SO32-驅(qū)動(dòng)自養(yǎng)短程反硝化工藝亞硝酸鹽積累特性研究

聶裕婷,周 鑫*,平彩霞

SO32-驅(qū)動(dòng)自養(yǎng)短程反硝化工藝亞硝酸鹽積累特性研究

聶裕婷1,2,周 鑫1,2*,平彩霞1,2

(1.太原理工大學(xué)環(huán)境科學(xué)與工程學(xué)院,山西 晉中 030600；2.山西省市政工程研究生教育創(chuàng)新中心,山西 晉中 030600)

構(gòu)建了一種亞硫酸鹽驅(qū)動(dòng)自養(yǎng)短程反硝化(SDAPD)新工藝旨在實(shí)現(xiàn)NO2--N快速積累.采用厭氧序批式生物膜反應(yīng)器,探究了不同進(jìn)水硝酸鹽濃度(25～250mg/L)及不同硫氮物質(zhì)的量比(0.8、1.7、2.6)對(duì)亞硝酸鹽積累特性的影響.結(jié)果表明,系統(tǒng)亞硝酸鹽積累率(NAR)隨進(jìn)水硝酸鹽濃度提高而增加.硫氮比能夠顯著影響NAR.S/N為1.7時(shí),NAR最高達(dá)(64.7±3.0)%.周期實(shí)驗(yàn)表明:硝酸鹽還原、亞硝酸鹽積累同時(shí)伴隨著亞硫酸鹽去除及硫酸鹽的生成.高S/N會(huì)促進(jìn)胞外聚合物(EPS)蛋白質(zhì)和多糖產(chǎn)生及PN/PS升高;三維熒光光譜顯示色氨酸類物質(zhì)是SDAPD系統(tǒng)中EPS的主要成分,其熒光峰、熒光強(qiáng)度與S/N密切相關(guān).高通量測(cè)序發(fā)現(xiàn)和是硫自養(yǎng)反硝化關(guān)鍵功能菌屬.

亞硫酸鹽；自養(yǎng)短程反硝化；亞硝酸鹽積累；硫氮比；微生物群落

厭氧氨氧化(Anammox)是一種公認(rèn)的最經(jīng)濟(jì)有效的簡(jiǎn)捷污水生物脫氮新技術(shù)[1-3].亞硝酸鹽(NO2-- N)是Anammox發(fā)生的關(guān)鍵底物.有研究表明:短程反硝化(NO3--N→NO2--N)是實(shí)現(xiàn)NO2--N高效積累的有效途徑[4-6].硫自養(yǎng)反硝化(SDAD)由于不需要外加碳源且污泥產(chǎn)生量低,引起了國內(nèi)外學(xué)者的廣泛關(guān)注.目前硫化物(S2-)、單質(zhì)硫(S0)、硫代硫酸鹽(S2O32-)均已被證明能夠作為S自養(yǎng)反硝化的電子供體[7-10].亞硫酸鹽(SO32-)因具有高溶解性、低毒性、能被大部分硫氧化菌利用且易于獲取等特性,作為S自養(yǎng)反硝化的可替代電子供體的潛在優(yōu)勢(shì)逐漸被重視[11-12].通過水質(zhì)和工藝參數(shù)的控制,可以將硝酸鹽自養(yǎng)反硝化控制到亞硝酸鹽階段,從而實(shí)現(xiàn)硫自養(yǎng)短程反硝化. Chen等[13]以S0為底物,通過溫度和pH控制,實(shí)現(xiàn)了SDAD體系95%以上的亞硝酸鹽積累;Liu等[14]的研究中以S2-為底物,在較短水力停留時(shí)間(HRT)下實(shí)現(xiàn)了92%的亞硝酸鹽積累.李維維等[15]以S2-為底物,通過控制HRT、pH值、溫度,實(shí)現(xiàn)了高效積累NO2--N的同時(shí)實(shí)現(xiàn)單質(zhì)硫的回收利用.Deng等[16]以硫代硫酸鹽為底物,實(shí)現(xiàn)了硫自養(yǎng)短程反硝化工藝的長(zhǎng)期穩(wěn)定運(yùn)行(392d).然而,SO32-能否作為自養(yǎng)短程反硝化(SDAPD)工藝合適的電子供體以積累亞硝酸鹽,目前國內(nèi)外尚無報(bào)道.

