煉化企業污水回用膜污染原因分析
1前言
目前,隨著我國水(shui)(shui)(shui)(shui)(shui)(shui)(shui)資源危機的(de)(de)不斷加劇,多數(shu)煉化(hua)(hua)(hua)企(qi)業(ye)(ye)(ye)新建(jian)、改擴建(jian)時不能(neng)增加用(yong)水(shui)(shui)(shui)(shui)(shui)(shui)(shui)指(zhi)標,急需實(shi)施節水(shui)(shui)(shui)(shui)(shui)(shui)(shui)減排措(cuo)施,以(yi)確保企(qi)業(ye)(ye)(ye)正常(chang)發(fa)展。煉化(hua)(hua)(hua)污(wu)(wu)水(shui)(shui)(shui)(shui)(shui)(shui)(shui)的(de)(de)回(hui)(hui)用(yong),是(shi)企(qi)業(ye)(ye)(ye)節水(shui)(shui)(shui)(shui)(shui)(shui)(shui)減排的(de)(de)重(zhong)要措(cuo)施之一。由(you)于(yu)用(yong)水(shui)(shui)(shui)(shui)(shui)(shui)(shui)指(zhi)標的(de)(de)嚴格要求,許多煉化(hua)(hua)(hua)企(qi)業(ye)(ye)(ye)采(cai)用(yong)雙膜處(chu)(chu)理(li)(li)(li)(li)工(gong)藝,將污(wu)(wu)水(shui)(shui)(shui)(shui)(shui)(shui)(shui)深(shen)度處(chu)(chu)理(li)(li)(li)(li)后,最大限度實(shi)現(xian)污(wu)(wu)水(shui)(shui)(shui)(shui)(shui)(shui)(shui)回(hui)(hui)用(yong)。包(bao)括微濾、超濾、納濾和(he)反滲透在(zai)內(nei)的(de)(de)膜分(fen)離技術(shu),在(zai)電(dian)力和(he)冶金行(xing)業(ye)(ye)(ye)的(de)(de)給水(shui)(shui)(shui)(shui)(shui)(shui)(shui)處(chu)(chu)理(li)(li)(li)(li)和(he)廢水(shui)(shui)(shui)(shui)(shui)(shui)(shui)回(hui)(hui)用(yong)中(zhong)已經得(de)到廣泛應(ying)用(yong),但(dan)對(dui)于(yu)石(shi)化(hua)(hua)(hua)廢水(shui)(shui)(shui)(shui)(shui)(shui)(shui)中(zhong)煉油廢水(shui)(shui)(shui)(shui)(shui)(shui)(shui)和(he)化(hua)(hua)(hua)工(gong)廢水(shui)(shui)(shui)(shui)(shui)(shui)(shui)的(de)(de)處(chu)(chu)理(li)(li)(li)(li),始(shi)終沒有得(de)到行(xing)業(ye)(ye)(ye)內(nei)部的(de)(de)認同,仍然處(chu)(chu)于(yu)實(shi)驗摸索階段。雙膜處(chu)(chu)理(li)(li)(li)(li)工(gong)藝在(zai)石(shi)化(hua)(hua)(hua)企(qi)業(ye)(ye)(ye)的(de)(de)應(ying)用(yong)將近十年(nian),各(ge)企(qi)業(ye)(ye)(ye)回(hui)(hui)用(yong)處(chu)(chu)理(li)(li)(li)(li)工(gong)藝操作基(ji)本(ben)成熟,但(dan)由(you)于(yu)煉化(hua)(hua)(hua)污(wu)(wu)水(shui)(shui)(shui)(shui)(shui)(shui)(shui)來(lai)水(shui)(shui)(shui)(shui)(shui)(shui)(shui)工(gong)藝復雜,導(dao)致膜污(wu)(wu)染(ran)現(xian)象嚴重(zhong),成為(wei)制約煉化(hua)(hua)(hua)企(qi)業(ye)(ye)(ye)污(wu)(wu)水(shui)(shui)(shui)(shui)(shui)(shui)(shui)回(hui)(hui)用(yong)的(de)(de)瓶(ping)頸(jing)。因(yin)此(ci),分(fen)析污(wu)(wu)水(shui)(shui)(shui)(shui)(shui)(shui)(shui)回(hui)(hui)用(yong)系統膜污(wu)(wu)染(ran)發(fa)生的(de)(de)原因(yin),確定(ding)膜污(wu)(wu)染(ran)控制技術(shu),是(shi)煉化(hua)(hua)(hua)企(qi)業(ye)(ye)(ye)污(wu)(wu)水(shui)(shui)(shui)(shui)(shui)(shui)(shui)回(hui)(hui)用(yong)需要解(jie)決的(de)(de)關鍵技術(shu)問題。
