活性炭對微濾膜的影響

　　活(huo)(huo)(huo)性(xing)(xing)炭(tan)吸附(fu)(fu)對微(wei)濾(lv)膜(mo)(mo)(mo)性(xing)(xing)能的(de)影響。結(jie)(jie)果表明，活(huo)(huo)(huo)性(xing)(xing)炭(tan)預處理為10-200 mg / L 在劑量下(xia)，溶解有(you)(you)機(ji)碳(DOC)和254 nm紫外吸收(shou)光譜(UV 254)都能提供(gong)高(gao)有(you)(you)機(ji)物(wu)去(qu)除率(lv)。通(tong)(tong)過(guo)MF隨著活(huo)(huo)(huo)性(xing)(xing)炭(tan)吸附(fu)(fu)有(you)(you)機(ji)物(wu)的(de)增加，膜(mo)(mo)(mo)過(guo)濾(lv)去(qu)除效率(lv)降低(di)。主要去(qu)除活(huo)(huo)(huo)性(xing)(xing)炭(tan)約3kDa有(you)(you)機(ji)物(wu)質(zhi)的(de)分子量。活(huo)(huo)(huo)性(xing)(xing)炭(tan)吸附(fu)(fu)后(hou)，膜(mo)(mo)(mo)在膜(mo)(mo)(mo)上保持超過(guo)5kDa有(you)(you)機(ji)物(wu)質(zhi)。膜(mo)(mo)(mo)過(guo)濾(lv)結(jie)(jie)果表明，無論活(huo)(huo)(huo)性(xing)(xing)炭(tan)劑量如何，活(huo)(huo)(huo)性(xing)(xing)炭(tan)的(de)預處理都略微(wei)促進膜(mo)(mo)(mo)通(tong)(tong)量。似乎有(you)(you)機(ji)污(wu)垢膜(mo)(mo)(mo)集中在3以上kDa的(de)微(wei)濾(lv)膜(mo)(mo)(mo)。活(huo)(huo)(huo)性(xing)(xing)炭(tan)去(qu)除明顯小(xiao)于33kDa 微(wei)濾(lv)膜(mo)(mo)(mo)有(you)(you)機(ji)物(wu)超過(guo)3種kDa有(you)(you)機(ji)物(wu)質(zhi)的(de)影響較小(xiao)。因(yin)此，活(huo)(huo)(huo)性(xing)(xing)炭(tan)不能減少膜(mo)(mo)(mo)污(wu)染。

　　膜(mo)污(wu)(wu)染(ran)是水處理的重要問(wen)題之一。膜(mo)結垢導致膜(mo)通量(liang)降低和(he)性能(neng)差。一些研究表明，天(tian)然(ran)有機(ji)物(NOM)負責炭吸附是飲用水中(zhong)負責微濾(lv)膜(mo)污(wu)(wu)染(ran)或垢。活(huo)性炭吸附是減少(shao)有機(ji)物污(wu)(wu)染(ran)膜(mo)的好選擇(ze)。

　　活(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)廣泛用(yong)作水處(chu)理(li)中(zhong)的(de)吸(xi)收劑。活(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)具有(you)(you)良好(hao)的(de)天(tian)然有(you)(you)機物(wu)吸(xi)附(fu)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)，因此采用(yong)預(yu)處(chu)理(li)，減(jian)少膜污(wu)染(ran)，提(ti)高(gao)膜性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)。然而，活(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)對(dui)提(ti)高(gao)膜性(xing)(xing)(xing)(xing)(xing)(xing)(xing)能(neng)的(de)效率有(you)(you)不同的(de)結論。一些(xie)研究表明，當活(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)保(bao)持(chi)膜表面時，活(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)可(ke)(ke)以增強膜通(tong)量(liang) 。活(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)懸浮(fu)在活(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)/超濾(lv)系統中(zhong)的(de)作用(yong)是(shi)吸(xi)收低分子(zi)腐殖(zhi)酸(HA)。膜提(ti)供物(wu)理(li)屏(ping)障，防止活(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)通(tong)過(guo)，從而保(bao)留吸(xi)附(fu)在活(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)上(shang)的(de)有(you)(you)機化合物(wu)。發現活(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)可(ke)(ke)能(neng)導致(zhi)更(geng)大(da)的(de)絮(xu)凝顆粒，并通(tong)過(guo)預(yu)處(chu)理(li)活(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)來減(jian)少每個過(guo)濾(lv)周期的(de)可(ke)(ke)逆性(xing)(xing)(xing)(xing)(xing)(xing)(xing)TMP增加(jia)。研究天(tian)然有(you)(you)機物(wu)在耦合超細活(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)/微濾(lv)膜過(guo)程中(zhong)的(de)作用(yong)表明，天(tian)然有(you)(you)機物(wu)被證明是(shi)膜污(wu)染(ran)和超細活(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)的(de)主要原因，活(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)實際(ji)上(shang)比單獨的(de)天(tian)然有(you)(you)機物(wu)減(jian)少了結垢(gou)。然而，一些(xie)研究人員報告說，活(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)的(de)存在會加(jia)重(zhong)膜污(wu)染(ran)或不影響膜通(tong)量(liang)。 在反洗水中(zhong)發現活(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)顆粒，因為(wei)它們可(ke)(ke)能(neng)在污(wu)垢(gou)層的(de)生長過(guo)程中(zhong)積累。活(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)既不促進也不控制膜可(ke)(ke)逆結垢(gou)。

