活性(xing)炭改性(xing)后處理(li)磺胺(an)廢水(shui)

　　磺胺(an)廢(fei)水(shui)(shui)經(jing)活(huo)性(xing)(xing)(xing)炭改性(xing)(xing)(xing)后處理(li)，活(huo)性(xing)(xing)(xing)炭經(jing)氯(lv)化鐵改性(xing)(xing)(xing)。并進行批量實(shi)驗以評估廢(fei)水(shui)(shui)中的磺胺(an)二甲嘧啶吸(xi)附(fu)(fu)到(dao)活(huo)性(xing)(xing)(xing)炭和改性(xing)(xing)(xing)活(huo)性(xing)(xing)(xing)炭上的平衡，分別分析動力學(xue)和熱力學(xue)特征(zheng)。結(jie)果表(biao)明，氯(lv)化鐵處理(li)后，活(huo)性(xing)(xing)(xing)炭改變了(le)表(biao)面積(ji)、孔隙體積(ji)和表(biao)面zeta電(dian)位還增加了(le)表(biao)面含氧(yang)官能團的數(shu)量。經(jing)試驗發(fa)現，磺胺(an)二甲啶在改性(xing)(xing)(xing)活(huo)性(xing)(xing)(xing)炭上的吸(xi)附(fu)(fu)得到(dao)了(le)顯(xian)著改善。

　　磺胺二甲啶是一種新型污染物，主要用于治療各種細菌感染引起的疾病。大多數磺胺二甲嘧啶以磺胺或代謝物的形式通過動物糞便和尿液釋放到環境中。這些磺胺或代謝物可能長期存在于環境中，可通過農場徑流和城市污水處理廠進入土壤、地表水、地下水甚至飲用水。傳統的污水處理技術只能去除廢水中的一些抗生素。這促使研究人員開發簡單高效的新技術，有效處理磺胺廢水。由于比表面積大，孔結構復雜，活性炭能有(you)效(xiao)去除顏色(se)、氣味、無機化合(he)物和大(da)多數有(you)機污(wu)染(ran)物。但其在實際(ji)應用中(zhong)的(de)使(shi)用受(shou)其吸(xi)(xi)(xi)附(fu)(fu)(fu)效(xiao)率(lv)和成本低的(de)限制(zhi)。金屬離子改性(xing)后的(de)活(huo)(huo)性(xing)炭(tan)生(sheng)產簡(jian)單(dan)便宜，能顯著提(ti)高活(huo)(huo)性(xing)炭(tan)的(de)吸(xi)(xi)(xi)附(fu)(fu)(fu)性(xing)能。然(ran)而，活(huo)(huo)性(xing)炭(tan)中(zhong)磺胺類廢(fei)水(shui)(shui)的(de)吸(xi)(xi)(xi)附(fu)(fu)(fu)機制(zhi)尚不(bu)清(qing)楚，對(dui)磺胺類的(de)吸(xi)(xi)(xi)附(fu)(fu)(fu)能力及其理化性(xing)質知之甚(shen)少。本研究采用鐵離子改性(xing)活(huo)(huo)性(xing)炭(tan)。用于探(tan)索吸(xi)(xi)(xi)附(fu)(fu)(fu)機制(zhi)的(de)批量吸(xi)(xi)(xi)附(fu)(fu)(fu)實驗。磺胺二(er)甲(jia)啶對(dui)活(huo)(huo)性(xing)炭(tan)和改性(xing)活(huo)(huo)性(xing)炭(tan)的(de)吸(xi)(xi)(xi)附(fu)(fu)(fu)特性(xing)通過吸(xi)(xi)(xi)附(fu)(fu)(fu)動力學(xue)(xue)、吸(xi)(xi)(xi)附(fu)(fu)(fu)熱力學(xue)(xue)和吸(xi)(xi)(xi)附(fu)(fu)(fu)等溫線進行了研究，為去除廢(fei)水(shui)(shui)中(zhong)的(de)磺胺污(wu)染(ran)物提(ti)供了科學(xue)(xue)依據。

　　活性(xing)炭改性(xing)后的特性(xing)

