致NOB完全失活,而AOB依然能夠保持一定的活性,分別為52.50%、72.30%.Wang等[9]利用側(cè)流FNA處理排出反應(yīng)器部分污泥,發(fā)現(xiàn)當(dāng)FNA濃度為0.24mg/L時(shí),可完全抑制短程硝化中NOB的活性,但同時(shí)造成了污泥的浪費(fèi).研究者在不同實(shí)驗(yàn)條件下得到的結(jié)論差異較大,并且多數(shù)實(shí)驗(yàn)都是在主流的短程硝化過(guò)程中實(shí)現(xiàn)的,在側(cè)流FNA抑制的實(shí)驗(yàn)中因?yàn)槲勰嗟牧魇?wèn)題對(duì)該策略的應(yīng)用也造成了困難,在CANON工藝中更是鮮有報(bào)道.

本實(shí)驗(yàn)提出了顆粒-絮體復(fù)合系統(tǒng)CANON工藝結(jié)合側(cè)流FNA處理抑制NOB活性的方法,探究了FNA處理不同沉降時(shí)間排出污泥的相關(guān)功能菌活性差異,選擇適宜的沉降時(shí)間;設(shè)置不同濃度梯度的FNA對(duì)排出的污泥處理不同的時(shí)間,通過(guò)對(duì)功能菌活性的分析優(yōu)選出最佳的組合;最后通過(guò)響應(yīng)曲面法驗(yàn)證FNA濃度和處理時(shí)間對(duì)AOB、NOB活性影響的相關(guān)性.

1 材料與方法

1.1 實(shí)驗(yàn)污泥

反應(yīng)器接種污泥為實(shí)驗(yàn)室運(yùn)行的顆粒-絮體復(fù)合系統(tǒng)CANON反應(yīng)器中的污泥,由于NOB的異常增殖導(dǎo)致該反應(yīng)器出水NO3--N嚴(yán)重積累,短程硝化被破壞.

1.2 實(shí)驗(yàn)裝置

圖1 實(shí)驗(yàn)裝置示意

1.攪拌器;2.進(jìn)水口;3.取樣口;4.排泥口;5.微孔曝氣盤;6.磁力攪拌器轉(zhuǎn)子

A.CANON反應(yīng)單元;B.FNA處理單元;C.主要為顆粒污泥;D.主要為絮體污泥

用于接種污泥的CANON反應(yīng)器R0有效容積為20L,每天運(yùn)行4個(gè)周期,每周期運(yùn)行6h,包括10min進(jìn)水,320min反應(yīng),20min沉淀,10min排水及閑置.進(jìn)水采用人工配水,添加NH4Cl提供80mg/L的NH4+-N,投加NaHCO3提供無(wú)機(jī)碳源,其他配水組分及實(shí)驗(yàn)條件參考文獻(xiàn)[10].采用機(jī)械攪拌,反應(yīng)器底部安裝曝氣盤,采用間歇曝氣方式,曝氣速率為30mL/min.通過(guò)氣體流量計(jì)控制曝氣量.使用加熱帶控制反應(yīng)器運(yùn)行溫度在(30±1)℃.反應(yīng)器的運(yùn)行通過(guò)KG316T時(shí)控開(kāi)關(guān)進(jìn)行控制,容積交換率為70%.實(shí)驗(yàn)裝置如圖1所示.

1.3 實(shí)驗(yàn)方法

為了優(yōu)化FNA側(cè)流處理顆粒-絮體復(fù)合系統(tǒng)CANON工藝結(jié)合水力篩分絮狀污泥抑制NOB活性的工藝參數(shù),恢復(fù)CANON工藝,本實(shí)驗(yàn)分2個(gè)批次進(jìn)行以優(yōu)化污泥沉降時(shí)間、FNA處理濃度以及FNA處理時(shí)間3項(xiàng)關(guān)鍵參數(shù).