以反(fan)(fan)(fan)滲透技術(shu)為核心(xin)的(de)(de)(de)(de)雙膜(mo)(mo)(mo)(mo)組合(he)工(gong)藝作為工(gong)業(ye)廢(fei)水回(hui)(hui)用(yong)領域的(de)(de)(de)(de)一(yi)項新技術(shu),引起了人們(men)越(yue)來越(yue)多(duo)的(de)(de)(de)(de)關注(zhu),也為工(gong)業(ye)企業(ye)污(wu)(wu)(wu)水回(hui)(hui)用(yong)提供(gong)了很(hen)好(hao)的(de)(de)(de)(de)處(chu)理工(gong)藝。但膜(mo)(mo)(mo)(mo)污(wu)(wu)(wu)染(ran)(ran)一(yi)直是(shi)反(fan)(fan)(fan)滲透技術(shu)在(zai)實(shi)際工(gong)程中(zhong)推廣應用(yong)所面(mian)臨的(de)(de)(de)(de)一(yi)大(da)障(zhang)礙。膜(mo)(mo)(mo)(mo)污(wu)(wu)(wu)染(ran)(ran)是(shi)由于膜(mo)(mo)(mo)(mo)表(biao)面(mian)形成(cheng)了附著層(ceng)、膜(mo)(mo)(mo)(mo)孔通(tong)道發生堵(du)塞引起的(de)(de)(de)(de)。反(fan)(fan)(fan)滲透膜(mo)(mo)(mo)(mo)污(wu)(wu)(wu)染(ran)(ran)究其原(yuan)因,主(zhu)要有(you)(you)以下幾種:①結(jie)垢(gou)污(wu)(wu)(wu)染(ran)(ran)。由于反(fan)(fan)(fan)滲透脫(tuo)鹽的(de)(de)(de)(de)特點,反(fan)(fan)(fan)滲透過(guo)(guo)程是(shi)一(yi)個原(yuan)水濃(nong)縮過(guo)(guo)程,在(zai)濃(nong)水側的(de)(de)(de)(de)膜(mo)(mo)(mo)(mo)表(biao)面(mian)極易生成(cheng)碳酸(suan)鈣、硫酸(suan)鈣、硫酸(suan)鋇、氟化(hua)(hua)鈣、金屬氧化(hua)(hua)物(wu)(wu)(wu)(wu)、硅(gui)(gui)酸(suan)化(hua)(hua)合(he)物(wu)(wu)(wu)(wu)等沉(chen)積(ji)物(wu)(wu)(wu)(wu),隨著原(yuan)水被(bei)濃(nong)縮,這些難溶鹽可能(neng)超(chao)過(guo)(guo)其溶度積(ji)而析出,在(zai)膜(mo)(mo)(mo)(mo)表(biao)面(mian)“結(jie)垢(gou)”,此外,濃(nong)差極化(hua)(hua)作用(yong)也會(hui)加劇這一(yi)現(xian)象的(de)(de)(de)(de)發生。②微(wei)生物(wu)(wu)(wu)(wu)污(wu)(wu)(wu)染(ran)(ran)。當微(wei)生物(wu)(wu)(wu)(wu)隨著反(fan)(fan)(fan)滲透進水進入(ru)系統(tong)(tong)后(hou),以有(you)(you)機物(wu)(wu)(wu)(wu)為營養,大(da)量生長繁(fan)殖,造成(cheng)膜(mo)(mo)(mo)(mo)的(de)(de)(de)(de)生物(wu)(wu)(wu)(wu)污(wu)(wu)(wu)染(ran)(ran)。③有(you)(you)機物(wu)(wu)(wu)(wu)污(wu)(wu)(wu)染(ran)(ran)。反(fan)(fan)(fan)滲透進水中(zhong)有(you)(you)時(shi)含(han)有(you)(you)大(da)量種類繁(fan)多(duo)的(de)(de)(de)(de)有(you)(you)機物(wu)(wu)(wu)(wu),在(zai)系統(tong)(tong)運行過(guo)(guo)程中(zhong),這些有(you)(you)機物(wu)(wu)(wu)(wu)會(hui)在(zai)膜(mo)(mo)(mo)(mo)表(biao)面(mian)上被(bei)吸附,引起膜(mo)(mo)(mo)(mo)通(tong)量的(de)(de)(de)(de)損(sun)失,特別嚴重(zhong)時(shi)會(hui)出現(xian)不可逆的(de)(de)(de)(de)通(tong)量損(sun)失。④膠體污(wu)(wu)(wu)染(ran)(ran)。膠體污(wu)(wu)(wu)染(ran)(ran)主(zhu)要是(shi)由于原(yuan)水濃(nong)縮和pH值(zhi)變(bian)化(hua)(hua)導致的(de)(de)(de)(de)。污(wu)(wu)(wu)染(ran)(ran)物(wu)(wu)(wu)(wu)成(cheng)分可能(neng)是(shi)有(you)(you)機、無(wu)機的(de)(de)(de)(de)單體或復合(he)物(wu)(wu)(wu)(wu),如硅(gui)(gui)酸(suan)化(hua)(hua)合(he)物(wu)(wu)(wu)(wu)、硫化(hua)(hua)物(wu)(wu)(wu)(wu)、腐(fu)殖酸(suan)、絮凝(ning)(ning)劑、助凝(ning)(ning)劑等。
2實驗設備與研究方法
