盧瑞朋,徐文江,李安峰,董 娜

強(qiáng)化反硝化除磷的新型多級(jí)缺氧-好氧工藝

盧瑞朋,徐文江,李安峰*,董 娜

(北京市生態(tài)環(huán)境保護(hù)科學(xué)研究院,國(guó)家環(huán)境保護(hù)工業(yè)廢水污染控制工程技術(shù)(北京)中心,北京 100037)

基于多級(jí)缺氧-好氧(MAO)工藝和反硝化除磷理論,設(shè)計(jì)一種具有反硝化除磷功能的新型MAO工藝(DPR-MAO).實(shí)驗(yàn)探究了該工藝的脫氮除磷效能以及各反應(yīng)池的微生物群落特征.工藝運(yùn)行結(jié)果表明,穩(wěn)定期COD、TN、NH4+-N和TP的平均出水濃度分別為7.07,9.04,0.34,和0.49mg/L,平均去除率分別為98%、87%、99%和93%.出水水質(zhì)滿足《城鎮(zhèn)污水處理廠污染物排放標(biāo)準(zhǔn)》(GB 18918-2002)一級(jí)A標(biāo)準(zhǔn).高通量測(cè)序結(jié)果表明,各反應(yīng)池中微生物以變形菌門(Proteobacteria)、擬桿菌門(Bacteroidota)和綠彎菌門(Chloroflexi)為主,分別占61.85%～75.58%、16.39%～22.60%、1.52%～4.76%.通過屬水平的研究進(jìn)一步分析發(fā)現(xiàn),、、、和是具有反硝化除磷功能的優(yōu)勢(shì)菌屬.DPR-MAO工藝實(shí)現(xiàn)了反硝化聚磷菌的富集以及污水中氮磷的高效去除.

反硝化除磷；多級(jí)缺氧-好氧；脫氮除磷；高通量測(cè)序；微生物群落

污水中氮、磷營(yíng)養(yǎng)鹽的過量排放會(huì)引起嚴(yán)重的水體富營(yíng)養(yǎng)化現(xiàn)象,因此在其排放到水體之前必須對(duì)其進(jìn)行有效地去除.生化處理技術(shù)是最為經(jīng)濟(jì)有效的脫氮除磷工藝.然而,應(yīng)用最為廣泛的傳統(tǒng)A2/O工藝很難適應(yīng)日益嚴(yán)格的排放標(biāo)準(zhǔn),且往往存在外加碳源需求量大、曝氣能耗高的問題[1-3].因此需要開發(fā)一種更為有效經(jīng)濟(jì)的生化處理工藝對(duì)污水中的氮、磷營(yíng)養(yǎng)鹽進(jìn)行有效地去除.

MAO工藝是通過多個(gè)缺氧池和好氧池串聯(lián)組合形成[4],從而人為地在一個(gè)處理系統(tǒng)中出現(xiàn)多次硝化反應(yīng)與反硝化反應(yīng)的疊加,因此這一工藝具有很高的脫氮率.工程實(shí)踐表明,相比于傳統(tǒng)A2/O工藝,MAO工藝具有更高的脫氮率,但除磷效果相對(duì)較差[5].因此,目前MAO工藝多采用前置厭氧段或者與A2/O和UCT(University of Cape Town)等工藝聯(lián)用,從而達(dá)到同步脫氮除磷的目的[6-11].盡管如此,MAO工藝依靠單純的生物處理仍然無法滿足嚴(yán)格的出水標(biāo)準(zhǔn),實(shí)際工程中往往需要增加化學(xué)除磷池、絮凝濾池等深度處理單元,造成成本的增加[12].

反硝化聚磷菌(DPAOs)可以通過“一碳兩用”的方式,將NO--N(NO3--N與NO2--N)代替O2作為電子受體,同時(shí)實(shí)現(xiàn)氮、磷的高效去除,節(jié)省了曝氣能耗、碳源需求以及降低了污泥產(chǎn)量[13-14],因此反硝化除磷(DPR)被認(rèn)為是一種可持續(xù)發(fā)展技術(shù).常見的反硝化除磷工藝有BCFS(Biologische Chemische Fosfaat Stikstof Verwijdering)工藝,A2N (Anaerobic Anoxic Nitrification)工藝和Dephanox工藝等[15-18].這些工藝雖然可以強(qiáng)化反硝化除磷,但BCFS工藝需化學(xué)除磷,A2N工藝和Dephanox工藝整體出水效果不好[15].

