生活污水復合處理工藝
氮(dan)(dan)和磷(lin)(lin)是導致水(shui)體富營(ying)養化(hua)的(de)(de)(de)(de)(de)主要物質,其中磷(lin)(lin)是控制水(shui)體富營(ying)養化(hua)的(de)(de)(de)(de)(de)重要限(xian)制因(yin)素。隨著含(han)氮(dan)(dan)、磷(lin)(lin)污(wu)(wu)水(shui)所帶來(lai)的(de)(de)(de)(de)(de)環境污(wu)(wu)染(ran)問題(ti)的(de)(de)(de)(de)(de)日趨(qu)嚴重,對(dui)污(wu)(wu)水(shui)中營(ying)養負荷的(de)(de)(de)(de)(de)削減需求越來(lai)越強(qiang)烈。生(sheng)活污(wu)(wu)水(shui)中氮(dan)(dan)、磷(lin)(lin)含(han)量豐(feng)富,據統計,目前(qian)(qian)全國每年產生(sheng)農村生(sheng)活污(wu)(wu)水(shui)約80多億噸,其中96%的(de)(de)(de)(de)(de)農村生(sheng)活污(wu)(wu)水(shui)未經處理(li)(li)直(zhi)接排放〔1〕,成為我(wo)國水(shui)體污(wu)(wu)染(ran)的(de)(de)(de)(de)(de)主要污(wu)(wu)染(ran)源之一。為此,廢水(shui)脫氮(dan)(dan)除(chu)(chu)磷(lin)(lin)工藝(yi)的(de)(de)(de)(de)(de)開發(fa)倍受關注。筆(bi)者結合(he)ABR反(fan)(fan)應器所具有的(de)(de)(de)(de)(de)能(neng)有效去(qu)除(chu)(chu)有機污(wu)(wu)染(ran)物和懸浮物、能(neng)耗低、效率高等優點〔2〕,將ABR反(fan)(fan)應器和好(hao)氧(yang)工藝(yi)進(jin)行(xing)(xing)優化(hua)組合(he)用(yong)于廢水(shui)的(de)(de)(de)(de)(de)脫氮(dan)(dan)除(chu)(chu)磷(lin)(lin),該(gai)組合(he)工藝(yi)利(li)用(yong)收集曝(pu)氣氣體的(de)(de)(de)(de)(de)提(ti)升作用(yong)取代混(hun)合(he)液回流泵實(shi)現(xian)混(hun)合(he)液的(de)(de)(de)(de)(de)回流,降低了(le)動(dong)力能(neng)耗。本研究在該(gai)工藝(yi)成功啟(qi)動(dong)前(qian)(qian)提(ti)下(xia)(xia),對(dui)其在不同運行(xing)(xing)條件(jian)下(xia)(xia)的(de)(de)(de)(de)(de)運行(xing)(xing)效果進(jin)行(xing)(xing)了(le)深入研究,探尋了(le)工藝(yi)最優生(sheng)物脫氮(dan)(dan)除(chu)(chu)磷(lin)(lin)的(de)(de)(de)(de)(de)運行(xing)(xing)條件(jian),以(yi)期開發(fa)出能(neng)耗低、占地(di)少(shao)、運行(xing)(xing)維(wei)護簡(jian)單(dan)并且處理(li)(li)效果優良(liang)的(de)(de)(de)(de)(de)污(wu)(wu)水(shui)處理(li)(li)工藝(yi)。
1材料和方法(fa)
1.1實(shi)驗水質(zhi)
反應器進水(shui)(shui)為(wei)(wei)模(mo)擬(ni)(ni)污(wu)水(shui)(shui)與(yu)某(mou)高校生(sheng)活污(wu)水(shui)(shui)(混合(he)體積比為(wei)(wei)1∶1)的(de)混合(he)液(ye)。模(mo)擬(ni)(ni)污(wu)水(shui)(shui)以葡(pu)萄糖(540mg/L)為(wei)(wei)主要(yao)碳源(yuan)(yuan),氯化銨(115mg/L)為(wei)(wei)主要(yao)氮源(yuan)(yuan),另外添(tian)加尿素(4mg/L)、蛋白胨(dong)(150mg/L)及乙酸、丙酸、丁酸、戊酸(乙酸、丙酸、丁酸、戊酸各0.01mL/L)。