2.1實驗設備:①日(ri)本JEOL公司JSM-7401F型(xing)場發射(she)掃描(miao)電(dian)鏡(jing)(FE-SEM),真空干燥,鍍金層厚為10nm,加速電(dian)壓為5kV,探測(ce)深(shen)度(du)為0.5~0.7μm。②英(ying)國ESCALAB250Xi型(xing)X射(she)線光(guang)電(dian)子(zi)能譜儀(yi)。待(dai)測(ce)物受X光(guang)照射(she)后,內部(bu)電(dian)子(zi)吸收(shou)光(guang)能而脫(tuo)離(li)待(dai)測(ce)物質表(biao)(biao)面(光(guang)電(dian)子(zi)),透過對光(guang)電(dian)子(zi)能量(liang)的(de)(de)分(fen)(fen)(fen)析(xi),可以了解待(dai)測(ce)物質的(de)(de)組(zu)成,XPS的(de)(de)主要功能是通過測(ce)定電(dian)子(zi)的(de)(de)結合能,來實現對表(biao)(biao)面元素(su)的(de)(de)定性分(fen)(fen)(fen)析(xi),包括價態分(fen)(fen)(fen)析(xi)。③電(dian)感耦(ou)合等(deng)離(li)子(zi)體質譜儀(yi),可測(ce)定元素(su)周(zhou)期表(biao)(biao)中(zhong)的(de)(de)大(da)部(bu)分(fen)(fen)(fen)元素(su),具有極(ji)低的(de)(de)檢出限,可進行微量(liang)(10-6)、痕量(liang)(10-9)和超痕量(liang)(10-12)元素(su)分(fen)(fen)(fen)析(xi)。
2.2分析(xi)(xi)方(fang)法:①異養菌(jun)分析(xi)(xi)方(fang)法:本(ben)文水(shui)(shui)(shui)(shui)(shui)中異養菌(jun)含量分析(xi)(xi)方(fang)法,采用(yong)(yong)(yong)(yong)原化(hua)工部標準(zhun)《工業(ye)循環冷卻水(shui)(shui)(shui)(shui)(shui)水(shui)(shui)(shui)(shui)(shui)質(zhi)分析(xi)(xi)方(fang)法》。實驗(yan)用(yong)(yong)(yong)(yong)水(shui)(shui)(shui)(shui)(shui)為采自錦西石化(hua)公司污(wu)(wu)水(shui)(shui)(shui)(shui)(shui)回用(yong)(yong)(yong)(yong)裝置的超濾(lv)(lv)(lv)(lv)進(jin)水(shui)(shui)(shui)(shui)(shui)和超濾(lv)(lv)(lv)(lv)產(chan)水(shui)(shui)(shui)(shui)(shui)。②水(shui)(shui)(shui)(shui)(shui)中元(yuan)素分析(xi)(xi):本(ben)文超濾(lv)(lv)(lv)(lv)出水(shui)(shui)(shui)(shui)(shui)元(yuan)素分析(xi)(xi)采用(yong)(yong)(yong)(yong)電(dian)感耦合等(deng)離子(zi)體質(zhi)譜(pu)儀,實驗(yan)用(yong)(yong)(yong)(yong)水(shui)(shui)(shui)(shui)(shui)為采自錦西石化(hua)公司污(wu)(wu)水(shui)(shui)(shui)(shui)(shui)回用(yong)(yong)(yong)(yong)裝置的超濾(lv)(lv)(lv)(lv)產(chan)水(shui)(shui)(shui)(shui)(shui)。③膜(mo)(mo)面污(wu)(wu)染(ran)(ran)物成分分析(xi)(xi):采用(yong)(yong)(yong)(yong)場發射掃(sao)描(miao)電(dian)鏡(jing)(FE-SEM)進(jin)行膜(mo)(mo)表面形態分析(xi)(xi),采用(yong)(yong)(yong)(yong)X射線光電(dian)子(zi)能譜(pu)儀進(jin)行污(wu)(wu)染(ran)(ran)物成分元(yuan)素分析(xi)(xi)。實驗(yan)樣(yang)品(pin)分別為錦西石化(hua)公司污(wu)(wu)水(shui)(shui)(shui)(shui)(shui)回用(yong)(yong)(yong)(yong)裝置的反滲透前保安過濾(lv)(lv)(lv)(lv)器污(wu)(wu)染(ran)(ran)濾(lv)(lv)(lv)(lv)芯樣(yang)品(pin)、超濾(lv)(lv)(lv)(lv)產(chan)水(shui)(shui)(shui)(shui)(shui)過濾(lv)(lv)(lv)(lv)污(wu)(wu)染(ran)(ran)膜(mo)(mo)樣(yang)品(pin)、超濾(lv)(lv)(lv)(lv)進(jin)水(shui)(shui)(shui)(shui)(shui)過濾(lv)(lv)(lv)(lv)污(wu)(wu)染(ran)(ran)膜(mo)(mo)樣(yang)品(pin)。
3結果與討論
3.1膜(mo)裝(zhuang)置(zhi)運(yun)行(xing)工況分析:錦(jin)西石化污(wu)水(shui)(shui)(shui)(shui)(shui)回用(yong)裝(zhuang)置(zhi)采用(yong)雙膜(mo)法進行(xing)處(chu)(chu)(chu)理,污(wu)水(shui)(shui)(shui)(shui)(shui)回用(yong)項目(mu)采用(yong)污(wu)水(shui)(shui)(shui)(shui)(shui)處(chu)(chu)(chu)理后達標排放的煉(lian)油污(wu)水(shui)(shui)(shui)(shui)(shui)作(zuo)為(wei)原水(shui)(shui)(shui)(shui)(shui),通(tong)過動態砂(sha)(sha)濾(lv)(lv)(lv)過濾(lv)(lv)(lv)單元(yuan)(yuan)、纖維球(qiu)(qiu)過濾(lv)(lv)(lv)單元(yuan)(yuan)、超(chao)濾(lv)(lv)(lv)單元(yuan)(yuan)、反(fan)滲(shen)透單元(yuan)(yuan),進行(xing)污(wu)水(shui)(shui)(shui)(shui)(shui)回用(yong)處(chu)(chu)(chu)理。