本研究基于反硝化除磷理論,提出一種具有反硝化除磷功能的MAO工藝(DPR-MAO工藝).該工藝在MAO工藝的前端增設(shè)厭氧-缺氧段,使其具有同步脫氮除磷功能,共采用兩級(jí)AO處理單元,并利用獨(dú)特的內(nèi)循環(huán)系統(tǒng)強(qiáng)化污水脫氮除磷效能.通過實(shí)驗(yàn)探究了該工藝的脫氮除磷效能以及各反應(yīng)池的微生物群落特征,以期為DPR-MAO工藝的實(shí)際應(yīng)用提供數(shù)據(jù)支持.

1 材料與方法

1.1 實(shí)驗(yàn)裝置及工藝運(yùn)行

DPR-MAO工藝實(shí)驗(yàn)裝置示意圖如圖1所示,由厭氧池、反硝化除磷池、一級(jí)缺氧池、一級(jí)好氧池、二級(jí)缺氧池和二級(jí)好氧池組成,其中反硝化除磷池按缺氧環(huán)境運(yùn)行.總有效容積24L,厭氧池、反硝化除磷池和各級(jí)缺氧池均為3L,各級(jí)好氧池均為6L.實(shí)驗(yàn)裝置的內(nèi)循環(huán)系統(tǒng)一共有兩個(gè),由一級(jí)缺氧池回流到厭氧池的厭氧-缺氧內(nèi)循環(huán)系統(tǒng)(AA內(nèi)循環(huán)系統(tǒng))一方面用于強(qiáng)化DPAOs的厭氧-缺氧環(huán)境,另一方面回流污泥至厭氧段,保證厭氧池污泥濃度;由二級(jí)好氧池回流至反硝化除磷池的缺氧-好氧內(nèi)循環(huán)系統(tǒng)(AO內(nèi)循環(huán)系統(tǒng))一方面通過硝化液回流提高脫氮率,另一方面為反硝化除磷池DPAOs的缺氧吸磷過程提供NO3--N.

實(shí)驗(yàn)裝置的運(yùn)行方式如下:污水分三段分別進(jìn)入?yún)捬醭?、一?jí)缺氧池和二級(jí)缺氧池,進(jìn)水流量配比為Q1:Q2:Q3=6:7:3,厭氧池利用Q1段污水中的碳源進(jìn)行厭氧釋磷,之后厭氧池混合液進(jìn)入反硝化除磷池,其中的DPAOs將來自AO內(nèi)循環(huán)系統(tǒng)的NO3--N作為電子受體進(jìn)行缺氧吸磷過程,反硝化除磷池的混合液進(jìn)入一級(jí)缺氧池,利用Q2段污水的碳源將混合液中的NO3--N進(jìn)一步通過反硝化細(xì)菌的反硝化作用去除,一級(jí)缺氧池的混合液進(jìn)入一級(jí)好氧池,一方面利用缺氧反硝化過程提供的堿度和污水中的NH4+-N進(jìn)行硝化反應(yīng),將污水中的NH4+-N轉(zhuǎn)化為NO3--N,另一方面進(jìn)行好氧吸磷過程,之后混合液進(jìn)入二級(jí)缺氧池利用Q3段污水中的碳源再次反硝化,隨后混合液進(jìn)入二級(jí)好氧池,再次進(jìn)行硝化反應(yīng)和好氧吸磷過程.最后的沉淀池用于泥水分離,污泥回流至反硝化除磷缺氧池,剩余污泥外排.

