主流厭氧氨氧化工藝的研究與應用進展
生(sheng)物(wu)(wu)脫氮(dan)技術(shu)被廣(guang)泛用于(yu)廢水(shui)中(zhong)氮(dan)的(de)(de)去(qu)除(chu),在傳統(tong)(tong)生(sheng)物(wu)(wu)脫氮(dan)技術(shu)中(zhong),氨(an)氮(dan)首先被嚴(yan)格好氧(yang)(yang)(yang)的(de)(de)氨(an)氧(yang)(yang)(yang)化(hua)(hua)(hua)細菌(jun)(ammonia-oxidizingbacteria,AOB)和亞硝酸(suan)鹽(yan)氧(yang)(yang)(yang)化(hua)(hua)(hua)菌(jun)(nitriteoxidizingbacteria,NOB)氧(yang)(yang)(yang)化(hua)(hua)(hua)為(wei)亞硝態氮(dan)(NO2--N)和硝態氮(dan)(NO3--N),之后異(yi)養菌(jun)(heterotrophicbacteria,HB)利用有機物(wu)(wu)提供的(de)(de)電子將硝酸(suan)鹽(yan)還(huan)原為(wei)氮(dan)氣(qi)。此(ci)過程不僅需(xu)(xu)要消(xiao)耗大量能量為(wei)硝化(hua)(hua)(hua)反(fan)(fan)應(ying)提供氧(yang)(yang)(yang)氣(qi),且常(chang)常(chang)需(xu)(xu)要額(e)外(wai)補充有機物(wu)(wu)保(bao)證反(fan)(fan)硝化(hua)(hua)(hua)脫氮(dan)的(de)(de)進行。厭(yan)氧(yang)(yang)(yang)氨(an)氧(yang)(yang)(yang)化(hua)(hua)(hua)技術(shu)(anammox)是(shi)(shi)20世紀(ji)90年代由(you)荷蘭代爾夫特大學開(kai)發的(de)(de)一(yi)種(zhong)新型自(zi)養生(sheng)物(wu)(wu)脫氮(dan)工(gong)藝,與傳統(tong)(tong)脫氮(dan)技術(shu)相比(bi),自(zi)養型厭(yan)氧(yang)(yang)(yang)氨(an)氧(yang)(yang)(yang)化(hua)(hua)(hua)工(gong)藝被認為(wei)是(shi)(shi)一(yi)種(zhong)更高效、節能的(de)(de)廢水(shui)處理方法,其在厭(yan)氧(yang)(yang)(yang)或(huo)缺氧(yang)(yang)(yang)條件(jian)下以NO2--N為(wei)電子受(shou)體(ti),利用厭(yan)氧(yang)(yang)(yang)氨(an)氧(yang)(yang)(yang)化(hua)(hua)(hua)細菌(jun)(anaerobicammoniaoxidationbacteria,AnAOB)將氨(an)氮(dan)直接氧(yang)(yang)(yang)化(hua)(hua)(hua)為(wei)氮(dan)氣(qi)。在節約了硝化(hua)(hua)(hua)反(fan)(fan)應(ying)曝氣(qi)能源的(de)(de)基礎上,還(huan)無需(xu)(xu)外(wai)加碳源,且由(you)于(yu)AnAOB屬自(zi)養型微生(sheng)物(wu)(wu),生(sheng)長緩慢,因此(ci),可大大減少工(gong)藝的(de)(de)污泥(ni)產量。
由于厭氧氨(an)氧化技術在污(wu)水廠(chang)節能(neng)降耗、綠(lv)色(se)環(huan)保方面表現出來的顯著優勢,過去二十年里(li),國(guo)(guo)內外研(yan)究(jiu)者對其(qi)展開(kai)了(le)大量研(yan)究(jiu)。截至2021年3月,根據WebofScience數據統計(ji),全(quan)(quan)球(qiu)已(yi)發(fa)表厭氧氨(an)氧化相關(guan)科技論文(wen)4403篇(pian),其(qi)中,中國(guo)(guo)是全(quan)(quan)球(qiu)發(fa)表厭氧氨(an)氧化相關(guan)文(wen)章最多的國(guo)(guo)家(jia)(共計(ji)2054篇(pian),占46.6%)。論文(wen)研(yan)究(jiu)方向涉及環(huan)境微生(sheng)(sheng)物學(xue)、水資源、生(sheng)(sheng)態學(xue)等83個方向,具體(ti)可細分為:
(1)研究抑制(zhi)厭(yan)氧(yang)(yang)氨氧(yang)(yang)化效果(guo)的(de)物質及(ji)其(qi)濃度,如氨氮、NO2--N、有機(ji)物、鹽、重金屬(shu)、磷酸鹽和(he)硫(liu)化物等對厭(yan)氧(yang)(yang)氨氧(yang)(yang)化過程的(de)抑制(zhi)作用影(ying)響;
(2)研究自(zi)養生物脫氮系統(tong)中涉(she)及的主(zhu)要微生物,如AOB、NOB、AnAOB、HB及其相互作用;
(3)研究控制NOB生長的方法(fa)及(ji)對(dui)應的運行(xing)參數,如改變缺氧(yang)/好氧(yang)狀(zhuang)態、維持高氨氮濃(nong)度、利(li)用底物如游(you)離(li)亞硝(xiao)酸(FNA)的抑(yi)制作用、控制曝氣時間(jian)等(deng);
(4)研究不同(tong)的厭氧氨氧化工藝、反應器(qi)和污泥(ni)存(cun)在形態(懸浮污泥(ni),生物(wu)膜)對處理效(xiao)果的影(ying)響;
(5)研究維持AnAOB生物量的方(fang)法(fa)。
基(ji)(ji)(ji)于(yu)(yu)以上多方面的(de)研(yan)究(jiu)工(gong)(gong)(gong)(gong)作,厭(yan)(yan)氧(yang)(yang)(yang)氨(an)(an)(an)氧(yang)(yang)(yang)化(hua)(hua)(hua)技(ji)術日益成(cheng)熟,且(qie)(qie)被廣泛應(ying)(ying)用(yong)(yong)(yong)于(yu)(yu)工(gong)(gong)(gong)(gong)業(ye)(ye)廢(fei)(fei)(fei)(fei)水(shui)(shui)(shui)、垃圾(ji)滲(shen)濾液(ye)、沼(zhao)液(ye)等高(gao)含氮廢(fei)(fei)(fei)(fei)水(shui)(shui)(shui)生物處(chu)理過(guo)程(cheng)中,據統計(ji),全球已有(you)超過(guo)110座生產(chan)性厭(yan)(yan)氧(yang)(yang)(yang)氨(an)(an)(an)氧(yang)(yang)(yang)化(hua)(hua)(hua)工(gong)(gong)(gong)(gong)程(cheng),但其中絕(jue)大部分用(yong)(yong)(yong)于(yu)(yu)市政污(wu)(wu)(wu)(wu)(wu)水(shui)(shui)(shui)的(de)側流(liu)處(chu)理。將厭(yan)(yan)氧(yang)(yang)(yang)氨(an)(an)(an)氧(yang)(yang)(yang)化(hua)(hua)(hua)技(ji)術引入市政污(wu)(wu)(wu)(wu)(wu)水(shui)(shui)(shui)主流(liu)工(gong)(gong)(gong)(gong)藝應(ying)(ying)用(yong)(yong)(yong),不僅可通(tong)過(guo)耦合(he)碳濃縮(suo)預處(chu)理實(shi)現(xian)污(wu)(wu)(wu)(wu)(wu)水(shui)(shui)(shui)能(neng)(neng)量(liang)回收最大化(hua)(hua)(hua),而且(qie)(qie)可顯(xian)著減少外加碳源量(liang),從而有(you)效降低污(wu)(wu)(wu)(wu)(wu)水(shui)(shui)(shui)的(de)脫(tuo)氮運行(xing)成(cheng)本。由于(yu)(yu)生活(huo)污(wu)(wu)(wu)(wu)(wu)水(shui)(shui)(shui)與工(gong)(gong)(gong)(gong)業(ye)(ye)廢(fei)(fei)(fei)(fei)水(shui)(shui)(shui)、垃圾(ji)滲(shen)濾液(ye)、沼(zhao)液(ye)等高(gao)含氮廢(fei)(fei)(fei)(fei)水(shui)(shui)(shui)在(zai)水(shui)(shui)(shui)質、水(shui)(shui)(shui)溫、水(shui)(shui)(shui)量(liang)等方面的(de)差異(yi),厭(yan)(yan)氧(yang)(yang)(yang)氨(an)(an)(an)氧(yang)(yang)(yang)化(hua)(hua)(hua)工(gong)(gong)(gong)(gong)藝在(zai)污(wu)(wu)(wu)(wu)(wu)水(shui)(shui)(shui)處(chu)理主流(liu)工(gong)(gong)(gong)(gong)藝應(ying)(ying)用(yong)(yong)(yong)上面臨很(hen)多技(ji)術瓶(ping)頸(jing)。在(zai)日益重視(shi)污(wu)(wu)(wu)(wu)(wu)水(shui)(shui)(shui)資源化(hua)(hua)(hua)、能(neng)(neng)源化(hua)(hua)(hua)發展(zhan)的(de)今(jin)天,這種綠(lv)色低碳且(qie)(qie)可持續的(de)脫(tuo)氮工(gong)(gong)(gong)(gong)藝受到越(yue)來越(yue)多關(guan)注和(he)(he)研(yan)究(jiu),主流(liu)厭(yan)(yan)氧(yang)(yang)(yang)氨(an)(an)(an)氧(yang)(yang)(yang)化(hua)(hua)(hua)工(gong)(gong)(gong)(gong)藝的(de)工(gong)(gong)(gong)(gong)程(cheng)應(ying)(ying)用(yong)(yong)(yong)也取得很(hen)大的(de)進步,下文基(ji)(ji)(ji)于(yu)(yu)現(xian)有(you)研(yan)究(jiu)和(he)(he)應(ying)(ying)用(yong)(yong)(yong)成(cheng)果,對該工(gong)(gong)(gong)(gong)藝基(ji)(ji)(ji)本情況、工(gong)(gong)(gong)(gong)程(cheng)應(ying)(ying)用(yong)(yong)(yong)進展(zhan)和(he)(he)主流(liu)工(gong)(gong)(gong)(gong)藝應(ying)(ying)用(yong)(yong)(yong)面臨的(de)技(ji)術難點(dian)展(zhan)開論述。
1 厭氧氨(an)氧化(hua)技術工藝及反應(ying)器
1. 1 工(gong)藝類型
污水的厭氧氨氧化自養(yang)脫氮過程一般(ban)包括兩個階段:
(1)有氧條件下,約一半的(de)氨(an)氮轉化為(wei)NO2--N的(de)部分(fen)硝化(partialnitritation,PN)反(fan)應階段,反(fan)應方程式(shi)如式(shi)(1);