本研究通過采用添加SO32-的自養(yǎng)反硝化工藝,為實(shí)現(xiàn)硫自養(yǎng)短程反硝化耦合Anammox提供一種新思路. 本研究考察了進(jìn)水NO3--N濃度和S/N對(duì)亞硝酸鹽積累及硫氮轉(zhuǎn)化影響,分析了EPS組分及三維熒光光譜變化;解析了微生物群落組成及優(yōu)勢(shì)功能菌,探究SO32-作為短程反硝化電子供體獲得NO2--N積累和SDAPD工藝建立的可行性.

1 材料與方法

1.1 反應(yīng)器的設(shè)置

采用三個(gè)以聚氨酯(PU)為生物載體填充,有效容積200mL的厭氧序批式生物膜反應(yīng)器,如圖1所示.反應(yīng)器的運(yùn)行周期隨氮負(fù)荷升高在后期由1d延長(zhǎng)至1.5d,其中進(jìn)水時(shí)間15min、沉淀10min和出水5min.反應(yīng)器頂部有三個(gè)出口,分別是廢水進(jìn)/出口、連接氮?dú)獯云胶獯髿鈮?、收集部分反硝化氣體產(chǎn)物.整個(gè)系統(tǒng)完全密封,并使用高純氮?dú)獬掷m(xù)吹掃,為自養(yǎng)短程反硝化提供嚴(yán)格的厭氧環(huán)境以避免亞硫酸鹽的非生物氧化[17].反應(yīng)器均置于恒溫震蕩箱,該系統(tǒng)控制在30±1°C,震蕩速度為100rpm.

1.2 接種污泥和試驗(yàn)用水

圖1 反應(yīng)器裝置

從添加亞硫酸鹽的1個(gè)5L的自養(yǎng)反硝化反應(yīng)器[11]中提取一定填料(MLVSS:約2.0g/L),均勻接種到三個(gè)反應(yīng)器中.采用人工配水的方式,將溶液A和B組成的合成廢水加入反應(yīng)器中.溶液A含有0.025-0.25g/L NaNO3--N、0.006-0.06g KH2PO4、0.1g NaHCO3和1mL/L微量元素溶液.溶液B含有0.18-1.8g/L Na2SO3.通過加入1M HCl或1M NaHCO3,調(diào)節(jié)進(jìn)水pH為7.5±0.1.

1.3 反應(yīng)器運(yùn)行

實(shí)驗(yàn)同時(shí)設(shè)置三個(gè)平行反應(yīng)器,共運(yùn)行67d.進(jìn)水硝酸鹽濃度從25mg/L逐步提高到250mg/L,每個(gè)進(jìn)水濃度下設(shè)置三個(gè)進(jìn)水硫氮摩爾比(A:0.8、B:1.7、C:2.6).整個(gè)實(shí)驗(yàn)運(yùn)行條件如表1所示.

1.4 周期實(shí)驗(yàn)

在第5d、36d、66d時(shí),NO3--N濃度50mg/L、150mg/L、250mg/L時(shí)分別對(duì)A、B、C三個(gè)反應(yīng)器進(jìn)行周期試驗(yàn),研究不同硝氮濃度和S/N條件下氮和硫的轉(zhuǎn)化規(guī)律.在每個(gè)循環(huán)中,分別在0、60、180、300、1200、1320、1440、1800和2160min時(shí)取出5mL出水樣品分析氮和硫的變化情況.所有樣本在24h內(nèi)進(jìn)行分析,三次重復(fù)測(cè)定后取平均值.

