反硝化型甲烷厭氧氧化(DAMO)系統pH值耦合模型研究

呂 嬌,樓菊青,徐 帆

反硝化型甲烷厭氧氧化(DAMO)系統pH值耦合模型研究

呂 嬌,樓菊青*,徐 帆

(浙江工商大學環境科學與工程學院,浙江 杭州 310018)

對3個具有不同優勢菌種反應器中厭氧氧化(DAMO)過程與pH值進行動力學耦合,結果表明,在25℃,Anammox-DAMO混培系統最大脫氮速率、硝酸鹽初始抑制濃度和銨鹽初始抑制濃度分別為3.95mg/(L·d),182.63,196.40mg/L;Nitrate-DAMO系統最大脫氮速率、硝酸鹽初始抑制濃度分別為4.30mg/(L·d), 367.69mg/L;Nitrite-DAMO系統最大脫氮速率、亞硝酸鹽初始抑制濃度分別為4.04mg/(L·d), 293.35mg/L.脫氮速率均隨pH值增加先增大后減小,3個系統最佳脫氮pH值分別為7.5±0.2,7.2±0.2,7.8±0.2.脫氮動力學表明,3個不同系統DAMO反應過程均可用Haldane-pH值耦合模型描述. Nitrate-DAMO系統、Nitrite-DAMO系統脫氮過程還可用Monod-pH值耦合方程描述,Nitrate-DAMO系統細菌生長速率、硝酸鹽親和常數和抑制常數分別為1291.21cfu/(L·d), 295.23, 72.63mg/L;Nitrite-DAMO系統細菌生長速率、亞硝酸鹽親和常數和抑制常數分別為4040.42cfu/(L·d), 264.51, 5.02mg/L.

反硝化型甲烷厭氧氧化；脫氮性能；Hanldane方程；Monod方程；pH值;耦合模型

反硝化厭氧甲烷氧化(DAMO)過程,是以硝酸鹽或亞硝酸鹽為電子受體,以溫室氣體甲烷為唯一電子供體的甲烷厭氧氧化耦合反硝化過程[1-2].研究表明,該過程在濕地[3]、河流[4]、深水湖泊[5]等大多數淡水沉積物深層和水稻田中均存在,是自然界偶聯碳氮循環的關鍵環節[6].主導該過程的功能微生物主要包括NC10門細菌的‘’()[1]和隸屬于厭氧甲烷氧化古菌(ANME)中的一個簇ANME-2d的‘’()[2].DAMO過程在自然環境中也常見與厭氧氨氧化(Anammox)過程共存,兩者可能會爭奪NO2-,但也有可能會形成一種協同作用[7]: Anammox細菌消耗NO2-使其轉化為NO3-,而后DAMO微生物還原NO3-[8].

數學模型是深入了解生物反應過程, 幫助和支持生物處理系統設計以及參數優化強有力的工具,現已被廣泛應用于廢水處理過程[9-10]. Ni等[11]對Anammox脫氮動力學模型的評價表明,格勞(Grau)二級基質去除模型和改進的斯托弗-金坎農(Stover-Kincannon)模型較一級基質去除模型、莫諾德(Monod)模型和康托斯(Contois)模型更適合描述Anammox脫氮過程;Rosenthal等[12]研究后發現Anammox細菌能夠耐受亞硝酸鹽濃度的升高,而亞硝酸鹽敏感性系數并不適用于Anammox細菌的生長建模;Hu等[13]基于Monod模型和擴散反應模型開發了一個-DAMO模型用于探討DAMO細菌的生長限制因素;Ni等[14]致力于模擬Anammox和DAMO微生物共培養系統模型,用以描述DAMO和Anammox微生物共培養系統生化過程.

目前未見有對硝酸鹽型反硝化甲烷厭氧氧化(Nitrate-DAMO)過程的模型探討.且已有的關于Nitrite-DAMO和Anammox的模型中也未考慮pH值這個對這些生化過程影響較大的因素.DAMO微生物與大多數傳統異養反硝化類細菌類似,更偏好弱堿性環境[15].Zhu等[7]研究發現當pH值在5.9～7.4范圍內,DAMO系統活性與pH值呈正相關.過往研究一般在pH值接近7.0的條件下培養DAMO微生物[2-3],過酸或過堿性環境可能會導致系統活性降低.然而目前未建立DAMO系統脫氮速率和系統內pH值的耦合模型,本文以穩定運行2000多天的3個具有不同優勢菌種的DAMO反應器為研究對象,基于霍爾頓(Haldane)模型和Monod模型,建立pH值耦合模型,用以描述DAMO微生物和Anammox微生物混培系統、Nitrate-DAMO系統以及亞硝酸鹽型反硝化甲烷厭氧氧化(Nitrite-DAMO)系統的反應動力學過程,探明電子受體與pH值對系統的協同影響,并確定該過程最佳脫氮速率和銨鹽、硝酸鹽、亞硝酸鹽對DAMO系統初始抑制濃度,為完善DAMO過程理論和提升系統性能提供參考.