批次試驗(yàn)1:污泥沉降性能優(yōu)化實(shí)驗(yàn).CANON反應(yīng)器R0停止攪拌和曝氣之后2min時(shí),從取樣口排出R0反應(yīng)器內(nèi)污泥,該取樣口可排出反應(yīng)器內(nèi)1/4有效容積的泥水混合物,排出污泥測(cè)量體積平均粒徑、污泥體積指數(shù)(SVI)、比厭氧氨氧化速率(SAA)、比氨氧化速率(SAOR)、比硝態(tài)氮生成速率(SNPR)、混合液懸浮固體濃度(MLSS)及混合液揮發(fā)性懸浮固體濃度(MLVSS),配水組分及實(shí)驗(yàn)條件見(jiàn)表1.實(shí)驗(yàn)結(jié)束將污泥返回R0.按相同方法進(jìn)行沉降時(shí)間為1.5,1,0.5,0min的批次試驗(yàn).SAA測(cè)定方法如下:在120mL厭氧瓶中加入NH4Cl和NaNO2,使NH4+-N、NO2--N濃度分別為(50±0.5)mg/ L、(60±0.5)mg/L,加入污泥,保持初始污泥濃度約為2000mg VSS/L,用N2吹脫15min,以去除反應(yīng)器溶解氧(DO).使用磁力攪拌器以90r/min的速率攪拌,每30min取一次樣,測(cè)NH4+-N、NO2--N、NO3--N濃度,由基質(zhì)濃度降解曲線,計(jì)算SAA[11].

表1 批次試驗(yàn)1配水組分及實(shí)驗(yàn)條件

批次試驗(yàn)2:FNA處理濃度、處理時(shí)間優(yōu)化實(shí)驗(yàn).在批次試驗(yàn)1的基礎(chǔ)上排出反應(yīng)器內(nèi)污泥用蒸餾水借助離心機(jī)(轉(zhuǎn)速為4000r/min)離心機(jī)洗泥3次,以去除溶解態(tài)有機(jī)物、NH4+-N、NO2--N和NO3--N.然后再將污泥分裝到10個(gè)容積為120mL的反應(yīng)瓶,并用人工配水定容,使得反應(yīng)器內(nèi)MLVSS約為2000mg/L.最后依次加入不同質(zhì)量NaNO2使FNA濃度依次為0,0.01,0.05,0.1,0.3,0.6,1.0,1.2,1.6,2mg/L.其中FNA濃度根據(jù)公式(1)計(jì)算[12].試驗(yàn)控制溫度為(26±1)℃,并通過(guò)添加0.1mol/L的HCl和NaOH控制反應(yīng)器內(nèi)pH值為7.0, DO>6mg/L.活性污泥經(jīng)FNA缺氧處理6,12,24h.

處理結(jié)束后進(jìn)行AOB和NOB活性測(cè)定.每30min取一次樣,測(cè)量NH4+-N、NO2--N和NO3--N. AOB、NOB活性分別采用SAOR和SNOR來(lái)表征.以FNA濃度為0mg/L為對(duì)照組,其余各組SAOR、SNPR以對(duì)照組的比值來(lái)表示AOB、NOB活性. 批次試驗(yàn)結(jié)束時(shí)測(cè)定MLSS、MLVSS.

考慮運(yùn)行策略和投資主體利益的電轉(zhuǎn)氣容量雙層優(yōu)化配置//許志恒,張勇軍,陳澤興,林曉明,陳伯達(dá)//(13):76

1.4 分析方法

NH4+-N采用納氏試劑光度法測(cè)定;NO2--N采用-(1-萘基)-乙二胺光度法測(cè)定;NO3--N采用紫外分光光度法;MLSS和MLVSS采用標(biāo)準(zhǔn)重量法測(cè)定;pH值、DO和溫度使用便攜式WTW pH/Oxi 340i 測(cè)定儀測(cè)定;污泥的粒徑分布使用激光粒度儀(Malvern Mastersizer2000)測(cè)定;其余水質(zhì)指標(biāo)的分析方法均采用國(guó)標(biāo)方法. SAA、SAOR、SNOR的測(cè)定方法參照文獻(xiàn)[13].

1.5 響應(yīng)曲面設(shè)計(jì)方案

根據(jù)AOB、NOB活性變化情況,設(shè)置FNA濃度、FNA處理時(shí)間2個(gè)影響因素,使用Design-Expert軟件Miscellaneous設(shè)計(jì)響應(yīng)面,最終確定的因素水平如表2所示.