圖1 DPR-MAO工藝實(shí)驗(yàn)裝置示意

實(shí)驗(yàn)總進(jìn)水流量2L/h,厭氧池溶解氧小于0.2mg/L,各缺氧池溶解氧量小于0.5mg/L,好氧池溶解氧含量在2～3mg/L.溫度保持在20～25℃,污泥濃度在3000mg/L左右.總水力停留時(shí)間12h,污泥回流比100%,AA內(nèi)循環(huán)比和AO內(nèi)循環(huán)比均為200%.

1.2 接種污泥與污水水質(zhì)

接種污泥來自于運(yùn)行狀況良好的污水處理廠,取A2/O工藝的沉淀池回流污泥.實(shí)驗(yàn)室進(jìn)水采用模擬廢水,以CH3COONa和CH3CH2COONa按4:3混合作為碳源.以NH4Cl和KH2PO4作為氮磷營(yíng)養(yǎng)物,各項(xiàng)水質(zhì)指標(biāo)見表1.投加MgCl2和CaCl2滿足微生物對(duì)Ca2+、Mg2+的需求.投加微量元素溶液0.6mL/L滿足微生物生長(zhǎng)繁殖所需,其成分為[19-20]:FeCl30.9g/L,H3BO40.15g/L,CuSO4×5H2O 0.03g/L, KI 0.18g/L, ZnSO4×7H2O 0.12g/L, MnSO40.05g/L, CoCl2×7H2O 0.15g/L, NaMo2H2O 0.06g/L.

表1 進(jìn)水水質(zhì)

1.3 水質(zhì)指標(biāo)檢測(cè)和分析方法

反應(yīng)器運(yùn)行期間,每3d采集一次水樣進(jìn)行檢測(cè).COD采用快速消解分光光度法,TN采用堿性過硫酸鉀消解紫外分光光度法,TP和PO43--P采用鉬酸銨分光光度法,NH4+-N采用納氏試劑分光光度法,NO3--N采用紫外分光光度法,污泥濃度(MLSS)采用濾紙稱重法,溶解氧(DO)采用哈希便攜式溶解氧儀測(cè)定.

1.4 高通量測(cè)序分析方法

1.4.1 樣本收集 在反應(yīng)器運(yùn)行的第60天,分別在各反應(yīng)池取污泥樣品,編號(hào)分別為R1(厭氧池)、R2(反硝化除磷池)、R3(一級(jí)缺氧池)、R4(一級(jí)好氧池)、R5(二級(jí)缺氧池)、R6(二級(jí)好氧池),經(jīng)離心分離后-20℃條件下冷凍保存.

1.4.2 DNA抽提和PCR 擴(kuò)增 完成微生物群落總DNA抽提,使用1%的瓊脂糖凝膠電泳檢測(cè)DNA的提取質(zhì)量,使用NanoDrop2000測(cè)定DNA 濃度和純度;使用338F (ACTCCTACGGGAGGCAGCAG)和806R (GGACTACHVGGGTWTCTAAT)對(duì)16SrRNA基因V3-V4 可變區(qū)進(jìn)行 PCR 擴(kuò)增.PCR反應(yīng)體系為:5×TransStart FastPfu緩沖液4μL, 2.5mM dNTPs 2μL,上游引物(5μM) 0.8μL,下游引物(5μM)0.8μL, TransStart FastPfu DNA聚合酶0.4μL,模板DNA 10ng,補(bǔ)足至20μL.每個(gè)樣本3個(gè)重復(fù).

1.4.3 Illumina Miseq 測(cè)序 將同一樣本的PCR產(chǎn)物混合后使用2%瓊脂糖凝膠回收PCR產(chǎn)物,利用AxyPrep DNA Gel Extraction Kit (Axygen Biosciences, Union City, CA, USA) 進(jìn)行回收產(chǎn)物純化,2%瓊脂糖凝膠電泳檢測(cè),并用Quantus? Fluorometer (Promega, USA) 對(duì)回收產(chǎn)物進(jìn)行檢測(cè)定量.使用NEXTFLEX Rapid DNA-Seq Kit進(jìn)行建庫(kù): (1)接頭鏈接;(2)使用磁珠篩選去除接頭自連片段;(3)利用PCR擴(kuò)增進(jìn)行文庫(kù)模板的富集;(4)磁珠回收PCR產(chǎn)物得到最終的文庫(kù).利用Illumina公司的Miseq PE300平臺(tái)進(jìn)行測(cè)序(上海美吉生物醫(yī)藥科技有限公司).