1 材料與方法

1.1 試驗材料

1.1.1 試驗系統 3個含DAMO微生物的系統分別是:Anammox-DAMO系統:以Nitrate-DAMO古菌(39.4%)和Anammox菌(45.8%)為優勢菌種[16],以西溪河底泥、西湖底泥與農田水稻土壤的混合污泥為接種物,供給CH4、NH4+、NO3-,反應過程見圖1A.

Nitrite-DAMO系統:以Nitrite-DAMO細菌(88.2%)為優勢菌種[17],接種物與Anammox-DAMO系統相同,供給CH4、NO2-,反應過程見圖1B.

Nitrate-DAMO系統:以Nitrite-DAMO細菌(62.2%)和Nitrate-DAMO古菌(26.5%)為優勢菌種[18],以西溪河底泥、杭州七格污水處理廠二沉池活性污泥與儲泥池厭氧消化污泥的混合污泥為接種物,供給CH4、NO3-,反應過程見圖1C.

各試驗系統內部始終保持厭氧狀態,結合經高純N2曝氣30min的以去離子水為溶劑配制的新鮮營養液[19],KH2PO4、CaCl2×2H2O、MgSO4分別為0.05,0.30, 0.10g/L,微量元素液為1.25mL/L,利用0.1mol/L HCl或0.1mol/L NaOH使pH值維持在7.0±0.2,在25℃環境溫度下運行穩定.

A. Anammox-DAMO系統;B. Nitrite-DAMO系統;C. Nitrate-DAMO系統

1.1.2 試驗裝置 如圖2,反應器:直徑16cm,高30cm,有效容積3.5L.取樣口與排氣口均設有閥門,所有閥門關閉時,反應器呈全封閉狀態,內部環境厭氧.

圖2 試驗裝置示意

a.排氣口;b. 頂蓋;c. 第一取樣口;d. 第二取樣口;e. 進樣口;f. 攪拌子

1.2 試驗方法

反應器已連續運行2547d,第1995～2367d的實驗數據被用于校準和驗證本文建立的DAMO反應過程動力學模型.第1995d開始作第1階段,pH值控制在5.5±0.20,將Anammox- DAMO、Nitrate-DAMO系統內硝酸鹽濃度控制為(10.0±0.50)mg N/L, Nitrite-DAMO系統內亞硝酸鹽濃度控制為(10.0± 0.50)mg N/L,試驗周期為7d,此后逐步將Anammox- DAMO系統硝酸鹽濃度提升為(20.0±0.50), (30.0± 0.50), (50.0±0.50), (100.0±0.50), (150.0±0.50)mg N/L;Nitrate-DAMO系統硝酸鹽濃度提升為(20.0± 0.50), (30.0±0.50), (50.0±0.50), (250.0±0.50) mg N/L; Nitrite-DAMO系統亞硝酸鹽濃度提升為(20.0± 0.50), (30.0±0.50), (50.0±0.50)mg N/L.隨著生物反應器性能的提高,在超過2054d的試驗期間, Anammox-DAMO系統進水硝酸鹽濃度從150.0mg N/L逐步提升至(250.0±0.50), (400.0±0.50), (500.0± 0.50), (800.0±0.50)mg N/L;Nitrate-DAMO系統進水硝酸鹽濃度從250.0mg N/L逐步提升至(500.0±0.50), (750.0±0.50), (1000.0±0.50), (1250.0±0.50), (1500.0± 0.50)mg N/L;Nitrite-DAMO系統亞硝酸鹽濃度從50.0mg N/L逐步提升至(100.0±0.50), (200.0±0.50), (350.0±0.50),(500.0±0.50),(650.0±0.50),(800.0±0.50)mg N/L.自第2085d開始,將Anammox- DAMO系統內銨鹽濃度控制為(10.0±0.50)mg N/L,試驗周期為7d,逐步將Anammox-DAMO系統進水銨鹽濃度提升為(20.0±0.50), (30.0±0.50),(50.0±0.50), (100.0± 0.50),(150.0±0.50),(250.0±0.50),(400.0±0.50),(500.0±0.50),(800.0±0.50)mg N/L.此后2、3、4、5階段控制pH值分別在6.0±0.20, 7.0±0.20, 8.0± 0.20, 8.5±0.20.

