活性炭對微濾膜的影響

　　活性(xing)炭(tan)吸(xi)附對微(wei)濾(lv)膜(mo)(mo)性(xing)能的(de)影(ying)響(xiang)。結(jie)果(guo)表明(ming)，活性(xing)炭(tan)預(yu)處理為10-200 mg / L 在(zai)劑量下，溶(rong)解有(you)(you)機(ji)碳(DOC)和254 nm紫外吸(xi)收光(guang)譜(UV 254)都(dou)能提(ti)供高有(you)(you)機(ji)物去(qu)除(chu)率。通(tong)過MF隨著活性(xing)炭(tan)吸(xi)附有(you)(you)機(ji)物的(de)增加(jia)，膜(mo)(mo)過濾(lv)去(qu)除(chu)效(xiao)率降低(di)。主(zhu)要去(qu)除(chu)活性(xing)炭(tan)約3kDa有(you)(you)機(ji)物質的(de)分子量。活性(xing)炭(tan)吸(xi)附后，膜(mo)(mo)在(zai)膜(mo)(mo)上保持超過5kDa有(you)(you)機(ji)物質。膜(mo)(mo)過濾(lv)結(jie)果(guo)表明(ming)，無論活性(xing)炭(tan)劑量如(ru)何(he)，活性(xing)炭(tan)的(de)預(yu)處理都(dou)略微(wei)促進膜(mo)(mo)通(tong)量。似乎有(you)(you)機(ji)污(wu)(wu)垢膜(mo)(mo)集中在(zai)3以上kDa的(de)微(wei)濾(lv)膜(mo)(mo)。活性(xing)炭(tan)去(qu)除(chu)明(ming)顯小(xiao)于33kDa 微(wei)濾(lv)膜(mo)(mo)有(you)(you)機(ji)物超過3種kDa有(you)(you)機(ji)物質的(de)影(ying)響(xiang)較小(xiao)。因此，活性(xing)炭(tan)不(bu)能減少膜(mo)(mo)污(wu)(wu)染。

　　膜污染(ran)(ran)是(shi)水(shui)處理的重要問題之一。膜結垢(gou)導致(zhi)膜通量降低和性能差。一些(xie)研究(jiu)表明，天(tian)然有機物(NOM)負(fu)責炭(tan)吸附(fu)是(shi)飲用水(shui)中負(fu)責微濾膜污染(ran)(ran)或垢(gou)。活(huo)性炭(tan)吸附(fu)是(shi)減少有機物污染(ran)(ran)膜的好選(xuan)擇。

　　活性(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)廣(guang)泛用作水處(chu)理中的(de)(de)(de)(de)吸收劑。活性(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)具有(you)(you)良(liang)好的(de)(de)(de)(de)天(tian)(tian)(tian)然有(you)(you)機(ji)物(wu)(wu)(wu)吸附性(xing)(xing)(xing)(xing)能(neng)，因(yin)此采用預處(chu)理，減少膜(mo)(mo)污染，提高(gao)膜(mo)(mo)性(xing)(xing)(xing)(xing)能(neng)。然而(er)，活性(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)對提高(gao)膜(mo)(mo)性(xing)(xing)(xing)(xing)能(neng)的(de)(de)(de)(de)效率(lv)有(you)(you)不(bu)同的(de)(de)(de)(de)結論(lun)。一些研(yan)究(jiu)(jiu)表(biao)明(ming)，當活性(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)保持膜(mo)(mo)表(biao)面時，活性(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)可(ke)以增(zeng)強膜(mo)(mo)通(tong)量 。活性(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)懸浮在活性(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)/超濾系統中的(de)(de)(de)(de)作用是(shi)吸收低(di)分子腐殖酸(HA)。膜(mo)(mo)提供物(wu)(wu)(wu)理屏障(zhang)，防止活性(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)通(tong)過，從而(er)保留吸附在活性(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)上(shang)(shang)的(de)(de)(de)(de)有(you)(you)機(ji)化合(he)物(wu)(wu)(wu)。發(fa)現(xian)(xian)活性(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)可(ke)能(neng)導(dao)致更大(da)的(de)(de)(de)(de)絮(xu)凝顆粒，并通(tong)過預處(chu)理活性(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)來(lai)減少每個過濾周期的(de)(de)(de)(de)可(ke)逆性(xing)(xing)(xing)(xing)TMP增(zeng)加。研(yan)究(jiu)(jiu)天(tian)(tian)(tian)然有(you)(you)機(ji)物(wu)(wu)(wu)在耦合(he)超細活性(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)/微濾膜(mo)(mo)過程(cheng)(cheng)中的(de)(de)(de)(de)作用表(biao)明(ming)，天(tian)(tian)(tian)然有(you)(you)機(ji)物(wu)(wu)(wu)被證(zheng)明(ming)是(shi)膜(mo)(mo)污染和超細活性(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)的(de)(de)(de)(de)主(zhu)要原因(yin)，活性(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)實際上(shang)(shang)比單獨(du)的(de)(de)(de)(de)天(tian)(tian)(tian)然有(you)(you)機(ji)物(wu)(wu)(wu)減少了結垢(gou)。然而(er)，一些研(yan)究(jiu)(jiu)人員(yuan)報告說，活性(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)的(de)(de)(de)(de)存在會加重膜(mo)(mo)污染或不(bu)影響膜(mo)(mo)通(tong)量。 在反洗水中發(fa)現(xian)(xian)活性(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)顆粒，因(yin)為它們(men)可(ke)能(neng)在污垢(gou)層的(de)(de)(de)(de)生長過程(cheng)(cheng)中積累。活性(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)既(ji)不(bu)促(cu)進也不(bu)控制膜(mo)(mo)可(ke)逆結垢(gou)。