(2)缺氧(yang)/厭(yan)氧(yang)條件下,AnAOB以(yi)第一階段產生的(de)(de)NO2--N為電子受體,將89%左右的(de)(de)氨(an)氮(dan)(dan)氧(yang)化為氮(dan)(dan)氣(qi)、剩下的(de)(de)氨(an)氮(dan)(dan)氧(yang)化為NO3--N的(de)(de)厭(yan)氧(yang)氨(an)氧(yang)化反應階段,反應方程式如式(2)。
基于自(zi)養脫(tuo)氮(dan)的(de)(de)兩(liang)個反(fan)(fan)(fan)應(ying)(ying)階段,目前,厭氧氨(an)氧化(hua)工(gong)藝可以分為(wei)兩(liang)段式和一(yi)體式兩(liang)種(zhong),分別(bie)是(shi)指在兩(liang)個單獨的(de)(de)反(fan)(fan)(fan)應(ying)(ying)器(qi)(qi)和在同一(yi)個反(fan)(fan)(fan)應(ying)(ying)器(qi)(qi)中進行PN和厭氧氨(an)氧化(hua)反(fan)(fan)(fan)應(ying)(ying)。在一(yi)體式系(xi)統中,兩(liang)個反(fan)(fan)(fan)應(ying)(ying)階段都在一(yi)個反(fan)(fan)(fan)應(ying)(ying)器(qi)(qi)中進行,兩(liang)種(zhong)功能細菌(jun)(AOB和AnAOB)并(bing)存,因此,需要嚴格控制曝氣,且由(you)于多種(zhong)微(wei)生物(wu)種(zhong)群共存,其反(fan)(fan)(fan)應(ying)(ying)器(qi)(qi)啟動(dong)時間較長(chang),易受負荷(he)沖擊影響,導致系(xi)統不穩定。但一(yi)體式系(xi)統具有建(jian)設成本低、占地(di)面積(ji)小(xiao)、體積(ji)負荷(he)大(da)、可有效避免亞硝(xiao)酸鹽積(ji)聚(ju)引起的(de)(de)抑(yi)制作用等優(you)點(dian),因此,工(gong)程應(ying)(ying)用更廣泛(fan)。
與一體(ti)式系統(tong)相(xiang)比,兩(liang)段(duan)(duan)(duan)式系統(tong)的(de)(de)反應(ying)器可(ke)以獨立調(diao)節和(he)控制,更(geng)加(jia)靈(ling)活穩定(ding)。將自養(yang)脫(tuo)氮的(de)(de)兩(liang)個反應(ying)階(jie)段(duan)(duan)(duan)分(fen)離,不僅可(ke)以優化(hua)富集AOB和(he)AnAOB,而且(qie)(qie)可(ke)以通過PN段(duan)(duan)(duan)消(xiao)除一些有(you)毒有(you)機(ji)污染物,避免(mian)有(you)毒物質和(he)有(you)機(ji)物直接進入后續的(de)(de)厭氧(yang)氨(an)氧(yang)化(hua)反應(ying)器中(zhong)。但兩(liang)段(duan)(duan)(duan)式系統(tong)投資成本(ben)更(geng)高,且(qie)(qie)由于PN段(duan)(duan)(duan)形成的(de)(de)NO2--N容易積聚,產生游離亞硝酸抑制作用(yong),系統(tong)需匹配PN和(he)厭氧(yang)氨(an)氧(yang)化(hua)兩(liang)反應(ying)階(jie)段(duan)(duan)(duan)的(de)(de)反應(ying)速率,系統(tong)設計(ji)更(geng)為復雜。
目(mu)(mu)前,在(zai)(zai)組合PN和厭(yan)(yan)氧(yang)(yang)(yang)氨(an)(an)氧(yang)(yang)(yang)化(hua)反(fan)應(ying)的(de)(de)(de)基礎上,已開發出多種工(gong)藝(yi)(yi),包括兩段式(shi)的(de)(de)(de)SHARON-Anammox工(gong)藝(yi)(yi)、一體式(shi)的(de)(de)(de)亞硝(xiao)(xiao)酸(suan)鹽完全(quan)自養脫(tuo)氮(dan)(dan)工(gong)藝(yi)(yi)(CANON)、脫(tuo)氨(an)(an)工(gong)藝(yi)(yi)(DEMON)、限氧(yang)(yang)(yang)自養硝(xiao)(xiao)化(hua)反(fan)硝(xiao)(xiao)化(hua)工(gong)藝(yi)(yi)(OLAND),以及同步亞硝(xiao)(xiao)化(hua)、厭(yan)(yan)氧(yang)(yang)(yang)氨(an)(an)氧(yang)(yang)(yang)化(hua)和反(fan)硝(xiao)(xiao)化(hua)工(gong)藝(yi)(yi)(SNAD)等。在(zai)(zai)厭(yan)(yan)氧(yang)(yang)(yang)氨(an)(an)氧(yang)(yang)(yang)化(hua)發展(zhan)的(de)(de)(de)早期階段,研(yan)究(jiu)(jiu)和應(ying)用主(zhu)要(yao)以SHARON-Anammox工(gong)藝(yi)(yi)為(wei)主(zhu),該(gai)(gai)(gai)工(gong)藝(yi)(yi)對高氨(an)(an)氮(dan)(dan)、低(di)亞硝(xiao)(xiao)酸(suan)鹽污水有(you)(you)較好的(de)(de)(de)處(chu)(chu)理效果。到2001年,可(ke)自發形成厭(yan)(yan)氧(yang)(yang)(yang)氨(an)(an)氧(yang)(yang)(yang)化(hua)顆粒(li)污泥(ni)的(de)(de)(de)CANON工(gong)藝(yi)(yi)問世(shi),并迅速受到廣泛(fan)歡(huan)迎(ying),該(gai)(gai)(gai)工(gong)藝(yi)(yi)中(zhong)氨(an)(an)氮(dan)(dan)在(zai)(zai)AOB和AnAOB的(de)(de)(de)共同作用下完成轉化(hua),可(ke)用于處(chu)(chu)理有(you)(you)機質(zhi)含量低(di)的(de)(de)(de)污水,是目(mu)(mu)前全(quan)世(shi)界研(yan)究(jiu)(jiu)應(ying)用最(zui)多的(de)(de)(de)厭(yan)(yan)氧(yang)(yang)(yang)氨(an)(an)氧(yang)(yang)(yang)化(hua)工(gong)藝(yi)(yi)。與CANON工(gong)藝(yi)(yi)相似的(de)(de)(de)OLAND工(gong)藝(yi)(yi)也逐(zhu)漸受到關注,該(gai)(gai)(gai)工(gong)藝(yi)(yi)采用生(sheng)物轉盤系統且(qie)運行過(guo)(guo)程(cheng)要(yao)求嚴格(ge)控(kong)制(zhi)(zhi)曝(pu)氣,因此(ci),在(zai)(zai)實(shi)際(ji)工(gong)程(cheng)中(zhong)比較少見,但(dan)在(zai)(zai)未來有(you)(you)望得到更廣泛(fan)的(de)(de)(de)應(ying)用。此(ci)外,以控(kong)制(zhi)(zhi)pH、使(shi)用水力旋流器分離(li)AnAOB為(wei)特點的(de)(de)(de)DEMON工(gong)藝(yi)(yi)也受到普遍歡(huan)迎(ying),已有(you)(you)超過(guo)(guo)30個污水處(chu)(chu)理廠(chang)采用該(gai)(gai)(gai)工(gong)藝(yi)(yi)。
1. 2 反應器應用
厭(yan)(yan)氧(yang)(yang)(yang)氨氧(yang)(yang)(yang)化工藝(yi)中(zhong)(zhong),反(fan)應(ying)(ying)(ying)器(qi)(qi)的(de)選擇必須滿足(zu)自養型微生(sheng)物(wu)長世代周期和(he)污泥(ni)截留的(de)需要。基于(yu)以上(shang)要求,工程應(ying)(ying)(ying)用(yong)中(zhong)(zhong)常(chang)采用(yong)序(xu)(xu)批(pi)式(shi)反(fan)應(ying)(ying)(ying)器(qi)(qi)(SBR)、序(xu)(xu)批(pi)式(shi)生(sheng)物(wu)膜反(fan)應(ying)(ying)(ying)器(qi)(qi)(SBBR)、移動床(chuang)生(sheng)物(wu)膜反(fan)應(ying)(ying)(ying)器(qi)(qi)(MBBR)、上(shang)流式(shi)厭(yan)(yan)氧(yang)(yang)(yang)污泥(ni)床(chuang)反(fan)應(ying)(ying)(ying)器(qi)(qi)(UASB)和(he)厭(yan)(yan)氧(yang)(yang)(yang)膨(peng)脹顆粒床(chuang)反(fan)應(ying)(ying)(ying)器(qi)(qi)(EGSB)等。其中(zhong)(zhong),SBR是厭(yan)(yan)氧(yang)(yang)(yang)氨氧(yang)(yang)(yang)化工藝(yi)中(zhong)(zhong)應(ying)(ying)(ying)用(yong)最(zui)廣(guang)泛的(de)反(fan)應(ying)(ying)(ying)器(qi)(qi),典型的(de)一(yi)體(ti)式(shi)DEMON工藝(yi)就是采用(yong)SBR運(yun)行。此外(wai)(wai),生(sheng)物(wu)膜反(fan)應(ying)(ying)(ying)器(qi)(qi)也(ye)非常(chang)適(shi)合厭(yan)(yan)氧(yang)(yang)(yang)氨氧(yang)(yang)(yang)化工藝(yi),在生(sheng)物(wu)膜反(fan)應(ying)(ying)(ying)器(qi)(qi)中(zhong)(zhong),氧(yang)(yang)(yang)氣可(ke)以被(bei)膜外(wai)(wai)層(ceng)的(de)AOB消(xiao)耗,而膜內部(bu)形成(cheng)的(de)缺氧(yang)(yang)(yang)區(qu)域有利于(yu)AnAOB生(sheng)長。配備40%~50%的(de)載(zai)體(ti)、攪拌器(qi)(qi)和(he)曝(pu)氣設施的(de)MBBR目前(qian)已(yi)在德國、瑞(rui)典等國家廣(guang)泛應(ying)(ying)(ying)用(yong)。
2 工程(cheng)應用進展
2. 1 國外(wai)工程應用
