東莞市污水處理廠升級改造工藝路線初探
摘要:針對(dui)東莞市38個(ge)污(wu)水(shui)處(chu)理(li)(li)(li)廠的實際情況，通過對(dui)目前(qian)城市污(wu)水(shui)處(chu)理(li)(li)(li)廠常用(yong)的二級(ji)(ji)(ji)處(chu)理(li)(li)(li)工(gong)(gong)藝(yi)(yi)進行技術(shu)升級(ji)(ji)(ji)改造時可(ke)(ke)能采用(yong)的深(shen)度處(chu)理(li)(li)(li)工(gong)(gong)藝(yi)(yi)技術(shu)的綜合分析(xi)比較，推薦了(le)(le)NPR、CNR、人工(gong)(gong)濕地(di)三種工(gong)(gong)藝(yi)(yi)作為(wei)尾水(shui)的深(shen)度處(chu)理(li)(li)(li)備選(xuan)技術(shu)，提(ti)出(chu)了(le)(le)東莞市污(wu)水(shui)處(chu)理(li)(li)(li)廠升級(ji)(ji)(ji)改造應優(you)先(xian)采用(yong)CNR工(gong)(gong)藝(yi)(yi)，并可(ke)(ke)為(wei)我國(guo)不(bu)同(tong)地(di)區(qu)、不(bu)同(tong)發展時期滿(man)足不(bu)同(tong)的水(shui)質需求(qiu)進行污(wu)水(shui)處(chu)理(li)(li)(li)廠工(gong)(gong)藝(yi)(yi)升級(ji)(ji)(ji)改造提(ti)供技術(shu)支(zhi)持。
關鍵詞:東莞市;污水處理(li)廠;升級改造(zao);污水深(shen)度處理(li)
1 東莞市城市污水處理廠概況
2005年以(yi)來(lai)，東(dong)(dong)莞(guan)市(shi)(shi)大規模地(di)(di)(di)建設了(le)(le)城(cheng)(cheng)市(shi)(shi)污(wu)(wu)(wu)水(shui)(shui)(shui)(shui)處(chu)(chu)理(li)(li)廠。目前全市(shi)(shi)的(de)(de)(de)(de)30多家城(cheng)(cheng)市(shi)(shi)污(wu)(wu)(wu)水(shui)(shui)(shui)(shui)處(chu)(chu)理(li)(li)廠普遍采用的(de)(de)(de)(de)工藝為A2/O、氧化(hua)溝和(he)CASS。污(wu)(wu)(wu)水(shui)(shui)(shui)(shui)處(chu)(chu)理(li)(li)廠出水(shui)(shui)(shui)(shui)水(shui)(shui)(shui)(shui)質(zhi)均采用《城(cheng)(cheng)鎮污(wu)(wu)(wu)水(shui)(shui)(shui)(shui)處(chu)(chu)理(li)(li)廠污(wu)(wu)(wu)染物排(pai)放標(biao)準》（GB18918- 2002）中的(de)(de)(de)(de)一(yi)級(ji)B排(pai)放標(biao)準。雖然這(zhe)(zhe)些污(wu)(wu)(wu)水(shui)(shui)(shui)(shui)處(chu)(chu)理(li)(li)廠投入(ru)運(yun)行后(hou)明顯地(di)(di)(di)緩解了(le)(le)東(dong)(dong)莞(guan)市(shi)(shi)河涌(yong)(yong)(yong)的(de)(de)(de)(de)污(wu)(wu)(wu)染狀況，但是(shi)按一(yi)級(ji)B標(biao)準排(pai)放的(de)(de)(de)(de)尾(wei)水(shui)(shui)(shui)(shui)水(shui)(shui)(shui)(shui)質(zhi)仍遠劣于地(di)(di)(di)表水(shui)(shui)(shui)(shui)Ⅳ類水(shui)(shui)(shui)(shui)質(zhi)標(biao)準。在非雨季，東(dong)(dong)莞(guan)市(shi)(shi)內的(de)(de)(de)(de)多條(tiao)河涌(yong)(yong)(yong)和(he)多個(ge)水(shui)(shui)(shui)(shui)庫的(de)(de)(de)(de)主要(yao)補充水(shui)(shui)(shui)(shui)源(yuan)是(shi)城(cheng)(cheng)市(shi)(shi)污(wu)(wu)(wu)水(shui)(shui)(shui)(shui)處(chu)(chu)理(li)(li)廠的(de)(de)(de)(de)尾(wei)水(shui)(shui)(shui)(shui)。這(zhe)(zhe)些河涌(yong)(yong)(yong)的(de)(de)(de)(de)水(shui)(shui)(shui)(shui)質(zhi)一(yi)般要(yao)求(qiu)達到(dao)地(di)(di)(di)表水(shui)(shui)(shui)(shui)Ⅳ或Ⅲ類標(biao)準。而城(cheng)(cheng)市(shi)(shi)污(wu)(wu)(wu)水(shui)(shui)(shui)(shui)處(chu)(chu)理(li)(li)廠排(pai)放的(de)(de)(de)(de)尾(wei)水(shui)(shui)(shui)(shui)屬于低(di)碳源(yuan)、高氮磷污(wu)(wu)(wu)水(shui)(shui)(shui)(shui)。在這(zhe)(zhe)種情(qing)況下，由于河涌(yong)(yong)(yong)和(he)水(shui)(shui)(shui)(shui)庫的(de)(de)(de)(de)補充水(shui)(shui)(shui)(shui)水(shui)(shui)(shui)(shui)質(zhi)很差(cha)，造成水(shui)(shui)(shui)(shui)體(ti)富營養化(hua)的(de)(de)(de)(de)風(feng)險極(ji)大。特別(bie)是(shi)東(dong)(dong)莞(guan)市(shi)(shi)的(de)(de)(de)(de)工業(ye)十分(fen)發達，還會有工業(ye)廢水(shui)(shui)(shui)(shui)排(pai)入(ru)市(shi)(shi)政管網系(xi)統，這(zhe)(zhe)就導致了(le)(le)污(wu)(wu)(wu)水(shui)(shui)(shui)(shui)處(chu)(chu)理(li)(li)廠尾(wei)水(shui)(shui)(shui)(shui)中必然含有重金屬等有毒有害物質(zhi)，帶來(lai)了(le)(le)新的(de)(de)(de)(de)地(di)(di)(di)表水(shui)(shui)(shui)(shui)污(wu)(wu)(wu)染隱患。尤其是(shi)作為備用水(shui)(shui)(shui)(shui)源(yuan)的(de)(de)(de)(de)一(yi)些水(shui)(shui)(shui)(shui)庫，水(shui)(shui)(shui)(shui)質(zhi)受尾(wei)水(shui)(shui)(shui)(shui)的(de)(de)(de)(de)影響將會更大。因此東(dong)(dong)莞(guan)市(shi)(shi)面臨著污(wu)(wu)(wu)水(shui)(shui)(shui)(shui)處(chu)(chu)理(li)(li)廠技術升(sheng)級(ji)改造的(de)(de)(de)(de)問題。
東莞市(shi)面臨(lin)的(de)(de)城(cheng)市(shi)污(wu)(wu)(wu)(wu)水(shui)(shui)處(chu)理(li)廠升(sheng)級改(gai)造的(de)(de)問題在全國(guo)(guo)普遍存在。目(mu)前我國(guo)(guo)各大(da)(da)城(cheng)市(shi)都建設了城(cheng)鎮污(wu)(wu)(wu)(wu)水(shui)(shui)處(chu)理(li)廠及截(jie)污(wu)(wu)(wu)(wu)管網(wang)，但是(shi)根據中(zhong)國(guo)(guo)環(huan)境監(jian)測總站《2008年全國(guo)(guo)環(huan)境質(zhi)(zhi)量狀況(kuang)》的(de)(de)數(shu)據，在我國(guo)(guo)七大(da)(da)水(shui)(shui)系197條河(he)(he)流的(de)(de) 407個水(shui)(shui)質(zhi)(zhi)監(jian)測斷(duan)面中(zhong)，靠近城(cheng)市(shi)附近的(de)(de)河(he)(he)流水(shui)(shui)質(zhi)(zhi)普遍最差(cha)。這是(shi)由于(yu)我國(guo)(guo)的(de)(de)很(hen)多(duo)城(cheng)市(shi)污(wu)(wu)(wu)(wu)水(shui)(shui)處(chu)理(li)廠在建設時(shi)，出于(yu)節約投(tou)資的(de)(de)考(kao)慮，普遍采用較低的(de)(de)排放(fang)(fang)標(biao)準，使得(de)排放(fang)(fang)的(de)(de)尾(wei)水(shui)(shui)中(zhong)的(de)(de)氨氮(dan)、總氮(dan)、總磷等指標(biao)高出地(di)面水(shui)(shui)環(huan)境質(zhi)(zhi)量標(biao)準10～20倍。