1.4.4 數(shù)據(jù)處理與表達(dá)方式 根據(jù)97%的相似度對(duì)序列進(jìn)行 OTU 聚類并剔除嵌合體.利用RDP classifier(http://rdp.cme.msu.edu/,version 2.2)對(duì)每條序列進(jìn)行物種分類注釋,比對(duì)Silva 16S rRNA數(shù)據(jù)庫(kù),設(shè)置比對(duì)閾值為70%.測(cè)序結(jié)果由上海美吉云平臺(tái)提供.

2 結(jié)果與討論

2.1 有機(jī)物和營(yíng)養(yǎng)物質(zhì)的去除性能

反應(yīng)器啟動(dòng)20d左右出水水質(zhì)基本穩(wěn)定.圖2記錄了適應(yīng)期和穩(wěn)定期進(jìn)出水的COD、TN、NH4+-N和TP濃度以及各自的去除率.運(yùn)行結(jié)果表明,穩(wěn)定期出水水質(zhì)良好,出水COD、TN、NH4+-N和TP的平均出水濃度分別為7.07,9.04,0.34和0.49mg/L,均達(dá)到了《城鎮(zhèn)污水處理廠污染物排放標(biāo)準(zhǔn)》(GB 18918-2002)一級(jí)A標(biāo)準(zhǔn)(COD: 50mg/L; TN: 15mg/ L; NH4+-N: 5mg/L; TP: 0.5mg/L)[21].其中COD、TN和NH4+-N的出水濃度達(dá)到了北京市地方標(biāo)準(zhǔn)《城鎮(zhèn)污水處理廠水污染物排放標(biāo)準(zhǔn)》(DB11/809-2012)中的A排放限值(COD: 20mg/L; TN: 10mg/L; NH4+-N: 1.0mg/L)[22].穩(wěn)定期COD、TN、NH4+-N和TP的平均去除率分別為98%、87%、99%和93%.研究結(jié)果表明,DPR-MAO系統(tǒng)可以有效地去除污水中的有機(jī)物和營(yíng)養(yǎng)物質(zhì).

DPR-MAO系統(tǒng)的COD去除效果如圖2(a)所示,進(jìn)水COD的濃度范圍在309.08～405.12mg/L,穩(wěn)定期平均出水COD濃度為7.07mg/L,并且,適應(yīng)期和穩(wěn)定期的出水COD濃度基本上均在20mg/L以下,滿足北京市《城鎮(zhèn)污水處理廠水污染物排放標(biāo)準(zhǔn)》(DB11/809-2012)中的A排放限值[22],穩(wěn)定期去除率達(dá)98%.良好的去除效果一方面在于厭氧釋磷過程、缺氧反硝化過程和好氧曝氣過程都參與了有機(jī)物降解;另一方面在于進(jìn)水COD較低以及采用乙酸鈉和丙酸鈉這樣的短鏈脂肪酸作為碳源.

穩(wěn)定期TN和NH4+-N的平均出水濃度分別為9.04和0.34mg/L,去除率分別為87%和99%.工藝啟動(dòng)過程中,通過調(diào)節(jié)好氧池曝氣量,可以保證NH4+- N有效去除.由圖2(b)和(c)可以看出,前期脫氮率較低,TN和NH4+-N的出水濃度高.主要原因在于硝化細(xì)菌生長(zhǎng)速率低,一定的運(yùn)行時(shí)間可以保證硝化細(xì)菌的生長(zhǎng)和繁殖.20d之后,脫氮率逐漸提高并穩(wěn)定. 在穩(wěn)定期NH4+-N出水濃度大部分時(shí)間都保持在1mg/L以下,TN出水濃度大部分時(shí)間都在10mg/L范圍內(nèi)波動(dòng).實(shí)驗(yàn)結(jié)果表明,該工藝可以保證良好的脫氮效果.