從20世(shi)紀90年代(dai)在荷(he)蘭問世(shi)至(zhi)今(jin),厭(yan)氧(yang)氨氧(yang)化(hua)水(shui)(shui)(shui)(shui)處(chu)(chu)理(li)(li)(li)(li)技術不斷取(qu)得突破,實際工(gong)程(cheng)應用(yong)也在全球范圍內迅(xun)速發展。如表1所示,處(chu)(chu)理(li)(li)(li)(li)對象已(yi)由工(gong)業(ye)廢(fei)(fei)水(shui)(shui)(shui)(shui)、污(wu)泥(ni)脫水(shui)(shui)(shui)(shui)液(ye)(ye)、垃圾(ji)滲濾液(ye)(ye)等高含(han)氮廢(fei)(fei)水(shui)(shui)(shui)(shui)發展到市(shi)政污(wu)水(shui)(shui)(shui)(shui)處(chu)(chu)理(li)(li)(li)(li)等領域。2002年,荷(he)蘭鹿特丹(dan)Dokhaven市(shi)政污(wu)水(shui)(shui)(shui)(shui)處(chu)(chu)理(li)(li)(li)(li)廠采用(yong)兩段式SHARON-Anammox工(gong)藝(yi)(yi)處(chu)(chu)理(li)(li)(li)(li)該廠污(wu)泥(ni)消化(hua)液(ye)(ye),建設了全球第一座生產性厭(yan)氧(yang)氨氧(yang)化(hua)反應器。之后,瑞典馬(ma)爾(er)默(mo)Sj?lunda廢(fei)(fei)水(shui)(shui)(shui)(shui)處(chu)(chu)理(li)(li)(li)(li)廠采用(yong)ANITATM-Mox工(gong)藝(yi)(yi)處(chu)(chu)理(li)(li)(li)(li)污(wu)泥(ni)脫水(shui)(shui)(shui)(shui)液(ye)(ye),荷(he)蘭Apeldoorn采用(yong)DEMON工(gong)藝(yi)(yi)對厭(yan)氧(yang)消化(hua)液(ye)(ye)進行處(chu)(chu)理(li)(li)(li)(li),美國Alex-andria的(de)污(wu)水(shui)(shui)(shui)(shui)處(chu)(chu)理(li)(li)(li)(li)廠等采用(yong)厭(yan)氧(yang)氨氧(yang)化(hua)作為污(wu)水(shui)(shui)(shui)(shui)處(chu)(chu)理(li)(li)(li)(li)側流(liu)工(gong)藝(yi)(yi)。
研究(jiu)發現,AnAOB廣泛存(cun)在于(yu)自(zi)然界(jie)中(zhong),因此,如何將厭氧(yang)(yang)氨(an)氧(yang)(yang)化(hua)(hua)(hua)工(gong)藝(yi)(yi)由(you)側流(liu)工(gong)藝(yi)(yi)轉為(wei)(wei)主流(liu)脫(tuo)氮工(gong)藝(yi)(yi)逐漸成(cheng)為(wei)(wei)全(quan)球厭氧(yang)(yang)氨(an)氧(yang)(yang)化(hua)(hua)(hua)技術研究(jiu)發展(zhan)的(de)重(zhong)點(dian)。奧地(di)利Strass污水廠(chang)(chang)(chang)為(wei)(wei)厭氧(yang)(yang)氨(an)氧(yang)(yang)化(hua)(hua)(hua)的(de)主流(liu)工(gong)藝(yi)(yi)應用(yong)拉開了帷(wei)幕(mu),成(cheng)為(wei)(wei)全(quan)球首個在主流(liu)工(gong)藝(yi)(yi)上實踐厭氧(yang)(yang)氨(an)氧(yang)(yang)化(hua)(hua)(hua)的(de)污水處理(li)廠(chang)(chang)(chang)。該(gai)廠(chang)(chang)(chang)主體采用(yong)AB工(gong)藝(yi)(yi)(圖1),A段(duan)污泥停留時間(SRT)較短(<0.5d),以保證進水有機物最大程(cheng)度地(di)進入污泥消化(hua)(hua)(hua)系統(tong)用(yong)于(yu)產(chan)沼氣;B段(duan)停留時間較長,以去(qu)除大部分(fen)的(de)氮。該(gai)廠(chang)(chang)(chang)于(yu)2004年首先在側流(liu)工(gong)藝(yi)(yi)中(zhong)引(yin)入厭氧(yang)(yang)氨(an)氧(yang)(yang)化(hua)(hua)(hua)DEMON工(gong)藝(yi)(yi),用(yong)于(yu)處理(li)高氮負(fu)荷的(de)污泥消化(hua)(hua)(hua)液和脫(tuo)水液,該(gai)工(gong)藝(yi)(yi)含有結合硝化(hua)(hua)(hua)和厭氧(yang)(yang)氨(an)氧(yang)(yang)化(hua)(hua)(hua)過程(cheng)的(de)SBR,并通(tong)過控制低(di)溶解氧(yang)(yang)和維持長SRT(30d),成(cheng)功抑(yi)制了亞硝酸鹽進一步氧(yang)(yang)化(hua)(hua)(hua)。隨后,該(gai)廠(chang)(chang)(chang)進一步采用(yong)DEMON工(gong)藝(yi)(yi)進行主流(liu)工(gong)藝(yi)(yi)B段(duan)升級(ji)改造,并通(tong)過將側流(liu)工(gong)藝(yi)(yi)穩定富(fu)集的(de)AnAOB向(xiang)主流(liu)工(gong)藝(yi)(yi)補給,以及(ji)主流(liu)工(gong)藝(yi)(yi)系統(tong)中(zhong)污泥顆(ke)粒化(hua)(hua)(hua)的(de)形成(cheng),其總氮年去(qu)除率高于(yu)80%,在實現出水TN<5mg/L,氨(an)氮<1.5mg/L的(de)同時,該(gai)廠(chang)(chang)(chang)還因實現完全(quan)能源自(zi)給和產(chan)能盈余聞名(ming)世界(jie)。
新加坡樟宜污水(shui)處理(li)廠實(shi)現了(le)世(shi)界首例(li)無需(xu)側流(liu)工(gong)藝(yi)接(jie)種的主流(liu)自養氨(an)氧化工(gong)程。該廠處理(li)城市污水(shui)達(da)80萬(wan)t/d,采用分段進水(shui)活性污泥工(gong)藝(yi)(SFAS),其工(gong)藝(yi)流(liu)程如圖2所示。
來自(zi)初(chu)沉池(chi)的(de)(de)污(wu)水(shui)(shui)被(bei)均(jun)勻分配到(dao)5個缺(que)氧(yang)(yang)(yang)/好(hao)氧(yang)(yang)(yang)池(chi)(體積比為1:1),每個缺(que)氧(yang)(yang)(yang)池(chi)又(you)被(bei)分為4格;缺(que)氧(yang)(yang)(yang)、好(hao)氧(yang)(yang)(yang)區的(de)(de)SRT各2.5d,水(shui)(shui)力停留時(shi)間(jian)(jian)(HRT)為5.7h左(zuo)右,二沉池(chi)污(wu)泥以50%回流比返回至第一個缺(que)氧(yang)(yang)(yang)池(chi)。Cao等對(dui)該(gai)廠總(zong)(zong)氮(dan)(dan)(dan)(dan)去(qu)除(chu)途徑進行(xing)(xing)(xing)研(yan)究,發(fa)現37.5%的(de)(de)總(zong)(zong)氮(dan)(dan)(dan)(dan)通過(guo)(guo)自(zi)養脫氮(dan)(dan)(dan)(dan)途徑去(qu)除(chu),27.1%的(de)(de)總(zong)(zong)氮(dan)(dan)(dan)(dan)通過(guo)(guo)傳(chuan)統生(sheng)(sheng)物脫氮(dan)(dan)(dan)(dan)途徑去(qu)除(chu),剩(sheng)下(xia)的(de)(de)氮(dan)(dan)(dan)(dan)則隨(sui)(sui)出水(shui)(shui)和污(wu)泥流出。該(gai)廠是迄今為止全(quan)球(qiu)第一座穩(wen)定運(yun)行(xing)(xing)(xing)主流厭(yan)氧(yang)(yang)(yang)氨(an)(an)氧(yang)(yang)(yang)化的(de)(de)污(wu)水(shui)(shui)處理廠,且實現了在不外加碳源的(de)(de)條(tiao)件下(xia)市政污(wu)水(shui)(shui)的(de)(de)高(gao)效生(sheng)(sheng)物脫氮(dan)(dan)(dan)(dan),有(you)學者(zhe)認(ren)為,樟宜污(wu)水(shui)(shui)廠的(de)(de)穩(wen)定運(yun)行(xing)(xing)(xing)得(de)(de)益于新加坡得(de)(de)天獨厚的(de)(de)水(shui)(shui)溫(wen)(wen)條(tiao)件(28~32℃),因為溫(wen)(wen)度(du)(du)對(dui)AOB、NOB和AnAOB活性(xing)有(you)顯(xian)著影(ying)響。研(yan)究報道(dao),隨(sui)(sui)著溫(wen)(wen)度(du)(du)降低(di)至20℃,AOB活性(xing)將高(gao)于NOB活性(xing);當(dang)水(shui)(shui)溫(wen)(wen)低(di)于15℃時(shi),AnAOB活性(xing)出現明(ming)顯(xian)下(xia)降,AOB變得(de)(de)比AnAOB更活躍(yue),此時(shi),AOB生(sheng)(sheng)成(cheng)的(de)(de)亞硝酸(suan)鹽和NOB、AnAOB消耗的(de)(de)亞硝酸(suan)鹽之間(jian)(jian)的(de)(de)不平衡(heng)將造(zao)成(cheng)系統中亞硝酸(suan)鹽明(ming)顯(xian)的(de)(de)積累,從而對(dui)厭(yan)氧(yang)(yang)(yang)氨(an)(an)氧(yang)(yang)(yang)化過(guo)(guo)程(cheng)造(zao)成(cheng)明(ming)顯(xian)抑(yi)制。因此,關(guan)于低(di)溫(wen)(wen)條(tiao)件下(xia)的(de)(de)厭(yan)氧(yang)(yang)(yang)氨(an)(an)氧(yang)(yang)(yang)化穩(wen)定運(yun)行(xing)(xing)(xing)還有(you)很大的(de)(de)研(yan)究空間(jian)(jian)。
2. 2 國內工程應用(yong)
