高氨氮重污染河流廢水的生物接觸氧化工藝研究
摘(zhai)要:以懸浮填料和火山(shan)巖為(wei)(wei)生(sheng)(sheng)(sheng)物(wu)(wu)(wu)(wu)(wu)載(zai)體,研究了單級好氧(yang)(yang)生(sheng)(sheng)(sheng)物(wu)(wu)(wu)(wu)(wu)接觸(chu)(chu)(chu)氧(yang)(yang)化(hua)(hua)工(gong)(gong)(gong)藝(yi)(yi)和缺氧(yang)(yang)/好氧(yang)(yang)兩(liang)(liang)級生(sheng)(sheng)(sheng)物(wu)(wu)(wu)(wu)(wu)接觸(chu)(chu)(chu)氧(yang)(yang)化(hua)(hua)工(gong)(gong)(gong)藝(yi)(yi)對(dui)模(mo)擬高氨氮重污染河水(shui)的處理效果(guo)。在進(jin)水(shui)COD濃度為(wei)(wei)150-350mg/L,NH-N為(wei)(wei)18-36mg/L,總水(shui)力停留(liu)時間為(wei)(wei)8h條件下,兩(liang)(liang)種工(gong)(gong)(gong)藝(yi)(yi)都能(neng)(neng)有效去(qu)(qu)除(chu)模(mo)擬河流污水(shui)中的有機污染物(wu)(wu)(wu)(wu)(wu),COD的平均去(qu)(qu)除(chu)率(lv)(lv)(lv)分(fen)別達到(dao)82%和92%。前置(zhi)缺氧(yang)(yang)區的缺氧(yang)(yang)/好氧(yang)(yang)兩(liang)(liang)級生(sheng)(sheng)(sheng)物(wu)(wu)(wu)(wu)(wu)接觸(chu)(chu)(chu)氧(yang)(yang)化(hua)(hua)工(gong)(gong)(gong)藝(yi)(yi)較單級生(sheng)(sheng)(sheng)物(wu)(wu)(wu)(wu)(wu)接觸(chu)(chu)(chu)氧(yang)(yang)化(hua)(hua)具有更(geng)強(qiang)的NH-N去(qu)(qu)除(chu)能(neng)(neng)力,二(er)者在整個(ge)運行過程中對(dui)NH-N平均去(qu)(qu)除(chu)率(lv)(lv)(lv)分(fen)別為(wei)(wei)83%和32%。硝化(hua)(hua)潛(qian)力實驗(yan)表明兩(liang)(liang)級生(sheng)(sheng)(sheng)物(wu)(wu)(wu)(wu)(wu)接觸(chu)(chu)(chu)氧(yang)(yang)化(hua)(hua)工(gong)(gong)(gong)藝(yi)(yi)中好氧(yang)(yang)生(sheng)(sheng)(sheng)物(wu)(wu)(wu)(wu)(wu)膜的氨氧(yang)(yang)化(hua)(hua)速率(lv)(lv)(lv)達到(dao)4.50×10g/(g·h),而單級生(sheng)(sheng)(sheng)物(wu)(wu)(wu)(wu)(wu)接觸(chu)(chu)(chu)氧(yang)(yang)化(hua)(hua)工(gong)(gong)(gong)藝(yi)(yi)的好氧(yang)(yang)生(sheng)(sheng)(sheng)物(wu)(wu)(wu)(wu)(wu)膜氨氧(yang)(yang)化(hua)(hua)速率(lv)(lv)(lv)僅為(wei)(wei)1.09×10g/(g·h)。通(tong)過前置(zhi)缺氧(yang)(yang)反應區能(neng)(neng)夠強(qiang)化(hua)(hua)好氧(yang)(yang)生(sheng)(sheng)(sheng)物(wu)(wu)(wu)(wu)(wu)接觸(chu)(chu)(chu)區對(dui)氨氮的去(qu)(qu)除(chu)能(neng)(neng)力,并有效降低接觸(chu)(chu)(chu)氧(yang)(yang)化(hua)(hua)工(gong)(gong)(gong)藝(yi)(yi)能(neng)(neng)耗。
論文關鍵詞(ci):生物(wu)(wu)膜,生物(wu)(wu)接觸氧化,氨氮,河(he)流,硝化能力
中國圖書分(fen)類號:X522
白洋(yang)淀是(shi)我國北(bei)方最(zui)(zui)大(da)的(de)(de)(de)草型湖泊(bo),近年來(lai)(lai)其污(wu)染(ran)越(yue)來(lai)(lai)越(yue)嚴重,對于其污(wu)染(ran)治理也越(yue)來(lai)(lai)越(yue)多的(de)(de)(de)引起國家的(de)(de)(de)重視(shi)。府河作為(wei)白洋(yang)淀最(zui)(zui)大(da)的(de)(de)(de)入淀河流,是(shi)白洋(yang)淀污(wu)染(ran)物的(de)(de)(de)主(zhu)(zhu)要來(lai)(lai)源之一(yi)。府河上(shang)游污(wu)染(ran)物主(zhu)(zhu)要以有機(ji)物為(wei)主(zhu)(zhu),隨(sui)著沿途各種點源面(mian)源污(wu)染(ran)物的(de)(de)(de)輸入導(dao)致下游河水(shui)中氨氮的(de)(de)(de)濃(nong)(nong)度嚴重超(chao)標(biao),許多年份平均濃(nong)(nong)度已超(chao)過20mg/L,氨氮污(wu)染(ran)問(wen)題亟待解(jie)決。
國(guo)內外已有很多研(yan)究利(li)用人工濕地技(ji)術處理氨氮濃度較(jiao)高(gao)的(de)鄉村入河(he)污水(shui),該技(ji)術雖然氨氮去(qu)除效果良好,但占地面積較(jiao)大。另外也(ye)有研(yan)究利(li)用水(shui)生植物對(dui)(dui)污染(ran)河(he)流的(de)進行原位(wei)修復,但對(dui)(dui)于類似府河(he)的(de)重污染(ran)河(he)流,由于水(shui)生植被對(dui)(dui)生長(chang)環境比較(jiao)高(gao)的(de)要求,難以形(xing)成(cheng)穩定的(de)植被。
生物(wu)(wu)接(jie)(jie)觸氧(yang)化(hua)(hua)(hua)(hua)(hua)工(gong)藝(yi)作為一種污染河流原(yuan)位修復方法,近年來備(bei)受(shou)關(guan)注。其(qi)具有(you)(you)環境適(shi)(shi)應(ying)能(neng)(neng)力強,占(zhan)地(di)面積小等(deng)優(you)點,但現有(you)(you)的(de)生物(wu)(wu)接(jie)(jie)觸氧(yang)化(hua)(hua)(hua)(hua)(hua)工(gong)藝(yi)普遍存在對(dui)(dui)氨氮有(you)(you)效去(qu)除(chu)需要的(de)水力停留時(shi)間長(chang),容(rong)易受(shou)水中有(you)(you)機物(wu)(wu)抑制,耐(nai)受(shou)氨氮負荷沖擊能(neng)(neng)力弱以及能(neng)(neng)耗巨大等(deng)缺點。因(yin)此,針對(dui)(dui)類(lei)似(si)府河的(de)高(gao)氨氮重(zhong)污染水體,有(you)(you)必要進一步探(tan)索(suo)與(yu)其(qi)適(shi)(shi)用(yong)的(de)生物(wu)(wu)接(jie)(jie)觸氧(yang)化(hua)(hua)(hua)(hua)(hua)工(gong)藝(yi)。