其簡(jian)要流程如下:污(wu)水(shui)(shui)(shui)(shui)(shui)達標外排水(shui)(shui)(shui)(shui)(shui)經動態砂(sha)(sha)濾(lv)(lv)(lv)過濾(lv)(lv)(lv),砂(sha)(sha)濾(lv)(lv)(lv)產(chan)(chan)水(shui)(shui)(shui)(shui)(shui)由(you)纖維球(qiu)(qiu)過濾(lv)(lv)(lv)器完成懸浮物和石油類的去除。纖維球(qiu)(qiu)過濾(lv)(lv)(lv)器產(chan)(chan)水(shui)(shui)(shui)(shui)(shui)送(song)(song)往超(chao)濾(lv)(lv)(lv)裝(zhuang)置(zhi),進入超(chao)濾(lv)(lv)(lv)膜(mo)組件(jian)前,先通(tong)過自清洗(xi)過濾(lv)(lv)(lv)器,再一次截留(liu)水(shui)(shui)(shui)(shui)(shui)中較大(da)顆粒(li)物或(huo)漂浮物。超(chao)濾(lv)(lv)(lv)裝(zhuang)置(zhi)運(yun)行(xing)由(you)PLC全自動控制,超(chao)濾(lv)(lv)(lv)產(chan)(chan)水(shui)(shui)(shui)(shui)(shui)排放至(zhi)超(chao)濾(lv)(lv)(lv)產(chan)(chan)水(shui)(shui)(shui)(shui)(shui)罐(guan),200m3/h的超(chao)濾(lv)(lv)(lv)產(chan)(chan)水(shui)(shui)(shui)(shui)(shui)送(song)(song)往循環水(shui)(shui)(shui)(shui)(shui)罐(guan);剩余送(song)(song)往反(fan)滲(shen)透系統。反(fan)滲(shen)透進水(shui)(shui)(shui)(shui)(shui)通(tong)過進水(shui)(shui)(shui)(shui)(shui)加(jia)(jia)藥裝(zhuang)置(zhi)投加(jia)(jia)還原劑(ji)和阻垢劑(ji)后,進入保安過濾(lv)(lv)(lv)器,截留(liu)水(shui)(shui)(shui)(shui)(shui)中可(ke)能存在的微(wei)小顆粒(li)物;保安過濾(lv)(lv)(lv)器出水(shui)(shui)(shui)(shui)(shui)再由(you)反(fan)滲(shen)透高(gao)壓泵加(jia)(jia)壓,送(song)(song)往反(fan)滲(shen)透裝(zhuang)置(zhi)進行(xing)除鹽(yan)。反(fan)滲(shen)透產(chan)(chan)水(shui)(shui)(shui)(shui)(shui)輸(shu)送(song)(song)至(zhi)化學水(shui)(shui)(shui)(shui)(shui)補(bu)水(shui)(shui)(shui)(shui)(shui)緩沖罐(guan),作(zuo)為(wei)離子(zi)交換(huan)系統補(bu)水(shui)(shui)(shui)(shui)(shui)。
錦西石化污(wu)水回用裝(zhuang)置運行半(ban)年后,反(fan)滲透(tou)系(xi)統的(de)(de)保安(an)過(guo)濾器(qi)出現(xian)(xian)壓(ya)差升(sheng)高現(xian)(xian)象,主要原因(yin)是保安(an)過(guo)濾器(qi)的(de)(de)濾芯(xin)出現(xian)(xian)嚴重堵塞,因(yin)此清洗(xi)保安(an)過(guo)濾器(qi),更換(huan)新的(de)(de)濾芯(xin),并在(zai)反(fan)滲透(tou)保安(an)過(guo)濾器(qi)入口管線上(shang)投加非氧化性殺菌劑,保證系(xi)統的(de)(de)穩定(ding)運行,但效果不明顯(xian)。新的(de)(de)保安(an)過(guo)濾器(qi)運行10d左右又(you)發(fa)生壓(ya)差升(sheng)高現(xian)(xian)象,現(xian)(xian)場打(da)開1號反(fan)滲膜一(yi)段中的(de)(de)一(yi)支膜殼(ke),抽(chou)出進水端口的(de)(de)第一(yi)支膜元件進行觀察,發(fa)現(xian)(xian)表面有(you)黃(huang)色絮(xu)狀、泥狀物體(ti)。
3.2水(shui)質(zhi)分析(xi):錦(jin)西(xi)石化污水(shui)回(hui)用(yong)裝(zhuang)(zhuang)置現用(yong)超濾膜孔徑(jing)為0.025μm,而(er)細菌(jun)顆(ke)粒(li)直徑(jing)一般為1~3μm,病(bing)毒直徑(jing)約為0.01~0.2μm,因(yin)此(ci)理論上超濾膜對細菌(jun)的截(jie)留率應該在99%以上。為考(kao)察超濾裝(zhuang)(zhuang)置對細菌(jun)的截(jie)留作(zuo)用(yong),對超濾裝(zhuang)(zhuang)置出水(shui)口的回(hui)用(yong)水(shui)采樣,進行(xing)異養菌(jun)含量(liang)分析(xi)(見表1)。