　　活(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)和(he)(he)(he)改(gai)(gai)(gai)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)活(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)的(de)(de)(de)化學(xue)結構和(he)(he)(he)物(wu)理化學(xue)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)質(zhi)差異很大(da)。鐵離(li)子改(gai)(gai)(gai)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)后，活(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)的(de)(de)(de)表(biao)面積、總孔(kong)(kong)(kong)(kong)容(rong)量(liang)、微(wei)孔(kong)(kong)(kong)(kong)體積和(he)(he)(he)中(zhong)孔(kong)(kong)(kong)(kong)體積都有(you)(you)(you)一定程度(du)的(de)(de)(de)增(zeng)(zeng)(zeng)加，可(ke)以為磺胺(an)二甲(jia)啶(ding)提供更(geng)多(duo)的(de)(de)(de)吸附點(dian)(dian)。由于改(gai)(gai)(gai)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)，活(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)的(de)(de)(de)微(wei)孔(kong)(kong)(kong)(kong)結構可(ke)能會產生較大(da)的(de)(de)(de)比表(biao)面積。在活(huo)(huo)(huo)(huo)化過程中(zhong)，鐵離(li)子主(zhu)要沉積在介(jie)孔(kong)(kong)(kong)(kong)中(zhong)，擴(kuo)大(da)孔(kong)(kong)(kong)(kong)徑并進入微(wei)孔(kong)(kong)(kong)(kong)。將金屬(shu)鹽(yan)釋(shi)放的(de)(de)(de)氧化氣體引(yin)入微(wei)孔(kong)(kong)(kong)(kong)，并與(yu)微(wei)孔(kong)(kong)(kong)(kong)碳壁(bi)反應。活(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)和(he)(he)(he)改(gai)(gai)(gai)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)活(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)SEM圖(tu)(tu)(tu)(tu)1顯示(shi)(shi)圖(tu)(tu)(tu)(tu)像(xiang)(a)和(he)(he)(he)(b)中(zhong)。活(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)的(de)(de)(de)形狀表(biao)明(ming)(ming)具有(you)(you)(you)規(gui)則孔(kong)(kong)(kong)(kong)結構的(de)(de)(de)光滑(hua)表(biao)面。與(yu)活(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)相比，改(gai)(gai)(gai)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)活(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)表(biao)面粗糙不規(gui)則。孔(kong)(kong)(kong)(kong)隙結構受(shou)損，孔(kong)(kong)(kong)(kong)隙率(lv)增(zeng)(zeng)(zeng)加。這可(ke)能是(shi)由于鐵離(li)子引(yin)入活(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)內孔(kong)(kong)(kong)(kong)，導致碳壁(bi)氧化和(he)(he)(he)孔(kong)(kong)(kong)(kong)徑增(zeng)(zeng)(zeng)加。活(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)中(zhong)磺胺(an)二甲(jia)啶(ding)的(de)(de)(de)擴(kuo)散有(you)(you)(you)利于粗糙的(de)(de)(de)表(biao)面結構和(he)(he)(he)多(duo)孔(kong)(kong)(kong)(kong)特性(xing)(xing)(xing)(xing)(xing)(xing)(xing)。活(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)和(he)(he)(he)改(gai)(gai)(gai)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)活(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)TEM圖(tu)(tu)(tu)(tu)像(xiang)如圖(tu)(tu)(tu)(tu)1(c)和(he)(he)(he)(d)所示(shi)(shi)。這些圖(tu)(tu)(tu)(tu)片(pian)表(biao)明(ming)(ming)活(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)是(shi)無(wu)定形的(de)(de)(de)。與(yu)活(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)相比，改(gai)(gai)(gai)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)活(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)表(biao)現出許多(duo)孔(kong)(kong)(kong)(kong)隙和(he)(he)(he)透明(ming)(ming)點(dian)(dian)，進一步(bu)表(biao)明(ming)(ming)表(biao)面積增(zeng)(zeng)(zeng)加。活(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)和(he)(he)(he)改(gai)(gai)(gai)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)活(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)EDS圖(tu)(tu)(tu)(tu)像(xiang)如圖(tu)(tu)(tu)(tu)1(e)和(he)(he)(he)(f)所示(shi)(shi)。與(yu)活(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)相比，改(gai)(gai)(gai)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)活(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)的(de)(de)(de)元素O和(he)(he)(he)Fe含(han)量(liang)顯著增(zeng)(zeng)(zeng)加，C活(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)上(shang)鐵離(li)子負荷的(de)(de)(de)含(han)量(liang)降低。此外，進一步(bu)證明(ming)(ming)表(biao)面含(han)氧量(liang)增(zeng)(zeng)(zeng)加，有(you)(you)(you)利于磺胺(an)二甲(jia)啶(ding)的(de)(de)(de)吸附。活(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)和(he)(he)(he)改(gai)(gai)(gai)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)活(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)XRD圖(tu)(tu)(tu)(tu)如圖(tu)(tu)(tu)(tu)1(g)和(he)(he)(he)(h)所示(shi)(shi)。而且沒有(you)(you)(you)活(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)和(he)(he)(he)改(gai)(gai)(gai)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)活(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)的(de)(de)(de)明(ming)(ming)顯特征峰值，說明(ming)(ming)它們是(shi)無(wu)形的(de)(de)(de)。這與(yu)TEM照片(pian)結果一致。