另外，我國(guo)(guo)很(hen)多(duo)受納水(shui)(shui)體的(de)(de)生態系統已經遭到破壞，水(shui)(shui)環(huan)境容(rong)量很(hen)小，自凈能力很(hen)差(cha)或完全喪失，不能有效(xiao)地(di)自凈污(wu)(wu)(wu)(wu)水(shui)(shui)處(chu)理(li)廠尾(wei)水(shui)(shui)中(zhong)的(de)(de)污(wu)(wu)(wu)(wu)染物，很(hen)容(rong)易造成水(shui)(shui)質(zhi)(zhi)惡化。因(yin)此污(wu)(wu)(wu)(wu)水(shui)(shui)處(chu)理(li)廠的(de)(de)升(sheng)級改(gai)造就十(shi)分必要，應盡(jin)快研發(fa)出適合于(yu)我國(guo)(guo)污(wu)(wu)(wu)(wu)水(shui)(shui)處(chu)理(li)現(xian)狀的(de)(de)投(tou)資少、見效(xiao)快的(de)(de)工藝提升(sheng)改(gai)造技術。
2 國內污水處理廠升級改造采用的傳統工藝
2.1 普遍采用的傳統工藝及升級改造(zao)
2.1.1 混(hun)凝沉(chen)淀(dian)過濾工藝(yi)
（1）混(hun)凝(ning)沉(chen)淀過濾工藝(yi)特點(dian)
混(hun)(hun)凝沉(chen)淀過濾(lv)工藝主(zhu)要(yao)能有效去(qu)除(chu)(chu)污水中呈膠體和(he)微小懸浮狀態(tai)的(de)(de)有機(ji)(ji)和(he)無機(ji)(ji)污染(ran)物(wu)(wu)。從表觀而言，就是能夠有效去(qu)除(chu)(chu)污水的(de)(de)色度、濁度及磷(lin)。混(hun)(hun)凝沉(chen)淀過濾(lv)只可(ke)以(yi)少量地(di)除(chu)(chu)污水中的(de)(de)一些(xie)有機(ji)(ji)物(wu)(wu)，但不能去(qu)除(chu)(chu)水中溶解的(de)(de)有機(ji)(ji)物(wu)(wu)及氮。
采用(yong)(yong)混凝(ning)(ning)沉淀過濾工藝的(de)關鍵是混凝(ning)(ning)劑(ji)(ji)(ji)的(de)選(xuan)(xuan)用(yong)(yong)，通常要(yao)(yao)通過試驗(yan)篩選(xuan)(xuan)出合適的(de)混凝(ning)(ning)劑(ji)(ji)(ji)和(he)確定(ding)投(tou)加劑(ji)(ji)(ji)量。如要(yao)(yao)利用(yong)(yong)混凝(ning)(ning)法去(qu)除污水中的(de)有機物就必(bi)須(xu)大量投(tou)加混凝(ning)(ning)劑(ji)(ji)(ji)和(he)絮凝(ning)(ning)劑(ji)(ji)(ji)。
（2）作為升級改造工藝的(de)優缺點
以采(cai)用A2/O工(gong)(gong)藝(yi)的污水處理廠升級(ji)改造(zao)(zao)(zao)為例，升級(ji)改造(zao)(zao)(zao)采(cai)用混(hun)凝沉淀工(gong)(gong)藝(yi)，改造(zao)(zao)(zao)后工(gong)(gong)藝(yi)流程見(jian)圖1（圖中虛線框部分(fen)為工(gong)(gong)藝(yi)升級(ji)改造(zao)(zao)(zao)部分(fen)）。
根據混(hun)(hun)凝沉淀(dian)過(guo)濾工藝(yi)(yi)的(de)特(te)點，該工藝(yi)(yi)可(ke)以很好地去除SS及(ji)磷，但對氮及(ji)溶解性污染物(wu)的(de)去除效(xiao)果較(jiao)差。特(te)別是采用混(hun)(hun)凝沉淀(dian)作(zuo)為深度處理技術時(shi)，工藝(yi)(yi)流(liu)程較(jiao)長，工程投資(zi)成本較(jiao)高(gao)；工藝(yi)(yi)操作(zuo)過(guo)程復雜、維護管理工作(zuo)量(liang)大；由于混(hun)(hun)凝劑的(de)使(shi)用量(liang)大，還會產生大量(liang)的(de)含水(shui)率(lv)很高(gao)的(de)污泥，給(gei)污泥處置帶來很大困難，同時(shi)還會明顯增(zeng)加處理成本、提(ti)高(gao)運行(xing)成本。
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| 圖1 A2/O+混凝沉淀過濾工藝流程 |
2.1.2 BAF（生(sheng)物濾池）工藝
（1）生物濾池工藝
生(sheng)物濾(lv)(lv)(lv)(lv)池(chi)(chi)底(di)(di)(di)部設(she)有(you)進水(shui)(shui)(shui)管(guan)(guan)和排(pai)泥(ni)管(guan)(guan)，中(zhong)上(shang)部是填(tian)(tian)(tian)料層(ceng)(ceng)，填(tian)(tian)(tian)料頂部裝(zhuang)有(you)擋板并安(an)裝(zhuang)有(you)出(chu)水(shui)(shui)(shui)濾(lv)(lv)(lv)(lv)頭。其內(nei)設(she)有(you)回流(liu)泵用(yong)(yong)(yong)以將濾(lv)(lv)(lv)(lv)池(chi)(chi)出(chu)水(shui)(shui)(shui)回流(liu)到濾(lv)(lv)(lv)(lv)池(chi)(chi)底(di)(di)(di)部實現(xian)反(fan)(fan)硝化。置于填(tian)(tian)(tian)料層(ceng)(ceng)內(nei)的(de)(de)(de)(de)空氣管(guan)(guan)用(yong)(yong)(yong)于曝氣供(gong)氧。生(sheng)物濾(lv)(lv)(lv)(lv)池(chi)(chi)上(shang)部為好氧區(qu)(qu)，下部為缺(que)氧區(qu)(qu)。污水(shui)(shui)(shui)處(chu)理(li)廠(chang)二級處(chu)理(li)出(chu)水(shui)(shui)(shui)與經過(guo)(guo)硝化后的(de)(de)(de)(de)濾(lv)(lv)(lv)(lv)池(chi)(chi)出(chu)水(shui)(shui)(shui)按(an)照回流(liu)比(bi)混合(he)后通過(guo)(guo)濾(lv)(lv)(lv)(lv)池(chi)(chi)進水(shui)(shui)(shui)管(guan)(guan)進入濾(lv)(lv)(lv)(lv)池(chi)(chi)底(di)(di)(di)部，并向上(shang)首先(xian)流(liu)經填(tian)(tian)(tian)料層(ceng)(ceng)的(de)(de)(de)(de)缺(que)氧區(qu)(qu)進行反(fan)(fan)硝化。填(tian)(tian)(tian)料上(shang)的(de)(de)(de)(de)微生(sheng)物利用(yong)(yong)(yong)進水(shui)(shui)(shui)中(zhong)的(de)(de)(de)(de)溶解氧和反(fan)(fan)硝化過(guo)(guo)程中(zhong)生(sheng)成的(de)(de)(de)(de)氧降解BOD，同時，SS被填(tian)(tian)(tian)料及其上(shang)面的(de)(de)(de)(de)生(sheng)物膜吸附截留(liu)在濾(lv)(lv)(lv)(lv)床內(nei)，NH3-N發生(sheng)硝化反(fan)(fan)應。流(liu)出(chu)填(tian)(tian)(tian)料層(ceng)(ceng)的(de)(de)(de)(de)凈(jing)化水(shui)(shui)(shui)通過(guo)(guo)濾(lv)(lv)(lv)(lv)池(chi)(chi)擋板上(shang)的(de)(de)(de)(de)濾(lv)(lv)(lv)(lv)頭排(pai)出(chu)濾(lv)(lv)(lv)(lv)池(chi)(chi)。選擇生(sheng)物濾(lv)(lv)(lv)(lv)池(chi)(chi)工藝(yi)對采用(yong)(yong)(yong)氧化溝工藝(yi)的(de)(de)(de)(de)污水(shui)(shui)(shui)處(chu)理(li)廠(chang)進行升級改造(zao)，改造(zao)后工藝(yi)流(liu)程見圖2。
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| 圖2 氧化溝+BAF 工藝流程 |
（2）生物濾池(chi)工(gong)藝的優點