本文以一種新(xin)型的(de)組合球形填料為主要載(zai)體,比較(jiao)了單(dan)級(ji)好(hao)(hao)氧(yang)生物(wu)(wu)接(jie)(jie)觸氧(yang)化(hua)(hua)(hua)(hua)(hua)與(yu)缺氧(yang)/好(hao)(hao)氧(yang)兩(liang)級(ji)生物(wu)(wu)接(jie)(jie)觸氧(yang)化(hua)(hua)(hua)(hua)(hua)工(gong)藝(yi)對(dui)(dui)污染河水中有(you)(you)機物(wu)(wu)及氨氮的(de)去(qu)除(chu)效果,旨在探(tan)索(suo)一套(tao)適(shi)(shi)用(yong)于重(zhong)污染河流的(de)高(gao)效、低耗的(de)原(yuan)位生物(wu)(wu)接(jie)(jie)觸氧(yang)化(hua)(hua)(hua)(hua)(hua)工(gong)藝(yi)。
1.材料與方法
1.1試驗裝置
兩套(tao)生(sheng)物(wu)接(jie)觸(chu)(chu)氧化反(fan)(fan)應(ying)器使(shi)用(yong)(yong)(yong)有機玻璃制成,為保證各段填料基質(zhi)與進水的充分接(jie)觸(chu)(chu),反(fan)(fan)應(ying)器采(cai)用(yong)(yong)(yong)隔(ge)板式構造。反(fan)(fan)應(ying)器的規格為80cm×31cm×35cm,有效容積為72L。反(fan)(fan)應(ying)器A采(cai)用(yong)(yong)(yong)單級(ji)生(sheng)物(wu)膜(mo)接(jie)觸(chu)(chu)氧化工(gong)(gong)藝(yi),反(fan)(fan)應(ying)器B采(cai)用(yong)(yong)(yong)缺(que)氧/好(hao)氧兩級(ji)生(sheng)物(wu)膜(mo)接(jie)觸(chu)(chu)氧化工(gong)(gong)藝(yi)。兩種工(gong)(gong)藝(yi)填料和區間的布置如圖(tu)1和圖(tu)2所示。
圖1.單級生物接觸接觸氧(yang)化反應器(反應器A)填料布置圖
Fig1.LayoutdiagramofcarrierinBiologicalcontactoxidationprocessreactor(ReactorA)
圖2.缺氧(yang)/好氧(yang)兩(liang)級生物接觸氧(yang)化(hua)反應器(qi)(反應器(qi)B)填料(liao)布置圖
Fig2.Layoutdiagramofcarrierinanoxic/aerobictwo-stepcontactoxidationprocessreactor(ReactorB)
接(jie)觸(chu)(chu)氧(yang)(yang)化反應器(qi)A采(cai)用聚(ju)乙烯(xi)懸浮(fu)(fu)球(qiu)(qiu)形(xing)填(tian)(tian)(tian)(tian)(tian)料(liao),該球(qiu)(qiu)形(xing)填(tian)(tian)(tian)(tian)(tian)料(liao)為本(ben)實驗室自行裝(zhuang)配(pei),主要構造為多孔聚(ju)乙烯(xi)球(qiu)(qiu)內(nei)置(zhi)適(shi)量(liang)齒輪(lun)形(xing)顆(ke)粒(li)懸浮(fu)(fu)填(tian)(tian)(tian)(tian)(tian)料(liao),其特(te)點是整個(ge)填(tian)(tian)(tian)(tian)(tian)料(liao)比表面積(ji)得到了增大(da),而且掛膜成(cheng)功(gong)后能夠懸浮(fu)(fu)在水中,填(tian)(tian)(tian)(tian)(tian)料(liao)直(zhi)徑為80mm,非常適(shi)合(he)于河流污(wu)染的(de)原(yuan)位修復。反應器(qi)B中,第一(yi)區(qu)(qu)段布(bu)設(she)缺氧(yang)(yang)接(jie)觸(chu)(chu)氧(yang)(yang)化床,采(cai)用天然礫石和火山巖兩(liang)種填(tian)(tian)(tian)(tian)(tian)料(liao)布(bu)置(zhi)而成(cheng),為防止內(nei)部短流,如圖2所示采(cai)用交錯布(bu)置(zhi),顆(ke)粒(li)比較小的(de)火山巖布(bu)置(zhi)在右下部分,顆(ke)粒(li)較大(da)的(de)天然礫石布(bu)置(zhi)在左(zuo)上部分。第二區(qu)(qu)段好氧(yang)(yang)接(jie)觸(chu)(chu)氧(yang)(yang)化區(qu)(qu)布(bu)置(zhi)與(yu)反應器(qi)A中相同的(de)球(qiu)(qiu)形(xing)懸浮(fu)(fu)填(tian)(tian)(tian)(tian)(tian)料(liao)。兩(liang)座反應器(qi)中,缺氧(yang)(yang)區(qu)(qu)填(tian)(tian)(tian)(tian)(tian)料(liao)的(de)填(tian)(tian)(tian)(tian)(tian)充(chong)率為30%,好氧(yang)(yang)區(qu)(qu)填(tian)(tian)(tian)(tian)(tian)料(liao)的(de)填(tian)(tian)(tian)(tian)(tian)充(chong)率為40%。
曝氣(qi)(qi)裝置的(de)布置如圖1和圖2所示,在反應器的(de)好氧(yang)區(qu)(qu)兩側底部布置條形(xing)曝氣(qi)(qi)頭(tou),試(shi)驗(yan)過(guo)程中采用氣(qi)(qi)體轉子流(liu)量(liang)計控制(zhi)曝氣(qi)(qi)量(liang),缺氧(yang)區(qu)(qu)不(bu)設(she)置曝氣(qi)(qi)頭(tou)。
1.2啟動與運(yun)行
兩套(tao)試驗裝置接種(zhong)來之北京高碑(bei)店污(wu)水處理廠(chang)A/O工藝污(wu)泥(ni)回流池(chi)污(wu)泥(ni)。接種(zhong)污(wu)泥(ni)后,前三(san)天(tian)采用(yong)序批式運行(xing)(xing),正常(chang)進(jin)行(xing)(xing)曝氣,每天(tian)更換一(yi)次反(fan)應器中的水。之后后采用(yong)連續流方式進(jin)水運行(xing)(xing),經過(guo)一(yi)段(duan)時間運行(xing)(xing),兩套(tao)裝置中生(sheng)物(wu)膜(mo)厚度逐漸(jian)增(zeng)加,最(zui)后達到穩(wen)定狀態,鏡(jing)檢生(sheng)物(wu)膜(mo)觀察發現(xian)大量(liang)的原后生(sheng)動物(wu),且各采樣點(dian)水質COD,NH-N,TN等主要指(zhi)標基本(ben)穩(wen)定,說明系統(tong)掛(gua)膜(mo)成(cheng)功,啟(qi)動基本(ben)完成(cheng)。此后改(gai)變進(jin)水主要污(wu)染物(wu)濃(nong)度,開(kai)始正常(chang)運行(xing)(xing)。