表1分析結果顯示,超(chao)濾回(hui)用水出口的異(yi)養菌含量有時超(chao)出再生(sheng)水控(kong)制指(zhi)標(biao)范圍(wei),與(yu)控(kong)制指(zhi)標(biao)相比,其微(wei)生(sheng)物控(kong)制效果沒有完全達(da)到(dao)預期目標(biao)。
理論上,大部分(fen)細菌(jun)不(bu)(bu)能(neng)透(tou)過超濾膜,分(fen)析其(qi)產水(shui)含有微(wei)生物污染的可能(neng)原(yuan)因主要有:裝置機械密(mi)封不(bu)(bu)嚴;來自被(bei)污染的排出口和(he)輸送管道系(xi)統表面(mian)的微(wei)生物污染;膜材料存在缺陷,或部分(fen)中空纖維(wei)出現斷絲現象,微(wei)生物透(tou)過膜材料局部微(wei)觀缺陷,導致微(wei)生物遷移。
為了進(jin)(jin)一步分(fen)析膜(mo)(mo)污染原(yuan)因,考察水中是否存在(zai)膠體物質對膜(mo)(mo)組(zu)件產生(sheng)影(ying)響,對超濾進(jin)(jin)水及超濾產出水中的總碳及主要元素進(jin)(jin)行分(fen)析,結果見(jian)表2。
表2數據(ju)顯示,超濾產(chan)出水與(yu)進水相比,水中的(de)(de)(de)(de)總有機碳含量(liang)明(ming)(ming)顯降低,說明(ming)(ming)超濾膜(mo)對大部(bu)分有機物進行了(le)截留;但元(yuan)素(su)分析(xi)結果顯示,超濾前后的(de)(de)(de)(de)水質基本無明(ming)(ming)顯變化(hua),尤其是易以膠(jiao)體形(xing)態存(cun)在的(de)(de)(de)(de)鋁、鐵和硅元(yuan)素(su)在水中的(de)(de)(de)(de)含量(liang)都(dou)不高,說明(ming)(ming)錦西石化(hua)超濾進水與(yu)產(chan)出水中的(de)(de)(de)(de)膠(jiao)體物質含量(liang)均(jun)較低。
3.3膜污(wu)染原因分析(xi)
3.3.1保安過(guo)濾(lv)(lv)器濾(lv)(lv)芯污染原因分(fen)(fen)析(xi):錦西石化(hua)污水回用膜(mo)處理裝置反滲透單元的保安過(guo)濾(lv)(lv)器濾(lv)(lv)芯堵塞嚴重,為(wei)分(fen)(fen)析(xi)其堵塞原因及(ji)污染物(wu)主要成分(fen)(fen),對(dui)污染濾(lv)(lv)芯表面(mian)進行電鏡(jing)分(fen)(fen)析(xi)和(he)能譜分(fen)(fen)析(xi)。電鏡(jing)圖(tu)(tu)片見圖(tu)(tu)1
能(neng)譜分析圖片見圖2。
圖1(a)為污(wu)(wu)(wu)(wu)染(ran)(ran)(ran)濾芯局部放大(da)150倍(bei)圖片(pian),從圖中可(ke)以清(qing)晰看出(chu),網狀(zhuang)的(de)濾芯纖維上堆(dui)掛著大(da)量污(wu)(wu)(wu)(wu)染(ran)(ran)(ran)物(wu)(wu),幾乎將纖維空隙全部堵塞。電鏡圖片(pian)(b)將(a)中的(de)污(wu)(wu)(wu)(wu)染(ran)(ran)(ran)物(wu)(wu)進(jin)一步放大(da)到10000倍(bei),圖中顯示(shi)(shi)(shi),污(wu)(wu)(wu)(wu)染(ran)(ran)(ran)物(wu)(wu)表(biao)面(mian)(mian)沒有晶體物(wu)(wu)質(zhi)存在(zai),說明(ming)污(wu)(wu)(wu)(wu)染(ran)(ran)(ran)原因(yin)(yin)不是金屬鹽結(jie)晶結(jie)垢(gou)污(wu)(wu)(wu)(wu)染(ran)(ran)(ran)造成的(de);污(wu)(wu)(wu)(wu)染(ran)(ran)(ran)物(wu)(wu)表(biao)面(mian)(mian)致密,其相態顯示(shi)(shi)(shi)為有機物(wu)(wu)沉積;污(wu)(wu)(wu)(wu)染(ran)(ran)(ran)物(wu)(wu)表(biao)面(mian)(mian)有條索狀(zhuang)物(wu)(wu)質(zhi),說明(ming)有微生(sheng)物(wu)(wu)胞外聚合物(wu)(wu)或者菌體出(chu)現。圖2中的(de)能譜(pu)圖也顯示(shi)(shi)(shi)出(chu),污(wu)(wu)(wu)(wu)染(ran)(ran)(ran)膜表(biao)面(mian)(mian)的(de)主(zhu)要元素含量為C、O,有機物(wu)(wu)主(zhu)要組成為C、O。因(yin)(yin)此(ci),可(ke)以基本判(pan)斷,保安過濾器污(wu)(wu)(wu)(wu)染(ran)(ran)(ran)物(wu)(wu)的(de)組成主(zhu)要是微生(sheng)物(wu)(wu)分泌物(wu)(wu)產(chan)生(sheng)的(de)有機物(wu)(wu)質(zhi)。
分析保安過濾器濾芯(xin)的污(wu)染(ran)原(yuan)因(yin)(yin),從污(wu)染(ran)物形態及(ji)污(wu)染(ran)物成(cheng)分分析上基本可以判斷:濾芯(xin)污(wu)染(ran)原(yuan)因(yin)(yin)主要(yao)是微生物滋生,產(chan)生胞外(wai)聚合(he)物,造成(cheng)濾芯(xin)堵塞(sai),導(dao)致濾芯(xin)污(wu)染(ran)。