據不(bu)完全統(tong)計,目(mu)(mu)前國內有(you)超過8座(zuo)的(de)(de)生(sheng)(sheng)產性厭(yan)(yan)(yan)氧(yang)(yang)(yang)(yang)氨(an)氧(yang)(yang)(yang)(yang)化(hua)(hua)污(wu)水處理(li)(li)廠(chang)(表2),其中(zhong),不(bu)少(shao)由荷(he)蘭帕克公司(si)參與設計建造。在(zai)通遼(liao)市梅(mei)花工(gong)業(ye)園區,帕克公司(si)于2009年建了(le)世(shi)界上最大(da)的(de)(de)自養脫(tuo)(tuo)氮反(fan)應器(qi)(qi),設計脫(tuo)(tuo)氮能(neng)力達(da)1.1萬kgN/d,采用(yong)一體式的(de)(de)CANON工(gong)藝(yi)(yi)處理(li)(li)谷氨(an)酸鈉(味精)生(sheng)(sheng)產中(zhong)的(de)(de)廢(fei)水。此外,山東(dong)湘(xiang)瑞藥業(ye)有(you)限公司(si)采用(yong)4300m3的(de)(de)厭(yan)(yan)(yan)氧(yang)(yang)(yang)(yang)氨(an)氧(yang)(yang)(yang)(yang)化(hua)(hua)反(fan)應器(qi)(qi)處理(li)(li)玉米淀(dian)粉(fen)和味精生(sheng)(sheng)產相(xiang)關(guan)的(de)(de)廢(fei)水,設計氨(an)氮負荷(he)達(da)1.42kgN/(m3·d)。山東(dong)省濱(bin)州(zhou)市安琪(qi)酵(jiao)(jiao)母公司(si)引進帕克公司(si)的(de)(de)厭(yan)(yan)(yan)氧(yang)(yang)(yang)(yang)氨(an)氧(yang)(yang)(yang)(yang)化(hua)(hua)工(gong)藝(yi)(yi)技術處理(li)(li)高氨(an)氮工(gong)業(ye)廢(fei)水,該項(xiang)目(mu)(mu)是厭(yan)(yan)(yan)氧(yang)(yang)(yang)(yang)氨(an)氧(yang)(yang)(yang)(yang)化(hua)(hua)技術在(zai)酵(jiao)(jiao)母廢(fei)水處理(li)(li)領域的(de)(de)首次工(gong)程應用(yong),與該公司(si)原AO工(gong)藝(yi)(yi)相(xiang)比,厭(yan)(yan)(yan)氧(yang)(yang)(yang)(yang)氨(an)氧(yang)(yang)(yang)(yang)化(hua)(hua)反(fan)應器(qi)(qi)在(zai)大(da)大(da)節省占地(di)的(de)(de)基礎上,實現了(le)2.0kgN/(m3·d)的(de)(de)高氨(an)氮負荷(he)穩(wen)定(ding)運(yun)行(xing),這(zhe)也是厭(yan)(yan)(yan)氧(yang)(yang)(yang)(yang)氨(an)氧(yang)(yang)(yang)(yang)化(hua)(hua)反(fan)應器(qi)(qi)目(mu)(mu)前可承受的(de)(de)最大(da)污(wu)泥負荷(he),其工(gong)業(ye)規模遠高于傳統(tong)工(gong)藝(yi)(yi)。這(zhe)些(xie)厭(yan)(yan)(yan)氧(yang)(yang)(yang)(yang)氨(an)氧(yang)(yang)(yang)(yang)化(hua)(hua)項(xiang)目(mu)(mu)的(de)(de)成功實施大(da)大(da)加速了(le)厭(yan)(yan)(yan)氧(yang)(yang)(yang)(yang)氨(an)氧(yang)(yang)(yang)(yang)化(hua)(hua)工(gong)藝(yi)(yi)在(zai)國內污(wu)水處理(li)(li)中(zhong)的(de)(de)應用(yong)。
除引(yin)進(jin)國外技術(shu),國內(nei)一些研究團(tuan)隊正(zheng)積極(ji)進(jin)行自(zi)主創新和(he)技術(shu)實踐,將厭氧(yang)(yang)氨(an)(an)氧(yang)(yang)化(hua)(hua)污(wu)水處(chu)理(li)(li)技術(shu)的(de)實驗室研究逐漸轉移(yi)到大(da)(da)型污(wu)水處(chu)理(li)(li)廠(chang)(chang)中。浙江(jiang)大(da)(da)學厭氧(yang)(yang)氨(an)(an)氧(yang)(yang)化(hua)(hua)研究團(tuan)隊已(yi)成(cheng)(cheng)功(gong)在(zai)浙江(jiang)建(jian)設了兩個生(sheng)產性厭氧(yang)(yang)氨(an)(an)氧(yang)(yang)化(hua)(hua)污(wu)水處(chu)理(li)(li)廠(chang)(chang),分別處(chu)理(li)(li)義烏市的(de)味精廢水(60m3)和(he)浙江(jiang)省東(dong)陽市的(de)制(zhi)(zhi)藥(yao)廢水(10m3)。北京工業大(da)(da)學的(de)彭永臻老師(shi)團(tuan)隊也展開了對基于厭氧(yang)(yang)氨(an)(an)氧(yang)(yang)化(hua)(hua)工藝的(de)城市污(wu)水廠(chang)(chang)實現能(neng)量自(zi)給的(de)可(ke)行性研究。隨(sui)著研究的(de)不斷發展,2015年(nian)湖北十堰垃圾填埋(mai)場滲(shen)(shen)濾液處(chu)理(li)(li)廠(chang)(chang)采用兩段式工藝,將兩級UASB、厭氧(yang)(yang)氨(an)(an)氧(yang)(yang)化(hua)(hua)、膜生(sheng)物反應器和(he)反滲(shen)(shen)透(MBR/RO)處(chu)理(li)(li)工藝相結合,設計處(chu)理(li)(li)量為150m3/d,COD控制(zhi)(zhi)在(zai)100mg/L,TN控制(zhi)(zhi)在(zai)40mg/L,氨(an)(an)氮控制(zhi)(zhi)在(zai)25mg/L,成(cheng)(cheng)為國內(nei)第一個使用厭氧(yang)(yang)氨(an)(an)氧(yang)(yang)化(hua)(hua)處(chu)理(li)(li)垃圾滲(shen)(shen)濾液,并(bing)解決垃圾滲(shen)(shen)濾液低碳(tan)氮比問題的(de)項目。
除(chu)了將(jiang)厭(yan)(yan)氧(yang)(yang)(yang)(yang)(yang)氨(an)氧(yang)(yang)(yang)(yang)(yang)化(hua)(hua)技術(shu)(shu)用于(yu)(yu)工(gong)(gong)業廢(fei)水(shui)(shui)(shui)和(he)污(wu)水(shui)(shui)(shui)處(chu)理(li)(li)側流(liu)工(gong)(gong)藝,我國在(zai)(zai)(zai)厭(yan)(yan)氧(yang)(yang)(yang)(yang)(yang)氨(an)氧(yang)(yang)(yang)(yang)(yang)化(hua)(hua)主(zhu)流(liu)工(gong)(gong)藝應(ying)用上也邁出了第一(yi)步(bu)。西安(an)市第四污(wu)水(shui)(shui)(shui)處(chu)理(li)(li)廠(chang)(chang)在(zai)(zai)(zai)原有缺氧(yang)(yang)(yang)(yang)(yang)/厭(yan)(yan)氧(yang)(yang)(yang)(yang)(yang)/好氧(yang)(yang)(yang)(yang)(yang)(倒置AAO)工(gong)(gong)藝上(圖3),通過在(zai)(zai)(zai)缺氧(yang)(yang)(yang)(yang)(yang)及厭(yan)(yan)氧(yang)(yang)(yang)(yang)(yang)池(chi)投加填(tian)料并延長HRT,利用攪(jiao)拌+曝氣(qi)實(shi)現填(tian)料流(liu)化(hua)(hua),將(jiang)工(gong)(gong)藝改造為(wei)(wei)反硝化(hua)(hua)/厭(yan)(yan)氧(yang)(yang)(yang)(yang)(yang)氨(an)氧(yang)(yang)(yang)(yang)(yang)化(hua)(hua)工(gong)(gong)藝,該(gai)廠(chang)(chang)進水(shui)(shui)(shui)氨(an)氮(dan)為(wei)(wei)20.3~40.8mg/L,COD/TN為(wei)(wei)1.2~7.9,全(quan)(quan)年水(shui)(shui)(shui)溫為(wei)(wei)10.7~25.2℃。在(zai)(zai)(zai)連續運行的(de)近兩年時間里,出水(shui)(shui)(shui)水(shui)(shui)(shui)質不僅成功由一(yi)級B標(biao)準(zhun)提升為(wei)(wei)一(yi)級A標(biao)準(zhun),且出水(shui)(shui)(shui)總氮(dan)顯著低于(yu)(yu)其他工(gong)(gong)藝,其中(zhong),厭(yan)(yan)氧(yang)(yang)(yang)(yang)(yang)氨(an)氧(yang)(yang)(yang)(yang)(yang)化(hua)(hua)工(gong)(gong)藝占(zhan)全(quan)(quan)廠(chang)(chang)脫(tuo)氮(dan)份額的(de)15.9%左右。該(gai)廠(chang)(chang)是目前全(quan)(quan)球(qiu)第3個實(shi)現主(zhu)流(liu)厭(yan)(yan)氧(yang)(yang)(yang)(yang)(yang)氨(an)氧(yang)(yang)(yang)(yang)(yang)化(hua)(hua)工(gong)(gong)藝的(de)污(wu)水(shui)(shui)(shui)處(chu)理(li)(li)廠(chang)(chang),且全(quan)(quan)球(qiu)已(yi)有超(chao)過5座污(wu)水(shui)(shui)(shui)廠(chang)(chang)正(zheng)在(zai)(zai)(zai)嘗試實(shi)踐主(zhu)流(liu)厭(yan)(yan)氧(yang)(yang)(yang)(yang)(yang)氨(an)氧(yang)(yang)(yang)(yang)(yang)化(hua)(hua)。該(gai)廠(chang)(chang)的(de)實(shi)踐表(biao)明,盡管厭(yan)(yan)氧(yang)(yang)(yang)(yang)(yang)氨(an)氧(yang)(yang)(yang)(yang)(yang)化(hua)(hua)主(zhu)流(liu)工(gong)(gong)藝應(ying)用仍存在(zai)(zai)(zai)一(yi)些技術(shu)(shu)難題(ti),但仍可(ke)預(yu)見將(jiang)會有更(geng)多污(wu)水(shui)(shui)(shui)處(chu)理(li)(li)廠(chang)(chang)將(jiang)其作(zuo)為(wei)(wei)主(zhu)流(liu)處(chu)理(li)(li)工(gong)(gong)藝試驗推(tui)廣(guang)。
3 主流厭氧(yang)氨氧(yang)化(hua)工藝(yi)技術難點