1.5 化學(xué)分析

每個(gè)周期出水進(jìn)行取樣并使用0.45μm濾膜進(jìn)行過濾,然后立即進(jìn)行化學(xué)測(cè)定分析.NO2?-N和NO3?-N使用紫外分光光度法測(cè)定.SO32?和SO42?由離子色譜法(Dionex ICS Aquion, USA)測(cè)定,溫度、pH由便攜式pH計(jì)(德國梅特勒托萊多FE20)監(jiān)測(cè),溶解氧(DO)通過便攜式多參數(shù)水質(zhì)分析儀(WTW Multi 3420,德國)監(jiān)測(cè).胞外聚合物蛋白質(zhì)(PN)和多糖(PS)分別采用考馬斯亮藍(lán)法[18]和硫酸-蒽酮比色法[19]測(cè)定.

3D-EEM采用三維熒光光譜分析儀(RF6000型,日本島津).實(shí)驗(yàn)參數(shù)設(shè)置為:激發(fā)波長(zhǎng)(Ex)為200～550nm,步長(zhǎng)2nm;發(fā)射波長(zhǎng)(Em)為200～550nm,步長(zhǎng)5nm,掃描速度為12000nm/min,激發(fā)光帶寬為10nm,發(fā)射光帶寬為10nm,以去離子水的熒光光譜圖為空白樣.

1.6 高通量測(cè)序分析

采集原始污泥和66d的三個(gè)硫氮比下的生物填料樣品(S0、S1、S2、S3)進(jìn)行微生物高通量測(cè)序分析(生工生物工程上海股份有限公司,上海).使用E.Z.N.A? Mag-Bind Soil DNA Kit對(duì)樣本進(jìn)行DNA抽提,引物采用Illumina Miseq測(cè)序平臺(tái),采用通用引物341F(5'-CCTACGGGAGGCAGCAG-3')和805R(5'-GACTACHVGGGTATCTAATCC-3')對(duì)16S rRNA 基因 V3-V4 區(qū)進(jìn)行第一輪PCR擴(kuò)增,目標(biāo)片段長(zhǎng)度464dp,然后進(jìn)行第二輪PCR擴(kuò)增引入Illumina橋式PCR兼容引物.然后根據(jù) NCBI BLAST軟件,將該序列與GenBank中的rRNA序列進(jìn)行對(duì)比分析.利用RDA分析環(huán)境因子與微生物群落之間的相關(guān)性.

1.7 指標(biāo)計(jì)算

硝酸鹽去除率(NRE)、亞硝酸鹽積累率(NAR)、亞硫酸鹽去除率(SRE)分別根據(jù)公式(1)-(3)計(jì)算.

式中:[NO3?-N]inf:進(jìn)水中NO3?-N濃度;[NO3?-N]eff:出水中NO3?-N濃度;[NO2?-N]eff:出水中NO2?-N濃度;[NO2?-N]inf:進(jìn)水中NO2?-N濃度;[SO32?-S]eff:出水中SO32?-S濃度;[SO32?-S]inf:進(jìn)水中SO32?-S濃度;

2 結(jié)果和討論

2.1 反應(yīng)器性能

如圖2所示,在運(yùn)行初期,三組反應(yīng)器均有較高濃度的NO3--N、SO32-殘留,出水NO2--N很低.隨著進(jìn)水硝酸鹽濃度逐步提高,亞硝酸鹽逐漸開始積累,當(dāng)NO3--N濃度提升到100mg/L時(shí),亞硝酸鹽開始出現(xiàn)了少量積累,說明短程反硝化菌活性恢復(fù),繼續(xù)提升濃度,在A、B、C三組均出現(xiàn)明顯的亞硝積累,特別在250mg/L硝酸鹽濃度下,A、B、C反應(yīng)器的平均亞硝積累率分別達(dá)到32.25%、64.67%、12.03%.表明高硝酸鹽負(fù)荷條件下,亞硫酸鹽驅(qū)動(dòng)下的短程自養(yǎng)反硝化容易快速建立.