試驗期間,每24h取水樣3.0mL,經0.22μm微孔濾膜過濾后測定NH4+-N、NO3--N、NO2--N濃度以及pH值,同時監測系統中甲烷含量.利用普析TU-1901雙光束紫外可見分光光度計測定NH4+- N、NO3--N、NO2--N的濃度[20].通過裝配有FID的氣相色譜儀(GC2030,島津)測定頂空甲烷氣體含量[21].利用梅特勒FG2便攜式pH值計監測反應器在試驗期間的pH值.

1.3 反應動力學模型

選用Haldane方程[式(1)][14]、Monod變型方程[式(2)、式(3)][13,22]為基礎模型,利用Origin軟件模擬氮素對DAMO過程的影響動力學.

式中:max為系統的最大脫氮速率, mg/(L·d);為硝酸鹽、亞硝酸鹽、銨鹽濃度, mg/L;s為飽和系數, mg/L;K為硝酸鹽、亞硝酸鹽、銨鹽對系統的初始抑制濃度,mg/L;max為微生物最大生長速率,cfu/(L·d);DA表示微生物產量系數;DA為微生物活性生物量,u/L;(NO2)為微生物對亞硝酸鹽親和常數, mg/L;'(NO2)為微生物對亞硝酸鹽抑制常數,mg/L;(NO3)為微生物對硝酸鹽親和常數,mg/L;'(NO3)為微生物對硝酸鹽抑制常數, mg/L.

N-DAMO系統脫氮速率在酸性環境隨pH值升高而升高,在堿性環境隨pH值的升高而降低[23],因此pH值對N-DAMO系統脫氮速率的影響可以看作一個近似一段的正弦函數方程[式(4)].

式中:為系統內pH值(取值范圍0.0～14.0),、、、均為固定系數.

將式(1)、(2)、(3)與式(4)耦合建立反硝化型甲烷厭氧氧化系統脫氮速率-pH值耦合模型[式(5)、(6)、(7)]

2 結果與討論

2.1 Anammox-DAMO系統脫氮擬合分析

由圖3可知,在同等pH值條件下,0～800mg/L銨鹽、硝酸鹽影響Anammox-DAMO系統的脫氮速率均隨鹽濃度的增加呈先增加后下降趨勢;在同等鹽濃度條件下,5.5～8.5pH值影響下脫氮速率也隨pH值的增加先增加后下降.Anammox-DAMO系統脫氮速率擬合參數見表1.

由圖3a可知,Haldane-pH值耦合方程的擬合度(2)和殘差平方和(SSE)分別為0.890和9.559, Anammox-DAMO系統的最佳脫氮速率為3.74mg/ (L·d),硝酸鹽對系統的初始抑制濃度為182.63mg/L, 0～800mg/L NO3--N條件下系統脫氮速率符合Haldane-pH值方程.由圖3b可知,Haldane-pH值耦合方程的2和SSE分別為0.867和12.330, Anammox-DAMO系統的最佳脫氮速率為3.95mg/ (L·d),銨鹽對系統的初始抑制濃度為196.40mg/L,0～ 800mg/L NH4+-N影響下系統脫氮速率也符合Haldane-pH值方程.

由圖3可知,硝酸鹽濃度高于182.63mg/L,銨鹽濃度高于196.40mg/L將限制DAMO古菌和Anammox細菌的生長,最佳鹽濃度是圖中擬合曲面的最高點.研究表明[24-25],隨著鹽度的增加,反硝化速率會受到抑制.因此當銨鹽和硝酸鹽濃度持續升高達到一定濃度后,Anammox-DAMO反應器反硝化速率下降.本文擬合結果中,硝酸鹽對Anammox- DAMO系統脫氮抑制濃度為182.63mg/L,而Li等[26]發現在50～400mg/L,硝酸鹽濃度增加對Anammox過程暫沒有抑制作用,這可能是由于Li等[26]所使用的上流式污泥床-過濾器(UBF)反應器內微生物受到馴化,進水硝酸鹽、銨鹽濃度(300～400mg/L)較高,Anammox菌的耐受性相應提高;銨鹽影響下的脫氮速率擬合結果低于Ni等[11]研究當銨濃度從210mg/L增加到380mg/L,氮負荷率(NLR)由0.43kg/ (m3×d)增加到0.72kg/(m3×d),反應器對基質濃度沖擊具有良好的耐受性.這可能是由于Anammox細菌細胞產率低(0.08～0.11g/g,以VSS/NH4+-N計),生長緩慢且在高細胞濃度(1010～1011個/mL)時才具有活性[27],本試驗所用反應系統內污泥生物量較Ni等[11]生物量低,導致Anammox細菌活性相對較低.

