活性炭對微濾膜的影響

　　活性(xing)(xing)(xing)炭(tan)(tan)(tan)吸(xi)(xi)附對微濾膜(mo)(mo)性(xing)(xing)(xing)能的(de)影響(xiang)。結果表明，活性(xing)(xing)(xing)炭(tan)(tan)(tan)預(yu)處(chu)理為10-200 mg / L 在(zai)劑量(liang)(liang)下，溶(rong)解有(you)(you)(you)機(ji)碳(DOC)和254 nm紫外吸(xi)(xi)收光譜(UV 254)都(dou)(dou)能提(ti)供高有(you)(you)(you)機(ji)物(wu)去(qu)除率。通過(guo)MF隨著活性(xing)(xing)(xing)炭(tan)(tan)(tan)吸(xi)(xi)附有(you)(you)(you)機(ji)物(wu)的(de)增加(jia)，膜(mo)(mo)過(guo)濾去(qu)除效率降低。主(zhu)要去(qu)除活性(xing)(xing)(xing)炭(tan)(tan)(tan)約3kDa有(you)(you)(you)機(ji)物(wu)質(zhi)的(de)分子量(liang)(liang)。活性(xing)(xing)(xing)炭(tan)(tan)(tan)吸(xi)(xi)附后，膜(mo)(mo)在(zai)膜(mo)(mo)上保(bao)持超(chao)過(guo)5kDa有(you)(you)(you)機(ji)物(wu)質(zhi)。膜(mo)(mo)過(guo)濾結果表明，無論活性(xing)(xing)(xing)炭(tan)(tan)(tan)劑量(liang)(liang)如何，活性(xing)(xing)(xing)炭(tan)(tan)(tan)的(de)預(yu)處(chu)理都(dou)(dou)略微促進膜(mo)(mo)通量(liang)(liang)。似乎(hu)有(you)(you)(you)機(ji)污垢膜(mo)(mo)集中在(zai)3以上kDa的(de)微濾膜(mo)(mo)。活性(xing)(xing)(xing)炭(tan)(tan)(tan)去(qu)除明顯小(xiao)于(yu)33kDa 微濾膜(mo)(mo)有(you)(you)(you)機(ji)物(wu)超(chao)過(guo)3種(zhong)kDa有(you)(you)(you)機(ji)物(wu)質(zhi)的(de)影響(xiang)較小(xiao)。因此，活性(xing)(xing)(xing)炭(tan)(tan)(tan)不能減少(shao)膜(mo)(mo)污染。

　　膜污染是(shi)水(shui)處(chu)理(li)的重要問題之一。膜結垢(gou)導致膜通量降低和性(xing)能差。一些研究(jiu)表明，天(tian)然有機物(NOM)負責(ze)炭吸(xi)附(fu)是(shi)飲用(yong)水(shui)中(zhong)負責(ze)微(wei)濾膜污染或垢(gou)。活性(xing)炭吸(xi)附(fu)是(shi)減少有機物污染膜的好選擇。