表2 響應(yīng)曲面實(shí)驗(yàn)因素水平

2 結(jié)果與討論

2.1 沉降時(shí)間優(yōu)化

如圖2所示,隨著沉降時(shí)間的延長(zhǎng),排出污泥的體積平均粒徑顯著降低,由0min的438.29μm下降至2min的102.59μm,僅為原來(lái)的23.41%.有研究指出在停止攪拌和曝氣后的SBR反應(yīng)器中因顆粒的大小差異會(huì)以不同的速度沉降[14].(10)、(50)、(90)分別表示有10%、50%、90%的顆粒粒徑小于該值[15].沉降時(shí)間從0min延長(zhǎng)到2min后,(90)從938.98μm下降到200.142μm,下降了78.69%.而(10)變化相對(duì)穩(wěn)定,從46.12mm下降至32.56μm,下降了29.40%,相比(90)下降的更少,說(shuō)明沉降時(shí)間影響較大的是混合污泥系統(tǒng)中的較大顆粒,Chu等[16]在對(duì)單級(jí)部分硝化-厭氧氨氧化的研究中發(fā)現(xiàn),顆粒中以AnAOB占主導(dǎo)地位.延長(zhǎng)沉降時(shí)間有利于將AnAOB留在反應(yīng)器內(nèi),利于本實(shí)驗(yàn)后續(xù)進(jìn)行.

圖2 不同沉降時(shí)間排出污泥體積平均粒徑及d(10)、d(50)、d(90)

90是(90)和(10)的比值,是評(píng)價(jià)顆粒污泥粒徑分布均勻性的關(guān)鍵參數(shù),該數(shù)值越大,系統(tǒng)中顆粒污泥粒徑分布的差異越大[17].SVI值反應(yīng)污泥的松散程度和凝聚沉降性.由表3可見(jiàn),0min排出的污泥90的值為20.35,說(shuō)明排出的污泥粒徑分布差異較大,屬于顆粒-絮體的復(fù)合系統(tǒng),有研究表明CANON反應(yīng)器中污泥更傾向于顆粒污泥和絮體污泥的共存狀態(tài)[18].隨著時(shí)間增加,90的值逐漸降低,第2min排出的污泥僅為6.14,粒徑相對(duì)較均勻,大部分為絮體.2min的沉降時(shí)間排出污泥的SVI是0min的3.51倍,沉降性能較差.

表3 不同沉降時(shí)間污泥的K90、SVI變化

由以上分析可知,沉降時(shí)間越長(zhǎng),能夠把大多數(shù)顆粒污泥留在反應(yīng)器內(nèi)不至于流失,但并不是沉降時(shí)間越長(zhǎng)越好,沉降時(shí)間過(guò)長(zhǎng)會(huì)導(dǎo)致NOB附著的大多數(shù)絮狀污泥同樣留在反應(yīng)器內(nèi)導(dǎo)致無(wú)法排出,而沉降時(shí)間過(guò)短則會(huì)導(dǎo)致大量顆粒污泥的流失.為了確定最佳沉降時(shí)間,對(duì)排出的污泥進(jìn)行了功能菌的活性測(cè)定,通過(guò)分析SAA、SAOR、SNPR變化規(guī)律確定最佳沉降時(shí)間.