3.3.2超(chao)(chao)濾(lv)(lv)進水(shui)與(yu)產(chan)水(shui)污(wu)染膜成分(fen)分(fen)析:為了(le)進一步判斷污(wu)染物來(lai)源,分(fen)別對超(chao)(chao)濾(lv)(lv)進水(shui)、超(chao)(chao)濾(lv)(lv)水(shui)儲罐出(chu)水(shui)、超(chao)(chao)濾(lv)(lv)產(chan)水(shui)進行過濾(lv)(lv),過濾(lv)(lv)時間為15min,過濾(lv)(lv)膜為測定SDI的膜片(pian),過濾(lv)(lv)后對過濾(lv)(lv)膜表面形(xing)態進行電(dian)鏡分(fen)析(見圖3~圖5)
對(dui)過濾膜表面成分進(jin)行能譜分析(見圖6~圖8)。
圖(tu)(tu)3(a)顯(xian)示,膜表(biao)面(mian)污(wu)染物(wu)(wu)(wu)(wu)沉積較多,幾乎(hu)將膜面(mian)全部(bu)覆(fu)蓋;從放大到10000倍(bei)(bei)的(de)(de)(de)電(dian)(dian)鏡照(zhao)片(pian)[圖(tu)(tu)3(b)]中,可以(yi)(yi)清(qing)晰(xi)看到微(wei)生(sheng)物(wu)(wu)(wu)(wu)胞外聚合(he)物(wu)(wu)(wu)(wu)條索(suo)狀物(wu)(wu)(wu)(wu)質(zhi)交(jiao)錯伸展,多層(ceng)密集(ji)堆疊。超濾(lv)(lv)出(chu)水(shui)過(guo)(guo)濾(lv)(lv)膜1000倍(bei)(bei)的(de)(de)(de)電(dian)(dian)鏡照(zhao)片(pian)[見圖(tu)(tu)4(a)和圖(tu)(tu)5(a)]顯(xian)示,過(guo)(guo)濾(lv)(lv)15min后,過(guo)(guo)濾(lv)(lv)膜表(biao)面(mian)污(wu)染物(wu)(wu)(wu)(wu)相對不多,但(dan)在10000倍(bei)(bei)的(de)(de)(de)電(dian)(dian)鏡照(zhao)片(pian)[見圖(tu)(tu)4(b)和圖(tu)(tu)5(b)]中,都發(fa)現了條索(suo)狀微(wei)生(sheng)物(wu)(wu)(wu)(wu)沉積物(wu)(wu)(wu)(wu)的(de)(de)(de)存在。因(yin)此(ci)(ci),超濾(lv)(lv)進水(shui)、超濾(lv)(lv)水(shui)儲罐出(chu)水(shui)、超濾(lv)(lv)產(chan)水(shui)過(guo)(guo)濾(lv)(lv)膜表(biao)面(mian)的(de)(de)(de)SEM分析顯(xian)示,膜面(mian)污(wu)染物(wu)(wu)(wu)(wu)主(zhu)(zhu)要成(cheng)分是微(wei)生(sheng)物(wu)(wu)(wu)(wu)產(chan)生(sheng)的(de)(de)(de)有機污(wu)染物(wu)(wu)(wu)(wu)(胞外聚合(he)物(wu)(wu)(wu)(wu))。圖(tu)(tu)6~圖(tu)(tu)8能譜分析結(jie)果(guo)同時顯(xian)示,膜面(mian)的(de)(de)(de)污(wu)染物(wu)(wu)(wu)(wu)主(zhu)(zhu)要元(yuan)素(su)為C、O。因(yin)此(ci)(ci)可以(yi)(yi)確定(ding),膜處(chu)理系統污(wu)染堵(du)塞的(de)(de)(de)主(zhu)(zhu)要原因(yin),是微(wei)生(sheng)物(wu)(wu)(wu)(wu)滋生(sheng)產(chan)生(sheng)的(de)(de)(de)有機污(wu)染物(wu)(wu)(wu)(wu)沉積造(zao)成(cheng)的(de)(de)(de)。
分(fen)析(xi)膜(mo)(mo)(mo)表面微(wei)生(sheng)(sheng)物(wu)(wu)污(wu)染(ran)的(de)(de)(de)機理(li)如(ru)下:膜(mo)(mo)(mo)表面的(de)(de)(de)生(sheng)(sheng)物(wu)(wu)污(wu)染(ran)現(xian)象可能是(shi)(shi)通過微(wei)生(sheng)(sheng)物(wu)(wu)的(de)(de)(de)細(xi)胞(bao)(bao)附(fu)著在膜(mo)(mo)(mo)表面的(de)(de)(de)初(chu)始黏(nian)合(he)與生(sheng)(sheng)物(wu)(wu)膜(mo)(mo)(mo)的(de)(de)(de)形成(cheng)(cheng)兩個過程形成(cheng)(cheng)的(de)(de)(de)。微(wei)生(sheng)(sheng)物(wu)(wu)初(chu)始附(fu)著后,附(fu)著的(de)(de)(de)細(xi)胞(bao)(bao)將被定(ding)植于膜(mo)(mo)(mo)的(de)(de)(de)表面,隨(sui)之(zhi)形成(cheng)(cheng)生(sheng)(sheng)物(wu)(wu)膜(mo)(mo)(mo),然后,附(fu)著的(de)(de)(de)微(wei)生(sheng)(sheng)物(wu)(wu)細(xi)胞(bao)(bao)都(dou)會(hui)產生(sheng)(sheng)細(xi)胞(bao)(bao)外聚合(he)物(wu)(wu)(EPS),并發展成(cheng)(cheng)小菌落。細(xi)胞(bao)(bao)外聚合(he)物(wu)(wu)(EPS)的(de)(de)(de)主(zhu)要成(cheng)(cheng)分(fen)是(shi)(shi)有機物(wu)(wu)的(de)(de)(de)代謝產物(wu)(wu),包括蛋白質、碳水化合(he)物(wu)(wu)、DNA和RNA等。