活性炭對微濾膜的影響

　　活(huo)性(xing)炭(tan)(tan)(tan)吸(xi)附對微濾(lv)膜性(xing)能(neng)的(de)影響(xiang)。結果(guo)表明，活(huo)性(xing)炭(tan)(tan)(tan)預處(chu)(chu)理為10-200 mg / L 在劑量(liang)(liang)(liang)下，溶(rong)解(jie)有(you)(you)機(ji)碳(DOC)和(he)254 nm紫外吸(xi)收光譜(UV 254)都(dou)能(neng)提供高(gao)有(you)(you)機(ji)物(wu)(wu)去除率。通(tong)過(guo)MF隨著(zhu)活(huo)性(xing)炭(tan)(tan)(tan)吸(xi)附有(you)(you)機(ji)物(wu)(wu)的(de)增加，膜過(guo)濾(lv)去除效率降低。主要去除活(huo)性(xing)炭(tan)(tan)(tan)約3kDa有(you)(you)機(ji)物(wu)(wu)質(zhi)的(de)分子量(liang)(liang)(liang)。活(huo)性(xing)炭(tan)(tan)(tan)吸(xi)附后，膜在膜上保持超(chao)過(guo)5kDa有(you)(you)機(ji)物(wu)(wu)質(zhi)。膜過(guo)濾(lv)結果(guo)表明，無論活(huo)性(xing)炭(tan)(tan)(tan)劑量(liang)(liang)(liang)如何，活(huo)性(xing)炭(tan)(tan)(tan)的(de)預處(chu)(chu)理都(dou)略微促進膜通(tong)量(liang)(liang)(liang)。似乎有(you)(you)機(ji)污(wu)垢膜集中在3以上kDa的(de)微濾(lv)膜。活(huo)性(xing)炭(tan)(tan)(tan)去除明顯小于(yu)33kDa 微濾(lv)膜有(you)(you)機(ji)物(wu)(wu)超(chao)過(guo)3種(zhong)kDa有(you)(you)機(ji)物(wu)(wu)質(zhi)的(de)影響(xiang)較小。因(yin)此(ci)，活(huo)性(xing)炭(tan)(tan)(tan)不能(neng)減少膜污(wu)染。

　　膜(mo)污染(ran)(ran)是(shi)(shi)水處理的(de)重要問題(ti)之一。膜(mo)結垢導致膜(mo)通量(liang)降低(di)和性能差。一些研究表明(ming)，天然有(you)(you)機物(NOM)負(fu)責炭吸附是(shi)(shi)飲用(yong)水中負(fu)責微濾膜(mo)污染(ran)(ran)或垢。活性炭吸附是(shi)(shi)減少有(you)(you)機物污染(ran)(ran)膜(mo)的(de)好選擇。

　　活(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)(tan)廣泛(fan)用(yong)作水處理(li)中(zhong)(zhong)的(de)吸(xi)收(shou)劑。活(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)(tan)具有(you)良好的(de)天(tian)然(ran)(ran)有(you)機(ji)物(wu)(wu)(wu)吸(xi)附性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)，因(yin)此采用(yong)預處理(li)，減(jian)少(shao)膜(mo)(mo)(mo)污(wu)染(ran)，提(ti)(ti)高膜(mo)(mo)(mo)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)。然(ran)(ran)而，活(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)(tan)對提(ti)(ti)高膜(mo)(mo)(mo)性(xing)(xing)(xing)(xing)(xing)(xing)能(neng)的(de)效(xiao)率有(you)不(bu)同(tong)的(de)結論(lun)。一些研(yan)究表(biao)明，當活(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)(tan)保持膜(mo)(mo)(mo)表(biao)面時，活(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)(tan)可(ke)以增強(qiang)膜(mo)(mo)(mo)通量(liang) 。活(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)(tan)懸浮在(zai)活(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)(tan)/超濾系統中(zhong)(zhong)的(de)作用(yong)是吸(xi)收(shou)低分子腐殖酸(HA)。膜(mo)(mo)(mo)提(ti)(ti)供(gong)物(wu)(wu)(wu)理(li)屏障，防止活(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)(tan)通過(guo)，從而保留吸(xi)附在(zai)活(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)(tan)上的(de)有(you)機(ji)化合(he)物(wu)(wu)(wu)。發現活(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)(tan)可(ke)能(neng)導致(zhi)更大的(de)絮凝顆粒，并通過(guo)預處理(li)活(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)(tan)來減(jian)少(shao)每(mei)個過(guo)濾周(zhou)期的(de)可(ke)逆性(xing)(xing)(xing)(xing)(xing)(xing)TMP增加。研(yan)究天(tian)然(ran)(ran)有(you)機(ji)物(wu)(wu)(wu)在(zai)耦合(he)超細活(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)(tan)/微濾膜(mo)(mo)(mo)過(guo)程中(zhong)(zhong)的(de)作用(yong)表(biao)明，天(tian)然(ran)(ran)有(you)機(ji)物(wu)(wu)(wu)被證明是膜(mo)(mo)(mo)污(wu)染(ran)和(he)超細活(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)(tan)的(de)主要原因(yin)，活(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)(tan)實(shi)際上比單獨的(de)天(tian)然(ran)(ran)有(you)機(ji)物(wu)(wu)(wu)減(jian)少(shao)了(le)結垢。然(ran)(ran)而，一些研(yan)究人員報告說(shuo)，活(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)(tan)的(de)存在(zai)會加重膜(mo)(mo)(mo)污(wu)染(ran)或不(bu)影響膜(mo)(mo)(mo)通量(liang)。 在(zai)反(fan)洗水中(zhong)(zhong)發現活(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)(tan)顆粒，因(yin)為它們可(ke)能(neng)在(zai)污(wu)垢層的(de)生長過(guo)程中(zhong)(zhong)積累。活(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)(tan)既不(bu)促進也不(bu)控制膜(mo)(mo)(mo)可(ke)逆結垢。