圖3 不同沉降時(shí)間AnAOB、AOB、NOB活性

以0min沉降時(shí)間SAA、SAOR、SNPR為基準(zhǔn),其他沉降時(shí)間與其的比值表示AnAOB、AOB、NOB的活性.由圖3可知,隨著沉降時(shí)間的延長(zhǎng),AnAOB的活性降低顯著,從第0.5min的50.58%下降至1.5min的5.26%,而2min的沉降時(shí)間未檢測(cè)到AnAOB活性.有研究指出顆粒污泥中的AnAOB豐度和活性隨著粒徑的增長(zhǎng)而升高[19].本研究1min以上的沉淀時(shí)間對(duì)AnAOB留在反應(yīng)器內(nèi)是有利的.NOB的活性在1min的沉降時(shí)間以后有明顯的下降,1～2min從68.63%下降至15.69%,在同一時(shí)間段內(nèi),AOB活性從54.55%下降到了20.00%.為了將更多的NOB排出反應(yīng)器,沉降時(shí)間不宜過(guò)長(zhǎng),超過(guò)1min的沉降時(shí)間NOB活性已經(jīng)很低,說(shuō)明排出的NOB已經(jīng)很少,不利于有效處理NOB.綜合以上分析,1min的排泥時(shí)間對(duì)本實(shí)驗(yàn)是相對(duì)較合適的,此時(shí)AnAOB、AOB和NOB的活性分別為34.21%、54.55%和68.63%,有利于排出更多NOB并且能夠?qū)⒏嗟腁nAOB留在反應(yīng)器內(nèi).

2.2 不同濃度、時(shí)間的FNA處理對(duì)AOB、NOB活性的影響

采用0～2mg/L不同濃度梯度的FNA處理排出的污泥6,12和24h后測(cè)定SAOR、SNPR.分別以0mg/L的FNA,處理時(shí)間6,12,24h為基準(zhǔn),其他FNA濃度與其的比值表示AOB、NOB活性,結(jié)果如圖4所示.

對(duì)NOB活性的變化情況,處理時(shí)間為6h時(shí), NOB活性隨FNA濃度升高依次為108.82%、120.59%、91.18%、79.41%、70.59%、47.06%、0.00%、0.00%、0.00%.當(dāng)FNA濃度小于0.05mg/L時(shí),非但沒(méi)有抑制NOB活性,反而促進(jìn)了NOB活性,并且隨著FNA濃度升高,NOB活性達(dá)到108.59%.分析原因FNA濃度由NO2--N提供,NO2--N既是NOB的底物,也是它的抑制物.較低濃度的FNA無(wú)法達(dá)到NOB的抑制閾值,在該閾值范圍內(nèi),隨著底物濃度的升高,NOB的氧化性提高,使NOB活性升高[20].在12和24h的處理時(shí)間也有同樣的現(xiàn)象,并且隨著時(shí)間的延長(zhǎng)這種促進(jìn)效果變得明顯.當(dāng)濃度超過(guò)0.1mg/L時(shí),FNA開(kāi)始對(duì)NOB有抑制效果,并且處理時(shí)間為6h時(shí),排出污泥經(jīng)1.2mg/L的FNA處理后已經(jīng)觀察不到NOB活性.處理時(shí)間越長(zhǎng),對(duì)NOB的抑制效果越強(qiáng).FNA濃度為0.6mg/L時(shí),12h的處理時(shí)間下,NOB活性僅為6h的17.71%,但處理時(shí)間延長(zhǎng)至24h時(shí),NOB活性是6h時(shí)的18.28%,相比較12h的處理時(shí)間并沒(méi)有對(duì)NOB有進(jìn)一步的抑制效果.當(dāng)FNA濃度進(jìn)一步升高,達(dá)到1.2mg/L時(shí),3個(gè)處理時(shí)間下均未檢測(cè)到NOB活性,此時(shí)NOB活性已經(jīng)完全被抑制.有研究表明,FNA對(duì)NOB的合成代謝具有強(qiáng)烈的抑制作用[21-22],并且能夠抑制基因轉(zhuǎn)錄過(guò)程并誤導(dǎo)酶組合使其失活[23].

綜合污泥沉降時(shí)間、FNA處理濃度及處理時(shí)間對(duì)NOB和AOB活性的影響,為了盡可能抑制NOB活性而讓AOB活性盡可能高,在污泥篩分階段宜采取1min的沉降時(shí)間進(jìn)行絮體污泥和顆粒污泥的分離,并在該沉降時(shí)間下對(duì)污泥進(jìn)行側(cè)流處理,處理階段采取0.6mg/L的FNA濃度處理12h較恰當(dāng),此時(shí)AOB活性為38.71%,而NOB活性僅為12.50%.雖然此濃度并未完全抑制NOB,但此時(shí)NOB活性已經(jīng)極低,大多數(shù)NOB已被殺死,而AOB活性雖然也被抑制一部分,但根據(jù)以前的研究,FNA對(duì)AOB的抑制作用是可逆的,在AOB恢復(fù)活性過(guò)程中會(huì)與殘留NOB競(jìng)爭(zhēng)DO,因?yàn)镹OB此時(shí)數(shù)量較低,AOB占主要部分,而AOB對(duì)DO親和力要高于NOB,會(huì)在DO的競(jìng)爭(zhēng)中占據(jù)優(yōu)勢(shì),NOB無(wú)法獲得充分DO而被逐漸淘洗出反應(yīng)器[24-25].