　　活(huo)性(xing)(xing)(xing)炭(tan)(tan)用(yong)于處理微濾(lv)膜(mo)前(qian)的(de)預處理和地(di)表(biao)(biao)水(shui)(shui)。實(shi)(shi)驗的(de)主要目(mu)的(de)是研究活(huo)性(xing)(xing)(xing)炭(tan)(tan)對膜(mo)性(xing)(xing)(xing)能的(de)影響(xiang)，特(te)別關(guan)注活(huo)性(xing)(xing)(xing)炭(tan)(tan)微濾(lv)膜(mo)工藝對有機物去除率和膜(mo)通量的(de)影響(xiang)。木質活(huo)性(xing)(xing)(xing)炭(tan)(tan)。粒(li)度分(fen)(fen)布為：>74μm-71%，>44μm-95%。使用(yong)前(qian)，加(jia)入少量去離子水(shui)(shui)均勻化活(huo)性(xing)(xing)(xing)炭(tan)(tan)。在(zai)原水(shui)(shui)中(zhong)加(jia)入10、50、100、200mg / L特(te)殊活(huo)性(xing)(xing)(xing)炭(tan)(tan)劑(ji)量。本實(shi)(shi)驗采用(yong)黃浦(pu)江地(di)表(biao)(biao)水(shui)(shui)。在(zai)水(shui)(shui)樣中(zhong)加(jia)入活(huo)性(xing)(xing)(xing)炭(tan)(tan)100rpm快(kuai)速攪(jiao)拌30分(fen)(fen)鐘(zhong)1分(fen)(fen)鐘(zhong)，攪(jiao)拌30分(fen)(fen)鐘(zhong)rpm緩慢混合(he)，然后用(yong)0.45μm過濾(lv)器過濾(lv)水(shui)(shui)樣品(pin)。以下膜(mo)過濾(lv)用(yong)過濾(lv)水(shui)(shui)樣品(pin)。

　　溶解有機(ji)碳和活性炭和微濾(lv)過程UV254去除率

　　活性炭和UV如圖所示，254的效率。活性炭溶(rong)解有(you)機(ji)(ji)(ji)碳(tan)(tan)去(qu)除率較高。活性炭劑(ji)量為10-2000 mg / L當溶(rong)解有(you)機(ji)(ji)(ji)碳(tan)(tan)的去(qu)除率從3開始(shi).0%提(ti)高到(dao)(dao)59.8%。活性炭吸附后，微濾(lv)(lv)膜(mo)過濾(lv)(lv)水樣，溶(rong)解有(you)機(ji)(ji)(ji)碳(tan)(tan)從21中去(qu)除滲透物.1%穩定增加到(dao)(dao)62.2%。然而，隨著(zhu)活性炭劑(ji)量的增加，微濾(lv)(lv)膜(mo)溶(rong)解有(you)機(ji)(ji)(ji)碳(tan)(tan)去(qu)除量略有(you)增加。

　　與溶解(jie)有機(ji)碳相(xiang)(xiang)比，UV254去(qu)(qu)除(chu)(chu)率(lv)高(gao)(gao)。隨著活(huo)(huo)性(xing)炭劑量從100開(kai)始mg / L增(zeng)加到(dao)(dao)200mg / L，超濾吸收去(qu)(qu)除(chu)(chu)率(lv)為10.1%增(zeng)加到(dao)(dao)70.3%。與微(wei)濾過濾后溶解(jie)有機(ji)碳去(qu)(qu)除(chu)(chu)率(lv)相(xiang)(xiang)似，活(huo)(huo)性(xing)炭用量越高(gao)(gao)，微(wei)濾膜(mo)去(qu)(qu)除(chu)(chu)UV254越低。可溶解(jie)有機(ji)碳和活(huo)(huo)性(xing)炭UV254去(qu)(qu)除(chu)(chu)率(lv)高(gao)(gao)，活(huo)(huo)性(xing)炭含量高(gao)(gao)，膜(mo)可去(qu)(qu)除(chu)(chu)殘留(liu)有機(ji)物。