1）采用生(sheng)物濾(lv)池對污水(shui)(shui)處(chu)理廠(chang)的(de)二級出(chu)水(shui)(shui)進行處(chu)理的(de)優點是在去除SS的(de)同時還可以有(you)效地去除污水(shui)(shui)中的(de)溶解性有(you)機物和氮；2）生(sheng)物濾(lv)池內生(sheng)物量大，處(chu)理負(fu)荷(he)高，水(shui)(shui)處(chu)理構筑(zhu)物容積(ji)小，占地省(sheng)；3）出(chu)水(shui)(shui)水(shui)(shui)質穩定，品質優良。
（3）作為升級改造(zao)工藝(yi)的缺點
1）生物(wu)濾(lv)(lv)池(chi)(chi)對進(jin)水(shui)(shui)SS的要求較高，理論(lun)上應保(bao)證 SS低于(yu)100mg/L以下，實際應低于(yu)60mg/L，否(fou)則(ze)會堵塞生物(wu)濾(lv)(lv)池(chi)(chi)，很難(nan)正常運行；2）生物(wu)濾(lv)(lv)池(chi)(chi)工(gong)(gong)藝(yi)水(shui)(shui)頭(tou)損(sun)失大，進(jin)水(shui)(shui)出水(shui)(shui)升級改造(zao)部分二(er)級出水(shui)(shui) BAF 沉淀池(chi)(chi)氧(yang)化(hua)池(chi)(chi)消(xiao)毒池(chi)(chi)二(er)沉池(chi)(chi)格柵間圖2 氧(yang)化(hua)溝(gou)+BAF 工(gong)(gong)藝(yi)流(liu)程動(dong)力消(xiao)耗大，造(zao)成(cheng)運行成(cheng)本增(zeng)(zeng)加；3）生物(wu)濾(lv)(lv)池(chi)(chi)工(gong)(gong)藝(yi)由(you)于(yu)必(bi)須(xu)定期進(jin)行反沖洗，當多(duo)池(chi)(chi)并聯(lian)運行時，必(bi)須(xu)自動(dong)化(hua)控制(zhi)，導(dao)致(zhi)維護管(guan)理工(gong)(gong)作(zuo)量大，維護成(cheng)本增(zeng)(zeng)加；4）工(gong)(gong)程投(tou)資較大。
2.1.3 MBR工藝(yi)
（1）MBR的結構及(ji)工作(zuo)機理(li)
MBR是一(yi)種將污(wu)水(shui)的生物(wu)處理和(he)膜(mo)過濾(lv)(lv)技(ji)術(shu)相結(jie)合的高效廢水(shui)生物(wu)處理工(gong)(gong)藝。它把膜(mo)分離(li)技(ji)術(shu)和(he)生物(wu)技(ji)術(shu)結(jie)合起來，采用(yong)膜(mo)組(zu)件(jian)取代常規二(er)級生化處理工(gong)(gong)藝中二(er)沉池、砂濾(lv)(lv)、消毒(du)等單元，用(yong)超(chao)（微）濾(lv)(lv)膜(mo)對曝(pu)氣池出水(shui)直接進(jin)行過濾(lv)(lv)。
常見的一體(ti)式MBR的結構如圖3。將(jiang)膜組件直接置(zhi)入生(sheng)物反(fan)應器內，曝氣器放在(zai)膜組件的下面，通過真空泵進行(xing)抽吸，得到過濾液。MBR作為污水(shui)經二級處理后的深(shen)度(du)處理工藝流(liu)程見圖4。
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| 圖3 一體式MBR結構示意 |
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| 圖4 A2/O+MBR工藝流程 |
（2）MBR作為升級(ji)改造工(gong)藝的優(you)缺點
MBR工(gong)藝的(de)主要(yao)優(you)點是(shi)：1）對懸(xuan)浮物去除率(lv)高，抵抗污(wu)(wu)泥(ni)膨(peng)脹能力(li)強(qiang)，出水(shui)水(shui)質穩定，而且(qie)可去除部分(fen)細(xi)菌(jun)(jun)、病毒(du)，是(shi)一種對原(yuan)水(shui)處理后不(bu)必(bi)消毒(du)的(de)工(gong)藝；2）實現(xian)了(le)(le)懸(xuan)浮固體(ti)停留時間(jian)（SRT）和(he)水(shui)力(li)停留時間(jian)（HRT）的(de)徹底(di)分(fen)離，運行控制(zhi)更加靈活(huo)、穩定，易(yi)于(yu)(yu)實現(xian)自動(dong)控制(zhi)； 3）由(you)于(yu)(yu)膜(mo)組件對混合液的(de)高效分(fen)離，活(huo)性污(wu)(wu)泥(ni)幾乎沒(mei)有流失，大大提(ti)高了(le)(le)曝氣池中活(huo)性污(wu)(wu)泥(ni)的(de)（MLSS）濃度， MLSS可達到10～20g／L（好氧型），比(bi)傳(chuan)統(tong)的(de)MLSS濃度高出近10倍，提(ti)高容積負荷，設(she)備占地省；4）SRT延長，有利于(yu)(yu)增殖(zhi)緩(huan)慢的(de)細(xi)菌(jun)(jun)生(sheng)長（如硝(xiao)化(hua)細(xi)菌(jun)(jun)），可使(shi)硝(xiao)化(hua)細(xi)菌(jun)(jun)在(zai)曝氣池內(nei)積累(lei)，從而提(ti)高系(xi)統(tong)的(de)硝(xiao)化(hua)能力(li)，還可以提(ti)高難(nan)降(jiang)解(jie)有機物的(de)降(jiang)解(jie)速率(lv)；5）剩余(yu)污(wu)(wu)泥(ni)產生(sheng)量少，污(wu)(wu)泥(ni)處置費用較低。
MBR工藝的(de)主要缺點為：1）對懸(xuan)浮物(wu)、有機物(wu)等的(de)去除效果較好，但是對N、P的(de)去除效果不夠理(li)想；2）由于膜(mo)生(sheng)物(wu)反應器的(de)壽命較短，膜(mo)更換(huan)成本(ben)高(gao)，造成設備的(de)維(wei)護費用較高(gao)；3）膜(mo)易污染(ran)，造成堵塞，必(bi)須(xu)(xu)定期采(cai)用化學藥品清洗，導(dao)致操(cao)作過程復雜，運行成本(ben)升高(gao)；4）膜(mo)組件在運行時，為了保證膜(mo)表面不易被生(sheng)物(wu)污染(ran)或堵塞，必(bi)須(xu)(xu)保證高(gao)的(de)汽水比（汽水比一般需25:1），這(zhe)樣造成了能耗升高(gao)，水處理(li)成本(ben)增加。
綜(zong)上所述，我國目前對污(wu)(wu)水(shui)處(chu)理(li)(li)廠出水(shui)深度處(chu)理(li)(li)采用的這些常規工(gong)藝技術，無論在(zai)操作運行管(guan)理(li)(li)，還是在(zai)工(gong)程投(tou)資(zi)，處(chu)理(li)(li)成本方面都不夠理(li)(li)想(xiang)，因此，開(kai)發更為經(jing)濟有效(xiao)的污(wu)(wu)水(shui)深度處(chu)理(li)(li)工(gong)藝技術具有十分重要的意義。
3 未來可能工程化應用的新技術
3.1 NPR工(gong)藝(yi)技術
（1）NPR工(gong)藝(yi)(yi)機(ji)(ji)理 NPR技術是(shi)A2/O與(yu)BAF工(gong)藝(yi)(yi)技術的(de)有(you)機(ji)(ji)結合。該工(gong)藝(yi)(yi)的(de)特(te)點是(shi)高效地解決了脫氮除(chu)磷(lin)問題(ti)。NPR工(gong)藝(yi)(yi)可分(fen)為兩(liang)個主(zhu)體(ti)生(sheng)(sheng)化(hua)(hua)(hua)段(duan)(duan)，第(di)一(yi)主(zhu)體(ti)生(sheng)(sheng)化(hua)(hua)(hua)段(duan)(duan)設(she)置(zhi)有(you)厭(yan)氧(yang)(yang)(yang)段(duan)(duan)、缺氧(yang)(yang)(yang)段(duan)(duan)和(he)好氧(yang)(yang)(yang)保持段(duan)(duan)三部(bu)分(fen)，與(yu)A2/O基本相似(si)。污水(shui)在(zai)厭(yan)氧(yang)(yang)(yang)段(duan)(duan)釋放(fang)磷(lin)、部(bu)分(fen)有(you)機(ji)(ji)物(wu)(wu)(wu)(wu)進(jin)行降(jiang)解，在(zai)缺氧(yang)(yang)(yang)段(duan)(duan)進(jin)行反(fan)硝(xiao)化(hua)(hua)(hua)脫氮，同(tong)時去除(chu)大部(bu)分(fen)有(you)機(ji)(ji)物(wu)(wu)(wu)(wu)。