投加NaHCO3(300mg/L),以保持溶液(ye)具有一定的(de)緩(huan)沖能(neng)力,使其堿度約為(wei)(wei)COD的(de)0.8倍〔3〕。模(mo)擬(ni)(ni)污(wu)水(shui)(shui)中(zhong)含有的(de)營養(yang)鹽(yan)和微量元(yuan)素〔4〕分別為(wei)(wei)H3BO330mg/L、ZnCl225mg/L、CuCl225mg/L、AlCl325mg/L、NiCl225mg/L、EDTA40mg/L、CaCll230mg/L;Na2SeO3·5H2O25mg/L、K2HPO4·3H2O25mg/L、FeCl3·6H2O25mg/L、MgSO4·7H2O30mg/L、CoCl2·6H2O25mg/L、MnSO4·H2O25mg/L、NaMoO4·2H2O25mg/L。蘇州某(mou)高校生(sheng)活區的(de)污(wu)水(shui)(shui)水(shui)(shui)質:COD232~459mg/L,NH4+-N20~46mg/L,TN25~56mg/L,TP1~7mg/L。
1.2污(wu)泥馴化與接種
接種(zhong)污泥(ni)取自(zi)蘇州(zhou)市某(mou)城市污水(shui)處理(li)廠重力濃縮池(chi)。污泥(ni)靜置1周(zhou)后,加(jia)入(ru)適量葡萄(tao)糖,再靜置2d,然后均勻移入(ru)ABR各(ge)隔室(shi),總(zong)接種(zhong)泥(ni)量約(yue)(yue)(yue)為(wei)各(ge)隔室(shi)有效(xiao)體(ti)積的(de)3/5。用配制的(de)生活(huo)污水(shui)填(tian)滿(man)各(ge)隔室(shi),閑置1d后開始連續(xu)進水(shui)。啟動時,ABR反應器各(ge)隔室(shi)MLSS約(yue)(yue)(yue)為(wei)28g/L,MLVSS/MLSS約(yue)(yue)(yue)為(wei)0.45。將取自(zi)蘇州(zhou)某(mou)污水(shui)處理(li)廠氧(yang)化溝的(de)活(huo)性污泥(ni)注(zhu)入(ru)好氧(yang)池(chi),投(tou)入(ru)量占好氧(yang)池(chi)有效(xiao)體(ti)積的(de)1/2,MLSS約(yue)(yue)(yue)為(wei)7.5g/L。
1.3復合(he)工(gong)藝(yi)
本(ben)實(shi)驗所采用的實(shi)驗裝(zhuang)置(zhi)由3隔室ABR反(fan)應(ying)器和(he)2個好(hao)氧(yang)池(chi)組合而成,為及(ji)時(shi)和(he)定(ding)性觀察反(fan)應(ying)器內的運行(xing)情況,反(fan)應(ying)器均(jun)由透明有機(ji)玻(bo)璃(li)加工制作(zuo)。ABR反(fan)應(ying)器、好(hao)氧(yang)池(chi)1和(he)好(hao)氧(yang)池(chi)2的有效容積分別(bie)為60、20、40L。實(shi)驗裝(zhuang)置(zhi)如圖1所示。
圖1實驗裝置示意
好氧池底部(bu)布設穿孔曝(pu)氣(qi)(qi)(qi)(qi)管,曝(pu)氣(qi)(qi)(qi)(qi)量可由空氣(qi)(qi)(qi)(qi)流(liu)量計調節(jie),DO控制在2mg/L左右,總(zong)水力停留時間為10h。通過調節(jie)混(hun)合(he)液(ye)出口(kou)高度控制回流(liu)比(bi)R1為100%左右,R2為50%。利用收集曝(pu)氣(qi)(qi)(qi)(qi)氣(qi)(qi)(qi)(qi)體的(de)提(ti)(ti)升(sheng)作用取代混(hun)合(he)液(ye)回流(liu)泵(beng),將泥(ni)(ni)水混(hun)合(he)液(ye)提(ti)(ti)升(sheng)至厭氧區(qu)(qu),實現泥(ni)(ni)、水的(de)回流(liu)。在ABR內實現反硝(xiao)化及反硝(xiao)化除磷(lin)(lin)脫氮(dan),同時基于厭氧反硝(xiao)化脫氮(dan)以(yi)及厭氧釋磷(lin)(lin)、好氧吸(xi)磷(lin)(lin)等特性(xing),最(zui)終通過沉(chen)淀區(qu)(qu)排泥(ni)(ni)來實現磷(lin)(lin)的(de)去除。部(bu)分污(wu)泥(ni)(ni)由沉(chen)淀區(qu)(qu)下方的(de)斜板(ban)回流(liu)至好氧區(qu)(qu)。