　　活(huo)(huo)性(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)廣泛用(yong)作水處(chu)理(li)中(zhong)(zhong)的吸(xi)收劑。活(huo)(huo)性(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)具有(you)良好的天然(ran)有(you)機(ji)(ji)物吸(xi)附(fu)性(xing)(xing)(xing)(xing)能(neng)(neng)，因此(ci)采用(yong)預處(chu)理(li)，減少膜(mo)污染，提(ti)(ti)高(gao)膜(mo)性(xing)(xing)(xing)(xing)能(neng)(neng)。然(ran)而，活(huo)(huo)性(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)對提(ti)(ti)高(gao)膜(mo)性(xing)(xing)(xing)(xing)能(neng)(neng)的效(xiao)率(lv)有(you)不(bu)同的結論。一些研究(jiu)表明，當活(huo)(huo)性(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)保持膜(mo)表面時，活(huo)(huo)性(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)可(ke)以增(zeng)強膜(mo)通(tong)量 。活(huo)(huo)性(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)懸浮在(zai)(zai)活(huo)(huo)性(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)/超(chao)(chao)濾(lv)系統中(zhong)(zhong)的作用(yong)是(shi)吸(xi)收低(di)分(fen)子腐殖(zhi)酸(HA)。膜(mo)提(ti)(ti)供(gong)物理(li)屏(ping)障，防止活(huo)(huo)性(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)通(tong)過(guo)(guo)，從而保留吸(xi)附(fu)在(zai)(zai)活(huo)(huo)性(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)上(shang)的有(you)機(ji)(ji)化合物。發(fa)現(xian)活(huo)(huo)性(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)可(ke)能(neng)(neng)導致更大的絮凝顆(ke)粒，并通(tong)過(guo)(guo)預處(chu)理(li)活(huo)(huo)性(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)來減少每個(ge)過(guo)(guo)濾(lv)周期的可(ke)逆性(xing)(xing)(xing)(xing)TMP增(zeng)加。研究(jiu)天然(ran)有(you)機(ji)(ji)物在(zai)(zai)耦合超(chao)(chao)細活(huo)(huo)性(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)/微(wei)濾(lv)膜(mo)過(guo)(guo)程中(zhong)(zhong)的作用(yong)表明，天然(ran)有(you)機(ji)(ji)物被證明是(shi)膜(mo)污染和超(chao)(chao)細活(huo)(huo)性(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)的主要原因，活(huo)(huo)性(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)實際(ji)上(shang)比單(dan)獨的天然(ran)有(you)機(ji)(ji)物減少了結垢。然(ran)而，一些研究(jiu)人(ren)員報(bao)告說，活(huo)(huo)性(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)的存在(zai)(zai)會加重膜(mo)污染或不(bu)影響膜(mo)通(tong)量。 在(zai)(zai)反洗水中(zhong)(zhong)發(fa)現(xian)活(huo)(huo)性(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)顆(ke)粒，因為它(ta)們可(ke)能(neng)(neng)在(zai)(zai)污垢層的生長過(guo)(guo)程中(zhong)(zhong)積累。活(huo)(huo)性(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)既(ji)不(bu)促(cu)進也不(bu)控(kong)制膜(mo)可(ke)逆結垢。

　　活性(xing)(xing)(xing)炭(tan)(tan)用(yong)(yong)于處理微濾(lv)(lv)膜(mo)前的(de)預處理和地表水(shui)(shui)(shui)。實(shi)驗(yan)的(de)主要(yao)目(mu)的(de)是研究活性(xing)(xing)(xing)炭(tan)(tan)對(dui)膜(mo)性(xing)(xing)(xing)能的(de)影響，特(te)別關注活性(xing)(xing)(xing)炭(tan)(tan)微濾(lv)(lv)膜(mo)工藝(yi)對(dui)有機物去除率和膜(mo)通量的(de)影響。木質活性(xing)(xing)(xing)炭(tan)(tan)。粒度分(fen)(fen)布為：>74μm-71%，>44μm-95%。使用(yong)(yong)前，加(jia)入少量去離子水(shui)(shui)(shui)均勻化活性(xing)(xing)(xing)炭(tan)(tan)。在原水(shui)(shui)(shui)中(zhong)加(jia)入10、50、100、200mg / L特(te)殊(shu)活性(xing)(xing)(xing)炭(tan)(tan)劑量。本實(shi)驗(yan)采(cai)用(yong)(yong)黃(huang)浦江地表水(shui)(shui)(shui)。在水(shui)(shui)(shui)樣(yang)中(zhong)加(jia)入活性(xing)(xing)(xing)炭(tan)(tan)100rpm快速(su)攪(jiao)拌30分(fen)(fen)鐘1分(fen)(fen)鐘，攪(jiao)拌30分(fen)(fen)鐘rpm緩慢混合，然后用(yong)(yong)0.45μm過濾(lv)(lv)器過濾(lv)(lv)水(shui)(shui)(shui)樣(yang)品。以下膜(mo)過濾(lv)(lv)用(yong)(yong)過濾(lv)(lv)水(shui)(shui)(shui)樣(yang)品。

　　溶解有機碳和(he)活(huo)性炭和(he)微濾(lv)過程(cheng)UV254去除率(lv)

　　活(huo)性(xing)(xing)炭(tan)和UV如(ru)圖所(suo)示，254的(de)效率。活(huo)性(xing)(xing)炭(tan)溶(rong)(rong)解有(you)機(ji)(ji)碳去(qu)除率較高。活(huo)性(xing)(xing)炭(tan)劑(ji)量(liang)為10-2000 mg / L當溶(rong)(rong)解有(you)機(ji)(ji)碳的(de)去(qu)除率從3開始(shi).0%提(ti)高到59.8%。活(huo)性(xing)(xing)炭(tan)吸附(fu)后(hou)，微(wei)濾(lv)(lv)膜(mo)過濾(lv)(lv)水樣，溶(rong)(rong)解有(you)機(ji)(ji)碳從21中(zhong)去(qu)除滲透(tou)物.1%穩定增加到62.2%。然而(er)，隨著活(huo)性(xing)(xing)炭(tan)劑(ji)量(liang)的(de)增加，微(wei)濾(lv)(lv)膜(mo)溶(rong)(rong)解有(you)機(ji)(ji)碳去(qu)除量(liang)略有(you)增加。