好氧(yang)(yang)(yang)段(duan)(duan)為氧(yang)(yang)(yang)保持段(duan)(duan)，不進(jin)行硝(xiao)化(hua)(hua)(hua)反(fan)應(ying)，只進(jin)行部(bu)分(fen)有(you)機(ji)(ji)物(wu)(wu)(wu)(wu)降(jiang)解。好氧(yang)(yang)(yang)段(duan)(duan)出(chu)(chu)水(shui)經二沉(chen)池(chi)(chi)沉(chen)降(jiang)處(chu)理后(hou)，進(jin)入第(di)二主(zhu)體(ti)生(sheng)(sheng)物(wu)(wu)(wu)(wu)段(duan)(duan)。該段(duan)(duan)安裝有(you)新型生(sheng)(sheng)物(wu)(wu)(wu)(wu)填料，對(dui)(dui)污水(shui)中(zhong)的(de)有(you)機(ji)(ji)物(wu)(wu)(wu)(wu)、氨氮、磷(lin)進(jin)一(yi)步吸附(fu)和(he)生(sheng)(sheng)物(wu)(wu)(wu)(wu)降(jiang)解。生(sheng)(sheng)物(wu)(wu)(wu)(wu)濾(lv)池(chi)(chi)出(chu)(chu)水(shui)一(yi)部(bu)分(fen)排放(fang)，另一(yi)部(bu)分(fen)回流(liu)到(dao)前置(zhi)的(de)缺氧(yang)(yang)(yang)反(fan)應(ying)池(chi)(chi)中(zhong)進(jin)行反(fan)硝(xiao)化(hua)(hua)(hua)。二沉(chen)池(chi)(chi)產(chan)生(sheng)(sheng)的(de)污泥一(yi)部(bu)分(fen)回流(liu)到(dao)厭(yan)氧(yang)(yang)(yang)段(duan)(duan)，另一(yi)部(bu)分(fen)剩余污泥排出(chu)(chu)系(xi)統(tong)后(hou)進(jin)行脫水(shui)處(chu)理。在(zai)NPR工(gong)藝(yi)(yi)中(zhong)，大量的(de)有(you)機(ji)(ji)物(wu)(wu)(wu)(wu)在(zai)缺氧(yang)(yang)(yang)段(duan)(duan)被去除(chu)；好氧(yang)(yang)(yang)段(duan)(duan)曝氣時間僅(jin)為A2/O工(gong)藝(yi)(yi)曝氣段(duan)(duan)的(de)1/5～ 1/4，短時間的(de)曝氣不產(chan)生(sheng)(sheng)硝(xiao)化(hua)(hua)(hua)反(fan)應(ying)，僅(jin)去除(chu)剩余的(de)部(bu)分(fen)有(you)機(ji)(ji)物(wu)(wu)(wu)(wu)；由于好氧(yang)(yang)(yang)段(duan)(duan)曝氣時間縮(suo)短，污泥齡短，排出(chu)(chu)的(de)污泥中(zhong)含磷(lin)量高，可以(yi)(yi)明(ming)顯(xian)提高系(xi)統(tong)對(dui)(dui)磷(lin)的(de)去除(chu)率。其(qi)工(gong)藝(yi)(yi)流(liu)程見圖5。在(zai)NPR工(gong)藝(yi)(yi)中(zhong)，生(sheng)(sheng)物(wu)(wu)(wu)(wu)濾(lv)池(chi)(chi)內無需設(she)置(zhi)缺氧(yang)(yang)(yang)區，僅(jin)設(she)置(zhi)好氧(yang)(yang)(yang)區，這(zhe)樣其(qi)操作過程以(yi)(yi)及施(shi)工(gong)安裝都(dou)極其(qi)簡單(dan)。
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| 圖5 NPR工藝流程 |
（2）NPR技術優點
1）NPR工(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)藝(yi)(yi)好(hao)氧(yang)段(duan)(duan)(duan)與(yu)A2/O的(de)(de)(de)(de)(de)好(hao)氧(yang)段(duan)(duan)(duan)完全(quan)不(bu)同(tong)， NPR工(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)藝(yi)(yi)中(zhong)(zhong)(zhong)(zhong)(zhong)好(hao)氧(yang)段(duan)(duan)(duan)實質(zhi)(zhi)上是(shi)溶解氧(yang)的(de)(de)(de)(de)(de)保(bao)持段(duan)(duan)(duan)，水(shui)(shui)力(li)停(ting)留時(shi)(shi)間僅為A2/O工(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)藝(yi)(yi)的(de)(de)(de)(de)(de)1/5～1/4，容(rong)積很小，相應(ying)減少了(le)(le)占(zhan)地(di)面(mian)積及工(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)程(cheng)(cheng)造價；2）NPR工(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)藝(yi)(yi)中(zhong)(zhong)(zhong)(zhong)(zhong)好(hao)氧(yang)段(duan)(duan)(duan)由于(yu)不(bu)進(jin)行(xing)硝化(hua)(hua)(hua)，混合液中(zhong)(zhong)(zhong)(zhong)(zhong)硝態氮很少，因(yin)此，在(zai)二(er)沉池(chi)(chi)(chi)(chi)(chi)中(zhong)(zhong)(zhong)(zhong)(zhong)幾乎(hu)(hu)沒有(you)反硝化(hua)(hua)(hua)發生(sheng)，也(ye)不(bu)產生(sheng)N2，這(zhe)樣改(gai)善了(le)(le)污(wu)(wu)泥(ni)(ni)的(de)(de)(de)(de)(de)沉降(jiang)性能，使污(wu)(wu)泥(ni)(ni)不(bu)易(yi)上浮(fu)，二(er)沉池(chi)(chi)(chi)(chi)(chi)表(biao)面(mian)負(fu)荷也(ye)可明(ming)顯提(ti)(ti)(ti)(ti)(ti)高(gao)(gao)(gao)，水(shui)(shui)力(li)停(ting)留時(shi)(shi)間縮(suo)短，池(chi)(chi)(chi)(chi)(chi)容(rong)減小，出(chu)水(shui)(shui)中(zhong)(zhong)(zhong)(zhong)(zhong)SS降(jiang)低(di)(di)； 3）NPR工(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)藝(yi)(yi)中(zhong)(zhong)(zhong)(zhong)(zhong)由于(yu)二(er)沉池(chi)(chi)(chi)(chi)(chi)分離(li)出(chu)的(de)(de)(de)(de)(de)回(hui)流(liu)污(wu)(wu)泥(ni)(ni)中(zhong)(zhong)(zhong)(zhong)(zhong)不(bu)含硝酸(suan)鹽和(he)亞硝酸(suan)鹽，當(dang)其(qi)(qi)回(hui)流(liu)至厭氧(yang)段(duan)(duan)(duan)后(hou)(hou)，無氧(yang)的(de)(de)(de)(de)(de)釋放過(guo)程(cheng)(cheng)，從而(er)容(rong)易(yi)形成(cheng)(cheng)(cheng)良好(hao)的(de)(de)(de)(de)(de)厭氧(yang)過(guo)程(cheng)(cheng)，提(ti)(ti)(ti)(ti)(ti)高(gao)(gao)(gao)了(le)(le)回(hui)流(liu)污(wu)(wu)泥(ni)(ni)中(zhong)(zhong)(zhong)(zhong)(zhong)微生(sheng)物(wu)(wu)對(dui)磷的(de)(de)(de)(de)(de)釋放效(xiao)(xiao)(xiao)果，也(ye)同(tong)時(shi)(shi)改(gai)善了(le)(le)好(hao)氧(yang)段(duan)(duan)(duan)聚(ju)磷菌(jun)對(dui)磷的(de)(de)(de)(de)(de)攝取作用(yong)(yong)(yong)。特別是(shi)NPR工(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)藝(yi)(yi)中(zhong)(zhong)(zhong)(zhong)(zhong)污(wu)(wu)泥(ni)(ni)齡很短，污(wu)(wu)泥(ni)(ni)產出(chu)率(lv)相對(dui)提(ti)(ti)(ti)(ti)(ti)高(gao)(gao)(gao)，這(zhe)樣大(da)大(da)提(ti)(ti)(ti)(ti)(ti)高(gao)(gao)(gao)了(le)(le)磷的(de)(de)(de)(de)(de)去(qu)(qu)除(chu)效(xiao)(xiao)(xiao)果。