反(fan)應(ying)器啟動成功后,采用連(lian)續流運行方式,每個反(fan)應(ying)器的總(zong)水(shui)力停(ting)(ting)留(liu)時間(jian)為8h,兩(liang)級式生物接觸(chu)氧化(hua)反(fan)應(ying)器兩(liang)個區段的水(shui)力停(ting)(ting)留(liu)時間(jian)分(fen)別為4h。根據(ju)本課題組對府河水(shui)質(zhi)(zhi)的長期監測數(shu)據(ju)以(yi)及(ji)相(xiang)關部(bu)門提供的府河多年背景數(shu)據(ju),采用人工配水(shui)模擬府河水(shui)質(zhi)(zhi),其主要(yao)成分(fen)如表1所示,并添加一定量(liang)的微量(liang)元素。
表1.人工模擬廢(fei)水(shui)基本組分(fen)
Table1.Maincontentsofartificialwastewater
在運(yun)行(xing)過(guo)程中分(fen)(fen)三(san)階(jie)段(duan)提升人工(gong)模擬廢水(shui)(shui)COD,氨氮的(de)負荷,考察反應(ying)(ying)器對污染(ran)物(wu)的(de)去(qu)除情況。三(san)個(ge)階(jie)段(duan)進水(shui)(shui)COD理論值(zhi)分(fen)(fen)別(bie)(bie)為(wei)(wei)(wei)150、250、350mg/L,NH-N理論值(zhi)分(fen)(fen)別(bie)(bie)為(wei)(wei)(wei)18、28、36mg/L,TN理論值(zhi)分(fen)(fen)別(bie)(bie)為(wei)(wei)(wei):24、34、42mg/L,其它(ta)指標在運(yun)行(xing)的(de)各(ge)個(ge)階(jie)段(duan)都保持不(bu)變,進水(shui)(shui)pH值(zhi)為(wei)(wei)(wei)7.2-8.0。單級(ji)好(hao)氧(yang)接觸氧(yang)化工(gong)藝(yi)的(de)好(hao)氧(yang)區(qu)曝氣(qi)(qi)(qi)量約為(wei)(wei)(wei)4-6L/min,兩級(ji)生(sheng)物(wu)接觸氧(yang)化工(gong)藝(yi)的(de)好(hao)氧(yang)段(duan)曝氣(qi)(qi)(qi)量為(wei)(wei)(wei)1.5-3L/min,缺氧(yang)段(duan)不(bu)曝氣(qi)(qi)(qi),整個(ge)反應(ying)(ying)器所需要的(de)曝氣(qi)(qi)(qi)量相(xiang)對于前者大大減小。兩個(ge)工(gong)藝(yi)好(hao)氧(yang)區(qu)DO質量濃度(du)控制(zhi)在5-8mg/L,缺氧(yang)區(qu)DO質量濃度(du)低于0.8mg/L。
溫度控制在室溫18-27℃范圍(wei)內。
1.3生物膜的硝化潛力(li)分析
從(cong)生物接觸反應器不(bu)同功能(neng)區段分別取一定量掛膜填料。用(yong)蒸(zheng)餾(liu)水(shui)輕輕洗滌三遍,加(jia)入(ru)到500ml的錐形瓶中,加(jia)入(ru)200mL反應液,其中NH-N濃度(du)為20mg/L。反應液配方為:NHCl76.4mg/L,NaHCO1.5g/L(無機碳源),NaCl30mg/L,KHPO50mg/L,KCl14.0mg/L,MgSO·7HO20.0mg/L,CaCl·2HO18.5mg/L,微(wei)量元素0.2ml/L,pH7.2。
采(cai)用微小(xiao)曝氣頭進行充(chong)氧,控(kong)制DO質(zhi)量濃度(du)在5mg/L以上,與生物接觸(chu)氧化(hua)工藝中DO值吻(wen)合。試驗(yan)在20℃恒溫箱中進行,定時取(qu)樣測定NH-N,NO-N及NO-N及TP濃度(du)變(bian)化(hua)。試驗(yan)完成后采(cai)用堿式浸泡法洗脫(tuo)填料表面附著生物膜(mo),用蒸餾水(shui)洗滌后過(guo)濾烘干稱重,測定每(mei)個錐形瓶(ping)中反應的生物膜(mo)總質(zhi)量。
平均(jun)氨(an)氧化(hua)速率計(ji)算公式(shi)為:
式中(zhong)r表(biao)示(shi)(shi)生物膜硝化速率,g/(g·h),C表(biao)示(shi)(shi)h時間(jian)點(dian)水(shui)體中(zhong)NH-N濃(nong)度(du)(du),C表(biao)示(shi)(shi)反應h時間(jian)點(dian)水(shui)體中(zhong)的NH-N濃(nong)度(du)(du),X表(biao)示(shi)(shi)反應裝置內生物膜濃(nong)度(du)(du),mg/L。
1.4采樣與分析
反(fan)應器運行(xing)過程中(zhong)從兩座反(fan)應器各區段(duan)后隔板(ban)間隙出水(shui)中(zhong)分(fen)(fen)別取水(shui)樣分(fen)(fen)析(xi)COD,NH-N、NO-N、NO-N、TN等指(zhi)標,反(fan)應器出水(shui)以沉降區水(shui)質為(wei)準(zhun)。COD采(cai)用重鉻酸鉀消(xiao)解(jie)法(fa)測(ce)(ce)定(ding),其(qi)它常規指(zhi)標都(dou)是采(cai)用美(mei)國SEALAA3型(xing)流動分(fen)(fen)析(xi)儀(yi)測(ce)(ce)定(ding),TN的測(ce)(ce)定(ding)采(cai)用國家標準(zhun)中(zhong)方法(fa)消(xiao)解(jie)。溶解(jie)氧(yang)濃度(du)(du)和溫度(du)(du)都(dou)采(cai)用HACHSens-ion6型(xing)便(bian)攜式溶氧(yang)儀(yi)測(ce)(ce)定(ding);pH采(cai)用德國SatariousPB-10pH計測(ce)(ce)定(ding)。
2.結果(guo)與討(tao)論
2.1兩種(zhong)生(sheng)物接觸氧化(hua)工(gong)藝(yi)的對CODcr的去除情況分析
兩(liang)套生(sheng)物接觸氧(yang)化工藝反應(ying)器(qi)A和B從2010年(nian)2月(yue)21日開始啟(qi)動運(yun)行(xing)(xing),連續取樣監(jian)測。經過21d系(xi)統(tong)成功啟(qi)動,之后開始變(bian)化水質分階段運(yun)行(xing)(xing),穩定(ding)運(yun)行(xing)(xing)反應(ying)器(qi)中的好氧(yang)生(sheng)物膜的VSS/SS比(bi)達到0.8以上(shang)。整個運(yun)行(xing)(xing)過程中生(sheng)物接觸氧(yang)化反應(ying)器(qi)對(dui)COD的去除(chu)情況(kuang)見表2。
表2.兩(liang)種生物接觸氧(yang)化工藝各階段對COD的去除(chu)情況
Table2.TheremovalofCODbythetwobiologicalcontactoxidationreactors