為探尋工藝(yi)最優生物脫(tuo)氮除磷的運行條件,設計了8個運行工況,如表1所(suo)示。
1.4實驗方(fang)案和監(jian)測方(fang)法
本實驗(yan)在工(gong)藝成(cheng)功(gong)啟動后(hou),在進(jin)(jin)(jin)水溫度為25℃左(zuo)右,pH為6.5~8.5的條件下對不同運行條件下該組(zu)合(he)工(gong)藝的運行效果進(jin)(jin)(jin)行研(yan)究。COD、NH4+-N、TN、TP、MLSS、MLVSS等(deng)均采用國家標(biao)準方法進(jin)(jin)(jin)行測定(ding)。
2結(jie)果與討論
2.1不同運行條件下COD的去(qu)除效果法
不同運行條(tiao)件(jian)下的COD去除(chu)效果(guo)如(ru)圖2所示。
圖2不同運行條件下的COD去除效(xiao)果(guo)
由圖2可知,當(dang)DO為(wei)(wei)(wei)(wei)2mg/L,R1為(wei)(wei)(wei)(wei)200%時,HRT越小(xiao),出水(shui)COD越大。當(dang)DO為(wei)(wei)(wei)(wei)2mg/L,HRT為(wei)(wei)(wei)(wei)7.5h時,R1增大,出水(shui)COD略有(you)減(jian)(jian)小(xiao),這可能(neng)與(yu)回流量增加,微(wei)生(sheng)物能(neng)與(yu)基質接觸更充分有(you)關。當(dang)HRT為(wei)(wei)(wei)(wei)7.5h、R1為(wei)(wei)(wei)(wei)200%時,系統出水(shui)COD隨DO的增大而(er)減(jian)(jian)小(xiao)。總體(ti)而(er)言,系統COD去(qu)除(chu)(chu)效果(guo)良好,COD去(qu)除(chu)(chu)率高于(yu)80%。除(chu)(chu)HRT為(wei)(wei)(wei)(wei)5h條件(jian)外,其他條件(jian)下的系統出水(shui)COD均(jun)低于(yu)50mg/L。實驗結(jie)果(guo)表明,當(dang)HRT為(wei)(wei)(wei)(wei)7.5h,R1為(wei)(wei)(wei)(wei)200%,DO為(wei)(wei)(wei)(wei)3mg/L時,ABR出水(shui)COD為(wei)(wei)(wei)(wei)101mg/L,COD去(qu)除(chu)(chu)率為(wei)(wei)(wei)(wei)75%,大部分COD在ABR內被消耗;好氧池COD去(qu)除(chu)(chu)率為(wei)(wei)(wei)(wei)15%,總COD去(qu)除(chu)(chu)率達到90%。
2.2不(bu)同運行(xing)條件(jian)下NH4+-N的去除(chu)效(xiao)果
不同運行條件下的(de)NH4+-N去除效果如圖3所示。
圖3不同運行條件(jian)下的NH4+-N去除效果
由圖3可知,當(dang)(dang)(dang)DO為(wei)(wei)(wei)2mg/L,HRT為(wei)(wei)(wei)10h或(huo)7.5h時(shi),系統出(chu)水(shui)NH4+-N﹤3.5mg/L。當(dang)(dang)(dang)HRT為(wei)(wei)(wei)7.5h時(shi),R1增大,出(chu)水(shui)NH4+-N略有(you)(you)降(jiang)低(di)(di),回流量增大,導致硝(xiao)化(hua)區有(you)(you)機(ji)物濃(nong)度因稀釋而減小,有(you)(you)利于(yu)自養(yang)型硝(xiao)化(hua)細(xi)菌在生物群落中進(jin)一步繁殖(zhi)富集,硝(xiao)化(hua)作(zuo)用增強。當(dang)(dang)(dang)HRT為(wei)(wei)(wei)7.5h,R1為(wei)(wei)(wei)200%時(shi),出(chu)水(shui)NH4+-N隨DO的增大明顯減小。當(dang)(dang)(dang)HRT為(wei)(wei)(wei)7.5h,R1為(wei)(wei)(wei)200%,DO≥3mg/L時(shi),出(chu)水(shui)NH4+-N較低(di)(di)。總體而言,組(zu)合工(gong)藝對NH4+-N的去除效果非(fei)常理想,NH4+-N去除率>81%。