TP的去除效果如圖2(d)所示,穩(wěn)定期TP的平均出水濃度為0.49mg/L,平均去除率為93%.在適應(yīng)期,TP的出水濃度波動(dòng)較大,部分時(shí)間可以降至1mg/L以下,主要原因在于污泥的吸附作用.穩(wěn)定期TP出水濃度大部分時(shí)間維持在0.5mg/L以下,后期出水濃度略有上升,其原因在于前期污泥培養(yǎng)過程中,排泥量較少,后期通過排泥措施可以保證出水TP濃度.實(shí)驗(yàn)結(jié)果表明,DPR-MAO工藝可以實(shí)現(xiàn)完全依靠生化手段除磷,這對(duì)于工程應(yīng)用中降低運(yùn)行成本至關(guān)重要.

2.2 各反應(yīng)池脫氮除磷過程分析

2.2.1 脫氮過程分析 脫氮過程主要是通過消化反應(yīng)和反硝化反應(yīng)實(shí)現(xiàn)的[23].DPR-MAO工藝中,一級(jí)缺氧池、一級(jí)好氧池、二級(jí)缺氧池和二級(jí)好氧池主要進(jìn)行兩次硝化、反硝化反應(yīng),從而達(dá)到脫氮目的.如圖3所示,厭氧池NO3--N含量極低,分析原因一方面在于裝置運(yùn)行過程中,污泥回流到反硝化除磷池而不是厭氧池,大量的NO3--N在反硝化除磷池被DPAOs利用而去除;另一方面,隨后的一級(jí)缺氧池利用Q2段進(jìn)水中的有機(jī)物進(jìn)行了反硝化脫氮,進(jìn)而去除了剩余的NO3--N.新工藝的這一設(shè)計(jì)目的主要是為了避免硝態(tài)氮對(duì)比厭氧釋磷過程的影響[24-25].

值得一提的是,一級(jí)好氧池的NO3--N濃度比二級(jí)好氧池高,主要原因在于一級(jí)缺氧池進(jìn)水配比相對(duì)較高,導(dǎo)致一大部分進(jìn)水NH4+-N在一級(jí)好氧池被轉(zhuǎn)化為NO3--N;另外,二級(jí)好氧池硝化反應(yīng)產(chǎn)生的NO3--N通過AO內(nèi)循環(huán)系統(tǒng)進(jìn)入反硝化除磷池被DPAOs去除.

圖3 各反應(yīng)池的NO3--N和PO43--P的變化

NA為厭氧池;DPR為反硝化除磷池;AN1為一級(jí)缺氧池;O1為一級(jí)好氧池;AN2為二級(jí)缺氧池;O2為二級(jí)好氧池

2.2.2 除磷過程分析 DPAOs除磷的原理是在缺氧條件下,DPAOs利用NO--N(NO3--N與NO2--N)作為電子受體實(shí)現(xiàn)磷的過量吸收,通過將富磷污泥排出系統(tǒng),達(dá)到除磷的目的[26-27].而傳統(tǒng)聚磷菌(PAOs)的吸磷過程是在好氧條件下進(jìn)行的.

由圖3可知,厭氧池首先進(jìn)行充分的釋磷過程,反硝化除磷池通過缺氧吸磷過程去除一部分磷,在一級(jí)好氧池和二級(jí)好氧池通過好氧吸磷過程去除剩余的磷.分析TP沿程濃度變化,DPAOs和PAOs都參與了除磷過程,這保證了工藝的高除磷率.并且,在反硝化除磷池PO43--P濃度從10.54mg/L下降到2.82mg/L,隨后的兩級(jí)好氧池進(jìn)一步去除混合液中剩余的磷.這表明DPR-MAO系統(tǒng)中大部分的磷由DPAOs去除,這也證明了該工藝可以通過DPAOs“一碳兩用”的方式脫氮除磷,尤其對(duì)于低C/N比污水來說,可以節(jié)約碳源,降低運(yùn)行成本.