反(fan)(fan)(fan)(fan)應(ying)(ying)器A和反(fan)(fan)(fan)(fan)應(ying)(ying)器B對(dui)(dui)COD的去(qu)除率在(zai)啟動(dong)完成后都(dou)趨于穩定(ding),反(fan)(fan)(fan)(fan)應(ying)(ying)器A在(zai)進(jin)水COD值為(wei)150、250、350mg/L的三個階段中(zhong)對(dui)(dui)COD的平均去(qu)除率都(dou)在(zai)80%左右,而B反(fan)(fan)(fan)(fan)應(ying)(ying)器在(zai)三個階段中(zhong)對(dui)(dui)COD的平均去(qu)除率都(dou)維(wei)持(chi)在(zai)90%以上。A反(fan)(fan)(fan)(fan)應(ying)(ying)器出水COD濃度(du)在(zai)20-50mg/L之間(jian),B反(fan)(fan)(fan)(fan)應(ying)(ying)器出水COD濃度(du)為(wei)10-30mg/L。兩種工(gong)藝(yi)都(dou)能(neng)夠有效去(qu)除進(jin)水中(zhong)的有機(ji)污染物。
反應器(qi)A曝氣量較大,在試驗過(guo)程(cheng)中(zhong)監測(ce)發現(xian),整(zheng)個反應器(qi)中(zhong)基質混合均勻,好氧區(qu)中(zhong)COD濃度基本相(xiang)同。而反應器(qi)B運行過(guo)程(cheng)中(zhong),缺氧區(qu)不曝氣,進水與火山巖和(he)礫石基質充分接觸后進入好氧區(qu),整(zheng)個反應器(qi)對(dui)COD的去(qu)除如(ru)圖3所示(shi)。
(A啟(qi)動期B運(yun)行第(di)一階(jie)段(duan)C運(yun)行第(di)二階(jie)段(duan)D運(yun)行第(di)三(san)階(jie)段(duan))
圖(tu)3缺(que)氧/好氧兩級(ji)生物接觸氧化系工藝(yi)對COD的去除情(qing)況
(AStartupperiodBPhaseoneCPhasetwoDPhasethree)
Fig3TheremovalofCODbyAnoxic/Aerobictwostepbiologicalcontactoxidationprocess
B反(fan)應(ying)器的(de)(de)(de)第(di)一級(ji)缺(que)(que)氧反(fan)應(ying)區(qu)出(chu)水中(zhong),大部(bu)(bu)分(fen)的(de)(de)(de)COD已被去除。三(san)個運(yun)行階段中(zhong),缺(que)(que)氧反(fan)應(ying)區(qu)對COD的(de)(de)(de)去除率分(fen)別(bie)為81%、83%和(he)78%。第(di)二級(ji)好氧區(qu)在(zai)(zai)三(san)個運(yun)行階段中(zhong)對COD的(de)(de)(de)平(ping)均(jun)去除率分(fen)別(bie)為12%、8%和(he)13%。這表明在(zai)(zai)整個運(yun)行過程中(zhong),B反(fan)應(ying)器的(de)(de)(de)進水中(zhong)大部(bu)(bu)分(fen)的(de)(de)(de)有機(ji)污染物都在(zai)(zai)第(di)一級(ji)缺(que)(que)氧區(qu)被降解去除。
2.2兩(liang)種(zhong)生(sheng)物接觸氧化工藝(yi)對NH-N的去除情況(kuang)分(fen)析(xi)
經過三個星期的啟動,兩種工藝系統(tong)對NH-N的降解(jie)能力逐漸穩(wen)定(ding)。此(ci)后(hou)考察(cha)了不(bu)同有機物負荷以及NH-N負荷對系統(tong)去除NH-N效(xiao)率(lv)的影響。
反應器(qi)A中(zhong)(zhong)單級生物(wu)接(jie)觸氧化工藝經(jing)過啟(qi)動期前一個星(xing)期的(de)(de)適應,對NH-N的(de)(de)去除(chu)率開始逐(zhu)漸上升。如圖4所示,在(zai)(zai)經(jing)過三個星(xing)期的(de)(de)啟(qi)動之后(hou),NH-N的(de)(de)去除(chu)率開始逐(zhu)漸穩定在(zai)(zai)40%左右。在(zai)(zai)運行(xing)過程(cheng)的(de)(de)三個階(jie)段中(zhong)(zhong),隨著進水NH-N和(he)COD負荷的(de)(de)變化,單級接(jie)觸氧化工藝對NH-N的(de)(de)平均去除(chu)率分別為47.9%、22.4%、29.1%。其中(zhong)(zhong),反應器(qi)A在(zai)(zai)第(di)二階(jie)段和(he)第(di)三階(jie)段對NH-N的(de)(de)降解率明顯(xian)低(di)于第(di)一階(jie)段。
圖4.單級好氧接觸氧化工藝對NH-N的(de)去除(chu)情況
Fig4TheremovalofNH-Nbyonestepaerobiccontactoxidationprocess
反應器B中缺氧(yang)/好(hao)氧(yang)兩級接觸(chu)氧(yang)化工藝對NH-N的去(qu)(qu)除(chu)率(lv)從啟(qi)動期(qi)開始后一直處于上升趨勢,到啟(qi)動期(qi)完成后,去(qu)(qu)除(chu)率(lv)一度超過90%。
B反應器(qi)(qi)第一級缺氧(yang)(yang)區去除NH-N的能力較(jiao)弱,進(jin)水(shui)中NH-N主要在(zai)第二級的好(hao)氧(yang)(yang)區中被去除,水(shui)力停留時間(jian)為(wei)(wei)4h。在(zai)三個(ge)(ge)階(jie)(jie)段運(yun)行過程中,反應器(qi)(qi)B對(dui)氨氮的平(ping)(ping)均去除率(lv)(lv)都(dou)穩定在(zai)80%以上,具體情(qing)況(kuang)如圖5所示。在(zai)三個(ge)(ge)階(jie)(jie)段的運(yun)行中,系統出(chu)水(shui)NH-N平(ping)(ping)均濃度穩定在(zai)3.6-5.2mg/L的范圍(wei)內,并且(qie)波(bo)動較(jiao)小,與A反應器(qi)(qi)相比,B反應器(qi)(qi)在(zai)進(jin)水(shui)負荷發生變(bian)化的三個(ge)(ge)運(yun)行階(jie)(jie)段中,其(qi)對(dui)NH-N的去除一直保持(chi)在(zai)較(jiao)高的水(shui)平(ping)(ping)。B反應器(qi)(qi)缺氧(yang)(yang)/好(hao)氧(yang)(yang)兩級接觸氧(yang)(yang)化工(gong)(gong)藝在(zai)整個(ge)(ge)運(yun)行過程中(不包含(han)啟動期)對(dui)NH-N的平(ping)(ping)均去除率(lv)(lv)為(wei)(wei)83%,比單級好(hao)氧(yang)(yang)接觸氧(yang)(yang)化工(gong)(gong)藝高出(chu)51%。
圖(tu)5.缺氧(yang)/好氧(yang)兩級接觸氧(yang)化工藝對NH-N的(de)去除(chu)情況(kuang)
Fig5.TheremovalofNH-NbyAnoxic/Aerobictwostepcontactoxidationprocess