2.3不同運行條件下TN的去除效果
不同運行條(tiao)件下的(de)TN去除效(xiao)果(guo)如(ru)圖4所(suo)示。
圖4不(bu)同(tong)運(yun)行(xing)條件下的TN去(qu)除效果
由(you)圖4可知(zhi),當(dang)(dang)(dang)DO為(wei)(wei)(wei)(wei)(wei)2mg/L,R1相(xiang)同(tong)時(shi)(shi),隨(sui)HRT的(de)(de)(de)(de)減小,系(xi)(xi)(xi)統(tong)出(chu)水(shui)TN略(lve)有增(zeng)(zeng)大(da)(da)。HRT大(da)(da),反(fan)(fan)硝(xiao)(xiao)(xiao)化(hua)菌就有充(chong)足的(de)(de)(de)(de)時(shi)(shi)間將(jiang)硝(xiao)(xiao)(xiao)態氮經反(fan)(fan)硝(xiao)(xiao)(xiao)化(hua)去(qu)(qu)除(chu)。當(dang)(dang)(dang)DO為(wei)(wei)(wei)(wei)(wei)2mg/L,HRT為(wei)(wei)(wei)(wei)(wei)7.5h時(shi)(shi),R1為(wei)(wei)(wei)(wei)(wei)200%的(de)(de)(de)(de)系(xi)(xi)(xi)統(tong)出(chu)水(shui)平(ping)均(jun)TN(14.1mg/L)小于(yu)R1為(wei)(wei)(wei)(wei)(wei)100%時(shi)(shi)的(de)(de)(de)(de)系(xi)(xi)(xi)統(tong)出(chu)水(shui)平(ping)均(jun)TN(15.3mg/L),TN去(qu)(qu)除(chu)率為(wei)(wei)(wei)(wei)(wei)72%;相(xiang)比于(yu)R1為(wei)(wei)(wei)(wei)(wei)200%,R1為(wei)(wei)(wei)(wei)(wei)100%時(shi)(shi),硝(xiao)(xiao)(xiao)化(hua)液回流量減小,因而TN去(qu)(qu)除(chu)率降(jiang)低。當(dang)(dang)(dang)DO為(wei)(wei)(wei)(wei)(wei)2mg/L,HRT為(wei)(wei)(wei)(wei)(wei)5h時(shi)(shi),系(xi)(xi)(xi)統(tong)出(chu)水(shui)平(ping)均(jun)TN隨(sui)R1的(de)(de)(de)(de)增(zeng)(zeng)大(da)(da)而增(zeng)(zeng)加(jia)(jia),出(chu)水(shui)平(ping)均(jun)TN>15mg/L;HRT太小,微(wei)生物與基質接觸(chu)不(bu)充(chong)分,不(bu)利于(yu)硝(xiao)(xiao)(xiao)化(hua)和反(fan)(fan)硝(xiao)(xiao)(xiao)化(hua)反(fan)(fan)應的(de)(de)(de)(de)充(chong)分進行,并且硝(xiao)(xiao)(xiao)化(hua)液的(de)(de)(de)(de)過度回流影響(xiang)了(le)(le)反(fan)(fan)硝(xiao)(xiao)(xiao)化(hua)效(xiao)果(guo)(guo),導(dao)致出(chu)水(shui)TN增(zeng)(zeng)加(jia)(jia)。當(dang)(dang)(dang)HRT為(wei)(wei)(wei)(wei)(wei)7.5h,R1為(wei)(wei)(wei)(wei)(wei)200%時(shi)(shi),DO為(wei)(wei)(wei)(wei)(wei)3mg/L的(de)(de)(de)(de)系(xi)(xi)(xi)統(tong)出(chu)水(shui)平(ping)均(jun)TN(12.1mg/L)略(lve)小于(yu)DO為(wei)(wei)(wei)(wei)(wei)2mg/L時(shi)(shi)的(de)(de)(de)(de)系(xi)(xi)(xi)統(tong)出(chu)水(shui)平(ping)均(jun)TN,這是(shi)由(you)于(yu)DO是(shi)決定硝(xiao)(xiao)(xiao)化(hua)效(xiao)果(guo)(guo)好(hao)壞的(de)(de)(de)(de)關鍵因素(su)〔5〕,增(zeng)(zeng)加(jia)(jia)DO,好(hao)氧硝(xiao)(xiao)(xiao)化(hua)作(zuo)用更加(jia)(jia)充(chong)分,更多的(de)(de)(de)(de)硝(xiao)(xiao)(xiao)態氮可經反(fan)(fan)硝(xiao)(xiao)(xiao)化(hua)作(zuo)用得以去(qu)(qu)除(chu),從而提高了(le)(le)TN去(qu)(qu)除(chu)率。但當(dang)(dang)(dang)DO增(zeng)(zeng)加(jia)(jia)到4mg/L時(shi)(shi),系(xi)(xi)(xi)統(tong)出(chu)水(shui)TN增(zeng)(zeng)大(da)(da),這是(shi)由(you)于(yu)DO過大(da)(da),破壞了(le)(le)反(fan)(fan)硝(xiao)(xiao)(xiao)化(hua)所需的(de)(de)(de)(de)缺氧環境,影響(xiang)了(le)(le)反(fan)(fan)硝(xiao)(xiao)(xiao)化(hua)脫氮效(xiao)果(guo)(guo),從而降(jiang)低了(le)(le)TN去(qu)(qu)除(chu)率。實驗結果(guo)(guo)表(biao)明,當(dang)(dang)(dang)HRT為(wei)(wei)(wei)(wei)(wei)7.5h,R1為(wei)(wei)(wei)(wei)(wei)200%,DO為(wei)(wei)(wei)(wei)(wei)3mg/L時(shi)(shi),該組合工藝對TN的(de)(de)(de)(de)去(qu)(qu)除(chu)效(xiao)果(guo)(guo)較好(hao)。
2.4不同(tong)運行條件下TP的(de)去除(chu)效果
不同運行(xing)條件下(xia)的TP去除效果如圖(tu)5所示。
圖(tu)5不同(tong)運行條件下的TP去除(chu)效(xiao)果(guo)
由圖5可知,當DO為(wei)(wei)(wei)(wei)(wei)2mg/L,HRT為(wei)(wei)(wei)(wei)(wei)7.5h時(shi),R1為(wei)(wei)(wei)(wei)(wei)200%的(de)(de)(de)系統(tong)(tong)出(chu)(chu)(chu)(chu)(chu)(chu)(chu)水(shui)(shui)(shui)(shui)(shui)平(ping)均(jun)(jun)TP(0.69mg/L)明(ming)顯小于(yu)R1為(wei)(wei)(wei)(wei)(wei)100%時(shi)的(de)(de)(de)系統(tong)(tong)出(chu)(chu)(chu)(chu)(chu)(chu)(chu)水(shui)(shui)(shui)(shui)(shui)平(ping)均(jun)(jun)TP(1.16mg/L),TP去(qu)除率達82%;R1增大(da)(da),系統(tong)(tong)污(wu)泥循環(huan)(huan)量增加,更多(duo)的(de)(de)(de)聚(ju)磷(lin)(lin)(lin)菌(jun)參與厭(yan)氧(yang)(yang)釋磷(lin)(lin)(lin)和好(hao)氧(yang)(yang)吸(xi)磷(lin)(lin)(lin),出(chu)(chu)(chu)(chu)(chu)(chu)(chu)水(shui)(shui)(shui)(shui)(shui)TP降(jiang)(jiang)低(di)(di)(di)(di)。