由表2可見,S/N:1.7的亞硝酸鹽積累率始終高于其他兩個(gè).S/N: 0.8時(shí)由于電子供體不足,亞硫酸鹽自養(yǎng)反硝化無法正常發(fā)生,亞硝積累率最高只有約30%,這在其他低S/N下的硫基自養(yǎng)反硝化中也存在類似的現(xiàn)象[20-21].而S/N: 2.6底物過剩,會(huì)導(dǎo)致全程反硝化,此時(shí)硝酸鹽去除率最高,但幾乎沒有亞硝酸鹽積累.本研究中1.7是亞硫酸鹽驅(qū)動(dòng)短程反硝化的最佳硫氮比.Yuan等[22]的研究中以S2-為底物的硫自養(yǎng)短程反硝化也有相似的結(jié)果,在S/N:0.91時(shí)亞硝酸鹽積累率最高;S/N:1.2時(shí)則明顯下降.因此選擇合適的進(jìn)水硝酸鹽負(fù)荷及S/N是亞硫酸鹽驅(qū)動(dòng)短程自養(yǎng)反硝化成功實(shí)現(xiàn)亞硝酸鹽積累的關(guān)鍵.此外,隨著進(jìn)水亞硫酸鹽濃度增加,將導(dǎo)致出水硫酸鹽濃度過高.盡管目前國家污水排放標(biāo)準(zhǔn)未對(duì)出水硫酸根濃度有排放要求,然而過高的硫酸根會(huì)對(duì)排放或回用水體產(chǎn)生較大危害.因此后續(xù)應(yīng)該考慮對(duì)出水進(jìn)行進(jìn)一步的微生物脫硫、離子交換、化學(xué)沉淀或膜處理(如反滲透膜)等方法,使得出水硫酸鹽低于1000mg/L.

表2 反應(yīng)器硝酸鹽去除、亞硫酸鹽去除及亞硝酸鹽積累

2.2 氮硫轉(zhuǎn)化特性

圖3a顯示了在NO3--N為25mg/L下不同S/N比(0.8、1.7、2.6)下典型運(yùn)行周期內(nèi)氮和硫的濃度走勢(shì).如圖所示,在最初的480min內(nèi),硝酸鹽的濃度下降最快,隨后至反應(yīng)結(jié)束硝酸鹽略微上升;硝酸鹽下降過程同時(shí)可以觀察到亞硫酸鹽的去除.整個(gè)過程均未出現(xiàn)NO2--N積累,表明在低進(jìn)水硝酸鹽底物條件下,主要發(fā)生的全程自養(yǎng)反硝化.圖3b和3c為NO3--N為150mg/L和250mg/L的情形.隨著硝氮濃度的提升,反應(yīng)周期內(nèi)均呈現(xiàn)亞硝酸鹽積累現(xiàn)象,且在1300min附近達(dá)到最高峰.與其他兩個(gè)S/N相比,S/N:1.7時(shí)NO2--N積累量最大.至反應(yīng)結(jié)束時(shí),依然能夠保持較高的NO2--N積累率.

在周期實(shí)驗(yàn)中,在硝酸鹽還原的同時(shí),始終伴隨著亞硫酸鹽濃度逐漸降低及硫酸鹽濃度逐漸升高,周期實(shí)驗(yàn)結(jié)束時(shí)硫轉(zhuǎn)化率接近100%.這表明亞硫酸鹽在還原硝酸鹽的同時(shí)被生物氧化成硫酸鹽,進(jìn)一步證實(shí)了SDAPD的發(fā)生.