反(fan)應(ying)器A在(zai)運(yun)行過程(cheng)中(zhong)(zhong)(zhong)(zhong),發(fa)生(sheng)(sheng)(sheng)(sheng)較(jiao)大變化(hua)的(de)(de)(de)(de)(de)參數(shu)主要(yao)有溫(wen)度(du),進(jin)(jin)水COD和NH-N負荷等(deng)要(yao)素(su)。其中(zhong)(zhong)(zhong)(zhong)溫(wen)度(du)的(de)(de)(de)(de)(de)變化(hua)比較(jiao)緩慢,而(er)且在(zai)整(zheng)個運(yun)行過程(cheng)中(zhong)(zhong)(zhong)(zhong)溫(wen)度(du)是(shi)逐漸上(shang)(shang)升(sheng)的(de)(de)(de)(de)(de),不會對(dui)(dui)(dui)NH-N的(de)(de)(de)(de)(de)去除產生(sheng)(sheng)(sheng)(sheng)抑(yi)制作用(yong),根據反(fan)應(ying)器B在(zai)運(yun)行過程(cheng)中(zhong)(zhong)(zhong)(zhong)始終保持對(dui)(dui)(dui)NH-N的(de)(de)(de)(de)(de)高(gao)降(jiang)(jiang)(jiang)解率(lv)可以證明這點,另外(wai)也說明在(zai)本研究(jiu)(jiu)范圍內的(de)(de)(de)(de)(de)NH-N濃度(du)負荷的(de)(de)(de)(de)(de)增加(jia)(jia)沒有對(dui)(dui)(dui)NH-N的(de)(de)(de)(de)(de)去除產生(sheng)(sheng)(sheng)(sheng)明顯(xian)抑(yi)制作用(yong),Kim等(deng)人的(de)(de)(de)(de)(de)研究(jiu)(jiu)也證實(shi)了這點。因此,反(fan)應(ying)器A在(zai)運(yun)行過程(cheng)中(zhong)(zhong)(zhong)(zhong)發(fa)生(sheng)(sheng)(sheng)(sheng)的(de)(de)(de)(de)(de)對(dui)(dui)(dui)NH-N降(jiang)(jiang)(jiang)解率(lv)下(xia)降(jiang)(jiang)(jiang)的(de)(de)(de)(de)(de)現(xian)象只(zhi)可能是(shi)COD負荷的(de)(de)(de)(de)(de)增加(jia)(jia)引起的(de)(de)(de)(de)(de)。Jokela等(deng)利用(yong)單級生(sheng)(sheng)(sheng)(sheng)物接觸氧化(hua)工(gong)藝(yi)(SBCP)處理(li)垃(la)圾填(tian)埋場滲濾液的(de)(de)(de)(de)(de)實(shi)驗研究(jiu)(jiu)中(zhong)(zhong)(zhong)(zhong)也發(fa)現(xian)了類似現(xian)象。進(jin)(jin)水正常情況(kuang)下(xia)工(gong)藝(yi)對(dui)(dui)(dui)NH-N的(de)(de)(de)(de)(de)去除率(lv)高(gao)達(da)90%以上(shang)(shang),而(er)當進(jin)(jin)水中(zhong)(zhong)(zhong)(zhong)BOD濃度(du)發(fa)生(sheng)(sheng)(sheng)(sheng)異(yi)常突然增高(gao)時,NH-N的(de)(de)(de)(de)(de)去除率(lv)急劇下(xia)降(jiang)(jiang)(jiang),BOD上(shang)(shang)升(sheng)導致生(sheng)(sheng)(sheng)(sheng)物膜(mo)系統中(zhong)(zhong)(zhong)(zhong)異(yi)養細菌對(dui)(dui)(dui)自養的(de)(de)(de)(de)(de)硝化(hua)細菌產生(sheng)(sheng)(sheng)(sheng)抑(yi)制作用(yong)。
COD及BOD濃(nong)度(du)等(deng)有(you)機(ji)(ji)污染(ran)物(wu)(wu)(wu)(wu)負荷對生(sheng)(sheng)(sheng)(sheng)(sheng)物(wu)(wu)(wu)(wu)膜(mo)(mo)硝(xiao)化(hua)能力(li)的抑制作(zuo)用是一(yi)個長期的過程(cheng)。根據(ju)Okabe等(deng)利用分子生(sheng)(sheng)(sheng)(sheng)(sheng)物(wu)(wu)(wu)(wu)學(xue)手(shou)段(duan)對生(sheng)(sheng)(sheng)(sheng)(sheng)物(wu)(wu)(wu)(wu)膜(mo)(mo)結構的研(yan)究,當好氧生(sheng)(sheng)(sheng)(sheng)(sheng)物(wu)(wu)(wu)(wu)膜(mo)(mo)工藝進水中(zhong)(zhong)有(you)機(ji)(ji)物(wu)(wu)(wu)(wu)濃(nong)度(du)的增加(jia)時,有(you)機(ji)(ji)物(wu)(wu)(wu)(wu)異養降(jiang)解細(xi)菌(jun)過度(du)繁殖,填料上(shang)附著的生(sheng)(sheng)(sheng)(sheng)(sheng)物(wu)(wu)(wu)(wu)膜(mo)(mo)厚度(du)不斷(duan)增加(jia),硝(xiao)化(hua)細(xi)菌(jun)被包裹在生(sheng)(sheng)(sheng)(sheng)(sheng)物(wu)(wu)(wu)(wu)膜(mo)(mo)內部(bu)。在硝(xiao)化(hua)潛力(li)實驗中(zhong)(zhong)測得(de)的單位質(zhi)(zhi)量填料上(shang)生(sheng)(sheng)(sheng)(sheng)(sheng)物(wu)(wu)(wu)(wu)膜(mo)(mo)的量也(ye)(ye)表明(ming),A反(fan)應(ying)器中(zhong)(zhong)填料上(shang)的生(sheng)(sheng)(sheng)(sheng)(sheng)物(wu)(wu)(wu)(wu)膜(mo)(mo)量明(ming)顯高于(yu)B反(fan)應(ying)器中(zhong)(zhong)的填料,鏡檢也(ye)(ye)反(fan)映了A反(fan)應(ying)器中(zhong)(zhong)填料表明(ming)生(sheng)(sheng)(sheng)(sheng)(sheng)物(wu)(wu)(wu)(wu)膜(mo)(mo)更厚。生(sheng)(sheng)(sheng)(sheng)(sheng)物(wu)(wu)(wu)(wu)膜(mo)(mo)厚度(du)增加(jia),DO和NH-N、碳源等(deng)營養物(wu)(wu)(wu)(wu)質(zhi)(zhi)的傳質(zhi)(zhi)阻力(li)也(ye)(ye)大大增加(jia),硝(xiao)化(hua)細(xi)菌(jun)難以有(you)效利用。而處(chu)于(yu)生(sheng)(sheng)(sheng)(sheng)(sheng)物(wu)(wu)(wu)(wu)膜(mo)(mo)外圍(wei)的異養有(you)機(ji)(ji)物(wu)(wu)(wu)(wu)降(jiang)解細(xi)菌(jun)對DO和營養物(wu)(wu)(wu)(wu)的競爭都處(chu)于(yu)優勢地位,將會嚴(yan)重(zhong)抑制生(sheng)(sheng)(sheng)(sheng)(sheng)物(wu)(wu)(wu)(wu)膜(mo)(mo)內部(bu)氨氧化(hua)細(xi)菌(jun)(AOB)和亞(ya)硝(xiao)酸鹽氧化(hua)細(xi)菌(jun)(NOB)的活力(li)。