　　與溶解(jie)有機(ji)碳相比，UV254去除率(lv)(lv)高。隨(sui)著(zhu)活性(xing)(xing)(xing)炭劑量(liang)從100開始(shi)mg / L增加到200mg / L，超(chao)濾(lv)吸(xi)收去除率(lv)(lv)為10.1%增加到70.3%。與微(wei)濾(lv)過濾(lv)后溶解(jie)有機(ji)碳去除率(lv)(lv)相似，活性(xing)(xing)(xing)炭用(yong)量(liang)越(yue)高，微(wei)濾(lv)膜(mo)去除UV254越(yue)低。可(ke)溶解(jie)有機(ji)碳和活性(xing)(xing)(xing)炭UV254去除率(lv)(lv)高，活性(xing)(xing)(xing)炭含量(liang)高，膜(mo)可(ke)去除殘留有機(ji)物。

　　在上述(shu)研究中，活性(xing)(xing)炭(tan)具有較高的(de)有機物去(qu)除率。然(ran)而(er)，即使(shi)在200年(nian)mg / L活性(xing)(xing)炭(tan)高的(de)劑量下(xia)，活性(xing)(xing)炭(tan)不(bu)(bu)能改(gai)善膜通量。原(yuan)水有機質(zhi)的(de)微(wei)濾濃度為(wei)2-7kDa，特別是3-5kDa。活性(xing)(xing)炭(tan)吸附的(de)有機物濃度約為(wei)3kDa 水中有機物分(fen)子(zi)量。顯然(ran)，活性(xing)(xing)炭(tan)對水中有機物分(fen)子(zi)物質(zhi)影響(xiang)不(bu)(bu)大(da)。

　　微(wei)(wei)(wei)濾膜(mo)(mo)過(guo)濾后原水(shui)(shui)的疏(shu)(shu)(shu)水(shui)(shui)性(xing)(xing)/親(qin)水(shui)(shui)性(xing)(xing)變化如圖6所示。可見(jian)，微(wei)(wei)(wei)濾膜(mo)(mo)主要去除疏(shu)(shu)(shu)水(shui)(shui)有(you)機物(wu)(wu)(wu)(wu)。圖7顯(xian)示了原水(shui)(shui)中不(bu)同水(shui)(shui)中有(you)機物(wu)(wu)(wu)(wu)分子量的疏(shu)(shu)(shu)水(shui)(shui)性(xing)(xing)/親(qin)水(shui)(shui)性(xing)(xing)變化。膜(mo)(mo)過(guo)濾后，疏(shu)(shu)(shu)水(shui)(shui)有(you)機質的比例(li)明(ming)顯(xian)下降，特別是2-7 kDa 有(you)機物(wu)(wu)(wu)(wu)。相比之下，親(qin)水(shui)(shui)性(xing)(xing)有(you)機物(wu)(wu)(wu)(wu)的比例(li)顯(xian)著增(zeng)加。本研究采(cai)用親(qin)水(shui)(shui)性(xing)(xing)PVDF膜(mo)(mo)。因此，疏(shu)(shu)(shu)水(shui)(shui)物(wu)(wu)(wu)(wu)質不(bu)能通(tong)過(guo)膜(mo)(mo)并停留(liu)在膜(mo)(mo)表面。親(qin)水(shui)(shui)性(xing)(xing)有(you)機物(wu)(wu)(wu)(wu)容易通(tong)過(guo)膜(mo)(mo)，然(ran)后親(qin)水(shui)(shui)性(xing)(xing)有(you)機物(wu)(wu)(wu)(wu)在滲透物(wu)(wu)(wu)(wu)中的比例(li)顯(xian)著增(zeng)加。膜(mo)(mo)有(you)機污(wu)(wu)染物(wu)(wu)(wu)(wu)似乎(hu)是2-7kDa 疏(shu)(shu)(shu)水(shui)(shui)有(you)機物(wu)(wu)(wu)(wu)是重點。活性(xing)(xing)炭(tan)僅部分吸(xi)附2-7 kDa 有(you)機物(wu)(wu)(wu)(wu)，輕微(wei)(wei)(wei)促進膜(mo)(mo)污(wu)(wu)染。這(zhe)是因為活性(xing)(xing)炭(tan)顯(xian)著去除有(you)機物(wu)(wu)(wu)(wu)，增(zeng)強膜(mo)(mo)通(tong)量。