圖4 不同濃度、不同時(shí)間FNA處理污泥對(duì)AOB、NOB活性的影響

2.3 FNA濃度、FNA處理時(shí)間響應(yīng)曲面分析

為驗(yàn)證批次實(shí)驗(yàn)是否反映了功能菌活性變化和FNA處理濃度、處理時(shí)間的相關(guān)性,并進(jìn)一步優(yōu)化處理組合方案,進(jìn)行了響應(yīng)曲面分析.如表4所示,Design-Expert軟件共設(shè)計(jì)了如下13組實(shí)驗(yàn)設(shè)計(jì)方案,包括FNA處理濃度和處理時(shí)間的交互項(xiàng),一次項(xiàng),二次項(xiàng)進(jìn)行組合及相應(yīng)組合下對(duì)AOB、NOB活性情況的預(yù)測(cè).

由表5可知,AOB活性模型的值小于0.05,該模型差異顯著,模型擬合度較高,結(jié)果可靠,適應(yīng)實(shí)際[26-27].相關(guān)系數(shù)2=0.9938.值為223.5,遠(yuǎn)比1大,說(shuō)明模型中輸入的數(shù)據(jù)變量足以解釋數(shù)據(jù)方差[28].調(diào)整確定系數(shù)2adj=0.9893,能夠解釋98.93%的響應(yīng)值變化,模型2校正值和預(yù)測(cè)值接近,模型合理[29].因此使用該模型來(lái)分析和預(yù)測(cè)不同濃度FNA、不同處理時(shí)間對(duì)AOB活性的影響可行.方差分析結(jié)果表明一次項(xiàng)、、二次項(xiàng)2、2對(duì)AOB活性影響顯著.表明各因素對(duì)AOB影響不是簡(jiǎn)單的線性關(guān)系,FNA濃度和處理時(shí)間均對(duì)AOB影響顯著.

表4 響應(yīng)曲面實(shí)驗(yàn)設(shè)計(jì)方案與結(jié)果

NOB活性模型的值小于0.05,該模型差異顯著.模型擬合度良好,相關(guān)系數(shù)2=0.9647.調(diào)整確定系數(shù)2adj=0.9394,能夠解釋93.94%的響應(yīng)值變化.因此使用該模型來(lái)分析和預(yù)測(cè)不同濃度FNA、不同處理時(shí)間對(duì)AOB活性的影響是可行的.方差分析結(jié)果表明一次項(xiàng),二次項(xiàng)2對(duì)NOB活性影響顯著.表明各因素對(duì)NOB影響不是簡(jiǎn)單的線性關(guān)系,FNA濃度對(duì)NOB影響比FNA處理時(shí)間顯著.使用Design-Expert 10軟件處理數(shù)據(jù),得到的FNA處理濃度和處理時(shí)間對(duì)AOB、NOB活性影響的二項(xiàng)式多項(xiàng)回歸方程分別為:

表5 AOB、NOB活性回歸方程方差分析

如圖5(a)、(c)所示,FNA濃度一定時(shí),隨著處理時(shí)間的延長(zhǎng),AOB活性有微弱降低的趨勢(shì);處理時(shí)間一定時(shí),FNA濃度升高,AOB活性顯著降低,FNA濃度對(duì)AOB的影響程度要比處理時(shí)間高.如圖5(b)、(d)所示,FNA濃度一定時(shí),隨著處理時(shí)間的延長(zhǎng), NOB活性有降低的趨勢(shì),且這種趨勢(shì)要比AOB的更微弱;處理時(shí)間一定時(shí),FNA濃度升高,NOB活性顯著降低.