根據(ju)實際工(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)程(cheng)(cheng)應(ying)用(yong)(yong)(yong)結(jie)(jie)果，總磷去(qu)(qu)除(chu)率(lv)可達到(dao)(dao)80%以(yi)上；4） NPR工(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)藝(yi)(yi)是(shi)A2/O工(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)藝(yi)(yi)與(yu)BAF工(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)藝(yi)(yi)相結(jie)(jie)合的(de)(de)(de)(de)(de)產物(wu)(wu)，二(er)沉池(chi)(chi)(chi)(chi)(chi)出(chu)水(shui)(shui)中(zhong)(zhong)(zhong)(zhong)(zhong)SS濃度(du)一般可低(di)(di)于(yu)40mg/L。這(zhe)樣就(jiu)保(bao)證(zheng)了(le)(le)BAF進(jin)水(shui)(shui)中(zhong)(zhong)(zhong)(zhong)(zhong)SS濃度(du)低(di)(di)于(yu)60mg/L的(de)(de)(de)(de)(de)要求，有(you)效(xiao)(xiao)(xiao)地(di)避免了(le)(le)生(sheng)物(wu)(wu)濾池(chi)(chi)(chi)(chi)(chi)堵(du)塞(sai)問題(ti)，同(tong)時(shi)(shi)NPR工(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)藝(yi)(yi)又充分利用(yong)(yong)(yong)了(le)(le)生(sheng)物(wu)(wu)濾池(chi)(chi)(chi)(chi)(chi)中(zhong)(zhong)(zhong)(zhong)(zhong)可以(yi)內裝(zhuang)對(dui)NH3-N具(ju)有(you)吸附作用(yong)(yong)(yong)的(de)(de)(de)(de)(de)濾料(liao)，生(sheng)物(wu)(wu)量可以(yi)提(ti)(ti)(ti)(ti)(ti)高(gao)(gao)(gao)， NH3-N硝化(hua)(hua)(hua)過(guo)程(cheng)(cheng)可以(yi)強化(hua)(hua)(hua)，有(you)利于(yu)對(dui)污(wu)(wu)水(shui)(shui)進(jin)行(xing)深(shen)度(du)處理(li)，從而(er)保(bao)證(zheng)了(le)(le)出(chu)水(shui)(shui)的(de)(de)(de)(de)(de)品質(zhi)(zhi)。一般而(er)言(yan)可以(yi)使出(chu)水(shui)(shui)水(shui)(shui)質(zhi)(zhi)達到(dao)(dao)中(zhong)(zhong)(zhong)(zhong)(zhong)水(shui)(shui)回(hui)用(yong)(yong)(yong)水(shui)(shui)平，與(yu)傳(chuan)統(tong)(tong)的(de)(de)(de)(de)(de)三級(ji)處理(li)工(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)藝(yi)(yi)相比（二(er)級(ji)生(sheng)化(hua)(hua)(hua)，一級(ji)物(wu)(wu)化(hua)(hua)(hua)）大(da)大(da)縮(suo)短了(le)(le)工(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)藝(yi)(yi)流(liu)程(cheng)(cheng)，省(sheng)去(qu)(qu)了(le)(le)混凝(ning)加(jia)藥過(guo)程(cheng)(cheng)，大(da)幅度(du)地(di)降(jiang)低(di)(di)了(le)(le)污(wu)(wu)水(shui)(shui)處理(li)成(cheng)(cheng)(cheng)本(ben)(ben)；5）在(zai)NPR工(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)藝(yi)(yi)中(zhong)(zhong)(zhong)(zhong)(zhong)，NH3-N的(de)(de)(de)(de)(de)硝化(hua)(hua)(hua)過(guo)程(cheng)(cheng)是(shi)在(zai)后(hou)(hou)置的(de)(de)(de)(de)(de)生(sheng)物(wu)(wu)濾池(chi)(chi)(chi)(chi)(chi)中(zhong)(zhong)(zhong)(zhong)(zhong)完成(cheng)(cheng)(cheng)，硝化(hua)(hua)(hua)液回(hui)流(liu)到(dao)(dao)前置的(de)(de)(de)(de)(de)缺氧(yang)段(duan)(duan)(duan)中(zhong)(zhong)(zhong)(zhong)(zhong)；這(zhe)樣省(sheng)去(qu)(qu)了(le)(le)典(dian)型的(de)(de)(de)(de)(de)BAF工(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)藝(yi)(yi)在(zai)生(sheng)物(wu)(wu)濾池(chi)(chi)(chi)(chi)(chi)中(zhong)(zhong)(zhong)(zhong)(zhong)設置缺氧(yang)層進(jin)行(xing)反硝過(guo)的(de)(de)(de)(de)(de)復雜過(guo)程(cheng)(cheng)，簡化(hua)(hua)(hua)了(le)(le)操作，提(ti)(ti)(ti)(ti)(ti)高(gao)(gao)(gao)了(le)(le)脫氮效(xiao)(xiao)(xiao)果，根據(ju)實際運行(xing)結(jie)(jie)果，總氮去(qu)(qu)除(chu)率(lv)可達到(dao)(dao)90%以(yi)上；6）雖(sui)然NPR工(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)藝(yi)(yi)中(zhong)(zhong)(zhong)(zhong)(zhong)在(zai)二(er)沉池(chi)(chi)(chi)(chi)(chi)之后(hou)(hou)增加(jia)了(le)(le)生(sheng)物(wu)(wu)濾池(chi)(chi)(chi)(chi)(chi)，在(zai)選用(yong)(yong)(yong)專用(yong)(yong)(yong)填料(liao)的(de)(de)(de)(de)(de)條(tiao)件(jian)下，其(qi)(qi)水(shui)(shui)力(li)停(ting)留時(shi)(shi)間僅為1.5～2h。全(quan)流(liu)程(cheng)(cheng)總的(de)(de)(de)(de)(de)水(shui)(shui)力(li)停(ting)留時(shi)(shi)間為 4～5h，與(yu)傳(chuan)統(tong)(tong)A2/O工(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)藝(yi)(yi)相比，池(chi)(chi)(chi)(chi)(chi)容(rong)積并未增加(jia)，只(zhi)是(shi)空(kong)間上進(jin)行(xing)了(le)(le)分割，構筑物(wu)(wu)增加(jia)了(le)(le)一個(ge)，并未增加(jia)工(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)程(cheng)(cheng)投(tou)資(zi)(zi)與(yu)運行(xing)成(cheng)(cheng)(cheng)本(ben)(ben)。