　　活(huo)(huo)性(xing)炭用(yong)于處(chu)理微(wei)濾(lv)膜(mo)(mo)前的(de)預處(chu)理和(he)地表水(shui)。實驗的(de)主要目的(de)是研(yan)究(jiu)活(huo)(huo)性(xing)炭對膜(mo)(mo)性(xing)能的(de)影(ying)響，特(te)別關注活(huo)(huo)性(xing)炭微(wei)濾(lv)膜(mo)(mo)工(gong)藝對有機物去除(chu)率(lv)和(he)膜(mo)(mo)通量(liang)(liang)的(de)影(ying)響。木質活(huo)(huo)性(xing)炭。粒度分(fen)(fen)布為：>74μm-71%，>44μm-95%。使用(yong)前，加(jia)(jia)入(ru)少量(liang)(liang)去離(li)子(zi)水(shui)均勻化活(huo)(huo)性(xing)炭。在原水(shui)中(zhong)加(jia)(jia)入(ru)10、50、100、200mg / L特(te)殊活(huo)(huo)性(xing)炭劑量(liang)(liang)。本實驗采用(yong)黃浦江(jiang)地表水(shui)。在水(shui)樣中(zhong)加(jia)(jia)入(ru)活(huo)(huo)性(xing)炭100rpm快(kuai)速(su)攪拌30分(fen)(fen)鐘1分(fen)(fen)鐘，攪拌30分(fen)(fen)鐘rpm緩慢混合，然后(hou)用(yong)0.45μm過濾(lv)器過濾(lv)水(shui)樣品(pin)。以(yi)下膜(mo)(mo)過濾(lv)用(yong)過濾(lv)水(shui)樣品(pin)。

　　溶解有機碳(tan)和活性(xing)炭和微濾過程UV254去(qu)除(chu)率

　　活(huo)性炭(tan)和UV如圖所示，254的(de)(de)效率(lv)。活(huo)性炭(tan)溶解(jie)(jie)有(you)機(ji)碳去除率(lv)較高(gao)。活(huo)性炭(tan)劑(ji)量(liang)為10-2000 mg / L當(dang)溶解(jie)(jie)有(you)機(ji)碳的(de)(de)去除率(lv)從(cong)3開始.0%提高(gao)到(dao)59.8%。活(huo)性炭(tan)吸附后，微濾膜過(guo)濾水樣，溶解(jie)(jie)有(you)機(ji)碳從(cong)21中(zhong)去除滲透物.1%穩定增(zeng)加(jia)(jia)到(dao)62.2%。然(ran)而(er)，隨著活(huo)性炭(tan)劑(ji)量(liang)的(de)(de)增(zeng)加(jia)(jia)，微濾膜溶解(jie)(jie)有(you)機(ji)碳去除量(liang)略有(you)增(zeng)加(jia)(jia)。

　　與溶(rong)(rong)解有(you)機(ji)碳(tan)(tan)相比，UV254去除(chu)(chu)率(lv)高(gao)。隨著活(huo)性炭劑量從100開始mg / L增(zeng)加(jia)到(dao)200mg / L，超(chao)濾吸(xi)收去除(chu)(chu)率(lv)為(wei)10.1%增(zeng)加(jia)到(dao)70.3%。與微濾過濾后溶(rong)(rong)解有(you)機(ji)碳(tan)(tan)去除(chu)(chu)率(lv)相似，活(huo)性炭用量越高(gao)，微濾膜去除(chu)(chu)UV254越低。可(ke)溶(rong)(rong)解有(you)機(ji)碳(tan)(tan)和活(huo)性炭UV254去除(chu)(chu)率(lv)高(gao)，活(huo)性炭含量高(gao)，膜可(ke)去除(chu)(chu)殘留(liu)有(you)機(ji)物(wu)。