　　活性(xing)(xing)(xing)炭(tan)用(yong)于處理微(wei)濾(lv)膜(mo)(mo)前的(de)(de)預處理和地表(biao)水。實驗的(de)(de)主要目的(de)(de)是研究活性(xing)(xing)(xing)炭(tan)對(dui)膜(mo)(mo)性(xing)(xing)(xing)能的(de)(de)影(ying)(ying)響(xiang)，特別關注(zhu)活性(xing)(xing)(xing)炭(tan)微(wei)濾(lv)膜(mo)(mo)工藝對(dui)有機物去(qu)除率和膜(mo)(mo)通量(liang)(liang)的(de)(de)影(ying)(ying)響(xiang)。木質(zhi)活性(xing)(xing)(xing)炭(tan)。粒度分(fen)布為：>74μm-71%，>44μm-95%。使用(yong)前，加(jia)入(ru)少量(liang)(liang)去(qu)離子水均勻化(hua)活性(xing)(xing)(xing)炭(tan)。在(zai)(zai)原水中(zhong)加(jia)入(ru)10、50、100、200mg / L特殊(shu)活性(xing)(xing)(xing)炭(tan)劑量(liang)(liang)。本實驗采用(yong)黃浦江地表(biao)水。在(zai)(zai)水樣(yang)中(zhong)加(jia)入(ru)活性(xing)(xing)(xing)炭(tan)100rpm快速攪拌30分(fen)鐘(zhong)1分(fen)鐘(zhong)，攪拌30分(fen)鐘(zhong)rpm緩(huan)慢混合，然后(hou)用(yong)0.45μm過(guo)濾(lv)器過(guo)濾(lv)水樣(yang)品。以下膜(mo)(mo)過(guo)濾(lv)用(yong)過(guo)濾(lv)水樣(yang)品。

　　溶解有機碳和活性炭和微濾過程UV254去除率

　　活(huo)性(xing)炭(tan)(tan)和UV如圖所示，254的(de)效率。活(huo)性(xing)炭(tan)(tan)溶(rong)解有(you)(you)機(ji)碳(tan)去除(chu)率較(jiao)高。活(huo)性(xing)炭(tan)(tan)劑量(liang)為10-2000 mg / L當溶(rong)解有(you)(you)機(ji)碳(tan)的(de)去除(chu)率從(cong)3開(kai)始.0%提高到(dao)59.8%。活(huo)性(xing)炭(tan)(tan)吸附后，微(wei)濾(lv)膜過(guo)濾(lv)水樣，溶(rong)解有(you)(you)機(ji)碳(tan)從(cong)21中(zhong)去除(chu)滲(shen)透物.1%穩定增加到(dao)62.2%。然而，隨著活(huo)性(xing)炭(tan)(tan)劑量(liang)的(de)增加，微(wei)濾(lv)膜溶(rong)解有(you)(you)機(ji)碳(tan)去除(chu)量(liang)略有(you)(you)增加。

　　與溶(rong)解(jie)有機碳相比，UV254去(qu)(qu)除率(lv)高。隨著活(huo)性炭劑(ji)量從100開始mg / L增加到(dao)200mg / L，超濾(lv)(lv)吸收去(qu)(qu)除率(lv)為10.1%增加到(dao)70.3%。與微(wei)濾(lv)(lv)過濾(lv)(lv)后溶(rong)解(jie)有機碳去(qu)(qu)除率(lv)相似(si)，活(huo)性炭用量越(yue)(yue)高，微(wei)濾(lv)(lv)膜去(qu)(qu)除UV254越(yue)(yue)低。可(ke)溶(rong)解(jie)有機碳和活(huo)性炭UV254去(qu)(qu)除率(lv)高，活(huo)性炭含量高，膜可(ke)去(qu)(qu)除殘留有機物(wu)。