盡管目前厭氧(yang)氨氧(yang)化(hua)工藝(yi)在(zai)(zai)國(guo)內外(wai)已(yi)有(you)不少(shao)工程應(ying)(ying)(ying)用(yong)案例,但與側流(liu)工藝(yi)應(ying)(ying)(ying)用(yong)不同,主流(liu)厭氧(yang)氨氧(yang)化(hua)工藝(yi)應(ying)(ying)(ying)用(yong)中面臨著市(shi)政污水(shui)(shui)氮濃(nong)度(du)低、有(you)機物濃(nong)度(du)高、冬(dong)季水(shui)(shui)溫低等(deng)技術(shu)難點,導致其(qi)在(zai)(zai)推廣和實踐上仍存在(zai)(zai)一定的(de)局限性。下(xia)面針對主流(liu)厭氧(yang)氨氧(yang)化(hua)工藝(yi)應(ying)(ying)(ying)用(yong)中出現的(de)AnAOB生長緩慢、難富集和工藝(yi)運行(xing)不穩定等(deng)主要問(wen)題(ti)及其(qi)研究進(jin)展展開(kai)論述(shu)。
3. 1 厭氧氨氧化工藝(yi)的(de)快速啟動
目前(qian)已(yi)知AnAOB廣(guang)泛分布(bu)于(yu)海(hai)洋沉積物(wu)(wu)、油田(tian)、河口沉積物(wu)(wu)、厭(yan)氧海(hai)洋盆地、紅樹林地區、海(hai)洋冰塊、淡(dan)水(shui)湖、稻田(tian)土(tu)壤、湖港區以及海(hai)底熱泉等自然環境中。已(yi)明確命名的AnAOB有6類屬,超過23類種。此外,也有一些文(wen)獻相(xiang)繼報道了6類屬之外一些未知的菌屬。
反(fan)應(ying)(ying)(ying)(ying)器(qi)中(zhong)AnAOB的(de)(de)(de)(de)(de)生(sheng)(sheng)(sheng)長(chang)和富集是實(shi)(shi)(shi)(shi)現(xian)(xian)厭氧(yang)(yang)(yang)(yang)氨(an)(an)(an)(an)氧(yang)(yang)(yang)(yang)化(hua)(hua)(hua)(hua)自養脫(tuo)氮(dan)的(de)(de)(de)(de)(de)基(ji)本前提(ti),然而,AnAOB屬(shu)于(yu)自養型微生(sheng)(sheng)(sheng)物,在(zai)(zai)(zai)(zai)(zai)自然環境條(tiao)件下(xia),其生(sheng)(sheng)(sheng)長(chang)速率緩慢,倍增時間較長(chang),難以進行快(kuai)速增殖,同時,其對(dui)生(sheng)(sheng)(sheng)長(chang)環境(如(ru)溫(wen)度(du)(du)、溶(rong)解氧(yang)(yang)(yang)(yang)、pH等(deng))的(de)(de)(de)(de)(de)要(yao)求(qiu)近乎(hu)苛刻(ke),導(dao)致厭氧(yang)(yang)(yang)(yang)氨(an)(an)(an)(an)氧(yang)(yang)(yang)(yang)化(hua)(hua)(hua)(hua)工(gong)(gong)藝(yi)的(de)(de)(de)(de)(de)啟動(dong)(dong)(dong)(dong)(dong)(dong)要(yao)比(bi)傳統的(de)(de)(de)(de)(de)硝化(hua)(hua)(hua)(hua)反(fan)硝化(hua)(hua)(hua)(hua)工(gong)(gong)藝(yi)慢,限制(zhi)了(le)(le)(le)(le)其在(zai)(zai)(zai)(zai)(zai)污(wu)(wu)水(shui)(shui)(shui)處理(li)中(zhong)的(de)(de)(de)(de)(de)工(gong)(gong)程(cheng)(cheng)應(ying)(ying)(ying)(ying)用(yong)(yong)。在(zai)(zai)(zai)(zai)(zai)荷蘭鹿特丹的(de)(de)(de)(de)(de)世界第(di)一(yi)座生(sheng)(sheng)(sheng)產(chan)(chan)性厭氧(yang)(yang)(yang)(yang)氨(an)(an)(an)(an)氧(yang)(yang)(yang)(yang)化(hua)(hua)(hua)(hua)污(wu)(wu)水(shui)(shui)(shui)廠(chang)中(zhong),由于(yu)AnAOB生(sheng)(sheng)(sheng)長(chang)速度(du)(du)緩慢且(qie)當(dang)時缺乏菌(jun)種(zhong)污(wu)(wu)泥,原(yuan)本計劃(hua)兩(liang)年啟動(dong)(dong)(dong)(dong)(dong)(dong)反(fan)應(ying)(ying)(ying)(ying)器(qi),但啟動(dong)(dong)(dong)(dong)(dong)(dong)過程(cheng)(cheng)中(zhong)出(chu)現(xian)(xian)亞硝酸鹽(yan)抑制(zhi)和硫化(hua)(hua)(hua)(hua)物抑制(zhi)等(deng)問(wen)題,實(shi)(shi)(shi)(shi)際用(yong)(yong)了(le)(le)(le)(le)3~5年才完成(cheng)啟動(dong)(dong)(dong)(dong)(dong)(dong)工(gong)(gong)作。第(di)一(yi)個采用(yong)(yong)DEMON工(gong)(gong)藝(yi)的(de)(de)(de)(de)(de)奧(ao)地利Strass污(wu)(wu)水(shui)(shui)(shui)廠(chang)也(ye)花了(le)(le)(le)(le)2.5年左右才完成(cheng)厭氧(yang)(yang)(yang)(yang)氨(an)(an)(an)(an)氧(yang)(yang)(yang)(yang)化(hua)(hua)(hua)(hua)啟動(dong)(dong)(dong)(dong)(dong)(dong)。為(wei)加(jia)(jia)快(kuai)啟動(dong)(dong)(dong)(dong)(dong)(dong)時間,研(yan)(yan)究(jiu)人員(yuan)對(dui)不同接(jie)種(zhong)種(zhong)泥、不同反(fan)應(ying)(ying)(ying)(ying)器(qi)類(lei)型、不同載體中(zhong)厭氧(yang)(yang)(yang)(yang)氨(an)(an)(an)(an)氧(yang)(yang)(yang)(yang)化(hua)(hua)(hua)(hua)工(gong)(gong)藝(yi)的(de)(de)(de)(de)(de)啟動(dong)(dong)(dong)(dong)(dong)(dong)效果展開(kai)了(le)(le)(le)(le)大量(liang)研(yan)(yan)究(jiu)。Wett等(deng)在(zai)(zai)(zai)(zai)(zai)Glarnerland污(wu)(wu)水(shui)(shui)(shui)處理(li)廠(chang)啟動(dong)(dong)(dong)(dong)(dong)(dong)中(zhong),通過接(jie)種(zhong)現(xian)(xian)有(you)厭氧(yang)(yang)(yang)(yang)氨(an)(an)(an)(an)氧(yang)(yang)(yang)(yang)化(hua)(hua)(hua)(hua)工(gong)(gong)藝(yi)種(zhong)泥,將其啟動(dong)(dong)(dong)(dong)(dong)(dong)時間縮(suo)(suo)短(duan)(duan)到50d。Christensson等(deng)為(wei)減(jian)少新(xin)反(fan)應(ying)(ying)(ying)(ying)器(qi)的(de)(de)(de)(de)(de)啟動(dong)(dong)(dong)(dong)(dong)(dong)時間,采用(yong)(yong)MBBR開(kai)發(fa)了(le)(le)(le)(le)一(yi)種(zhong)ANITA?Mox工(gong)(gong)藝(yi),其原(yuan)理(li)是在(zai)(zai)(zai)(zai)(zai)啟動(dong)(dong)(dong)(dong)(dong)(dong)新(xin)反(fan)應(ying)(ying)(ying)(ying)器(qi)時,投加(jia)(jia)3%~15%已經形成(cheng)了(le)(le)(le)(le)AnAOB生(sheng)(sheng)(sheng)物膜的(de)(de)(de)(de)(de)載體,剩下(xia)的(de)(de)(de)(de)(de)則加(jia)(jia)入新(xin)載體材料。為(wei)了(le)(le)(le)(le)驗(yan)證這(zhe)一(yi)工(gong)(gong)藝(yi)的(de)(de)(de)(de)(de)可行性,2010年瑞(rui)(rui)典(dian)馬爾默的(de)(de)(de)(de)(de)Sj?lunda污(wu)(wu)水(shui)(shui)(shui)廠(chang)首(shou)次采用(yong)(yong)這(zhe)種(zhong)方(fang)法(fa)(fa),在(zai)(zai)(zai)(zai)(zai)4個月內完成(cheng)了(le)(le)(le)(le)厭氧(yang)(yang)(yang)(yang)氨(an)(an)(an)(an)氧(yang)(yang)(yang)(yang)化(hua)(hua)(hua)(hua)反(fan)應(ying)(ying)(ying)(ying)器(qi)啟動(dong)(dong)(dong)(dong)(dong)(dong),氨(an)(an)(an)(an)氮(dan)去(qu)除(chu)率達90%,且(qie)系統運(yun)行非常穩定;之(zhi)后在(zai)(zai)(zai)(zai)(zai)瑞(rui)(rui)典(dian)的(de)(de)(de)(de)(de)Sundets污(wu)(wu)水(shui)(shui)(shui)處理(li)廠(chang)再次驗(yan)證了(le)(le)(le)(le)這(zhe)種(zhong)啟動(dong)(dong)(dong)(dong)(dong)(dong)方(fang)式的(de)(de)(de)(de)(de)可行性,該廠(chang)在(zai)(zai)(zai)(zai)(zai)2個月內便實(shi)(shi)(shi)(shi)現(xian)(xian)了(le)(le)(le)(le)滿負荷生(sheng)(sheng)(sheng)產(chan)(chan)。