a. NO3--N-pH值影響;b. NH4+-N-pH值影響

表1 Anammox-DAMO系統動力學參數

圖3中所示pH值對Anammox-DAMO系統脫氮速率的影響可以近似看作一段正弦曲線方程,在酸性范圍內隨pH值增大,脫氮速率逐步提升, 7.5± 0.2達到最佳脫氮速率,在堿性范圍內隨pH值增大,脫氮速率逐漸受到抑制.Achlesh等[28]通過構建二維等高線圖和三維響應面圖可視化溫度和酸堿度對Anammox系統的交互影響結果表明, Anammox系統最佳pH值8.0～8.5,相較本文擬合結果更大,證明在Anammox-DAMO體系中,脫氮速率受DAMO古菌與Anammox菌共同作用,因此推測DAMO古菌更傾向于酸性環境,這與Lou等[17]推論相似.研究表明,游離氨(FA)對厭氧氨氧化系統有負面影響[29],且FA與pH值有關[21].本研究中堿性條件(7.0～8.5)下,隨著pH值升高,FA濃度升高,脫氮速率下降.當pH=8.5,氨氮濃度為87.61mg/L時,FA濃度為13.34mg/L,此時脫氮速率不到最大脫氮速率的一半,而在酸性條件下(pH值5.5～7.0),對脫氮速率進行單因素方差分析發現并無顯著性差異.說明在堿性條件下, Anammox- DAMO系統限制性抑制因子是FA.而在酸性條件下,抑制效果與FA濃度無關,只與離子化氨氮的濃度相關,離子化氨氮是限制性抑制因子.這與文獻報道的最佳pH值范圍(7.0～8.5)一致[30].

2.2 Nitrate-DAMO系統脫氮擬合分析

由圖4可見,在相同pH值條件下,0～1500mg/L硝酸鹽影響Nitrate-DAMO系統的脫氮速率隨硝酸鹽濃度的增加呈先增加后下降趨勢;在相同硝酸鹽條件下, pH值5.5～8.5范圍內脫氮速率也隨pH值的增加先增加后下降.Nitrate-DAMO系統脫氮速率擬合參數見表2.

由圖4a可知,Haldane-pH值耦合方程的2和SSE分別為0.823和12.098, Nitrate-DAMO系統的最佳脫氮速率為4.30mg/(L·d),硝酸鹽對系統的初始抑制濃度為367.69mg/L,0～1500mg/L NO3--N條件下系統脫氮速率符合Haldane-pH值方程.由圖4b可知,Monod-pH值耦合方程2和SSE分別為0.822和12.098,Nitrate-DAMO系統的最佳脫氮速率為4.28mg/(L·d),細菌生長速率為1291.21cfu/(L·d),硝酸鹽親和常數和抑制常數分別為295.23,72.63mg/ L.0～1500mg/L NO3--N條件下系統脫氮速率也符合Monod-pH值方程.用這2個模型擬合后得到的結果吻合程度非常高.

a. Haldane-pH值耦合模型;b. Monod-pH值耦合模型

表2 Nitrate-DAMO系統動力學參數

由圖4可知,低濃度硝酸鹽(0～350mg/L)影響下,Nitrate-DAMO系統脫氮能力與鹽濃度呈正相關,這與Li等[31]發現的亞熱帶河口沉積物中DAMO速率與沉積物NO3--N呈正線性關系相類似.當硝酸鹽濃度高于367.69mg/L時對系統產生抑制效應, Nitrate-DAMO系統脫氮性能隨鹽濃度升高而降低.鹽度是決定DAMO細菌多樣性和豐度的關鍵因素,高鹽度對DAMO細菌和DAMO古菌的菌群結構、豐度以及活性產生抑制作用[21,32].Shen等[4]觀察到鹽度與杭州灣沉積物中DAMO細菌的豐度和活性呈負相關.這些結果證實了鹽度會對DAMO過程產生一定的負面影響.隨著鹽度的增加,DAMO過程脫氮速率下降,也可能歸因于鹽度對反硝化作用的抑制[26].Li等[31]研究發現鹽度也通過限制和抑制反硝化作用而間接影響DAMO系統反應速率.本研究也發現,當硝酸鹽濃度達到一定濃度時,也對系統產生了負面作用,Nitrate-DAMO系統脫氮速率受到抑制.硝酸鹽對Anammox-DAMO系統初始抑制濃度為182.63mg/L,對Nitrate-DAMO系統初始抑制濃度為367.69mg/L,這可能是由于DAMO細菌與DAMO古菌對高鹽廢水可以表現出更強的抗沖擊負荷能力[33].