當DO為(wei)(wei)(wei)(wei)(wei)2mg/L,HRT為(wei)(wei)(wei)(wei)(wei)5h時(shi),系統(tong)(tong)出(chu)(chu)(chu)(chu)(chu)(chu)(chu)水(shui)(shui)(shui)(shui)(shui)平(ping)均(jun)(jun)TP隨(sui)R1的(de)(de)(de)增大(da)(da)而(er)顯著(zhu)(zhu)增加,出(chu)(chu)(chu)(chu)(chu)(chu)(chu)水(shui)(shui)(shui)(shui)(shui)平(ping)均(jun)(jun)TP>0.6mg/L;HRT太短,并且過(guo)多(duo)的(de)(de)(de)硝酸鹽回流(liu)到ABR厭(yan)氧(yang)(yang)區,大(da)(da)部分有機物優先用于(yu)反(fan)硝化脫氮過(guo)程,致(zhi)(zhi)使(shi)厭(yan)氧(yang)(yang)釋磷(lin)(lin)(lin)不完全,以致(zhi)(zhi)后續吸(xi)磷(lin)(lin)(lin)能力降(jiang)(jiang)低(di)(di)(di)(di)〔6〕,最終導致(zhi)(zhi)出(chu)(chu)(chu)(chu)(chu)(chu)(chu)水(shui)(shui)(shui)(shui)(shui)TP偏高(gao)。當DO為(wei)(wei)(wei)(wei)(wei)2mg/L,R1為(wei)(wei)(wei)(wei)(wei)100%時(shi),系統(tong)(tong)出(chu)(chu)(chu)(chu)(chu)(chu)(chu)水(shui)(shui)(shui)(shui)(shui)平(ping)均(jun)(jun)TP隨(sui)HRT的(de)(de)(de)減(jian)小而(er)顯著(zhu)(zhu)降(jiang)(jiang)低(di)(di)(di)(di),這(zhe)是因為(wei)(wei)(wei)(wei)(wei)隨(sui)HRT的(de)(de)(de)減(jian)小,各池水(shui)(shui)(shui)(shui)(shui)流(liu)上升速率增大(da)(da),更多(duo)的(de)(de)(de)污(wu)泥在反(fan)應器內循環(huan)(huan),從(cong)而(er)有更多(duo)的(de)(de)(de)聚(ju)磷(lin)(lin)(lin)菌(jun)進(jin)行厭(yan)氧(yang)(yang)釋磷(lin)(lin)(lin)和好(hao)氧(yang)(yang)吸(xi)磷(lin)(lin)(lin)過(guo)程,使(shi)得出(chu)(chu)(chu)(chu)(chu)(chu)(chu)水(shui)(shui)(shui)(shui)(shui)TP降(jiang)(jiang)低(di)(di)(di)(di)。當HRT為(wei)(wei)(wei)(wei)(wei)7.5h,R1為(wei)(wei)(wei)(wei)(wei)200%時(shi),DO為(wei)(wei)(wei)(wei)(wei)3mg/L或(huo)4mg/L的(de)(de)(de)系統(tong)(tong)出(chu)(chu)(chu)(chu)(chu)(chu)(chu)水(shui)(shui)(shui)(shui)(shui)平(ping)均(jun)(jun)TP小于(yu)DO為(wei)(wei)(wei)(wei)(wei)2mg/L時(shi)的(de)(de)(de)系統(tong)(tong)出(chu)(chu)(chu)(chu)(chu)(chu)(chu)水(shui)(shui)(shui)(shui)(shui)平(ping)均(jun)(jun)TP;增加DO,使(shi)得聚(ju)磷(lin)(lin)(lin)菌(jun)好(hao)氧(yang)(yang)吸(xi)磷(lin)(lin)(lin)更加充(chong)分,從(cong)而(er)降(jiang)(jiang)低(di)(di)(di)(di)了出(chu)(chu)(chu)(chu)(chu)(chu)(chu)水(shui)(shui)(shui)(shui)(shui)TP。與DO為(wei)(wei)(wei)(wei)(wei)3mg/L時(shi)相比,DO為(wei)(wei)(wei)(wei)(wei)4mg/L的(de)(de)(de)系統(tong)(tong)出(chu)(chu)(chu)(chu)(chu)(chu)(chu)水(shui)(shui)(shui)(shui)(shui)平(ping)均(jun)(jun)TP略有增大(da)(da),這(zhe)可能是由于(yu)DO過(guo)高(gao),減(jian)弱了聚(ju)磷(lin)(lin)(lin)菌(jun)厭(yan)氧(yang)(yang)釋磷(lin)(lin)(lin)效(xiao)果(guo),從(cong)而(er)降(jiang)(jiang)低(di)(di)(di)(di)了聚(ju)磷(lin)(lin)(lin)菌(jun)的(de)(de)(de)吸(xi)磷(lin)(lin)(lin)量,使(shi)出(chu)(chu)(chu)(chu)(chu)(chu)(chu)水(shui)(shui)(shui)(shui)(shui)TP有所增加。