此外,一(yi)些(xie)(xie)研(yan)(yan)究(jiu)者通過將微生(sheng)(sheng)(sheng)物固定在(zai)(zai)(zai)(zai)(zai)聚乙烯醇(PVA)-海藻(zao)酸鈉(SA)凝膠(jiao)中(zhong),實(shi)(shi)(shi)(shi)現(xian)(xian)了(le)(le)(le)(le)上升(sheng)流塔(ta)式反(fan)應(ying)(ying)(ying)(ying)器(qi)中(zhong)厭氧(yang)(yang)(yang)(yang)氨(an)(an)(an)(an)氧(yang)(yang)(yang)(yang)化(hua)(hua)(hua)(hua)工(gong)(gong)藝(yi)的(de)(de)(de)(de)(de)快(kuai)速啟動(dong)(dong)(dong)(dong)(dong)(dong);也(ye)有(you)研(yan)(yan)究(jiu)發(fa)現(xian)(xian),AnAOB的(de)(de)(de)(de)(de)生(sheng)(sheng)(sheng)長(chang)嚴重依賴含鐵蛋(dan)白,鐵鹽(yan)的(de)(de)(de)(de)(de)添加(jia)(jia)有(you)利于(yu)促(cu)進AnAOB的(de)(de)(de)(de)(de)生(sheng)(sheng)(sheng)長(chang)富集,當(dang)添加(jia)(jia)0.09mmol的(de)(de)(de)(de)(de)Fe2+時,厭氧(yang)(yang)(yang)(yang)氨(an)(an)(an)(an)氧(yang)(yang)(yang)(yang)化(hua)(hua)(hua)(hua)啟動(dong)(dong)(dong)(dong)(dong)(dong)由70d縮(suo)(suo)短(duan)(duan)至50d。還有(you)一(yi)些(xie)(xie)研(yan)(yan)究(jiu)結果表明,AnAOB的(de)(de)(de)(de)(de)最大生(sheng)(sheng)(sheng)長(chang)速率并非受其細胞內在(zai)(zai)(zai)(zai)(zai)特性限制(zhi),而與細胞培養條(tiao)件有(you)關(guan)(guan),當(dang)對(dui)AnAOB施加(jia)(jia)適宜的(de)(de)(de)(de)(de)培養條(tiao)件時,其生(sheng)(sheng)(sheng)長(chang)速率可以顯(xian)著提(ti)高,部分AnAOB細胞倍增時間可縮(suo)(suo)短(duan)(duan)至2~5d。這(zhe)些(xie)(xie)研(yan)(yan)究(jiu)成(cheng)果為(wei)厭氧(yang)(yang)(yang)(yang)氨(an)(an)(an)(an)氧(yang)(yang)(yang)(yang)化(hua)(hua)(hua)(hua)工(gong)(gong)藝(yi)的(de)(de)(de)(de)(de)快(kuai)速啟動(dong)(dong)(dong)(dong)(dong)(dong)運(yun)行和推(tui)廣奠(dian)定了(le)(le)(le)(le)理(li)論基(ji)礎,但在(zai)(zai)(zai)(zai)(zai)實(shi)(shi)(shi)(shi)際應(ying)(ying)(ying)(ying)用(yong)(yong)中(zhong),AnAOB的(de)(de)(de)(de)(de)快(kuai)速生(sheng)(sheng)(sheng)長(chang)與污(wu)(wu)水(shui)(shui)(shui)的(de)(de)(de)(de)(de)pH、溫(wen)度(du)(du)、亞硝酸鹽(yan)濃度(du)(du)、溶(rong)解氧(yang)(yang)(yang)(yang)、SRT、有(you)機(ji)物濃度(du)(du)、鹽(yan)度(du)(du)等(deng)因素緊密(mi)相關(guan)(guan)。此外,污(wu)(wu)水(shui)(shui)(shui)的(de)(de)(de)(de)(de)組成(cheng)、有(you)毒(du)化(hua)(hua)(hua)(hua)合物的(de)(de)(de)(de)(de)存(cun)在(zai)(zai)(zai)(zai)(zai)和反(fan)應(ying)(ying)(ying)(ying)器(qi)的(de)(de)(de)(de)(de)類(lei)型等(deng)因素也(ye)會影響AnAOB的(de)(de)(de)(de)(de)活動(dong)(dong)(dong)(dong)(dong)(dong),并改變其群(qun)落結構。盡(jin)管目前實(shi)(shi)(shi)(shi)驗(yan)室已提(ti)出(chu)了(le)(le)(le)(le)一(yi)些(xie)(xie)縮(suo)(suo)短(duan)(duan)厭氧(yang)(yang)(yang)(yang)氨(an)(an)(an)(an)氧(yang)(yang)(yang)(yang)化(hua)(hua)(hua)(hua)反(fan)應(ying)(ying)(ying)(ying)器(qi)啟動(dong)(dong)(dong)(dong)(dong)(dong)時間的(de)(de)(de)(de)(de)方(fang)法(fa)(fa),但未(wei)來仍需工(gong)(gong)程(cheng)(cheng)實(shi)(shi)(shi)(shi)踐(jian)來進一(yi)步(bu)驗(yan)證這(zhe)些(xie)(xie)方(fang)法(fa)(fa)的(de)(de)(de)(de)(de)可行性。
3. 2 AnAOB 的富集
AnAOB的(de)(de)(de)(de)(de)(de)(de)(de)(de)富(fu)(fu)集(ji)方法可(ke)(ke)(ke)大(da)(da)致分(fen)(fen)為兩大(da)(da)類。一(yi)類是通(tong)過將懸浮態的(de)(de)(de)(de)(de)(de)(de)(de)(de)活(huo)性污(wu)(wu)泥(ni)(ni)(ni)固(gu)定(ding)(ding),形(xing)成(cheng)(cheng)生(sheng)(sheng)(sheng)物(wu)(wu)(wu)膜或(huo)顆(ke)(ke)(ke)(ke)(ke)(ke)(ke)粒(li)(li)(li)(li)污(wu)(wu)泥(ni)(ni)(ni),實(shi)現AnAOB的(de)(de)(de)(de)(de)(de)(de)(de)(de)截(jie)留,由于(yu)細菌種(zhong)群的(de)(de)(de)(de)(de)(de)(de)(de)(de)緩慢生(sheng)(sheng)(sheng)長(chang),保持厭氧(yang)菌生(sheng)(sheng)(sheng)物(wu)(wu)(wu)量對于(yu)厭氧(yang)氨(an)氧(yang)化(hua)工藝(yi)的(de)(de)(de)(de)(de)(de)(de)(de)(de)穩(wen)定(ding)(ding)運行(xing)(xing)至(zhi)關重要。Jia等(deng)(deng)研究(jiu)發(fa)(fa)現,在反(fan)應(ying)(ying)(ying)器內投加載(zai)(zai)體(ti)(ti)(ti)材料(liao)形(xing)成(cheng)(cheng)生(sheng)(sheng)(sheng)物(wu)(wu)(wu)膜,或(huo)通(tong)過培(pei)養形(xing)成(cheng)(cheng)顆(ke)(ke)(ke)(ke)(ke)(ke)(ke)粒(li)(li)(li)(li)污(wu)(wu)泥(ni)(ni)(ni)的(de)(de)(de)(de)(de)(de)(de)(de)(de)方法可(ke)(ke)(ke)有(you)(you)(you)效避免AnAOB的(de)(de)(de)(de)(de)(de)(de)(de)(de)流失。目前,已有(you)(you)(you)多種(zhong)載(zai)(zai)體(ti)(ti)(ti)材料(liao)被用(yong)于(yu)AnAOB的(de)(de)(de)(de)(de)(de)(de)(de)(de)富(fu)(fu)集(ji)。Fernández等(deng)(deng)用(yong)沸石(shi)顆(ke)(ke)(ke)(ke)(ke)(ke)(ke)粒(li)(li)(li)(li)作為載(zai)(zai)體(ti)(ti)(ti)材料(liao),發(fa)(fa)現帶負電(dian)荷(he)的(de)(de)(de)(de)(de)(de)(de)(de)(de)沸石(shi)能夠吸引并聚集(ji)帶正電(dian)荷(he)的(de)(de)(de)(de)(de)(de)(de)(de)(de)銨(an)離子,沸石(shi)的(de)(de)(de)(de)(de)(de)(de)(de)(de)投加可(ke)(ke)(ke)提(ti)高(gao)(gao)反(fan)應(ying)(ying)(ying)器內AnAOB的(de)(de)(de)(de)(de)(de)(de)(de)(de)富(fu)(fu)集(ji)度(du)(du),隨出(chu)水流失的(de)(de)(de)(de)(de)(de)(de)(de)(de)生(sheng)(sheng)(sheng)物(wu)(wu)(wu)質量顯著降(jiang)低。Miao等(deng)(deng)用(yong)聚乙烯(xi)海綿作載(zai)(zai)體(ti)(ti)(ti)材料(liao)處理(li)滲(shen)濾(lv)液,發(fa)(fa)現基于(yu)該載(zai)(zai)體(ti)(ti)(ti)的(de)(de)(de)(de)(de)(de)(de)(de)(de)處理(li)工藝(yi)能實(shi)現很高(gao)(gao)的(de)(de)(de)(de)(de)(de)(de)(de)(de)脫(tuo)氮效率,形(xing)成(cheng)(cheng)的(de)(de)(de)(de)(de)(de)(de)(de)(de)生(sheng)(sheng)(sheng)物(wu)(wu)(wu)膜使AnAOB的(de)(de)(de)(de)(de)(de)(de)(de)(de)基因比(bi)例(li)從1.3%增加到(dao)13.3%。此(ci)外(wai),由緊密的(de)(de)(de)(de)(de)(de)(de)(de)(de)微生(sheng)(sheng)(sheng)物(wu)(wu)(wu)聚集(ji)體(ti)(ti)(ti)組成(cheng)(cheng)的(de)(de)(de)(de)(de)(de)(de)(de)(de)顆(ke)(ke)(ke)(ke)(ke)(ke)(ke)粒(li)(li)(li)(li)污(wu)(wu)泥(ni)(ni)(ni)不僅具(ju)有(you)(you)(you)較高(gao)(gao)的(de)(de)(de)(de)(de)(de)(de)(de)(de)沉(chen)降(jiang)速(su)度(du)(du),而且可(ke)(ke)(ke)以(yi)避免生(sheng)(sheng)(sheng)物(wu)(wu)(wu)量隨出(chu)水流失,形(xing)成(cheng)(cheng)的(de)(de)(de)(de)(de)(de)(de)(de)(de)厭氧(yang)氨(an)氧(yang)化(hua)顆(ke)(ke)(ke)(ke)(ke)(ke)(ke)粒(li)(li)(li)(li)污(wu)(wu)泥(ni)(ni)(ni)具(ju)有(you)(you)(you)較高(gao)(gao)的(de)(de)(de)(de)(de)(de)(de)(de)(de)沉(chen)降(jiang)速(su)度(du)(du)、較高(gao)(gao)的(de)(de)(de)(de)(de)(de)(de)(de)(de)脫(tuo)氮率、較低的(de)(de)(de)(de)(de)(de)(de)(de)(de)基礎設施(shi)成(cheng)(cheng)本的(de)(de)(de)(de)(de)(de)(de)(de)(de)顯著優勢(shi)。