2.3 出水pH值

由圖4可以看到進(jìn)水pH為7.5,不同硫氮比下的三個(gè)反應(yīng)器的出水pH具有明顯差異.在S/N:2.6的出水pH明顯升高,甚至高于8.0,而在S/N較低時(shí)出水pH低于進(jìn)水pH.根據(jù)化學(xué)計(jì)量學(xué)公式[12]:

圖4 不同硫氮比下進(jìn)出水pH

Fig. 4 Influent and effluent pH at different S/N ratios

當(dāng)S/N:2.6時(shí),此時(shí)發(fā)生徹底的亞硫酸鹽驅(qū)動(dòng)的自養(yǎng)反硝化,為耗酸反應(yīng),因此出水高于7.5;而在硫氮比接近1時(shí),發(fā)生短程反硝化反應(yīng),既不耗酸也不耗堿,而實(shí)驗(yàn)中出水pH略低于7.5,因此無需額外投加堿度維持反應(yīng).

2.4 胞外聚合物(EPS)分析

EPS包括蛋白質(zhì)、多糖、磷脂等,是維持顆粒污泥結(jié)構(gòu)和穩(wěn)定性的重要物質(zhì).取實(shí)驗(yàn)?zāi)┢?第67d)的A、B、C反應(yīng)器的填料提取EPS,分析不同S/N時(shí)硫自養(yǎng)反硝化生物填料EPS組分濃度.如圖5所示,蛋白質(zhì)(PN)含量始終高于多糖(PS)含量,且隨S/N升高,EPS總量、PN/PS均呈增加態(tài)勢(shì).高S/N由于底物更加充足,發(fā)生自養(yǎng)反硝化效果更加顯著,因此會(huì)促進(jìn)分泌更多的EPS.EPS是微生物能量供應(yīng)的重要組成部分,較高的EPS有助于微生物生化反應(yīng)的維持[23].PN有助于維持微生物生長(zhǎng)和代謝活性,因此在較高的S/N下,EPS和PN/PS的提高有利于維持微生物進(jìn)行自養(yǎng)反硝化反應(yīng).

圖5 不同S/N下EPS組分含量及PN/PS

圖6顯示了不同S/N下SB-EPS、LB-EPS和TB-EPS三維熒光光譜.樣品各層EPS提取物中各個(gè)熒光峰的位置基本一致,說明其物質(zhì)的組成成分類型基本相似,TB-EPS熒光強(qiáng)度均遠(yuǎn)高于SB-EPS和LB-EPS.根據(jù)Coble等[24]、Hudson等[25]的劃分A、B、C中均可以觀察到明顯的熒光峰:T1峰(x/m:275～296/330～380nm)和T2峰(xm:216～247/329～380nm),A中還出現(xiàn)了C峰(xm:300～370/400～500nm),研究表明,峰T1位于IV區(qū)(溶解性微生物副產(chǎn)物(SMPs),與色氨酸和蛋白質(zhì)樣物質(zhì)有關(guān),T2峰位于II(芳香蛋白)區(qū),與色氨酸相對(duì)應(yīng)[26],C峰位于Ⅴ區(qū),與類腐殖酸有關(guān).

在SDAPD反應(yīng)器中,S/N:0.8時(shí)T1熒光強(qiáng)度大于S/N:1.7時(shí),T1為溶解性微生物副產(chǎn)物,與自養(yǎng)脫氮菌的代謝有關(guān).在亞硫酸鹽底物不足時(shí),EPS分泌被加速,產(chǎn)生的溶解性微生物副產(chǎn)物增加了色氨酸類殘留物的熒光信號(hào).已有研究表明[27]在底物不足時(shí),部分EPS可被細(xì)菌利用作為能量來源,而類腐殖質(zhì)因結(jié)構(gòu)復(fù)雜,難以被降解,因此有類腐殖質(zhì)殘留.

S/N:2.6時(shí)T1、T2均有更高的熒光強(qiáng)度,說明高濃度的亞硫酸鹽會(huì)增強(qiáng)微生物代謝活性,導(dǎo)致溶解性微生物副產(chǎn)物和芳香蛋白增加.Zhu等[28]的研究中強(qiáng)調(diào)了芳香族蛋白類物質(zhì)的增加有利于微生物之間的電子轉(zhuǎn)移,從而促進(jìn)自養(yǎng)反硝化.綜上, SDAPD反應(yīng)器中的微生物會(huì)釋放出色氨酸類物質(zhì),且熒光強(qiáng)度與S/N密切相關(guān).