實驗結(jie)果(guo)表(biao)明(ming),當控制HRT為(wei)(wei)(wei)(wei)(wei)7.5h,R1為(wei)(wei)(wei)(wei)(wei)200%,DO為(wei)(wei)(wei)(wei)(wei)3mg/L時(shi),出(chu)(chu)(chu)(chu)(chu)(chu)(chu)水(shui)(shui)(shui)(shui)(shui)TP最低(di)(di)(di)(di)。
2.5脫氮除磷(lin)機(ji)理分(fen)析(xi)
綜上所(suo)述,工藝的最佳運(yun)行條件:HRT為(wei)7.5h,R1為(wei)200%,DO為(wei)3mg/L。在(zai)最佳運(yun)行條件下(xia),對工藝各單元(yuan)的運(yun)行情況進(jin)行了檢測,結果如表2所(suo)示(shi)。
由表2可(ke)知,由于(yu)硝(xiao)(xiao)(xiao)化(hua)(hua)液回流(liu)ABR1隔(ge)室(shi)中(zhong)(zhong)NH4+-N迅速下(xia)(xia)降(jiang),而ABR2隔(ge)室(shi)中(zhong)(zhong)的(de)NH4+-N略高于(yu)ABR3隔(ge)室(shi),這與(yu)厭(yan)氧(yang)(yang)(yang)條件下(xia)(xia),有(you)機含氮污染物(wu)通過(guo)厭(yan)氧(yang)(yang)(yang)微生(sheng)(sheng)物(wu)作用轉化(hua)(hua)的(de)氨多于(yu)厭(yan)氧(yang)(yang)(yang)微生(sheng)(sheng)物(wu)利(li)用氨作為氮源(yuan)同化(hua)(hua)作用合成生(sheng)(sheng)命物(wu)質氨基酸所需(xu)的(de)氨有(you)關;另(ling)外,厭(yan)氧(yang)(yang)(yang)反(fan)(fan)(fan)硝(xiao)(xiao)(xiao)化(hua)(hua)過(guo)程也能夠將NO3--N通過(guo)同化(hua)(hua)作用還原成NH4+-N,造成ABR2隔(ge)室(shi)中(zhong)(zhong)NH4+-N略有(you)升高。好氧(yang)(yang)(yang)池1內(nei)(nei)(nei)(nei)(nei)NH4+-N急劇減少,表明好氧(yang)(yang)(yang)池1內(nei)(nei)(nei)(nei)(nei)微生(sheng)(sheng)物(wu)硝(xiao)(xiao)(xiao)化(hua)(hua)能力較(jiao)(jiao)強(qiang)。在(zai)(zai)好氧(yang)(yang)(yang)池1內(nei)(nei)(nei)(nei)(nei)沒有(you)去(qu)除(chu)(chu)的(de)NH4+-N,在(zai)(zai)好氧(yang)(yang)(yang)池2內(nei)(nei)(nei)(nei)(nei)可(ke)進一步去(qu)除(chu)(chu)。ABR內(nei)(nei)(nei)(nei)(nei)NO3--N大(da)幅下(xia)(xia)降(jiang)表明,反(fan)(fan)(fan)應器內(nei)(nei)(nei)(nei)(nei)反(fan)(fan)(fan)硝(xiao)(xiao)(xiao)化(hua)(hua)菌的(de)反(fan)(fan)(fan)硝(xiao)(xiao)(xiao)化(hua)(hua)脫(tuo)氮能力較(jiao)(jiao)強(qiang)。