　　兩種吸附(fu)劑(ji)的代表性SEM，TEM和EDS圖像。(a)活(huo)性炭的SEM(比例尺(chi)(chi)為(wei)2μm)，(b)活(huo)性炭的TEM(比例尺(chi)(chi)為(wei)100nm)，(c)活(huo)性炭的EDS，(d)改(gai)(gai)(gai)性活(huo)性炭SEM(比例尺(chi)(chi)為(wei)2μm)，(e)改(gai)(gai)(gai)性活(huo)性炭TEM(比例尺(chi)(chi)為(wei)100nm)，(f)改(gai)(gai)(gai)性活(huo)性炭EDS，(g)活(huo)性炭的XRD，(h)改(gai)(gai)(gai)性活(huo)性炭XRD。

　　活(huo)性炭吸附磺(huang)胺的三個階段

　　活(huo)(huo)(huo)性(xing)(xing)(xing)炭(tan)和改(gai)性(xing)(xing)(xing)活(huo)(huo)(huo)性(xing)(xing)(xing)炭(tan)和改(gai)性(xing)(xing)(xing)活(huo)(huo)(huo)性(xing)(xing)(xing)炭(tan)上(shang)的(de)吸附和擴散(san)(san)過程(cheng)可分三個(ge)階(jie)段(duan)描述，如圖(tu)2所示。由于**階(jie)段(duan)吸附在活(huo)(huo)(huo)性(xing)(xing)(xing)炭(tan)表面(mian)，吸附率(lv)(lv)*初(chu)很高。然后，在顆粒內快(kuai)速(su)擴散(san)(san)的(de)過程(cheng)中，磺胺二甲啶(ding)逐漸吸附在活(huo)(huo)(huo)性(xing)(xing)(xing)炭(tan)上(shang)，吸附率(lv)(lv)常數逐漸降低。在第三階(jie)段(duan)，邊界層和傳質(zhi)阻力的(de)影響增(zeng)加，導致(zhi)顆粒擴散(san)(san)減慢(man)。所有(you)三個(ge)階(jie)段(duan)的(de)擬合方程(cheng)都沒有(you)通過坐標的(de)原(yuan)點，這表明顆粒的(de)擴散(san)(san)并不是控制吸附率(lv)(lv)的(de)**步驟。因此，吸附過程(cheng)也受(shou)膜(mo)擴散(san)(san)和表面(mian)吸附的(de)影響。

　　磺胺二甲(jia)啶在活性炭上(shang)吸附(fu)的顆粒中擴散。

　　改性(xing)活(huo)性(xing)炭的表面顯示出(chu)許多孔隙(xi)和透(tou)明度，大量(liang)含(han)氧(yang)官能(neng)團被(bei)改性(xing)，導致磺(huang)胺二甲啶吸(xi)附(fu)機(ji)制的變化。根(gen)據(ju)本研究的相關研究結(jie)果，活(huo)性(xing)炭表面磺(huang)胺二甲啶的吸(xi)附(fu)機(ji)制總結(jie)如下(xia)（圖3）：

　　1.微孔捕獲

　　SEM圖(tu)像(xiang)顯(xian)示，活性炭(tan)的(de)規則孔結構受損，孔隙率增(zeng)加。TEM圖(tu)像(xiang)顯(xian)示，改性活性炭(tan)表面含有(you)許(xu)多透(tou)明(ming)(ming)點(dian)，表明(ming)(ming)孔結構更發達，修改后可(ke)獲得更多的(de)吸(xi)附點(dian)。這有(you)利于磺胺二甲(jia)啶吸(xi)附到黑碳分子(zi)層的(de)孔中(zhong)。此外，經鐵(tie)離子(zi)改性后，活性炭(tan)的(de)表面積(ji)(ji)、總(zong)孔容量、微孔體積(ji)(ji)和中(zhong)孔體積(ji)(ji)都(dou)有(you)一定(ding)程(cheng)度的(de)增(zeng)加。

　　2.氫鍵(jian)相互作用

　　通過FTIR通過促(cu)進(jin)改性(xing)(xing)活(huo)性(xing)(xing)炭表(biao)(biao)面(mian)(mian)與磺胺(an)二(er)甲啶(ding)(ding)之(zhi)間(jian)(jian)氫鍵的(de)相互作用，促(cu)進(jin)磺胺(an)二(er)甲啶(ding)(ding)的(de)吸(xi)附。從數據圖(tu)中發現(xian)，3400和2850cm-1處寬吸(xi)收峰表(biao)(biao)明改性(xing)(xing)活(huo)性(xing)(xing)炭表(biao)(biao)面(mian)(mian)存在-OH。這些分(fen)子間(jian)(jian)氫鍵增(zeng)強了磺胺(an)二(er)甲啶(ding)(ding)與活(huo)性(xing)(xing)炭的(de)表(biao)(biao)面(mian)(mian)相互作用，預計將有助于活(huo)性(xing)(xing)炭與異(yi)磺胺(an)二(er)甲啶(ding)(ding)之(zhi)間(jian)(jian)的(de)親和力(li)吸(xi)附。