反應(ying)器B的(de)(de)(de)(de)缺(que)氧/好氧兩級接觸氧化(hua)工(gong)藝中,缺(que)氧段(duan)去除了(le)78%以(yi)上的(de)(de)(de)(de)COD及25%以(yi)下的(de)(de)(de)(de)NH-N,好氧段(duan)進水(shui)有(you)(you)機物(wu)(wu)濃度大大降低,但NH-N濃度仍然(ran)較高。Terada及王文斌等人的(de)(de)(de)(de)研究證(zheng)明(ming),這種營養(yang)環境能(neng)夠抑制(zhi)生(sheng)物(wu)(wu)膜(mo)(mo)(mo)(mo)中異養(yang)微生(sheng)物(wu)(wu)的(de)(de)(de)(de)繁殖,而有(you)(you)利于(yu)自(zi)養(yang)的(de)(de)(de)(de)AOB和NOB細菌(jun)的(de)(de)(de)(de)生(sheng)長。異養(yang)微生(sheng)物(wu)(wu)生(sheng)長速度被抑制(zhi),接觸氧化(hua)工(gong)藝的(de)(de)(de)(de)生(sheng)物(wu)(wu)膜(mo)(mo)(mo)(mo)厚度得(de)到有(you)(you)效控制(zhi),生(sheng)物(wu)(wu)膜(mo)(mo)(mo)(mo)內(nei)的(de)(de)(de)(de)AOB和NOB細菌(jun)能(neng)夠更(geng)好地(di)獲取水(shui)體中的(de)(de)(de)(de)NH-N、DO以(yi)及其(qi)它營養(yang)物(wu)(wu)質,使其(qi)數(shu)量(liang)增加,生(sheng)物(wu)(wu)膜(mo)(mo)(mo)(mo)總體的(de)(de)(de)(de)硝化(hua)活性也(ye)得(de)到增強。
反應器B在三(san)個階(jie)段(duan)的運行過程中,進(jin)水COD濃(nong)(nong)度不斷增大,但由于缺氧(yang)(yang)區(qu)對COD的高(gao)效去除(chu)(chu)(chu),缺氧(yang)(yang)區(qu)的出(chu)水中有(you)機物(wu)濃(nong)(nong)度始(shi)終維持(chi)在較(jiao)低的濃(nong)(nong)度,這樣(yang)就不會對好氧(yang)(yang)區(qu)生(sheng)物(wu)膜中的硝化細菌的生(sheng)長產生(sheng)抑制作(zuo)用,好氧(yang)(yang)區(qu)生(sheng)物(wu)膜對NH-N的去除(chu)(chu)(chu)率始(shi)終維持(chi)在較(jiao)高(gao)的水平。增加前置缺氧(yang)(yang)區(qu)的接觸氧(yang)(yang)化工藝能夠更快(kuai)速有(you)效地去除(chu)(chu)(chu)模擬河流(liu)廢水中較(jiao)高(gao)濃(nong)(nong)度的NH-N。
2.3兩種接觸氧化工藝對TN的(de)去除情況(kuang)分析
生物接觸氧化氧化工藝在整個運(yun)行過(guo)程中(zhong)對(dui)TN都保(bao)持一定的去(qu)除(chu)率,期間進出(chu)水與去(qu)除(chu)率變化如表4中(zhong)所示。
表3兩套接觸接觸氧(yang)化(hua)工藝進(jin)出(chu)水(shui)TN變化(hua)情(qing)況
Table3TheremovalofTNbybothbiologicalcontactoxidationprocess
反(fan)應(ying)器A對(dui)TN的(de)去除(chu)率始終維持(chi)在30%左右(you),反(fan)應(ying)器B對(dui)TN的(de)平均去除(chu)率為50%左右(you)。單級生(sheng)物(wu)(wu)膜(mo)接觸氧化工藝對(dui)NH-N去除(chu)能力較弱,大量(liang)的(de)TN仍然以NH-N形式存在。胡(hu)紹偉等利(li)用膜(mo)曝(pu)氣生(sheng)物(wu)(wu)膜(mo)反(fan)應(ying)器處理人工合成廢水的(de)過(guo)(guo)程(cheng)中,當進水有機負荷過(guo)(guo)高,導致載體上微生(sheng)物(wu)(wu)增長過(guo)(guo)量(liang)時(shi),也導致系統對(dui)TN的(de)去除(chu)率明顯下(xia)降,這(zhe)與本(ben)研究得出的(de)結(jie)果(guo)基本(ben)一致。
在(zai)兩級接觸氧化(hua)(hua)生工(gong)藝(yi)中(zhong),大部(bu)分NH-N都能(neng)被降(jiang)解為(wei)硝酸鹽,但由(you)于缺氧區對(dui)有(you)機物的(de)(de)大量消耗,不(bu)能(neng)為(wei)后續的(de)(de)反硝化(hua)(hua)細菌提供足夠的(de)(de)碳源(yuan),反硝化(hua)(hua)作(zuo)用難(nan)以進行,出水(shui)中(zhong)NO-N濃(nong)度仍然較高,其對(dui)TN的(de)(de)去除率(lv)(lv)也始終維(wei)持在(zai)40%-55%的(de)(de)偏低(di)水(shui)平上(shang),而(er)隨著COD負荷的(de)(de)提升(sheng)(sheng),TN的(de)(de)去除率(lv)(lv)在(zai)第二和第三階段較之(zhi)前都有(you)部(bu)分上(shang)升(sheng)(sheng)。Li等人研究生物接觸氧化(hua)(hua)工(gong)藝(yi)處理滇池流域河流廢水(shui)時也發現當進水(shui)中(zhong)COD濃(nong)度短(duan)時間內出現大幅(fu)度下降(jiang)時,反硝化(hua)(hua)作(zuo)用無法有(you)效進行,TN去除率(lv)(lv)會相應大幅(fu)度降(jiang)低(di)。
2.4硝(xiao)化潛力分析
兩種工藝在連續運行(xing)過(guo)程中對NH-N去(qu)除能(neng)力差異(yi)明顯,通過(guo)批次試驗(yan)進一步探討生(sheng)(sheng)物(wu)(wu)膜的(de)硝化(hua)能(neng)力,三個區段的(de)生(sheng)(sheng)物(wu)(wu)膜氨氧化(hua)能(neng)力的(de)如圖6所示,A反應(ying)(ying)器好(hao)氧區生(sheng)(sheng)物(wu)(wu)膜為A,B反應(ying)(ying)器缺氧區和好(hao)氧區生(sheng)(sheng)物(wu)(wu)膜分別為B1、B2。
圖6.三種生物膜氧化NH-N速率比較
Fig6.NH-Nremovalratebythreekindsofbiofilm