系(xi)(xi)統(tong)(tong)出(chu)水(shui)NO3--N比ABR3隔(ge)室(shi)增加8.6mg/L,但是比NH4+-N的(de)減少量(18.8mg/L)低(di)約10.2mg/L,說明好氧(yang)(yang)(yang)池內(nei)(nei)(nei)(nei)(nei)存在(zai)(zai)同步硝(xiao)(xiao)(xiao)化(hua)(hua)反(fan)(fan)(fan)硝(xiao)(xiao)(xiao)化(hua)(hua)過(guo)程,由同步硝(xiao)(xiao)(xiao)化(hua)(hua)反(fan)(fan)(fan)硝(xiao)(xiao)(xiao)化(hua)(hua)作用去(qu)除(chu)(chu)的(de)氮占19%。ABR出(chu)水(shui)沒有(you)檢測到NO3--N,且系(xi)(xi)統(tong)(tong)出(chu)水(shui)NH4+-N低(di)至0.7mg/L,可(ke)判斷工藝中(zhong)(zhong)硝(xiao)(xiao)(xiao)化(hua)(hua)和反(fan)(fan)(fan)硝(xiao)(xiao)(xiao)化(hua)(hua)2個過(guo)程達到動(dong)態平(ping)衡(heng),反(fan)(fan)(fan)硝(xiao)(xiao)(xiao)化(hua)(hua)脫(tuo)氮效果良好。生(sheng)(sheng)物(wu)脫(tuo)氮主(zhu)要發(fa)生(sheng)(sheng)在(zai)(zai)ABR內(nei)(nei)(nei)(nei)(nei),ABR內(nei)(nei)(nei)(nei)(nei)TN去(qu)除(chu)(chu)率為52%,好氧(yang)(yang)(yang)池TN去(qu)除(chu)(chu)率為24%,系(xi)(xi)統(tong)(tong)TN去(qu)除(chu)(chu)率為76%。
此外,實(shi)驗(yan)結果表明(ming),ABR1隔室(shi)首(shou)先保證了(le)回流(liu)的硝化液與原(yuan)水混合以快速地完成(cheng)反(fan)硝化過程,由于ABR1隔室(shi)硝態氮降(jiang)低到了(le)一定濃度,隨(sui)即發生了(le)釋磷(lin)現象。ABR2隔室(shi)聚磷(lin)菌釋磷(lin)量(liang)增強(qiang),TP達12.86mg/L。ABR3隔室(shi)反(fan)硝化除(chu)磷(lin)菌吸(xi)磷(lin)現象明(ming)顯,TP降(jiang)低至(zhi)6.73mg/L。好氧(yang)池1TP顯著降(jiang)低,說明(ming)聚磷(lin)菌能過量(liang)吸(xi)磷(lin),TP降(jiang)至(zhi)1.05mg/L。在(zai)好氧(yang)池2進一步吸(xi)磷(lin)后,出水TP降(jiang)低至(zhi)0.51mg/L,系統TP去除(chu)率達87%。
3結(jie)論
以(yi)ABR-好氧(yang)(yang)復合工(gong)(gong)藝處理生活污水(shui)(shui)能有(you)效節(jie)能降耗,同(tong)時可獲(huo)得(de)良(liang)好的(de)出水(shui)(shui)水(shui)(shui)質。綜(zong)合考(kao)慮其對COD、NH4+-N、TN和TP的(de)去(qu)除(chu)效果,可以(yi)確定工(gong)(gong)藝的(de)最佳運(yun)行條件:HRT為7.5h,回流比(bi)R1為200%,DO為3mg/L。此運(yun)行條件下(xia),系統出水(shui)(shui)水(shui)(shui)質良(liang)好,出水(shui)(shui)COD、NH4+-N、TN和TP平均分別(bie)為38、0.7、12.1、0.51mg/L,COD、NH4+-N、TN和TP去(qu)除(chu)率分別(bie)為90%、97%、76%和87%。其中,ABR內TN去(qu)除(chu)率為52%,好氧(yang)(yang)池(chi)同(tong)步硝化反(fan)硝化強(qiang)(qiang)化了(le)脫氮效果,TN去(qu)除(chu)率達19%。ABR2隔(ge)室(shi)聚磷菌(jun)過度釋磷能力強(qiang)(qiang),ABR3隔(ge)室(shi)反(fan)硝化除(chu)磷菌(jun)能有(you)效吸磷,好氧(yang)(yang)池(chi)聚磷菌(jun)進(jin)一(yi)步大(da)量(liang)吸磷,使TP最終(zhong)通過排泥得(de)到有(you)效去(qu)除(chu)。

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