這(zhe)樣在(zai)支付了(le)(le)A2/O二(er)級(ji)處理(li)效(xiao)(xiao)(xiao)果成(cheng)(cheng)(cheng)本(ben)(ben)的(de)(de)(de)(de)(de)條(tiao)件(jian)下卻(que)得到(dao)(dao)了(le)(le)三級(ji)處理(li)的(de)(de)(de)(de)(de)高(gao)(gao)(gao)品質(zhi)(zhi)用(yong)(yong)(yong)水(shui)(shui)；7）NPR工(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)藝(yi)(yi)中(zhong)(zhong)(zhong)(zhong)(zhong)硝化(hua)(hua)(hua)液從生(sheng)物(wu)(wu)濾池(chi)(chi)(chi)(chi)(chi)回(hui)流(liu)到(dao)(dao)缺氧(yang)段(duan)(duan)(duan)，與(yu)A2/O工(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)藝(yi)(yi)中(zhong)(zhong)(zhong)(zhong)(zhong)硝化(hua)(hua)(hua)液從曝氣(qi)池(chi)(chi)(chi)(chi)(chi)末端回(hui)流(liu)相比，并不(bu)增加(jia)投(tou)資(zi)(zi)和(he)動(dong)力(li)費用(yong)(yong)(yong)；8）NPR中(zhong)(zhong)(zhong)(zhong)(zhong)硝化(hua)(hua)(hua)液回(hui)流(liu)后(hou)(hou)，二(er)沉池(chi)(chi)(chi)(chi)(chi)系統(tong)(tong)應(ying)增加(jia)水(shui)(shui)力(li)負(fu)荷，但(dan)是(shi)由于(yu)進(jin)入(ru)二(er)沉池(chi)(chi)(chi)(chi)(chi)的(de)(de)(de)(de)(de)污(wu)(wu)泥(ni)(ni)沉降(jiang)性能改(gai)善，表(biao)面(mian)負(fu)荷提(ti)(ti)(ti)(ti)(ti)高(gao)(gao)(gao)，二(er)沉池(chi)(chi)(chi)(chi)(chi)的(de)(de)(de)(de)(de)容(rong)積幾乎(hu)(hu)不(bu)增加(jia)。因(yin)此，NPR工(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)藝(yi)(yi)的(de)(de)(de)(de)(de)工(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)程(cheng)(cheng)投(tou)資(zi)(zi)、運行(xing)成(cheng)(cheng)(cheng)本(ben)(ben)費幾乎(hu)(hu)與(yu)A2/O相同(tong)，但(dan)其(qi)(qi)出(chu)水(shui)(shui)水(shui)(shui)質(zhi)(zhi)比A2/O大(da)大(da)提(ti)(ti)(ti)(ti)(ti)高(gao)(gao)(gao)。
（3）NPR技術(shu)的缺(que)點
1）生物濾(lv)池(chi)工藝(yi)部分(fen)的(de)水頭損失大(da)，動(dong)力消耗大(da)； 2）生物濾(lv)池(chi)工藝(yi)部分(fen)由于必(bi)(bi)須(xu)定(ding)期反沖洗，當多池(chi)并聯運行(xing)時，必(bi)(bi)須(xu)自(zi)動(dong)控制(zhi)，導致維(wei)護管理復雜(za)。
（4）NPR技(ji)術的(de)應用(yong)前景
根據實(shi)驗研究結果(guo)以(yi)(yi)及對國外已(yi)運(yun)行(xing)工(gong)(gong)程的(de)實(shi)地考察分析，NPR工(gong)(gong)藝(yi)是由兩個在我(wo)國已(yi)經長期運(yun)行(xing)成(cheng)(cheng)熟的(de)工(gong)(gong)藝(yi)有(you)機組合形成(cheng)(cheng)的(de)新工(gong)(gong)藝(yi)，其(qi)工(gong)(gong)程應(ying)(ying)用比較(jiao)成(cheng)(cheng)熟可靠。NPR工(gong)(gong)藝(yi)與(yu)傳統(tong)的(de)活性污(wu)泥(ni)工(gong)(gong)藝(yi)相比，在同等的(de)投資費用和運(yun)行(xing)成(cheng)(cheng)本條件(jian)下，可以(yi)(yi)直(zhi)接將(jiang)城市(shi)污(wu)水處理(li)成(cheng)(cheng)回用水水質，生物除磷效果(guo)可以(yi)(yi)提高2倍(bei)以(yi)(yi)上，脫氮效率可以(yi)(yi)提高50%～70%。因此，NPR工(gong)(gong)藝(yi)在我(wo)國具有(you)廣闊的(de)應(ying)(ying)用前景。
3.2 CNR（纖毛狀生物膜脫氮除磷）工藝
（1）CNR技術(shu)簡介
CNR技(ji)術是在活性污(wu)(wu)泥法好氧(yang)池中(zhong)通過(guo)使用有選擇性吸附NH4+離(li)子(zi)能力的纖毛狀生物(wu)填料增(zeng)加好氧(yang)池中(zhong)總生物(wu)量（主要(yao)是硝化菌類），達(da)到強(qiang)化生物(wu)深度(du)脫氮除磷的一種(zhong)新(xin)型的工藝(yi)技(ji)術。作為一種(zhong)適宜(yi)于對現有污(wu)(wu)水處理廠(chang)進(jin)行(xing)改(gai)造的強(qiang)化工藝(yi)，因其簡單(dan)易行(xing)，可以廣泛地應用于需要(yao)污(wu)(wu)水深度(du)處理的工藝(yi)技(ji)術改(gai)造中(zhong)。
CNR工藝(yi)在好氧池中(zhong)(zhong)填(tian)充(chong)有(you)(you)高效纖(xian)毛(mao)狀生(sheng)物(wu)(wu)膜(mo)填(tian)料。這種(zhong)纖(xian)毛(mao)狀生(sheng)物(wu)(wu)膜(mo)填(tian)料能(neng)有(you)(you)效地固定增殖速度較慢(man)的(de)(de)硝化微生(sheng)物(wu)(wu)，可明(ming)顯提(ti)高硝化反應(ying)速率(lv)。在裝填(tian)有(you)(you)這種(zhong)填(tian)料的(de)(de)反應(ying)池中(zhong)(zhong)，依靠附著微生(sheng)物(wu)(wu)和分散的(de)(de)浮游(you)微生(sheng)物(wu)(wu)提(ti)高污(wu)染(ran)物(wu)(wu)的(de)(de)去除效率(lv)。微生(sheng)物(wu)(wu)在纖(xian)毛(mao)中(zhong)(zhong)具有(you)(you)優良的(de)(de)附著和脫落能(neng)力(li)，不易產(chan)生(sheng)堵塞現象。纖(xian)毛(mao)狀生(sheng)物(wu)(wu)膜(mo)填(tian)料見(jian)圖6，CNR工藝(yi)流程見(jian)圖7。
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| 圖6 纖毛狀生物填料微生物附著示意 |
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| 圖7 CNR工藝流程 |
（2）纖毛填料的特點(dian)
1）改良的直毛狀生物填料比表面積大（1000m2/m3以上），附著的生物量多，處理(li)效率高。因此水力(li)停留時間短；工程(cheng)投資省；2）微生物容易掛膜、脫膜，無堵(du)塞現(xian)象，不需(xu)要反沖洗(xi)，維護和管理(li)簡單容易；3）耐久性強，10年不用(yong)更換；4）具有對NH4+強吸附能力(li)；硝化(hua)能力(li)強，脫氮率高。
（3）CNR工(gong)藝的優點(dian)
1）抗沖(chong)擊(ji)能力強，出水(shui)水(shui)質穩定。其(qi)抗沖(chong)擊(ji)負荷強的(de)(de)優勢(shi)主要(yao)來自以下(xia)幾(ji)種(zhong)作用(yong)：纖毛(mao)狀(zhuang)生(sheng)物膜中(zhong)大量附著(zhu)的(de)(de)微生(sheng)物和(he)大量分散浮游的(de)(de)微生(sheng)物的(de)(de)協(xie)同作用(yong)，保證了穩定地高效(xiao)處理各種(zhong)污水(shui)及其(qi)耐沖(chong)擊(ji)能力；纖毛(mao)狀(zhuang)生(sheng)物膜的(de)(de)生(sheng)物種(zhong)群和(he)水(shui)膜作用(yong)，在低水(shui)溫（7℃～10℃）環境(jing)下(xia)，仍能保持高的(de)(de)處理效(xiao)率(lv)。