圖5 AOB、NOB活性的等高線和響應(yīng)面

3 結(jié)論

3.1 在0～2min的沉降時(shí)間范圍內(nèi),隨著時(shí)間延長(zhǎng),排出污泥的AnAOB、AOB、NOB活性呈下降趨勢(shì),且粒徑分布變得更均勻.1min的排泥時(shí)間有利于顆粒-絮體復(fù)合系統(tǒng)排出更多NOB并且保留AnAOB,此時(shí)排出污泥的AnAOB、AOB、NOB活性分別為34.21%、54.55%和68.63%.

3.2 FNA濃度小于0.1mg/L時(shí),AOB活性隨處理時(shí)間延長(zhǎng)變化不明顯,主要受FNA濃度影響. 當(dāng)FNA濃度超過(guò)0.1mg/L時(shí),處理時(shí)間對(duì)AOB活性影響變大.

3.3 FNA對(duì)NOB的活性具有雙重影響.FNA< 0.1mg/L時(shí),對(duì)NOB活性具有促進(jìn)效果,FNA濃度越高,處理時(shí)間越長(zhǎng),這種效果越明顯.FNA濃度超過(guò)0.1mg/L時(shí)開(kāi)始對(duì)NOB活性有抑制效果,且處理時(shí)間越長(zhǎng),抑制越明顯.當(dāng)FNA>1.2mg/L時(shí),NOB活性被完全抑制.

3.4 最適宜本研究的FNA處理?xiàng)l件是0.6mg/L處理12h.此時(shí)AOB、NOB活性分別是38.71%、12.5%,既有利于AOB活性的恢復(fù),又能夠抑制更多的NOB活性.

3.5 響應(yīng)曲面分析結(jié)果驗(yàn)證了FNA處理濃度、處理時(shí)間與AOB、NOB活性的顯著相關(guān)性.

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Parameter optimization of CANON granular-flocculate composite system with side-flow FNA suppression.

REN Zhi-qiang1,LI Dong1*, WANG Wen-qiang1, ZHANG Jie1,2

(1.Key Laboratory of Beijing Water Quality Science and Water Environment Recovery Engineering, Beijing University of Technology, Beijing 100124, China；2.State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China)., 2022,42(11)：5100～5107

In order to explore the best combination of process parameters related to the strategy of inhibiting nitrite oxidizing bacteria (NOB) by side flow free nitrous acid (FNA) treatment, in the completely autotrophic nitrogen removal over nitrite (CANON) process of granular-flocculate composite system, batch test was used to explore the effects of sludge sedimentation time, FNA treatment concentration and FNA processing and processing time to the related functional bacteria activity influence. The NOB activity was targeted inhibition and treatment time on the activity of relevant functional bacteria, so as to inhibit the activity of NOB and reduce the effect of FNA on the activity of functional bacteria. The result showed that the settling time affected the activity of functional bacteria in the treated sludge. With the prolongation of the settling time, the activity of anaerobic ammonium oxidizing bacteria (AnAOB) in the discharged sludge gradually decreased. After settling for 1min, most of the discharged sludge was NOB, and retained as much AnAOB as possible in the reactor. At this time, the relative activities of AnAOB, ammonia oxidizing bacteria (AOB) and NOB were 15.79%, 54.55% and 68.63%, respectively. Considering the effect of FNA on the activity of NOB and AOB, the activity of AOB was 38.71%, while the NOB activity was only 12.5% after inhibition with 0.6mg/L FNA for 12h. The results of response surface analysis showed that the treatment time and treatment concentration of FNA were the key factors affecting the activity of NOB and AOB.

granular-flocculate；CANON；FNA；NOB；response surface

X703.1

A

1000-6923(2022)11-5100-08

任志強(qiáng)(1995-),男,遼寧凌源人,北京工業(yè)大學(xué)碩士研究生,主要研究方向?yàn)槲鬯疃忍幚砼c再生回用技術(shù).發(fā)表論文3篇.

2022-04-02

北京高校卓越青年科學(xué)家計(jì)劃項(xiàng)目(BJJWZYJH012019 10005019)

* 責(zé)任作者, 教授, lidong2006@bjut.edu.cn