　　在上述研究(jiu)中，活(huo)(huo)性(xing)炭(tan)具有(you)(you)較(jiao)高的(de)(de)有(you)(you)機物去除率。然(ran)而，即使在200年mg / L活(huo)(huo)性(xing)炭(tan)高的(de)(de)劑(ji)量下(xia)，活(huo)(huo)性(xing)炭(tan)不能改善膜通量。原水(shui)有(you)(you)機質的(de)(de)微濾濃度為2-7kDa，特別是3-5kDa。活(huo)(huo)性(xing)炭(tan)吸附的(de)(de)有(you)(you)機物濃度約(yue)為3kDa 水(shui)中有(you)(you)機物分(fen)子(zi)量。顯然(ran)，活(huo)(huo)性(xing)炭(tan)對水(shui)中有(you)(you)機物分(fen)子(zi)物質影響不大。

　　微(wei)(wei)濾(lv)(lv)膜(mo)過(guo)(guo)濾(lv)(lv)后(hou)(hou)原水(shui)(shui)(shui)(shui)的疏(shu)水(shui)(shui)(shui)(shui)性(xing)(xing)/親(qin)(qin)水(shui)(shui)(shui)(shui)性(xing)(xing)變化如圖(tu)6所(suo)示(shi)。可見，微(wei)(wei)濾(lv)(lv)膜(mo)主要去除疏(shu)水(shui)(shui)(shui)(shui)有(you)(you)機(ji)(ji)(ji)物(wu)(wu)(wu)(wu)。圖(tu)7顯(xian)示(shi)了原水(shui)(shui)(shui)(shui)中(zhong)不同水(shui)(shui)(shui)(shui)中(zhong)有(you)(you)機(ji)(ji)(ji)物(wu)(wu)(wu)(wu)分(fen)子量(liang)的疏(shu)水(shui)(shui)(shui)(shui)性(xing)(xing)/親(qin)(qin)水(shui)(shui)(shui)(shui)性(xing)(xing)變化。膜(mo)過(guo)(guo)濾(lv)(lv)后(hou)(hou)，疏(shu)水(shui)(shui)(shui)(shui)有(you)(you)機(ji)(ji)(ji)質(zhi)的比例(li)明顯(xian)下(xia)(xia)降(jiang)，特別(bie)是(shi)2-7 kDa 有(you)(you)機(ji)(ji)(ji)物(wu)(wu)(wu)(wu)。相比之(zhi)下(xia)(xia)，親(qin)(qin)水(shui)(shui)(shui)(shui)性(xing)(xing)有(you)(you)機(ji)(ji)(ji)物(wu)(wu)(wu)(wu)的比例(li)顯(xian)著(zhu)增(zeng)加。本研究(jiu)采(cai)用(yong)親(qin)(qin)水(shui)(shui)(shui)(shui)性(xing)(xing)PVDF膜(mo)。因此，疏(shu)水(shui)(shui)(shui)(shui)物(wu)(wu)(wu)(wu)質(zhi)不能通過(guo)(guo)膜(mo)并停(ting)留在膜(mo)表面。親(qin)(qin)水(shui)(shui)(shui)(shui)性(xing)(xing)有(you)(you)機(ji)(ji)(ji)物(wu)(wu)(wu)(wu)容易(yi)通過(guo)(guo)膜(mo)，然后(hou)(hou)親(qin)(qin)水(shui)(shui)(shui)(shui)性(xing)(xing)有(you)(you)機(ji)(ji)(ji)物(wu)(wu)(wu)(wu)在滲透物(wu)(wu)(wu)(wu)中(zhong)的比例(li)顯(xian)著(zhu)增(zeng)加。膜(mo)有(you)(you)機(ji)(ji)(ji)污染(ran)物(wu)(wu)(wu)(wu)似乎是(shi)2-7kDa 疏(shu)水(shui)(shui)(shui)(shui)有(you)(you)機(ji)(ji)(ji)物(wu)(wu)(wu)(wu)是(shi)重(zhong)點。活性(xing)(xing)炭僅部分(fen)吸附(fu)2-7 kDa 有(you)(you)機(ji)(ji)(ji)物(wu)(wu)(wu)(wu)，輕(qing)微(wei)(wei)促進膜(mo)污染(ran)。這是(shi)因為活性(xing)(xing)炭顯(xian)著(zhu)去除有(you)(you)機(ji)(ji)(ji)物(wu)(wu)(wu)(wu)，增(zeng)強膜(mo)通量(liang)。