2）用于(yu)污水深(shen)度(du)(du)處(chu)(chu)理(li)(li)工(gong)(gong)(gong)程(cheng)的(de)投資少，運行成(cheng)本較低。其經濟優(you)勢主要(yao)來(lai)自以下幾方(fang)面：停留時間短（HRT≤6h），因此需要(yao)的(de)水處(chu)(chu)理(li)(li)構筑物占地面積小，工(gong)(gong)(gong)程(cheng)投資少；由(you)附著微生物膜內部的(de)缺氧(yang)區域產(chan)生反硝(xiao)(xiao)化(hua)作用，不需要(yao)大量的(de)硝(xiao)(xiao)化(hua)液回流，與其他工(gong)(gong)(gong)藝(yi)相比，對(dui)于(yu)污水深(shen)度(du)(du)處(chu)(chu)理(li)(li)不會明顯(xian)增(zeng)加(jia)動力消耗，從而減少了(le)運行成(cheng)本；由(you)于(yu)這種工(gong)(gong)(gong)藝(yi)排出(chu)的(de)污泥中(zhong)磷含量明顯(xian)增(zeng)加(jia)，提(ti)高了(le)生物除磷效果(guo)，與需要(yao)化(hua)學(xue)除磷的(de)其他工(gong)(gong)(gong)藝(yi)相比，節約了(le)運行成(cheng)本。
3）CNR工(gong)藝用于處理(li)污水時(shi)，附著在填料上的微生(sheng)物和后(hou)生(sheng)動物的協同作用會引(yin)起有機物的深度(du)氧化，與常(chang)規處理(li)工(gong)藝相比，可使污泥產生(sheng)量減少20%～30%。
4）CNR工(gong)(gong)藝(yi)操作(zuo)(zuo)方(fang)便，維護管理簡(jian)單(dan)。CNR工(gong)(gong)藝(yi)與 A2/O工(gong)(gong)藝(yi)全部為連續流，不(bu)需要反沖洗過程，因此操作(zuo)(zuo)過程十分簡(jian)單(dan)；直毛狀(zhuang)纖維生物膜具有(you)比表(biao)面積大(da)、耐(nai)久性(xing)強的優勢；而且具有(you)掛膜容易(yi)、脫膜快(kuai)的特點，無堵(du)塞現象，不(bu)需要經常更換，減少了維護工(gong)(gong)作(zuo)(zuo)，也降低了運行成本。
（3）CNR技術的缺點
該填料目前仍在國(guo)產化階段，因此需(xu)要從國(guo)外(wai)進口才能滿足國(guo)內市場需(xu)要。
（4）CNR技(ji)術的應用前景(jing)
根據實(shi)驗研究(jiu)結果(guo)(guo)以(yi)及對國(guo)外(wai)已(yi)運行工(gong)(gong)程(cheng)的(de)實(shi)地考察分析，CNR技術(shu)工(gong)(gong)程(cheng)應(ying)(ying)用(yong)已(yi)經比較成熟可(ke)靠。CNR技術(shu)用(yong)于污(wu)水(shui)(shui)(shui)(shui)深(shen)度處理(li)，具(ju)有(you)明顯的(de)優勢。特(te)別(bie)是CNR技術(shu)用(yong)于二(er)級(ji)(ji)污(wu)水(shui)(shui)(shui)(shui)處理(li)廠升(sheng)級(ji)(ji)改造時與(yu)傳統的(de)其他(ta)工(gong)(gong)藝相比，基本上(shang)只(zhi)需在(zai)好氧池中(zhong)增設填料，在(zai)工(gong)(gong)程(cheng)投資很(hen)少（300元/m3）以(yi)及運行成本與(yu)二(er)級(ji)(ji)污(wu)水(shui)(shui)(shui)(shui)處理(li)成本相差不(bu)多(duo)的(de)條件(jian)下(xia)，就可(ke)以(yi)直接將城市污(wu)水(shui)(shui)(shui)(shui)處理(li)成回(hui)用(yong)標準水(shui)(shui)(shui)(shui)的(de)水(shui)(shui)(shui)(shui)質，生物除磷效果(guo)(guo)可(ke)提(ti)高2倍以(yi)上(shang)，脫氮效率可(ke)提(ti)高50%。因(yin)此，CNR工(gong)(gong)藝技術(shu)在(zai)我國(guo)具(ju)有(you)廣(guang)闊的(de)應(ying)(ying)用(yong)前景。
3.3 人工濕地
（1）人工濕地技術簡介
人(ren)(ren)工濕(shi)地技術是由人(ren)(ren)工基質(zhi)、水(shui)生(sheng)(sheng)植(zhi)物(wu)和微生(sheng)(sheng)物(wu)組(zu)成的(de)水(shui)處理(li)構(gou)筑物(wu)。人(ren)(ren)工基質(zhi)為微生(sheng)(sheng)物(wu)的(de)生(sheng)(sheng)長(chang)提供了(le)穩定的(de)依附表面，為水(shui)生(sheng)(sheng)植(zhi)物(wu)提供載體。人(ren)(ren)工濕(shi)地通過一系(xi)列的(de)物(wu)理(li)、化(hua)學(xue)、生(sheng)(sheng)物(wu)的(de)作用(yong)(yong)凈化(hua)污(wu)(wu)水(shui)。水(shui)生(sheng)(sheng)植(zhi)物(wu)除直接吸(xi)收(shou)、富集(ji)、利(li)用(yong)(yong)污(wu)(wu)水(shui)中的(de)有毒有害物(wu)質(zhi)外，還有輸送氧氣到根區和維持水(shui)力(li)傳輸的(de)作用(yong)(yong)；微生(sheng)(sheng)物(wu)的(de)代謝(xie)作用(yong)(yong)是污(wu)(wu)水(shui)中有機物(wu)降解(jie)的(de)主(zhu)要機制(zhi)。
人(ren)工濕地(di)曾用于直接處(chu)理生活污(wu)水(shui)，但由于易(yi)發生堵塞(sai)等問題，導致處(chu)理效(xiao)果不(bu)好。目前普遍認為(wei)人(ren)工濕地(di)技(ji)(ji)術適用于處(chu)理低(di)濃度、微污(wu)染的(de)含有(you)易(yi)降解(jie)有(you)機污(wu)染物(wu)的(de)污(wu)水(shui)。也適用于處(chu)理污(wu)水(shui)處(chu)理廠排出的(de)尾(wei)水(shui)，也就(jiu)是說可作為(wei)污(wu)水(shui)處(chu)理廠升級改造的(de)備選技(ji)(ji)術。近幾年來(lai)，人(ren)工濕地(di)技(ji)(ji)術在我國得(de)到迅速發展，也被大量用于地(di)表水(shui)體(ti)的(de)修復。
（2）人工濕地技術的優點
1）工(gong)程投(tou)資較少；運行(xing)成本較低；2）在進行(xing)污水處(chu)理的(de)同時還可增加綠(lv)地面積(ji)，改善生態(tai)環境，具有良好(hao)的(de)景(jing)觀效果(guo)；3）人工(gong)濕地植物不僅能(neng)凈化(hua)污水，收割后(hou)還有較高的(de)利用價值，能(neng)夠(gou)帶來一定的(de)經(jing)濟(ji)效益； 4）工(gong)藝過程簡單，運行(xing)維護方便。
（3）人工濕地技術(shu)的缺點(dian)
1）占地(di)(di)面(mian)積較(jiao)大(da)；2）容(rong)易發(fa)生堵塞(sai)。作為污(wu)水處理廠升級改(gai)造的(de)后續工藝時，要(yao)求污(wu)水處理廠出水的(de)SS濃度不能太(tai)高，以防(fang)止人(ren)工濕地(di)(di)堵塞(sai)；3）要(yao)求適(shi)宜的(de)自(zi)然氣候(hou)條件，比(bi)較(jiao)適(shi)用于南(nan)方地(di)(di)區，不適(shi)合北(bei)方寒冷地(di)(di)區使用。
（4）人工濕地技(ji)術的應用(yong)前景
目前，我國(guo)絕大部分污水(shui)(shui)(shui)(shui)處理(li)廠的(de)尾水(shui)(shui)(shui)(shui)都是直(zhi)接排入地(di)(di)表(biao)水(shui)(shui)(shui)(shui)體(ti)中。即(ji)使排放的(de)尾水(shui)(shui)(shui)(shui)水(shui)(shui)(shui)(shui)質達到(dao)一(yi)級A標(biao)準，也(ye)不能(neng)滿(man)足地(di)(di)表(biao)水(shui)(shui)(shui)(shui)體(ti)的(de)水(shui)(shui)(shui)(shui)質要(yao)求(qiu)。尤其(qi)是尾水(shui)(shui)(shui)(shui)中氮(dan)(dan)磷(lin)濃度(du)較高，已(yi)成為排入地(di)(di)表(biao)水(shui)(shui)(shui)(shui)體(ti)的(de)約束指標(biao)。采(cai)用(yong)其(qi)他工(gong)藝(yi)技術(shu)削減這種低濃度(du)的(de)氮(dan)(dan)磷(lin)都不經(jing)濟，人工(gong)濕(shi)地(di)(di)工(gong)藝(yi)則更為適(shi)宜。為了防止污水(shui)(shui)(shui)(shui)處理(li)廠尾水(shui)(shui)(shui)(shui)排入地(di)(di)表(biao)水(shui)(shui)(shui)(shui)體(ti)后造成的(de)富營養化，采(cai)用(yong)人工(gong)濕(shi)地(di)(di)工(gong)藝(yi)是一(yi)個行之有效的(de)工(gong)程技術(shu)手段，因此人工(gong)濕(shi)地(di)(di)工(gong)藝(yi)在(zai)我國(guo)污水(shui)(shui)(shui)(shui)處理(li)廠排放的(de)尾水(shui)(shui)(shui)(shui)深度(du)處理(li)中具有廣闊的(de)應(ying)用(yong)前景。