由圖4可知,Nitrate-DAMO系統脫氮速率受pH值影響,先增高后降低,在pH7.2±0.2達到最佳. Nitrate-DAMO系統由62.2% Nitrite-DAMO細菌與26.5%Nitrate-DAMO古菌組成,脫氮速率受細菌與古菌協同影響,其中細菌起主導作用.與Nitrite-DAMO系統相比,由于偏弱酸性古菌影響, Nitrate- DAMO系統更適應中性環境,脫氮速率達到最佳,與Anammox-DAMO系統相比, Nitrate- DAMO系統內不含偏堿性的Anammox菌,最適pH值更低.

2.3 Nitrite-DAMO系統脫氮擬合分析

由圖5可見,在相同pH值條件下,在0～800mg/L亞硝酸鹽影響下,Nitrite-DAMO系統的脫氮速率隨亞硝酸鹽濃度的增加呈先增加后下降趨勢;在同等亞硝酸鹽條件下, pH值5.5～8.5時,脫氮速率也隨pH值的增加先增加后下降.Nitrite-DAMO系統脫氮速率擬合參數見表3.

a. Haldane-pH值耦合模型;b. Monod-pH值耦合模型

表3 Nitrite-DAMO系統動力學參數

由圖5a可知,Haldane-pH值耦合方程的2和SSE分別為0.954和1.629, Nitrite-DAMO系統的最佳脫氮速率為3.61mg/(L·d),亞硝酸鹽對系統的初始抑制濃度為293.35mg/L, 0～800mg/L NO2--N條件下系統脫氮速率符合Haldane-pH值方程.由圖5b可知,Monod-pH值耦合方程的2和SSE分別為0.955和1.591,Nitrite-DAMO系統的最佳脫氮速率為4.04mg/(L·d),細菌生長速率為4040.42cfu/(L·d),亞硝酸鹽親和常數和抑制常數分別為264.51, 5.02mg/ L.0～800mg/L NO2--N條件下系統脫氮速率也符合Monod-pH值方程.

Nitrite-DAMO系統脫氮趨勢與其他研究的亞硝酸鹽對活性污泥中多種微生物的抑制范圍相比,表現出對高濃度亞硝酸鹽更強的抗沖擊負荷的能力.Dapena-Mora等[33]發現,當亞硝酸鹽濃度為5～40mg/L時,會嚴重抑制厭氧氨氧化反應.亞硝酸鹽積累濃度達到140～700mg/L時,會對反硝化細菌的活性產生抑制作用[34].由圖4b可知,Monod-pH值耦合模型能夠較好地描述Nitrite- DAMO系統脫氮過程,這與Hu等[13]擬合結果相似,且該模型可以在一定時間內很好地預測廢水中亞硝酸鹽的濃度.亞硝酸鹽消耗率在達到最大值后下降[35-36]也與本文擬合結果相符.

如圖5,Nitrite-DAMO系統脫氮速率在各濃度下均隨pH值增大先提升后降低,在7.8±0.2達到最佳.這與He等[21]的擬合結果類似:pH7.6左右修正方程的最佳擬合值.與大多數異養反硝化菌類似, Nitrite-DAMO細菌更傾向于pH7.0～9.0的弱堿性環境[37].過往研究對于N-DAMO的培養大多保持在6.8～7.6[38-39],7.6左右的pH值脫氮速率優于7.0,以上結論均與本文擬合結果相符.He等[40]認為,游離亞硝酸鹽氮(FNA)是反硝化過程的抑制因子.Chen等[41]發現,當pH8.0～8.9時, FNA濃度較低,即使亞硝酸鹽氮濃度高達2000mg/L,也未對系統產生抑制作用.Puyol等[42]發現,膨脹顆粒污泥床(EGSB)厭氧氨氧化工藝對pH值沖擊非常敏感,亞硝酸鹽在反應器中積累產生的高FNA濃度的抑制作用在酸性pH值沖擊后惡化了反應器性能.本實驗中當溫度為25℃, pH6.0,亞硝酸鹽氮濃度74.72mg/L時,FNA濃度74.72mg N/L,Nitrite- DAMO系統脫氮率不到最佳脫氮速率的1/2.單因素方差分析表明,在酸性條件下,亞硝酸鹽氮對體系的影響與FNA值有關,FNA是限制性抑制因子.在堿性條件下,亞硝酸鹽對體系的抑制作用與FNA值無關,此時離子化的亞硝酸鹽是限制性抑制因子.該結果與Puyol等[42]的研究結果一致.