2.5 微生物群落分析

S0為實(shí)驗(yàn)啟動(dòng)前的污泥樣本,S1、S2、S3代表反應(yīng)器A、B、C(S/N: 0.8、1.7、2.6)在250mg/L NO3--N的生物膜樣品.如圖7a所示,實(shí)驗(yàn)初期系統(tǒng)中占優(yōu)勢(shì)的是變形菌門(Proteobacteria)、浮霉菌門(Planctomycetes)、綠菌門(Chloroflexi)和惰桿菌門(Ignavibacteriae),其相對(duì)豐度分別為31.29%、29.21%、20.57%和9.75%.實(shí)驗(yàn)?zāi)┢跁r(shí)A、B、C中Proteobacteria均成為最豐富的門,相對(duì)豐度分別增加到67.13%、74.44%、66.70%.據(jù)報(bào)道,Proteobacteria是自養(yǎng)反硝化系統(tǒng)中重要的硫氧化門之一[10].而Planctomycetes、Ignavibacteriae、Chloroflexi等門的豐度均急劇下降.這些結(jié)果表明反應(yīng)器啟動(dòng)后不同S/N會(huì)導(dǎo)致門水平上的微生物群落結(jié)構(gòu)發(fā)生較大改變.

在屬水平上(圖7b),初始相對(duì)豐度僅為0.17%,而實(shí)驗(yàn)結(jié)束時(shí)S1、S2、S3分別增加到0.49%(S/N:0.8)、0.69%(S/N:1.7)、1.79%(S/N:2.6).是一種革蘭氏陰性,無色化能自養(yǎng)細(xì)菌,屬于β-[29],是一種最為常見的硫氧化細(xì)菌(SOB),能夠在亞硫酸鹽作為電子供體的情況下還原硝酸鹽或亞硝酸鹽[30],在生長(zhǎng)生物能量學(xué)方面具有很高的效率[31].Liu等[14]的研究中發(fā)現(xiàn)包含將硝酸鹽完全還原為氮?dú)馑璧乃谢?但由于Nap/Nar和Nir的電子傳遞距離不同,在有限的電子供體條件下(如S/N<1),出水中會(huì)發(fā)生亞硝酸鹽積累.其相對(duì)豐度在S0時(shí)為0.05%,而S1、S2、S3分別增加到0.41%、0.48%、0.50%.是革蘭氏陰性絲狀菌,屬于-,在硫自養(yǎng)反硝化反應(yīng)器中曾被報(bào)道[19].盡管nirK基因在中被發(fā)現(xiàn)[32],然而這種細(xì)菌在短程自養(yǎng)反硝化過程中作用需要進(jìn)一步研究.以上表明添加亞硫酸鹽作為電子供體能夠促進(jìn)SOB富集.此外,還發(fā)現(xiàn)了一些異養(yǎng)反硝化菌.初期未測(cè)出,在S3時(shí)相對(duì)豐度最高(0.02%),已有報(bào)道表明作為一種兼性反硝化菌[33],可以將NO3-還原;而作為一種兼性反硝化菌,在S2時(shí)相對(duì)豐度最高(0.08%),研究表明是短程反硝化反應(yīng)NO2-積累的功能菌[34].

由于、自養(yǎng)反硝化菌和等反硝化菌具有從硝酸鹽還原到氮?dú)獾耐暾?而硝酸鹽氮濃度升高及合理S/N促進(jìn)了系統(tǒng)中硫自養(yǎng)反硝化菌及短程脫氮菌的生長(zhǎng)富集.因此本研究是通過特定工藝參數(shù)的控制,培馴出了具有硝酸鹽短程反硝化能力的特定條件功能微生物.