為了(le)優化(hua)實(shi)際工程應(ying)(ying)(ying)用(yong)效果,涌現出(chu)大(da)(da)量關于(yu)厭氧(yang)氨(an)氧(yang)化(hua)顆(ke)(ke)(ke)(ke)(ke)(ke)(ke)粒(li)(li)(li)(li)污(wu)(wu)泥(ni)(ni)(ni)的(de)(de)(de)(de)(de)(de)(de)(de)(de)研究(jiu)。Tang等(deng)(deng)認為,選(xuan)擇合適的(de)(de)(de)(de)(de)(de)(de)(de)(de)接種(zhong)污(wu)(wu)泥(ni)(ni)(ni),同(tong)時增加進水氮負荷(he)可(ke)(ke)(ke)以(yi)有(you)(you)(you)效提(ti)高(gao)(gao)顆(ke)(ke)(ke)(ke)(ke)(ke)(ke)粒(li)(li)(li)(li)污(wu)(wu)泥(ni)(ni)(ni)的(de)(de)(de)(de)(de)(de)(de)(de)(de)形(xing)成(cheng)(cheng)速(su)率,從而提(ti)高(gao)(gao)反(fan)應(ying)(ying)(ying)器的(de)(de)(de)(de)(de)(de)(de)(de)(de)脫(tuo)氮性能。但顆(ke)(ke)(ke)(ke)(ke)(ke)(ke)粒(li)(li)(li)(li)污(wu)(wu)泥(ni)(ni)(ni)的(de)(de)(de)(de)(de)(de)(de)(de)(de)實(shi)際應(ying)(ying)(ying)用(yong)也存在一(yi)些局限性,Chen等(deng)(deng)研究(jiu)表(biao)明,這種(zhong)厭氧(yang)菌顆(ke)(ke)(ke)(ke)(ke)(ke)(ke)粒(li)(li)(li)(li)浮選(xuan)和后續的(de)(de)(de)(de)(de)(de)(de)(de)(de)沖洗過程會(hui)破壞厭氧(yang)氨(an)氧(yang)化(hua)工藝(yi)的(de)(de)(de)(de)(de)(de)(de)(de)(de)穩(wen)定(ding)(ding)運行(xing)(xing)。此(ci)外(wai),顆(ke)(ke)(ke)(ke)(ke)(ke)(ke)粒(li)(li)(li)(li)污(wu)(wu)泥(ni)(ni)(ni)的(de)(de)(de)(de)(de)(de)(de)(de)(de)尺(chi)(chi)寸(cun)(cun)大(da)(da)小也會(hui)影響厭氧(yang)氨(an)氧(yang)化(hua)反(fan)應(ying)(ying)(ying)的(de)(de)(de)(de)(de)(de)(de)(de)(de)進行(xing)(xing),過大(da)(da)的(de)(de)(de)(de)(de)(de)(de)(de)(de)顆(ke)(ke)(ke)(ke)(ke)(ke)(ke)粒(li)(li)(li)(li)污(wu)(wu)泥(ni)(ni)(ni)會(hui)影響基質的(de)(de)(de)(de)(de)(de)(de)(de)(de)擴散(san)和反(fan)應(ying)(ying)(ying)速(su)率,反(fan)而抑制了(le)AnAOB的(de)(de)(de)(de)(de)(de)(de)(de)(de)活(huo)性。An等(deng)(deng)研究(jiu)了(le)不同(tong)大(da)(da)小(0.5~1.0、1.0~1.5、>1.5mm)的(de)(de)(de)(de)(de)(de)(de)(de)(de)顆(ke)(ke)(ke)(ke)(ke)(ke)(ke)粒(li)(li)(li)(li)污(wu)(wu)泥(ni)(ni)(ni)的(de)(de)(de)(de)(de)(de)(de)(de)(de)物(wu)(wu)(wu)理(li)性質和反(fan)應(ying)(ying)(ying)性能,結果表(biao)明,1.0~1.5mm的(de)(de)(de)(de)(de)(de)(de)(de)(de)顆(ke)(ke)(ke)(ke)(ke)(ke)(ke)粒(li)(li)(li)(li)污(wu)(wu)泥(ni)(ni)(ni)AnAOB活(huo)性最高(gao)(gao),3種(zhong)尺(chi)(chi)寸(cun)(cun)的(de)(de)(de)(de)(de)(de)(de)(de)(de)顆(ke)(ke)(ke)(ke)(ke)(ke)(ke)粒(li)(li)(li)(li)污(wu)(wu)泥(ni)(ni)(ni)的(de)(de)(de)(de)(de)(de)(de)(de)(de)氮負荷(he)分(fen)(fen)別為0.55、0.62、0.52gN/(gVSS·d)。
另一類AnAOB富集的(de)方法是利用(yong)NOB、HB和AnAOB之間的(de)競爭關(guan)系(xi),保證AnAOB在體系(xi)中(zhong)(zhong)成為優勢菌屬,三(san)者之間的(de)關(guan)系(xi)如(ru)圖4所(suo)示(shi)。目前,已發現(xian)可通(tong)(tong)過(guo)減少SRT、降低(di)(di)(di)(di)pH、控(kong)(kong)(kong)制曝(pu)氣時(shi)間降低(di)(di)(di)(di)DO等方法來調(diao)控(kong)(kong)(kong)NOB和HB的(de)生長,以增加體系(xi)中(zhong)(zhong)AnAOB的(de)生物(wu)量(liang)。這(zhe)(zhe)些方法可分為兩(liang)大途(tu)徑(jing):(1)通(tong)(tong)過(guo)調(diao)控(kong)(kong)(kong)工況促(cu)進AOB和AnAOB的(de)生長活(huo)性(xing),并通(tong)(tong)過(guo)調(diao)控(kong)(kong)(kong)NO2--N和NO3--N濃度(du),在降低(di)(di)(di)(di)HB的(de)同時(shi)抑制NOB的(de)生長;(2)從系(xi)統(tong)中(zhong)(zhong)清除NOB(NO2--N→NO3--N)和HB,同時(shi)保留(liu)AOB(NH4+-N→NO2--N)和AnAOB。但由于(yu)這(zhe)(zhe)些方法要(yao)求特(te)殊的(de)生長條(tiao)件,如(ru)低(di)(di)(di)(di)pH值(zhi)和較(jiao)高水溫(wen),或是只適用(yong)于(yu)間歇曝(pu)氣的(de)反應器(qi)中(zhong)(zhong)(嚴格控(kong)(kong)(kong)制曝(pu)氣時(shi)間),甚至可能(neng)會(hui)降低(di)(di)(di)(di)AOB活(huo)性(xing)(如(ru)較(jiao)低(di)(di)(di)(di)DO),因此,這(zhe)(zhe)類富集方法還不(bu)能(neng)廣(guang)泛在全規(gui)模污水廠中(zhong)(zhong)采用(yong)。
進(jin)(jin)(jin)水有(you)機(ji)(ji)物的(de)(de)濃度也會對(dui)AOB和AnAOB的(de)(de)生(sheng)長造成顯著(zhu)影響。由表3可知,厭(yan)氧(yang)(yang)(yang)(yang)氨(an)(an)氧(yang)(yang)(yang)(yang)化(hua)工(gong)(gong)(gong)藝(yi)適用(yong)于(yu)處理(li)進(jin)(jin)(jin)水C/N較低的(de)(de)廢水,因(yin)(yin)為(wei)在高有(you)機(ji)(ji)物濃度條件(jian)下,HB會與(yu)自養的(de)(de)AOB和AnAOB競爭底物(DO和NO2--N)和生(sheng)存空間,不利于(yu)自養脫(tuo)氮過程(cheng)。Chen等(deng)發現,當進(jin)(jin)(jin)水C/N從(cong)0.5:1增加到0.75:1時,硝(xiao)化(hua)/厭(yan)氧(yang)(yang)(yang)(yang)氨(an)(an)氧(yang)(yang)(yang)(yang)化(hua)工(gong)(gong)(gong)藝(yi)的(de)(de)脫(tuo)氮效率(lv)從(cong)79%降低到52%。但對(dui)主流厭(yan)氧(yang)(yang)(yang)(yang)氨(an)(an)氧(yang)(yang)(yang)(yang)化(hua)工(gong)(gong)(gong)藝(yi)的(de)(de)應用(yong)來說,實際市政污水的(de)(de)進(jin)(jin)(jin)水有(you)機(ji)(ji)物含(han)量(liang)(一(yi)(yi)般(ban)C/N為(wei)4:1~12:1)遠遠高于(yu)自養微生(sheng)物生(sheng)長所需(xu)的(de)(de)有(you)機(ji)(ji)物含(han)量(liang)。因(yin)(yin)此(ci),一(yi)(yi)些(xie)研(yan)究(jiu)者(zhe)提出,可在PN/厭(yan)氧(yang)(yang)(yang)(yang)氨(an)(an)氧(yang)(yang)(yang)(yang)化(hua)工(gong)(gong)(gong)藝(yi)之前進(jin)(jin)(jin)行脫(tuo)碳預(yu)處理(li)(如(ru)進(jin)(jin)(jin)行消化(hua)產(chan)能等(deng)),以降低進(jin)(jin)(jin)入(ru)厭(yan)氧(yang)(yang)(yang)(yang)氨(an)(an)氧(yang)(yang)(yang)(yang)化(hua)工(gong)(gong)(gong)藝(yi)中的(de)(de)有(you)機(ji)(ji)物含(han)量(liang)。但關于(yu)脫(tuo)碳預(yu)處理(li)工(gong)(gong)(gong)藝(yi)的(de)(de)實際應用(yong)和控(kong)制條件(jian)等(deng)仍需(xu)要進(jin)(jin)(jin)行實踐(jian)研(yan)究(jiu)。
3. 3 厭氧氨氧化(hua)工藝的穩(wen)定運行(xing)
3. 3. 1 穩(wen)定(ding)NO2--N供應(ying)