3 結論

3.1 Anammox-DAMO、Nitrate-DAMO、Nitrite- DAMO系統耦合pH值反應動力學皆符合Haldane- pH值方程.其中,Anammox-DAMO系統最大脫氮速率為3.95mg/(L·d),硝酸鹽初始抑制濃度為182.63mg/L,銨鹽初始抑制濃度為196.40mg/L; Nitrate-DAMO系統最大脫氮速率為4.30mg/(L·d),硝酸鹽初始抑制濃度為367.69mg/L;Nitrite-DAMO系統最大脫氮速率為4.04mg/(L·d),亞硝酸鹽初始抑制濃度為293.35mg/L.

3.2 Nitrate-DAMO系統和Nitrite-DAMO系統也符合Monod-pH值耦合模型,且擬合結果與Haldane-pH值方程擬合結果具有很高的吻合程度. Nitrate-DAMO細菌生長速率為1291.21cfu/(L·d),硝酸鹽親和常數為295.23mg/L,硝酸鹽抑制常數為72.63mg/L;Nitrite-DAMO細菌生長速率為4040.42cfu/(L·d),亞硝酸鹽親和常數為264.51mg/L,亞硝酸鹽抑制常數為5.02mg/L.

3.3 各系統脫氮速率受pH值影響皆呈一段正弦曲線分布,其中Anammox菌、Nitrite-DAMO細菌適應弱堿環境,Nitrate-DAMO古菌更傾向于弱酸環境,在3類微生物的協同作用下Anammox-DAMO系統最佳脫氮速率pH值為7.5±0.2, Nitrate-DAMO系統為7.2±0.2,Nitrite-DAMO系統為7.8±0.2.

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pH coupling model of denitrifying anaerobic methane oxidation (DAMO) system.

LU Jiao, LOU Ju-qing*, XU Fan

(College of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310018, China)., 2022,42(2)：612～619

This study tried to couple the pH value with the reaction kinetics of the denitrification-type methane anaerobic oxidation process. The Denitrifying Anaerobic Methane Oxidation (DAMO) reaction rate and pH value were coupled and evaluated in three reactors with different dominant bacteria. The results show that the Anammox-DAMO maximum denitrification rate and the initial inhibition concentration of nitrate ammonium at 25℃ were 3.95mg/(L×d), 182.63mg/L and 196.40mg/L, respectively. The maximum denitrification rate and the initial inhibition concentration of nitrate in Nitrate-DAMO system were 4.30mg/(L×d) and 367.69mg/L, respectively. The maximum denitrification rate and the initial inhibition concentration of nitrite in Nitrite-DAMO system were 4.04mg/(L×d) and 293.35mg/L, respectively. The denitrification rate of the systems increased first and then decreased with the increase of pH. The optimum pH was 7.5±0.2, 7.2±0.2, 7.8±0.2, respectively. The bacterial growth rate, nitrate affinity constant and inhibition constant of Nitrate-DAMO system were 1291.21cfu/(L×d), 295.23mg/L and 72.63mg/L, respectively; The bacterial growth rate, nitrite affinity constant and inhibition constant of Nitrite-DAMO system were 4040.42cfu/(L×d), 264.51mg/L and 5.02mg/L, respectively. All the three DAMO systems could be described by the coupled Haldane pH model; the denitrification process of Nitrate-DAMO system and Nitrite-DAMO system could also be described by Monod-pH coupling equation.

denitrifying anaerobic methane oxidation；denitrification performance；Hanldane equation；Monod equation；pH；coupling model

X703

A

1000-6923(2022)02-0612-08

呂 嬌(1996-),女,浙江湖州人,浙江工商大學碩士研究生,主要研究方向為廢水生物處理及資源化.發表論文1篇.

2021-05-21

浙江省自然科學基金資助項目(LY21D030003);浙江工商大學研究生科研創新基金一般項目(19020160029)

* 責任作者, 副教授, ljq7393@163.com