4 東莞市污水處理廠升級改造技術路線
東莞市(shi)絕(jue)大部分污水(shui)(shui)(shui)處理(li)廠排(pai)放的(de)(de)尾水(shui)(shui)(shui)都直接進入東莞運河或其他河涌，這些(xie)尾水(shui)(shui)(shui)水(shui)(shui)(shui)質(zhi)遠(yuan)劣于地表水(shui)(shui)(shui)水(shui)(shui)(shui)質(zhi)的(de)(de)要求，尤其是作為(wei)備用水(shui)(shui)(shui)源的(de)(de)一(yi)些(xie)水(shui)(shui)(shui)庫，水(shui)(shui)(shui)質(zhi)受尾水(shui)(shui)(shui)的(de)(de)影(ying)響將會(hui)更大。因(yin)此東莞市(shi)面臨著污水(shui)(shui)(shui)處理(li)廠技術升級改造的(de)(de)問題。
鑒于(yu)東莞市幾十座(zuo)污(wu)(wu)水(shui)(shui)處(chu)理廠絕大(da)多數采(cai)用的(de)(de)(de)都(dou)是(shi)(shi) BOT的(de)(de)(de)建設(she)模式，基本(ben)(ben)采(cai)用了(le)A2/O、CASS、氧化溝三種工藝(yi)，地表水(shui)(shui)體的(de)(de)(de)水(shui)(shui)質(zhi)要求應(ying)優于(yu)Ⅳ類(lei)水(shui)(shui)質(zhi)。特別是(shi)(shi)考(kao)慮到污(wu)(wu)水(shui)(shui)處(chu)理廠升(sheng)級(ji)改(gai)造(zao)的(de)(de)(de)經(jing)濟成(cheng)本(ben)(ben)，為(wei)了(le)盡可(ke)能減少政(zheng)府經(jing)濟負擔，對于(yu)這(zhe)(zhe)些(xie)污(wu)(wu)水(shui)(shui)處(chu)理廠升(sheng)級(ji)改(gai)造(zao)技(ji)術方面(mian)最為(wei)有效、經(jing)濟方面(mian)最為(wei)節約的(de)(de)(de)工藝(yi)應(ying)是(shi)(shi)CNR工藝(yi)技(ji)術。這(zhe)(zhe)種工藝(yi)只需在(zai)原有工藝(yi)的(de)(de)(de)好氧反應(ying)池中(zhong)安裝(zhuang)特種生物(wu)填(tian)料，在(zai)其后(hou)加一(yi)個過(guo)濾設(she)施即可(ke)達(da)到一(yi)級(ji)A的(de)(de)(de)出(chu)水(shui)(shui)標準。處(chu)理每(mei)噸水(shui)(shui)的(de)(de)(de)技(ji)改(gai)工程總投資不(bu)超過(guo)500元，運行成(cheng)本(ben)(ben)不(bu)超過(guo)0.2元。
5 結論
（1）鑒于(yu)目前東(dong)莞市污(wu)水(shui)(shui)(shui)(shui)處理廠(chang)排放(fang)(fang)的(de)(de)(de)尾水(shui)(shui)(shui)(shui)普遍是一(yi)級B標準，而(er)這(zhe)些排放(fang)(fang)的(de)(de)(de)尾水(shui)(shui)(shui)(shui)又(you)是東(dong)莞運(yun)(yun)河的(de)(de)(de)主(zhu)要(yao)(yao)補充水(shui)(shui)(shui)(shui)源，這(zhe)種尾水(shui)(shui)(shui)(shui)的(de)(de)(de)水(shui)(shui)(shui)(shui)質與(yu)東(dong)莞運(yun)(yun)河地表水(shui)(shui)(shui)(shui)的(de)(de)(de)水(shui)(shui)(shui)(shui)質要(yao)(yao)求(qiu)相差甚遠，從而(er)使東(dong)莞運(yun)(yun)河面臨水(shui)(shui)(shui)(shui)體(ti)富(fu)營養化及水(shui)(shui)(shui)(shui)質不能(neng)達標的(de)(de)(de)風(feng)險，因此，對這(zhe)些污(wu)水(shui)(shui)(shui)(shui)處理廠(chang)進行(xing)升級改(gai)造使其排放(fang)(fang)的(de)(de)(de)尾水(shui)(shui)(shui)(shui)水(shui)(shui)(shui)(shui)質滿(man)足(zu)東(dong)莞運(yun)(yun)河或水(shui)(shui)(shui)(shui)庫受納水(shui)(shui)(shui)(shui)體(ti)的(de)(de)(de)要(yao)(yao)求(qiu)十分必(bi)要(yao)(yao)，勢在必(bi)行(xing)。
（2）通(tong)過對目(mu)前(qian)國內(nei)污(wu)水處(chu)(chu)理(li)(li)(li)(li)(li)廠(chang)升級(ji)(ji)改造普遍采用的(de)(de)(de)(de)(de)傳統(tong)工(gong)(gong)藝以及目(mu)前(qian)新開發的(de)(de)(de)(de)(de)在(zai)未來具有(you)廣(guang)闊應用前(qian)景的(de)(de)(de)(de)(de)幾(ji)種工(gong)(gong)藝的(de)(de)(de)(de)(de)綜合分(fen)析比較(jiao)發現，CNR工(gong)(gong)藝具有(you)技改工(gong)(gong)程(cheng)投(tou)資(zi)少、運(yun)行(xing)成本(ben)低、操作(zuo)管理(li)(li)(li)(li)(li)方便的(de)(de)(de)(de)(de)優(you)點，而且已經有(you)十多(duo)座污(wu)水處(chu)(chu)理(li)(li)(li)(li)(li)廠(chang)改造運(yun)行(xing)的(de)(de)(de)(de)(de)經驗，對于污(wu)水處(chu)(chu)理(li)(li)(li)(li)(li)廠(chang)的(de)(de)(de)(de)(de)升級(ji)(ji)改造具有(you)較(jiao)多(duo)的(de)(de)(de)(de)(de)優(you)勢；NPR工(gong)(gong)藝對于新建(jian)污(wu)水處(chu)(chu)理(li)(li)(li)(li)(li)廠(chang)要求直接將污(wu)水處(chu)(chu)理(li)(li)(li)(li)(li)成一(yi)級(ji)(ji)A或回用標準(zhun)的(de)(de)(de)(de)(de)污(wu)水處(chu)(chu)理(li)(li)(li)(li)(li)工(gong)(gong)程(cheng)更為適宜；人工(gong)(gong)濕地更適用于對污(wu)水處(chu)(chu)理(li)(li)(li)(li)(li)廠(chang)排放的(de)(de)(de)(de)(de)尾水進行(xing)更高標準(zhun)的(de)(de)(de)(de)(de)深(shen)度處(chu)(chu)理(li)(li)(li)(li)(li)。
（3）鑒于東莞市(shi)污水處理(li)(li)廠(chang)采用(yong)采用(yong)CNR工藝(yi)(yi)具有(you)技改(gai)工程投資少，運行成本低，操作管理(li)(li)方便的優(you)(you)點，東莞市(shi)城市(shi)污水處理(li)(li)廠(chang)的升級改(gai)造應優(you)(you)先選(xuan)擇CNR工藝(yi)(yi)。
（4）東莞市(shi)是一個被水(shui)污(wu)染嚴重困擾的(de)(de)城市(shi)，在全(quan)國具有(you)代表性和典型性，同時東莞市(shi)具有(you)較強的(de)(de)經濟(ji)實力(li)，應(ying)當積極推動城市(shi)污(wu)水(shui)處(chu)理廠(chang)升級(ji)改(gai)(gai)造，為東莞市(shi)水(shui)環(huan)境(jing)的(de)(de)徹底改(gai)(gai)善奠定基礎，為全(quan)國的(de)(de)水(shui)污(wu)染防治積累更多的(de)(de)經驗。
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