胞(bao)(bao)外聚合(he)物(wu)(wu)在膜(mo)(mo)(mo)組件積累(lei),導致膜(mo)(mo)(mo)孔阻塞,是(shi)(shi)膜(mo)(mo)(mo)污(wu)染(ran)加劇(ju)的(de)(de)(de)重(zhong)要原因。膜(mo)(mo)(mo)絲(si)被微(wei)生(sheng)(sheng)物(wu)(wu)胞(bao)(bao)外聚合(he)物(wu)(wu)或(huo)者(zhe)微(wei)生(sheng)(sheng)物(wu)(wu)菌體緊密黏(nian)附(fu),阻塞了膜(mo)(mo)(mo)孔,導致膜(mo)(mo)(mo)通量降低,即發生(sheng)(sheng)膜(mo)(mo)(mo)污(wu)染(ran)。
微(wei)生(sheng)(sheng)物(wu)(wu)細(xi)菌以(yi)黏著、穿(chuan)透膜材料(liao)等(deng)固定形式,增(zeng)加了膜表面污(wu)染(ran)物(wu)(wu)的(de)(de)(de)附著強度,由微(wei)生(sheng)(sheng)物(wu)(wu)附著滋生(sheng)(sheng)造(zao)成(cheng)的(de)(de)(de)膜污(wu)染(ran)幾(ji)乎(hu)是不可(ke)逆(ni)的(de)(de)(de)。因此,控制膜污(wu)染(ran)可(ke)以(yi)利用生(sheng)(sheng)物(wu)(wu)手(shou)段(duan),使產(chan)生(sheng)(sheng)胞外聚合物(wu)(wu)的(de)(de)(de)微(wei)生(sheng)(sheng)物(wu)(wu)種群(qun)處于劣勢,降低(di)其(qi)在系(xi)統中的(de)(de)(de)種群(qun)數量(liang),從而達到減少胞外聚合物(wu)(wu)的(de)(de)(de)積累,延緩膜污(wu)染(ran)的(de)(de)(de)發生(sheng)(sheng)。
3.4膜裝置(zhi)運行污染原因分(fen)析:錦西石化(hua)污水(shui)(shui)回(hui)用(yong)裝置(zhi)現用(yong)的超(chao)濾(lv)(lv)(lv)(lv)(lv)(lv)(lv)(lv)膜孔徑為(wei)(wei)0.025μm,而細(xi)菌(jun)顆粒一般(ban)為(wei)(wei)1~3μm,理論上超(chao)濾(lv)(lv)(lv)(lv)(lv)(lv)(lv)(lv)膜產(chan)出水(shui)(shui)中(zhong)的微生(sheng)物(wu)(wu)含量應(ying)該很(hen)低。為(wei)(wei)此,對超(chao)濾(lv)(lv)(lv)(lv)(lv)(lv)(lv)(lv)裝置(zhi)的完(wan)整性進(jin)(jin)(jin)行排查(cha),查(cha)出有2根超(chao)濾(lv)(lv)(lv)(lv)(lv)(lv)(lv)(lv)膜管件封(feng)口不(bu)嚴,超(chao)濾(lv)(lv)(lv)(lv)(lv)(lv)(lv)(lv)進(jin)(jin)(jin)水(shui)(shui)污染了超(chao)濾(lv)(lv)(lv)(lv)(lv)(lv)(lv)(lv)產(chan)水(shui)(shui),前(qian)期造成(cheng)超(chao)濾(lv)(lv)(lv)(lv)(lv)(lv)(lv)(lv)產(chan)水(shui)(shui)中(zhong)微生(sheng)物(wu)(wu)含量達不(bu)到(dao)再生(sheng)水(shui)(shui)控制指標要求,后期因為(wei)(wei)加(jia)強(qiang)了超(chao)濾(lv)(lv)(lv)(lv)(lv)(lv)(lv)(lv)進(jin)(jin)(jin)水(shui)(shui)的殺菌(jun)措施,細(xi)菌(jun)生(sheng)長(chang)受到(dao)抑(yi)制,但在反(fan)滲(shen)透(tou)單元,由于投加(jia)還原劑,中(zhong)和了水(shui)(shui)中(zhong)的余氯(lv),使微生(sheng)物(wu)(wu)在保(bao)安(an)過(guo)濾(lv)(lv)(lv)(lv)(lv)(lv)(lv)(lv)器濾(lv)(lv)(lv)(lv)(lv)(lv)(lv)(lv)芯(xin)上爆發式生(sheng)長(chang),很(hen)短時(shi)間內(nei)(3~5d)就造成(cheng)濾(lv)(lv)(lv)(lv)(lv)(lv)(lv)(lv)芯(xin)嚴重堵塞失效。反(fan)滲(shen)透(tou)進(jin)(jin)(jin)水(shui)(shui)保(bao)安(an)過(guo)濾(lv)(lv)(lv)(lv)(lv)(lv)(lv)(lv)器是反(fan)滲(shen)透(tou)設備(bei)的配套系統,過(guo)濾(lv)(lv)(lv)(lv)(lv)(lv)(lv)(lv)器濾(lv)(lv)(lv)(lv)(lv)(lv)(lv)(lv)芯(xin)材(cai)質(zhi)采用(yong)SUS-304,過(guo)濾(lv)(lv)(lv)(lv)(lv)(lv)(lv)(lv)孔徑為(wei)(wei)5μm,濾(lv)(lv)(lv)(lv)(lv)(lv)(lv)(lv)芯(xin)多層褶皺結(jie)(jie)構更(geng)易造成(cheng)微生(sheng)物(wu)(wu)吸附繁殖,微生(sheng)物(wu)(wu)產(chan)生(sheng)的分(fen)泌物(wu)(wu)-有機污染物(wu)(wu)與濾(lv)(lv)(lv)(lv)(lv)(lv)(lv)(lv)芯(xin)材(cai)料緊密結(jie)(jie)合(he),難以徹底清洗恢復(fu)。