2.3 微生物群落分析

2.3.1 微生物群落豐富度和生物多樣性 本實(shí)驗(yàn)6組微生物樣本通過高通量測(cè)序所獲得的優(yōu)化序列,以及將優(yōu)化序列在97%的相似性下聚類,所獲得的OTU 數(shù)量如表2所示.并且,由表2可知,6個(gè)樣本的Coverage指數(shù)值均大于99.6%,表明樣本中絕大部分微生物已被檢出,此次高通量測(cè)序的結(jié)果足以代表樣本中微生物的真實(shí)情況.

Sobs指數(shù)、Ace指數(shù)和Chao指數(shù)反映了微生物群落的豐富度,指數(shù)越高代表越豐富[11, 28-29].由表2可知,6個(gè)反應(yīng)池的豐富度指數(shù)相似,反硝化除磷池的豐富度最高,二級(jí)好氧池的豐富度最低,主要原因在于進(jìn)水中的有機(jī)物在缺氧池被大量利用,相反二級(jí)好氧池處于工藝末端,沒有足夠的有機(jī)物導(dǎo)致營(yíng)養(yǎng)環(huán)境差,抑制了部分微生物的生長(zhǎng)繁殖[11]. Shannon指數(shù)和Simpson指數(shù)反映了微生物群落的多樣性,Shannon指數(shù)越高代表越豐富,Simpson指數(shù)則相反[11,29].處于末端的二級(jí)好氧池的多樣性指數(shù)相對(duì)較低,但是6個(gè)反應(yīng)池微生物的多樣性指數(shù)沒有顯著性差異.

2.3.2 微生物群落組成 污泥樣品中的微生物在門水平的種群組成如圖4所示,共發(fā)現(xiàn)7個(gè)主要門,其中以變形菌門(Proteobacteria)、擬桿菌門(Bacteroidota)和綠彎菌門(Chloroflexi)為主,三者的相對(duì)豐度占比為88.24%～94.36%.其中,變形菌門的相對(duì)豐度為61.85%～75.58%、擬桿菌門的相對(duì)豐度為16.39%～22.60%、綠彎菌門的相對(duì)豐度為1.52%～4.76%.可以看出,變形菌門是系統(tǒng)中的優(yōu)勢(shì)菌群,占有系統(tǒng)最大的比例,大多數(shù)關(guān)于脫氮除磷工藝的微生物群落都有相似的結(jié)論[28-30].這是由于大部分具有脫氮除磷功能的微生物都為變形菌門,部分為擬桿菌門[31-32].

通過對(duì)變形菌門在綱水平上的分布特征進(jìn)行分析,發(fā)現(xiàn)6個(gè)樣品中占比最多的是γ-變形菌綱(),各反應(yīng)池分別占比90.57%、90.87%、91.37%、92.79%、92.02%、92.26%.

在屬水平上,選取相對(duì)豐度最高的γ-變形菌綱()進(jìn)行分析,如圖5所示.其中,和是常見的反硝化細(xì)菌[33-34].是一種聚糖菌,早期研究表明[35],聚糖菌會(huì)與DPAOs競(jìng)爭(zhēng)碳源,但無法參與除磷過程,因而被認(rèn)為是除磷效果變差的因素之一.但近年來的研究表明,可與DPAOs共存,也具有脫氮能力[36-38].另外,GAOs對(duì)DPAOs缺氧吸磷過程有正向促進(jìn)作用[39-40].而且GAOs的內(nèi)源部分反硝化與DPAOs反硝化除磷的協(xié)同作用還可以充分利用內(nèi)部碳源,解決污水處理過程中碳源不足的問題[14,41].

圖4 微生物門水平組成

圖5 γ-變形菌綱(Gamaproteobacteria)微生物的屬水平組成

表2 微生物菌群的多樣性和豐富度

常見的反硝化聚磷菌是、、、和[28,42-44],這些菌屬在各個(gè)反應(yīng)池中的占比情況如表3所示.其中占比最大,在各反應(yīng)池的相對(duì)豐度分別為61.70%、62.70%、56.87%、58.13%、53.97%和57.86%.可以發(fā)現(xiàn)6個(gè)反應(yīng)池中,反硝化除磷池的DPAOs優(yōu)勢(shì)菌屬相對(duì)豐度最高,為65.27%.