從上圖中(zhong)(zhong)可(ke)以(yi)看(kan)出B反(fan)應(ying)器的(de)(de)(de)(de)缺氧(yang)(yang)(yang)(yang)區生(sheng)物(wu)(wu)(wu)(wu)膜氨(an)(an)氧(yang)(yang)(yang)(yang)化(hua)(hua)(hua)(hua)(hua)(hua)(hua)(hua)能(neng)(neng)(neng)力相比好(hao)(hao)氧(yang)(yang)(yang)(yang)區生(sheng)物(wu)(wu)(wu)(wu)膜幾乎(hu)可(ke)以(yi)忽略不(bu)計(ji),A反(fan)應(ying)器中(zhong)(zhong)和B反(fan)應(ying)器好(hao)(hao)氧(yang)(yang)(yang)(yang)生(sheng)物(wu)(wu)(wu)(wu)膜都(dou)具有氧(yang)(yang)(yang)(yang)化(hua)(hua)(hua)(hua)(hua)(hua)(hua)(hua)氨(an)(an)氮的(de)(de)(de)(de)能(neng)(neng)(neng)力,如圖中(zhong)(zhong)所示,兩級(ji)接(jie)(jie)(jie)觸(chu)氧(yang)(yang)(yang)(yang)化(hua)(hua)(hua)(hua)(hua)(hua)(hua)(hua)的(de)(de)(de)(de)好(hao)(hao)氧(yang)(yang)(yang)(yang)生(sheng)物(wu)(wu)(wu)(wu)膜的(de)(de)(de)(de)氨(an)(an)氧(yang)(yang)(yang)(yang)化(hua)(hua)(hua)(hua)(hua)(hua)(hua)(hua)能(neng)(neng)(neng)力要大(da)(da)于單級(ji)接(jie)(jie)(jie)觸(chu)氧(yang)(yang)(yang)(yang)化(hua)(hua)(hua)(hua)(hua)(hua)(hua)(hua)工藝(yi)(yi)中(zhong)(zhong)的(de)(de)(de)(de)好(hao)(hao)氧(yang)(yang)(yang)(yang)生(sheng)物(wu)(wu)(wu)(wu)膜。單級(ji)好(hao)(hao)氧(yang)(yang)(yang)(yang)接(jie)(jie)(jie)觸(chu)氧(yang)(yang)(yang)(yang)化(hua)(hua)(hua)(hua)(hua)(hua)(hua)(hua)工藝(yi)(yi)中(zhong)(zhong)的(de)(de)(de)(de)生(sheng)物(wu)(wu)(wu)(wu)膜能(neng)(neng)(neng)夠在(zai)9h內(nei)將20mg/L濃度的(de)(de)(de)(de)NH-N去除到檢測(ce)限以(yi)下(xia),平(ping)均氨(an)(an)氧(yang)(yang)(yang)(yang)化(hua)(hua)(hua)(hua)(hua)(hua)(hua)(hua)速(su)率(lv)為1.09×10g/(g·h)。而(er)兩級(ji)接(jie)(jie)(jie)觸(chu)氧(yang)(yang)(yang)(yang)化(hua)(hua)(hua)(hua)(hua)(hua)(hua)(hua)工藝(yi)(yi)中(zhong)(zhong)的(de)(de)(de)(de)好(hao)(hao)氧(yang)(yang)(yang)(yang)生(sheng)物(wu)(wu)(wu)(wu)膜在(zai)3h就(jiu)完成了對(dui)氨(an)(an)氮的(de)(de)(de)(de)氧(yang)(yang)(yang)(yang)化(hua)(hua)(hua)(hua)(hua)(hua)(hua)(hua)過程,平(ping)均氨(an)(an)氧(yang)(yang)(yang)(yang)化(hua)(hua)(hua)(hua)(hua)(hua)(hua)(hua)速(su)率(lv)為4.50×10g/(g·h),是單級(ji)好(hao)(hao)氧(yang)(yang)(yang)(yang)生(sheng)物(wu)(wu)(wu)(wu)膜氨(an)(an)氧(yang)(yang)(yang)(yang)化(hua)(hua)(hua)(hua)(hua)(hua)(hua)(hua)速(su)率(lv)的(de)(de)(de)(de)4倍以(yi)上,李先(xian)寧等人在(zai)研究水耕植物(wu)(wu)(wu)(wu)過濾法凈(jing)(jing)水系(xi)統(tong)底泥的(de)(de)(de)(de)硝(xiao)化(hua)(hua)(hua)(hua)(hua)(hua)(hua)(hua)潛力的(de)(de)(de)(de)試驗(yan)中(zhong)(zhong),測(ce)定(ding)了該凈(jing)(jing)化(hua)(hua)(hua)(hua)(hua)(hua)(hua)(hua)系(xi)統(tong)底泥的(de)(de)(de)(de)最大(da)(da)氨(an)(an)氧(yang)(yang)(yang)(yang)化(hua)(hua)(hua)(hua)(hua)(hua)(hua)(hua)速(su)率(lv)為僅4.76×10g/(g·h),遠遠小于本(ben)實驗(yan)生(sheng)物(wu)(wu)(wu)(wu)膜系(xi)統(tong)的(de)(de)(de)(de)氨(an)(an)氧(yang)(yang)(yang)(yang)化(hua)(hua)(hua)(hua)(hua)(hua)(hua)(hua)速(su)率(lv),這表明生(sheng)物(wu)(wu)(wu)(wu)膜接(jie)(jie)(jie)觸(chu)氧(yang)(yang)(yang)(yang)化(hua)(hua)(hua)(hua)(hua)(hua)(hua)(hua)工藝(yi)(yi)能(neng)(neng)(neng)夠極大(da)(da)地提高(gao)凈(jing)(jing)化(hua)(hua)(hua)(hua)(hua)(hua)(hua)(hua)系(xi)統(tong)的(de)(de)(de)(de)硝(xiao)化(hua)(hua)(hua)(hua)(hua)(hua)(hua)(hua)能(neng)(neng)(neng)力,而(er)其(qi)中(zhong)(zhong)缺氧(yang)(yang)(yang)(yang)/好(hao)(hao)氧(yang)(yang)(yang)(yang)兩級(ji)生(sheng)物(wu)(wu)(wu)(wu)接(jie)(jie)(jie)觸(chu)氧(yang)(yang)(yang)(yang)化(hua)(hua)(hua)(hua)(hua)(hua)(hua)(hua)工藝(yi)(yi)具有更大(da)(da)的(de)(de)(de)(de)優勢。
與類似(si)生物接觸(chu)氧化(hua)工藝(yi)(yi)(yi)的(de)(de)(de)(de)研(yan)究相比(bi),本試驗研(yan)究的(de)(de)(de)(de)生物接觸(chu)氧化(hua)工藝(yi)(yi)(yi)在河流原位治理中(zhong)的(de)(de)(de)(de)應(ying)(ying)用(yong)(yong)具有(you)更(geng)大的(de)(de)(de)(de)實際意義(yi)。周(zhou)婷等人(ren)利(li)用(yong)(yong)溝渠式(shi)生物接觸(chu)氧化(hua)工藝(yi)(yi)(yi)處理含30-40mg/LNH-N,120-180mg/LCOD的(de)(de)(de)(de)村莊面源(yuan)模(mo)擬(ni)廢水(shui)(shui)(shui)的(de)(de)(de)(de)試驗研(yan)究中(zhong),取得了(le)80%以上的(de)(de)(de)(de)NH-N去除(chu)率,但廢水(shui)(shui)(shui)在溝渠式(shi)接觸(chu)氧化(hua)系統(tong)中(zhong)的(de)(de)(de)(de)停留時(shi)間(jian)長達(da)4-5天。