4結論與建議
①微生物分析結果顯示,超濾(lv)回用水出口的異養菌含量有時(shi)超出再生水控(kong)制指標(biao)范圍,與(yu)控(kong)制指標(biao)相比,其微生物控(kong)制沒有完全達到預期(qi)效果。
②通過(guo)SEM和XPS分析(xi)可以基(ji)本判斷,保安過(guo)濾器濾芯(xin)的污染物主要是(shi)微生(sheng)物滋生(sheng)的有(you)機物。
③超濾(lv)(lv)進(jin)水(shui)(shui)、超濾(lv)(lv)水(shui)(shui)儲(chu)罐(guan)出(chu)水(shui)(shui)、超濾(lv)(lv)產(chan)水(shui)(shui)過濾(lv)(lv)膜(mo)表(biao)面(mian)(mian)的(de)SEM分析(xi)顯示,膜(mo)面(mian)(mian)污(wu)染(ran)(ran)物(wu)(wu)(wu)主要(yao)成分是微生物(wu)(wu)(wu)產(chan)生的(de)有(you)機污(wu)染(ran)(ran)物(wu)(wu)(wu)。能譜(pu)分析(xi)結果(guo)同時顯示,膜(mo)面(mian)(mian)的(de)污(wu)染(ran)(ran)物(wu)(wu)(wu)主要(yao)元(yuan)素為C、O。因(yin)此可以確定,膜(mo)處(chu)理系(xi)統污(wu)染(ran)(ran)堵塞(sai)的(de)主要(yao)原因(yin),就是微生物(wu)(wu)(wu)滋生產(chan)生的(de)有(you)機污(wu)染(ran)(ran)物(wu)(wu)(wu)造成的(de)。
④通過(guo)(guo)對超濾(lv)(lv)(lv)裝置(zhi)的完整性排查結(jie)果顯示,有2根超濾(lv)(lv)(lv)膜管件(jian)封口不嚴,超濾(lv)(lv)(lv)進水污(wu)染(ran)了超濾(lv)(lv)(lv)產水,使微生(sheng)物在保安過(guo)(guo)濾(lv)(lv)(lv)器濾(lv)(lv)(lv)芯上爆發式(shi)生(sheng)長,很短時間內就(jiu)造(zao)成濾(lv)(lv)(lv)芯嚴重(zhong)堵塞失效。
⑤由于(yu)雙膜(mo)法(fa)污水(shui)(shui)深度處(chu)理(li)系(xi)(xi)統(tong)來水(shui)(shui)中(zhong)有微(wei)量有機物(wu)存在,膜(mo)內極(ji)易滋生(sheng)(sheng)微(wei)生(sheng)(sheng)物(wu),因此(ci)(ci)建議(yi),可在以超濾前投加NaClO等殺菌劑,且保證一(yi)定(ding)的(de)(de)(de)余氯含量,預(yu)(yu)防膜(mo)的(de)(de)(de)生(sheng)(sheng)物(wu)污染(ran)(ran)。同時(shi),在反(fan)(fan)(fan)滲透(tou)(tou)(tou)前投加適當(dang)富裕量的(de)(de)(de)NaHSO3,防止氧化(hua)劑對反(fan)(fan)(fan)滲透(tou)(tou)(tou)膜(mo)的(de)(de)(de)破壞,有效預(yu)(yu)防反(fan)(fan)(fan)滲透(tou)(tou)(tou)膜(mo)的(de)(de)(de)微(wei)生(sheng)(sheng)物(wu)污染(ran)(ran)。同時(shi),超濾裝(zhuang)置(zhi)作為反(fan)(fan)(fan)滲透(tou)(tou)(tou)裝(zhuang)置(zhi)的(de)(de)(de)預(yu)(yu)處(chu)理(li)系(xi)(xi)統(tong),其出(chu)水(shui)(shui)微(wei)生(sheng)(sheng)物(wu)含量高會(hui)造(zao)成(cheng)反(fan)(fan)(fan)滲透(tou)(tou)(tou)膜(mo)的(de)(de)(de)微(wei)生(sheng)(sheng)物(wu)污染(ran)(ran)。許(xu)多(duo)實例證明,預(yu)(yu)處(chu)理(li)系(xi)(xi)統(tong)被微(wei)生(sheng)(sheng)物(wu)污染(ran)(ran)后,反(fan)(fan)(fan)滲透(tou)(tou)(tou)系(xi)(xi)統(tong)很難得到徹底有效的(de)(de)(de)清洗,即使反(fan)(fan)(fan)滲透(tou)(tou)(tou)膜(mo)剛剛清洗過(guo),又會(hui)被來自預(yu)(yu)處(chu)理(li)系(xi)(xi)統(tong)的(de)(de)(de)污染(ran)(ran)源(yuan)再次污染(ran)(ran),這(zhe)種污染(ran)(ran)往往迅(xun)速而頻(pin)繁。因此(ci)(ci),做好(hao)預(yu)(yu)處(chu)理(li)工作,嚴格控(kong)制進(jin)水(shui)(shui)中(zhong)的(de)(de)(de)微(wei)生(sheng)(sheng)物(wu)含量,是控(kong)制反(fan)(fan)(fan)滲透(tou)(tou)(tou)系(xi)(xi)統(tong)微(wei)生(sheng)(sheng)物(wu)污染(ran)(ran)的(de)(de)(de)首要(yao)任務(wu)。

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