NO2--N和氨(an)氮(dan)(dan)是厭(yan)氧(yang)氨(an)氧(yang)化(hua)(hua)(hua)(hua)反(fan)應的(de)(de)(de)底物(wu),由(you)于(yu)(yu)氨(an)氮(dan)(dan)是污水(shui)中含氮(dan)(dan)化(hua)(hua)(hua)(hua)合物(wu)的(de)(de)(de)主(zhu)要存(cun)在(zai)形式(shi),因此,穩定(ding)地為(wei)厭(yan)氧(yang)氨(an)氧(yang)化(hua)(hua)(hua)(hua)反(fan)應提供NO2-成為(wei)了污水(shui)自養脫氮(dan)(dan)工藝(yi)的(de)(de)(de)關鍵。污水(shui)中NO2--N有(you)兩(liang)個形成途(tu)徑:其(qi)一是通過(guo)(guo)將(jiang)氨(an)氮(dan)(dan)氧(yang)化(hua)(hua)(hua)(hua)為(wei)NO2-的(de)(de)(de)亞硝化(hua)(hua)(hua)(hua)過(guo)(guo)程產(chan)生(sheng)(sheng)(NH4+-N→NO2--N);其(qi)二是通過(guo)(guo)將(jiang)NO3-還(huan)原為(wei)NO2-的(de)(de)(de)部(bu)分(fen)反(fan)硝化(hua)(hua)(hua)(hua)過(guo)(guo)程產(chan)生(sheng)(sheng)(NO3--N→NO2--N)。后者可同時實現NO3--N的(de)(de)(de)去(qu)除(chu)和NO2--N的(de)(de)(de)供應,且相(xiang)較(jiao)于(yu)(yu)完全反(fan)硝化(hua)(hua)(hua)(hua)過(guo)(guo)程,部(bu)分(fen)反(fan)硝化(hua)(hua)(hua)(hua)過(guo)(guo)程還(huan)可減(jian)少(shao)N2O等(deng)溫室氣體(ti)的(de)(de)(de)排放(fang)以及(ji)減(jian)少(shao)40%左右的(de)(de)(de)碳(tan)源投加量(liang),大幅(fu)節省運營成本。因此,作為(wei)一種綠色(se)經濟(ji)有(you)效的(de)(de)(de)主(zhu)流(liu)脫氮(dan)(dan)工藝(yi)替(ti)代(dai)方式(shi),基于(yu)(yu)部(bu)分(fen)反(fan)硝化(hua)(hua)(hua)(hua)/厭(yan)氧(yang)氨(an)氧(yang)化(hua)(hua)(hua)(hua)的(de)(de)(de)工藝(yi)得(de)到了全球研究者的(de)(de)(de)廣泛關注。
盡管NO2-是厭(yan)氧(yang)氨(an)(an)氧(yang)化(hua)過程的重要底物,但過量的NO2-累(lei)積在厭(yan)氧(yang)氨(an)(an)氧(yang)化(hua)系(xi)(xi)統內時會(hui)對AnAOB有毒害作用(yong)。不同來源(yuan)的AnAOB以(yi)及不同污水處理系(xi)(xi)統中NO2-的抑制濃(nong)度不同(表4)。此(ci)外(wai),試驗發現,反應器中氨(an)(an)氮的存在與否(fou)也(ye)會(hui)顯著(zhu)影響NO2-對AnAOB的毒害作用(yong)。在氨(an)(an)氮存在的條(tiao)件下,抑制50%的AnAOB活性需要384mg/L的NO2--N。但在無氨(an)(an)氮的條(tiao)件下,質量濃(nong)度為53mg/L的NO2--N就(jiu)能降低(di)AnAOB一半(ban)的活性。
3. 3. 2 低溫(wen)運行
AnAOB的(de)(de)最適生長溫度為30~40℃,如(ru)何(he)在(zai)(zai)低(di)(di)溫(10~16°C)條件下(xia)實(shi)現厭(yan)氧(yang)氨氧(yang)化工(gong)藝的(de)(de)穩定運(yun)行是(shi)厭(yan)氧(yang)氨氧(yang)化技術(shu)主流工(gong)藝應(ying)(ying)用(yong)和推廣的(de)(de)瓶頸之一(yi)。盡管已有(you)一(yi)些(xie)實(shi)驗室(shi)研究報(bao)道厭(yan)氧(yang)氨氧(yang)化工(gong)藝在(zai)(zai)低(di)(di)溫下(xia)也可(ke)取得(de)較好的(de)(de)脫氮效果,但(dan)由于(yu)AnAOB在(zai)(zai)低(di)(di)溫下(xia)的(de)(de)低(di)(di)活性(xing)、低(di)(di)生長速率,以及市政污水(shui)水(shui)溫的(de)(de)季節性(xing)波動,主流工(gong)藝應(ying)(ying)用(yong)中(zhong)可(ke)能還需要延長生物膜SRT來保(bao)證反應(ying)(ying)器(qi)內有(you)足夠量的(de)(de)AnAOB。
3. 3. 3 主流(liu)工藝應用
目前,全(quan)球范圍內正在(zai)積極(ji)展開對主流厭(yan)氧(yang)氨氧(yang)化(hua)(hua)工(gong)藝(yi)(yi)的(de)(de)試點(dian)和(he)(he)工(gong)程化(hua)(hua)研究,但還沒有能長期穩(wen)定(ding)運(yun)行的(de)(de)成熟主流厭(yan)氧(yang)氨氧(yang)化(hua)(hua)技(ji)術。因此(ci)(ci),為了推進(jin)主流工(gong)藝(yi)(yi)應(ying)用的(de)(de)進(jin)程,一(yi)些(xie)研究者(zhe)提出(chu),可以通過將側(ce)流工(gong)藝(yi)(yi)中的(de)(de)優勢(shi)微生物(wu)接(jie)種至主流工(gong)藝(yi)(yi)中,增強主流工(gong)藝(yi)(yi)系統(tong)中有益的(de)(de)微生物(wu)群(qun)落(如AOB和(he)(he)AnAOB),從(cong)而(er)加速反應(ying)器(qi)的(de)(de)啟動和(he)(he)穩(wen)定(ding)運(yun)行。此(ci)(ci)外(wai),在(zai)線(xian)監測(ce)和(he)(he)智能化(hua)(hua)控(kong)制也是(shi)保(bao)障(zhang)主流厭(yan)氧(yang)氨氧(yang)化(hua)(hua)工(gong)藝(yi)(yi)穩(wen)定(ding)運(yun)行的(de)(de)關鍵,系統(tong)的(de)(de)穩(wen)定(ding)運(yun)行必(bi)須依(yi)靠在(zai)線(xian)傳感器(qi)對NH4+-N、NO3--N、NO2--N、pH和(he)(he)DO含量的(de)(de)及時(shi)測(ce)定(ding)和(he)(he)調控(kong)。
4 結語與展望
盡管目前厭(yan)氧(yang)(yang)氨氧(yang)(yang)化(hua)(hua)(hua)技(ji)(ji)(ji)術的(de)(de)(de)主(zhu)(zhu)流(liu)工藝(yi)應(ying)(ying)(ying)用(yong)技(ji)(ji)(ji)術還不(bu)十分(fen)成熟,但經(jing)過幾十年的(de)(de)(de)發展,厭(yan)氧(yang)(yang)氨氧(yang)(yang)化(hua)(hua)(hua)技(ji)(ji)(ji)術工程應(ying)(ying)(ying)用(yong)已遍布全球(qiu),近幾年國內對(dui)厭(yan)氧(yang)(yang)氨氧(yang)(yang)化(hua)(hua)(hua)的(de)(de)(de)研究和工程應(ying)(ying)(ying)用(yong)也取得了很(hen)大的(de)(de)(de)進展和突破。鑒(jian)于(yu)市(shi)政污水(shui)(shui)處理廠主(zhu)(zhu)流(liu)工藝(yi)應(ying)(ying)(ying)用(yong)與側流(liu)工藝(yi)應(ying)(ying)(ying)用(yong)在(zai)水(shui)(shui)質(zhi)、水(shui)(shui)溫、處理規(gui)模等(deng)方面(mian)的(de)(de)(de)差異(yi),針對(dui)主(zhu)(zhu)流(liu)厭(yan)氧(yang)(yang)氨氧(yang)(yang)化(hua)(hua)(hua)工藝(yi)面(mian)臨的(de)(de)(de)工藝(yi)啟動較慢、AnAOB富集、硝酸(suan)鹽(yan)濃度控(kong)制困難、冬季水(shui)(shui)溫低(di)等(deng)技(ji)(ji)(ji)術難點,現(xian)有研究已發現(xian),可(ke)通過接種現(xian)有厭(yan)氧(yang)(yang)氨氧(yang)(yang)化(hua)(hua)(hua)工藝(yi)種泥、形成生物膜(mo)或顆粒污泥、調(diao)控(kong)微(wei)生物種群(qun)、組合(he)其他工藝(yi)等(deng)方法破解以(yi)上(shang)難題。面(mian)對(dui)巨大的(de)(de)(de)污水(shui)(shui)處理市(shi)場,預計(ji)我國將(jiang)在(zai)不(bu)久的(de)(de)(de)將(jiang)來成為厭(yan)氧(yang)(yang)氨氧(yang)(yang)化(hua)(hua)(hua)技(ji)(ji)(ji)術應(ying)(ying)(ying)用(yong)的(de)(de)(de)主(zhu)(zhu)要市(shi)場,未來的(de)(de)(de)研究在(zai)優化(hua)(hua)(hua)操作條件(jian)和開發智能化(hua)(hua)(hua)控(kong)制系(xi)統的(de)(de)(de)同時,還可(ke)在(zai)以(yi)下幾方面(mian)作進一步研究。
(1)一(yi)(yi)體(ti)式厭(yan)(yan)氧(yang)氨氧(yang)化(hua)工(gong)藝由于具有較低的(de)建設和運營成本,在(zai)實際(ji)應用中受到歡迎(ying),未來可(ke)針對一(yi)(yi)體(ti)式厭(yan)(yan)氧(yang)氨氧(yang)化(hua)系統(tong)過程控(kong)制(zhi)和工(gong)藝操作參(can)數優化(hua)做進一(yi)(yi)步研究,在(zai)保障穩定運行的(de)同時(shi),還應強化(hua)控(kong)制(zhi)N2O的(de)排放。
(2)盡(jin)管實驗室研(yan)(yan)究已(yi)經證明厭(yan)氧(yang)(yang)氨氧(yang)(yang)化工(gong)藝適(shi)用(yong)于處理(li)各類廢(fei)水(shui),但在實際工(gong)程應用(yong)中,面對污水(shui)復雜(za)的(de)組成(cheng)成(cheng)分,厭(yan)氧(yang)(yang)氨氧(yang)(yang)化工(gong)藝的(de)成(cheng)功穩定運(yun)行仍面臨巨(ju)大的(de)技(ji)術難題。例如,目前(qian)尚未對抗生素(su)、各種藥物和酚(fen)等(deng)與厭(yan)氧(yang)(yang)氨氧(yang)(yang)化系統的(de)相容性進(jin)行充(chong)分的(de)研(yan)(yan)究,未來應擴(kuo)大各種新興污染物對厭(yan)氧(yang)(yang)氨氧(yang)(yang)化工(gong)藝影響及機理(li)的(de)研(yan)(yan)究。
(3)將厭氧氨氧化工藝由側流(liu)(liu)工藝轉向主流(liu)(liu)工藝應(ying)用(yong)已(yi)經成為全(quan)球厭氧氨氧化技術發(fa)展(zhan)的趨勢,但主流(liu)(liu)工藝應(ying)用(yong)仍面(mian)臨(lin)著啟動(dong)緩(huan)慢(man)、市政污水有機物濃度高、低(di)溫與低(di)氮條(tiao)件難運(yun)行等(deng)問題,除解(jie)決這些問題,未來還(huan)應(ying)加強厭氧氨氧化工藝生物除磷效(xiao)果和機理(li)的研究。
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