表3 各反應(yīng)池主要的DPAOs菌屬的分布

3 結(jié)論

3.1 實(shí)驗(yàn)結(jié)果表明,DPR-MAO工藝具有從污水中去除有機(jī)物和營(yíng)養(yǎng)物的極大潛力,通過優(yōu)化工藝運(yùn)行參數(shù),COD、TN、NH4+-N和TP的平均出水濃度均可以達(dá)到《城鎮(zhèn)污水處理廠污染物排放標(biāo)準(zhǔn)》(GB 18918-2002)一級(jí)A標(biāo)準(zhǔn),其中COD、TN和NH4+-N的平均出水濃度還可以滿足北京市《城鎮(zhèn)污水處理廠水污染物排放標(biāo)準(zhǔn)》(DB11/809-2012)中的A排放限值.

3.2 高通量測(cè)序結(jié)果表明,各反應(yīng)池中微生物以變形菌門(Proteobacteria)、擬桿菌門(Bacteroidota)和綠彎菌門(Chloroflexi)為主,其中變形菌門的相對(duì)豐度最高,為61.85%～75.58%.變形菌門的微生物主要以γ-變形菌綱()為主.

3.3、、、和是具有反硝化除磷功能的優(yōu)勢(shì)菌屬,其中以相對(duì)豐度最高,各反應(yīng)池相對(duì)豐度分別為61.70%、62.70%、56.87%、58.13%、53.97%、57.86%.

3.4 在6個(gè)反應(yīng)池中,具有反硝化除磷功能的菌屬在反硝化除磷池的相對(duì)豐度最高,為65.27%.

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Enhanced denitrifying phosphorus removal in novel multistage anoxic-oxic process.

LU Rei-peng, XU Wen-jiang, LI An-feng*, Dong Na

(State Environmental Protection Engineering (Beijing) Center for Industrial Wastewater Pollution Control, Beijing Municipal Research Institute of Eco-Environmental Protection, Beijing 100037, China)., 2022,42(4)：1706～1713

Based on the multistage anoxic-oxic (MAO) process and the theory of denitrifying phosphorus removal, a noval MAO process (DPR-MAO) with ability of denitrifying phosphorus removal was designed. In this study, the nitrogen and phosphorus removal performance and the microbial community characteristics of each reaction tank were investigated. During period of stable operation, the average COD, TN, NH4+-N and TP concentration in effluent were 7.07, 9.04, 0.34 and 0.49mg/L, respectively. Meanwhile, the average removal efficiecny of COD, TN, NH4+-N and TP were 98%, 87%, 99% and 93%, respectively. The effluent quality of DPR-MAO process could meet the first A level of the "Discharge standard of pollutants for municipal wastewater treatment plant” (GB 18918～2002). High-throughput sequencing results suggested that Proteobacteria, Bacteroidetes and Chloroflexiwere the dominant phyla in each reaction tank, accounting for 61.85%～75.58%、16.39%～22.60% and 1.52%～4.76% of the total phyla, respectively. Further analysis at the genus level found that,,andwere the dominant genus for denitrifying phosphorus removal. The DPR-MAO process realized the enrichment of denitrifying phosphorus accumulating organisms and the efficient removal of nitrogen and phosphorus from wastewater.

denitrifying phosphorus removal；multistage anoxic-oxic；nitrogen and phosphorus removal；microbial community；high throughput sequencing

X703.1

A

1000-6923(2022)04-1706-08

盧瑞朋(1995-),男,河南洛陽(yáng)人,北京市生態(tài)環(huán)境保護(hù)科學(xué)研究院碩士研究生,主要從事水污染控制方向技術(shù)研發(fā)及應(yīng)用.

2021-09-27

北京市生態(tài)環(huán)境保護(hù)科學(xué)研究院基金資助項(xiàng)目(Y2020-004)

*責(zé)任作者, 研究員, lianfeng@cee.cn