　　在上(shang)述研究(jiu)中，活(huo)性(xing)炭(tan)具(ju)有(you)(you)較(jiao)高的有(you)(you)機(ji)物(wu)去除率(lv)。然(ran)而，即(ji)使在200年(nian)mg / L活(huo)性(xing)炭(tan)高的劑量下，活(huo)性(xing)炭(tan)不能改(gai)善(shan)膜(mo)通量。原水(shui)(shui)有(you)(you)機(ji)質(zhi)的微(wei)濾(lv)濃(nong)度為2-7kDa，特別是3-5kDa。活(huo)性(xing)炭(tan)吸(xi)附的有(you)(you)機(ji)物(wu)濃(nong)度約為3kDa 水(shui)(shui)中有(you)(you)機(ji)物(wu)分(fen)子量。顯然(ran)，活(huo)性(xing)炭(tan)對(dui)水(shui)(shui)中有(you)(you)機(ji)物(wu)分(fen)子物(wu)質(zhi)影響不大。

　　微濾(lv)膜(mo)(mo)(mo)過濾(lv)后原(yuan)水(shui)(shui)(shui)的疏(shu)水(shui)(shui)(shui)性(xing)(xing)(xing)(xing)/親水(shui)(shui)(shui)性(xing)(xing)(xing)(xing)變(bian)化如圖6所示。可見，微濾(lv)膜(mo)(mo)(mo)主要(yao)去除(chu)疏(shu)水(shui)(shui)(shui)有(you)(you)(you)機(ji)(ji)物(wu)(wu)。圖7顯(xian)(xian)(xian)示了原(yuan)水(shui)(shui)(shui)中(zhong)不同(tong)水(shui)(shui)(shui)中(zhong)有(you)(you)(you)機(ji)(ji)物(wu)(wu)分(fen)(fen)子量(liang)的疏(shu)水(shui)(shui)(shui)性(xing)(xing)(xing)(xing)/親水(shui)(shui)(shui)性(xing)(xing)(xing)(xing)變(bian)化。膜(mo)(mo)(mo)過濾(lv)后，疏(shu)水(shui)(shui)(shui)有(you)(you)(you)機(ji)(ji)質(zhi)的比(bi)例(li)明(ming)顯(xian)(xian)(xian)下降，特別是(shi)2-7 kDa 有(you)(you)(you)機(ji)(ji)物(wu)(wu)。相比(bi)之下，親水(shui)(shui)(shui)性(xing)(xing)(xing)(xing)有(you)(you)(you)機(ji)(ji)物(wu)(wu)的比(bi)例(li)顯(xian)(xian)(xian)著(zhu)(zhu)增(zeng)加。本(ben)研究(jiu)采用親水(shui)(shui)(shui)性(xing)(xing)(xing)(xing)PVDF膜(mo)(mo)(mo)。因此，疏(shu)水(shui)(shui)(shui)物(wu)(wu)質(zhi)不能通(tong)(tong)過膜(mo)(mo)(mo)并停留在膜(mo)(mo)(mo)表面(mian)。親水(shui)(shui)(shui)性(xing)(xing)(xing)(xing)有(you)(you)(you)機(ji)(ji)物(wu)(wu)容易(yi)通(tong)(tong)過膜(mo)(mo)(mo)，然后親水(shui)(shui)(shui)性(xing)(xing)(xing)(xing)有(you)(you)(you)機(ji)(ji)物(wu)(wu)在滲(shen)透(tou)物(wu)(wu)中(zhong)的比(bi)例(li)顯(xian)(xian)(xian)著(zhu)(zhu)增(zeng)加。膜(mo)(mo)(mo)有(you)(you)(you)機(ji)(ji)污染(ran)物(wu)(wu)似(si)乎是(shi)2-7kDa 疏(shu)水(shui)(shui)(shui)有(you)(you)(you)機(ji)(ji)物(wu)(wu)是(shi)重點。活(huo)性(xing)(xing)(xing)(xing)炭僅部(bu)分(fen)(fen)吸(xi)附(fu)2-7 kDa 有(you)(you)(you)機(ji)(ji)物(wu)(wu)，輕(qing)微促進膜(mo)(mo)(mo)污染(ran)。這是(shi)因為活(huo)性(xing)(xing)(xing)(xing)炭顯(xian)(xian)(xian)著(zhu)(zhu)去除(chu)有(you)(you)(you)機(ji)(ji)物(wu)(wu)，增(zeng)強膜(mo)(mo)(mo)通(tong)(tong)量(liang)。