　　在(zai)上述研究中(zhong)(zhong)，活(huo)性(xing)(xing)炭(tan)具有(you)(you)較高的(de)(de)有(you)(you)機(ji)(ji)物(wu)去(qu)除率(lv)。然(ran)而，即(ji)使在(zai)200年mg / L活(huo)性(xing)(xing)炭(tan)高的(de)(de)劑量(liang)下，活(huo)性(xing)(xing)炭(tan)不能改善膜(mo)通量(liang)。原(yuan)水有(you)(you)機(ji)(ji)質的(de)(de)微濾濃度(du)為(wei)2-7kDa，特別是3-5kDa。活(huo)性(xing)(xing)炭(tan)吸附的(de)(de)有(you)(you)機(ji)(ji)物(wu)濃度(du)約(yue)為(wei)3kDa 水中(zhong)(zhong)有(you)(you)機(ji)(ji)物(wu)分子(zi)量(liang)。顯然(ran)，活(huo)性(xing)(xing)炭(tan)對(dui)水中(zhong)(zhong)有(you)(you)機(ji)(ji)物(wu)分子(zi)物(wu)質影(ying)響不大。

　　微(wei)(wei)濾(lv)膜(mo)過濾(lv)后原(yuan)水(shui)(shui)(shui)(shui)(shui)的(de)疏水(shui)(shui)(shui)(shui)(shui)性(xing)(xing)/親(qin)水(shui)(shui)(shui)(shui)(shui)性(xing)(xing)變化如圖(tu)(tu)6所示(shi)。可見，微(wei)(wei)濾(lv)膜(mo)主要去除疏水(shui)(shui)(shui)(shui)(shui)有機(ji)(ji)(ji)物(wu)(wu)(wu)(wu)。圖(tu)(tu)7顯示(shi)了原(yuan)水(shui)(shui)(shui)(shui)(shui)中不同水(shui)(shui)(shui)(shui)(shui)中有機(ji)(ji)(ji)物(wu)(wu)(wu)(wu)分子(zi)量(liang)的(de)疏水(shui)(shui)(shui)(shui)(shui)性(xing)(xing)/親(qin)水(shui)(shui)(shui)(shui)(shui)性(xing)(xing)變化。膜(mo)過濾(lv)后，疏水(shui)(shui)(shui)(shui)(shui)有機(ji)(ji)(ji)質的(de)比(bi)例(li)明(ming)顯下降，特(te)別是(shi)2-7 kDa 有機(ji)(ji)(ji)物(wu)(wu)(wu)(wu)。相比(bi)之下，親(qin)水(shui)(shui)(shui)(shui)(shui)性(xing)(xing)有機(ji)(ji)(ji)物(wu)(wu)(wu)(wu)的(de)比(bi)例(li)顯著(zhu)增(zeng)加(jia)。本研(yan)究采用親(qin)水(shui)(shui)(shui)(shui)(shui)性(xing)(xing)PVDF膜(mo)。因此，疏水(shui)(shui)(shui)(shui)(shui)物(wu)(wu)(wu)(wu)質不能通(tong)過膜(mo)并停留(liu)在(zai)膜(mo)表(biao)面。親(qin)水(shui)(shui)(shui)(shui)(shui)性(xing)(xing)有機(ji)(ji)(ji)物(wu)(wu)(wu)(wu)容易(yi)通(tong)過膜(mo)，然后親(qin)水(shui)(shui)(shui)(shui)(shui)性(xing)(xing)有機(ji)(ji)(ji)物(wu)(wu)(wu)(wu)在(zai)滲(shen)透(tou)物(wu)(wu)(wu)(wu)中的(de)比(bi)例(li)顯著(zhu)增(zeng)加(jia)。膜(mo)有機(ji)(ji)(ji)污染(ran)物(wu)(wu)(wu)(wu)似乎(hu)是(shi)2-7kDa 疏水(shui)(shui)(shui)(shui)(shui)有機(ji)(ji)(ji)物(wu)(wu)(wu)(wu)是(shi)重(zhong)點。活性(xing)(xing)炭僅部(bu)分吸附(fu)2-7 kDa 有機(ji)(ji)(ji)物(wu)(wu)(wu)(wu)，輕微(wei)(wei)促進(jin)膜(mo)污染(ran)。這是(shi)因為活性(xing)(xing)炭顯著(zhu)去除有機(ji)(ji)(ji)物(wu)(wu)(wu)(wu)，增(zeng)強(qiang)膜(mo)通(tong)量(liang)。