　　3.π-π電子供體-受體(EDA)相互作用。

　　磺胺二甲啶(ding)與改性活性炭合理相(xiang)(xiang)(xiang)(xiang)互作(zuo)(zuo)(zuo)用(yong)(yong)的示(shi)意圖。1.微孔捕獲(huo)。2.氫鍵相(xiang)(xiang)(xiang)(xiang)互作(zuo)(zuo)(zuo)用(yong)(yong)。.π-πEDA相(xiang)(xiang)(xiang)(xiang)互作(zuo)(zuo)(zuo)用(yong)(yong)。4.靜電相(xiang)(xiang)(xiang)(xiang)互作(zuo)(zuo)(zuo)用(yong)(yong)。5.配位(wei)相(xiang)(xiang)(xiang)(xiang)互作(zuo)(zuo)(zuo)用(yong)(yong)。

　　鐵離子改(gai)性(xing)(xing)(xing)后(hou)，活(huo)(huo)性(xing)(xing)(xing)炭活(huo)(huo)性(xing)(xing)(xing)炭的表(biao)(biao)面積(ji)、總孔容(rong)量(liang)(liang)、微孔體積(ji)和中孔體積(ji)。含氧加了活(huo)(huo)性(xing)(xing)(xing)炭表(biao)(biao)面含氧官能(neng)(neng)團的數(shu)量(liang)(liang)，可以(yi)大(da)(da)大(da)(da)提高(gao)吸(xi)(xi)(xi)附(fu)(fu)能(neng)(neng)力。磺(huang)胺(an)二(er)甲(jia)(jia)(jia)嘧啶(ding)在(zai)(zai)改(gai)性(xing)(xing)(xing)活(huo)(huo)性(xing)(xing)(xing)炭上(shang)去除磺(huang)胺(an)廢水中顯著(zhu)增加，并在(zai)(zai)25℃下磺(huang)胺(an)二(er)甲(jia)(jia)(jia)嘧啶(ding)在(zai)(zai)改(gai)性(xing)(xing)(xing)活(huo)(huo)性(xing)(xing)(xing)炭上(shang)的*大(da)(da)吸(xi)(xi)(xi)附(fu)(fu)量(liang)(liang)為(wei)17.261mg/g。然(ran)而，吸(xi)(xi)(xi)附(fu)(fu)平(ping)衡時間幾乎保持不變。磺(huang)胺(an)二(er)甲(jia)(jia)(jia)啶(ding)在(zai)(zai)原(yuan)始(shi)和改(gai)性(xing)(xing)(xing)活(huo)(huo)性(xing)(xing)(xing)炭上(shang)的吸(xi)(xi)(xi)附(fu)(fu)動力學分為(wei)快速和慢(man)速吸(xi)(xi)(xi)附(fu)(fu)階段，磺(huang)胺(an)二(er)甲(jia)(jia)(jia)啶(ding)吸(xi)(xi)(xi)附(fu)(fu)在(zai)(zai)12小時內(nei)快速完成。pH該值(zhi)對磺(huang)胺(an)二(er)甲(jia)(jia)(jia)啶(ding)的吸(xi)(xi)(xi)附(fu)(fu)有顯著(zhu)影響。當(dang)pH磺(huang)胺(an)二(er)甲(jia)(jia)(jia)啶(ding)的吸(xi)(xi)(xi)附(fu)(fu)量(liang)(liang)在(zai)(zai)3-10之間增加，然(ran)后(hou)減少(shao)。微孔捕獲，靜電(dian)相互作(zuo)用，氫鍵相互作(zuo)用，π-πEDA相互作(zuo)用和配位相互作(zuo)用是(shi)吸(xi)(xi)(xi)附(fu)(fu)的可能(neng)(neng)機(ji)制。降低溫度促進吸(xi)(xi)(xi)附(fu)(fu)反應。pH該值(zhi)對磺(huang)胺(an)二(er)甲(jia)(jia)(jia)啶(ding)的吸(xi)(xi)(xi)附(fu)(fu)有顯著(zhu)影響。當(dang)pH磺(huang)胺(an)二(er)甲(jia)(jia)(jia)啶(ding)的吸(xi)(xi)(xi)附(fu)(fu)量(liang)(liang)在(zai)(zai)3-10之間增加，然(ran)后(hou)減少(shao)。