RDA(圖7c)進(jìn)一步分析了關(guān)鍵菌屬與處理效果之間的相關(guān)性.可以看出、和等菌屬與進(jìn)水S/N、出水NRE、NAR呈高度正相關(guān),表明這些功能微生物在亞硫酸鹽驅(qū)動(dòng)的短程自養(yǎng)反硝化中發(fā)揮了重要作用.與出水NAR也呈正相關(guān),表明存在有利于亞硝酸鹽積累,而與出水效果呈負(fù)相關(guān),表明該菌對(duì)自養(yǎng)反硝化作用有著不利影響.

3 結(jié)論

3.1 采用SDAPD反應(yīng)器處理高濃度硝酸鹽廢水,通過添加亞硫酸鹽,經(jīng)過67d成功啟動(dòng)了硫自養(yǎng)短程反硝化.

3.2 在S/N為1.7時(shí),自養(yǎng)短程反硝化效果最好,亞硝酸鹽的積累率達(dá)到70%.

3.3 EPS中PN、PS及PN/PS均隨S/N升高而增加,系統(tǒng)中微生物釋放的主要熒光物質(zhì)是色氨酸類物質(zhì),且其熒光強(qiáng)度與S/N密切相關(guān).

3.4 不同S/N下微生物群落組成具有差異,和是影響亞硫酸鹽短程自養(yǎng)脫氮的關(guān)鍵功能菌屬.

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Nitrite accumulation characteristics in a SO32--driven partial autotrophic denitrification process.

NIE Yu-ting1,2, ZHOU Xin1,2*, PING Cai-xia1,2

(1.College of Environmental Science and Engineering, Taiyuan University of Technology, Jinzhong 030600, China；2.Innovation Center for Postgraduate Education in Municipal Engineering of Shanxi, Jingzhong 030600, China)., 2023,43(11)：5719～5727

This study developed a novel process of sulfite-driven autotrophic partial denitrification (SDAPD) to achieve the rapid accumulation of NO2--N. Anaerobic sequencing batch biofilm reactors were used to explore the effects on nitrite accumulation under different influent nitrate concentration (25～250mg/L) and different S/N molar ratios (0.8,1.7,2.6). The results show that nitrite accumulation rate (NAR) increased with the increase of influent nitrate concentration, and the S/N can significantly affect the NAR. The NAR was the highest up to (64.7%±3.0%) at S/N of 1.7. Periodic experiments show that nitrate reduction and nitrite accumulation were accompanied by sulfite removal and sulfate production. High S/N could promote the production of protein and polysaccharide in extracellular polymer (EPS) and increase the ratio of PN/PS. Three-dimensional fluorescence spectra shows that the tryptophan was the main component of EPS in SDAPD system, and its fluorescence peak and fluorescence intensity were closely related to S/N. High-throughput sequencing found thatandwere key bacteria with the function of sulfur autotrophic denitrification.

sulfite；autotrophic partial denitrification；nitrite accumulation；sulfur to nitrogen ratio；microbial community

X703

A

1000-6923(2023)11-5719-09

聶裕婷(1994-),女,山西太原人,太原理工大學(xué)碩士研究生,主要從事生物脫氮新技術(shù)方面研究.13110012979@163.com.

聶裕婷,周 鑫,平彩霞.SO32-驅(qū)動(dòng)自養(yǎng)短程反硝化工藝亞硝酸鹽積累特性研究 [J]. 中國環(huán)境科學(xué), 2023,43(11):5719-5727.

Nie Y T, Zhou X, Ping C X. Nitrite accumulation characteristics in a SO32--driven partial autotrophic denitrification process [J]. China Environmental Science, 2023,43(11):5719-5727.

2023-04-06

國家自然科學(xué)基金資助項(xiàng)目(21607111);山西省基礎(chǔ)研究計(jì)劃項(xiàng)目(20210302123198)

* 責(zé)任作者, 教授, raymans2006@163.com