Li等人(ren)利(li)用(yong)(yong)分(fen)段進(jin)水(shui)(shui)(shui)的(de)(de)(de)(de)生物接觸(chu)氧化(hua)工藝(yi)(yi)(yi)處理滇池流域(yu)的(de)(de)(de)(de)污染河水(shui)(shui)(shui),在進(jin)水(shui)(shui)(shui)NH-N濃度(du)為(wei)10-30mg/L,COD濃度(du)為(wei)50-180mg/L,水(shui)(shui)(shui)力(li)停留時(shi)間(jian)為(wei)5.4h,水(shui)(shui)(shui)溫在18-25℃條件(jian)下對COD和(he)NH-N的(de)(de)(de)(de)平(ping)(ping)均去除(chu)率分(fen)別達(da)到(dao)了(le)66.5%和(he)66.2%。王(wang)榮昌等人(ren)研(yan)究懸浮載體生物膜反應(ying)(ying)器(qi)對清華大學校園內污染河流廢水(shui)(shui)(shui)的(de)(de)(de)(de)修復(fu),經過(guo)25天運(yun)行(xing),在進(jin)水(shui)(shui)(shui)COD濃度(du)為(wei)70-100mg/L,NH-N濃度(du)為(wei)8-20mg/L,水(shui)(shui)(shui)溫為(wei)15-20℃,水(shui)(shui)(shui)力(li)停留時(shi)間(jian)為(wei)1h的(de)(de)(de)(de)條件(jian)下,該反應(ying)(ying)器(qi)對COD和(he)NH-N的(de)(de)(de)(de)平(ping)(ping)均去除(chu)率分(fen)別為(wei)56.9%和(he)76.0%。相比(bi)之下,本研(yan)究中(zhong)的(de)(de)(de)(de)兩級(ji)式(shi)生物接觸(chu)氧化(hua)工藝(yi)(yi)(yi)對COD和(he)NH-N都具有(you)最高的(de)(de)(de)(de)平(ping)(ping)均去除(chu)率,另外它還具有(you)能夠適應(ying)(ying)進(jin)水(shui)(shui)(shui)有(you)機(ji)物濃度(du)負(fu)荷變化(hua),對NH-N的(de)(de)(de)(de)去除(chu)也更(geng)加穩定的(de)(de)(de)(de)優點(dian)。
綜上(shang)所述,本研究中缺(que)(que)氧(yang)(yang)/好氧(yang)(yang)兩級(ji)生物(wu)接(jie)(jie)觸氧(yang)(yang)化(hua)工(gong)藝(yi)(yi)不僅(jin)能夠(gou)有(you)效地去(qu)除(chu)模擬(ni)河(he)流(liu)廢水中的(de)有(you)機物(wu),實(shi)驗結果證明,它還能夠(gou)強(qiang)化(hua)生物(wu)接(jie)(jie)觸氧(yang)(yang)化(hua)系統對氨氮(dan)的(de)降(jiang)(jiang)解(jie)(jie)能力(li),與其(qi)它類似生物(wu)接(jie)(jie)觸氧(yang)(yang)化(hua)工(gong)藝(yi)(yi)相比具有(you)更高的(de)COD和NH-N去(qu)除(chu)率,縮短(duan)了氨氮(dan)降(jiang)(jiang)解(jie)(jie)的(de)水力(li)停留(liu)時間。另外(wai),缺(que)(que)氧(yang)(yang)/好氧(yang)(yang)兩級(ji)接(jie)(jie)觸氧(yang)(yang)化(hua)工(gong)藝(yi)(yi)利(li)用(yong)缺(que)(que)氧(yang)(yang)過程降(jiang)(jiang)解(jie)(jie)有(you)機污染物(wu),整(zheng)個工(gong)藝(yi)(yi)所需要的(de)曝氣量(liang)(liang)大大減少,在很大程度上(shang)減少了能量(liang)(liang)的(de)消耗(hao)。這使得其(qi)在實(shi)際(ji)的(de)河(he)流(liu)原位治理中具有(you)更大的(de)實(shi)用(yong)價值。
3.結論
①在進(jin)水(shui)(shui)COD濃度(du)為150-350mg/L范圍內,生物接(jie)觸氧(yang)(yang)化(hua)(hua)工藝對能夠非常(chang)有效地(di)去除(chu)(chu)污水(shui)(shui)中(zhong)的COD,單級接(jie)觸氧(yang)(yang)化(hua)(hua)工藝和(he)兩級接(jie)觸氧(yang)(yang)化(hua)(hua)工藝對COD的平均(jun)去除(chu)(chu)率分別為82%和(he)92%,其中(zhong)兩級式接(jie)觸氧(yang)(yang)化(hua)(hua)工藝中(zhong)的缺氧(yang)(yang)區(qu)去除(chu)(chu)了進(jin)水(shui)(shui)中(zhong)大部分COD。
②兩級式接觸氧(yang)(yang)(yang)(yang)化工藝中缺氧(yang)(yang)(yang)(yang)區(qu)對(dui)進(jin)水中有機物(wu)(wu)的高(gao)效去除強化了好(hao)氧(yang)(yang)(yang)(yang)區(qu)生(sheng)物(wu)(wu)膜對(dui)氨氮的氧(yang)(yang)(yang)(yang)化能力。該工藝中好(hao)氧(yang)(yang)(yang)(yang)區(qu)生(sheng)物(wu)(wu)膜20℃時氨氧(yang)(yang)(yang)(yang)化速(su)率(lv)為4.50×10g/(g·h),相同條件(jian)下單級生(sheng)物(wu)(wu)接觸氧(yang)(yang)(yang)(yang)化工藝中的好(hao)氧(yang)(yang)(yang)(yang)生(sheng)物(wu)(wu)膜氨氧(yang)(yang)(yang)(yang)化速(su)率(lv)僅為1.09×10g/(g·h)。
③在進水NH-N濃度(du)為18-36mg/L的范圍內,缺氧/好氧兩級(ji)(ji)(ji)接(jie)(jie)(jie)觸(chu)氧化(hua)(hua)工(gong)藝(yi)有效地(di)提高了生物接(jie)(jie)(jie)觸(chu)氧化(hua)(hua)工(gong)藝(yi)對(dui)(dui)(dui)氨氮的去除率,其(qi)對(dui)(dui)(dui)氨氮的平(ping)均(jun)去除效率達到83%,而單(dan)級(ji)(ji)(ji)接(jie)(jie)(jie)觸(chu)氧化(hua)(hua)工(gong)藝(yi)在同(tong)等條(tiao)件下(xia)對(dui)(dui)(dui)氨氮的去除率僅為32%。另(ling)外相比(bi)單(dan)級(ji)(ji)(ji)接(jie)(jie)(jie)觸(chu)氧化(hua)(hua)工(gong)藝(yi),兩級(ji)(ji)(ji)接(jie)(jie)(jie)觸(chu)氧化(hua)(hua)工(gong)藝(yi)需要(yao)的耗能更(geng)少。
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