活性(xing)炭改(gai)性(xing)后處理磺胺廢水

　　磺(huang)胺廢水經(jing)活(huo)性(xing)(xing)炭(tan)改性(xing)(xing)后處(chu)理(li)，活(huo)性(xing)(xing)炭(tan)經(jing)氯化鐵改性(xing)(xing)。并進行批(pi)量(liang)實驗以評估廢水中的(de)磺(huang)胺二甲(jia)(jia)嘧啶吸附到(dao)活(huo)性(xing)(xing)炭(tan)和改性(xing)(xing)活(huo)性(xing)(xing)炭(tan)上(shang)的(de)平衡，分別分析動力(li)學和熱力(li)學特征(zheng)。結果表明(ming)，氯化鐵處(chu)理(li)后，活(huo)性(xing)(xing)炭(tan)改變了表面積(ji)、孔隙體積(ji)和表面zeta電(dian)位還增加了表面含(han)氧官能團的(de)數量(liang)。經(jing)試驗發現，磺(huang)胺二甲(jia)(jia)啶在改性(xing)(xing)活(huo)性(xing)(xing)炭(tan)上(shang)的(de)吸附得到(dao)了顯著改善。

　　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(neng)有(you)效(xiao)去除顏(yan)色(se)、氣味、無機(ji)化合物(wu)和(he)大多數有(you)機(ji)污染(ran)(ran)物(wu)。但其在(zai)實際(ji)應用(yong)中的(de)使用(yong)受其吸(xi)(xi)(xi)(xi)附(fu)(fu)(fu)(fu)效(xiao)率和(he)成本(ben)低的(de)限制。金屬離子改(gai)性(xing)后的(de)活(huo)(huo)性(xing)炭(tan)生產(chan)簡單便宜，能(neng)顯著提高活(huo)(huo)性(xing)炭(tan)的(de)吸(xi)(xi)(xi)(xi)附(fu)(fu)(fu)(fu)性(xing)能(neng)。然而，活(huo)(huo)性(xing)炭(tan)中磺(huang)胺類廢(fei)水的(de)吸(xi)(xi)(xi)(xi)附(fu)(fu)(fu)(fu)機(ji)制尚(shang)不(bu)清楚，對磺(huang)胺類的(de)吸(xi)(xi)(xi)(xi)附(fu)(fu)(fu)(fu)能(neng)力(li)及其理化性(xing)質知之甚少。本(ben)研(yan)究(jiu)采用(yong)鐵離子改(gai)性(xing)活(huo)(huo)性(xing)炭(tan)。用(yong)于探索吸(xi)(xi)(xi)(xi)附(fu)(fu)(fu)(fu)機(ji)制的(de)批量(liang)吸(xi)(xi)(xi)(xi)附(fu)(fu)(fu)(fu)實驗。磺(huang)胺二(er)甲(jia)啶對活(huo)(huo)性(xing)炭(tan)和(he)改(gai)性(xing)活(huo)(huo)性(xing)炭(tan)的(de)吸(xi)(xi)(xi)(xi)附(fu)(fu)(fu)(fu)特性(xing)通過吸(xi)(xi)(xi)(xi)附(fu)(fu)(fu)(fu)動力(li)學、吸(xi)(xi)(xi)(xi)附(fu)(fu)(fu)(fu)熱力(li)學和(he)吸(xi)(xi)(xi)(xi)附(fu)(fu)(fu)(fu)等溫線進行了研(yan)究(jiu)，為(wei)去除廢(fei)水中的(de)磺(huang)胺污染(ran)(ran)物(wu)提供了科學依據(ju)。

　　活性炭(tan)改性后的特性

　　活(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)和(he)(he)改(gai)(gai)(gai)(gai)性(xing)(xing)(xing)(xing)(xing)(xing)活(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)的(de)(de)(de)(de)(de)化(hua)(hua)(hua)學結(jie)構(gou)和(he)(he)物理化(hua)(hua)(hua)學性(xing)(xing)(xing)(xing)(xing)(xing)質差異很大(da)。鐵離(li)子改(gai)(gai)(gai)(gai)性(xing)(xing)(xing)(xing)(xing)(xing)后(hou)，活(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)的(de)(de)(de)(de)(de)表(biao)(biao)(biao)(biao)(biao)面積(ji)(ji)、總孔(kong)(kong)(kong)(kong)(kong)容量(liang)、微孔(kong)(kong)(kong)(kong)(kong)體積(ji)(ji)和(he)(he)中(zhong)(zhong)孔(kong)(kong)(kong)(kong)(kong)體積(ji)(ji)都有一定(ding)(ding)程度的(de)(de)(de)(de)(de)增(zeng)加，可(ke)以為磺胺(an)二(er)甲啶(ding)提(ti)供(gong)更多(duo)(duo)的(de)(de)(de)(de)(de)吸附點。由(you)于改(gai)(gai)(gai)(gai)性(xing)(xing)(xing)(xing)(xing)(xing)，活(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)的(de)(de)(de)(de)(de)微孔(kong)(kong)(kong)(kong)(kong)結(jie)構(gou)可(ke)能會產生較大(da)的(de)(de)(de)(de)(de)比表(biao)(biao)(biao)(biao)(biao)面積(ji)(ji)。在(zai)活(huo)(huo)化(hua)(hua)(hua)過程中(zhong)(zhong)，鐵離(li)子主要沉積(ji)(ji)在(zai)介孔(kong)(kong)(kong)(kong)(kong)中(zhong)(zhong)，擴大(da)孔(kong)(kong)(kong)(kong)(kong)徑并進入(ru)微孔(kong)(kong)(kong)(kong)(kong)。將金屬鹽(yan)釋放的(de)(de)(de)(de)(de)氧化(hua)(hua)(hua)氣(qi)體引(yin)入(ru)微孔(kong)(kong)(kong)(kong)(kong)，并與(yu)微孔(kong)(kong)(kong)(kong)(kong)碳壁(bi)反應。活(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)和(he)(he)改(gai)(gai)(gai)(gai)性(xing)(xing)(xing)(xing)(xing)(xing)活(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)SEM圖1顯(xian)示(shi)(shi)圖像(xiang)(a)和(he)(he)(b)中(zhong)(zhong)。活(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)的(de)(de)(de)(de)(de)形(xing)狀表(biao)(biao)(biao)(biao)(biao)明(ming)具有規則孔(kong)(kong)(kong)(kong)(kong)結(jie)構(gou)的(de)(de)(de)(de)(de)光(guang)滑表(biao)(biao)(biao)(biao)(biao)面。與(yu)活(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)相比，改(gai)(gai)(gai)(gai)性(xing)(xing)(xing)(xing)(xing)(xing)活(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)表(biao)(biao)(biao)(biao)(biao)面粗糙不規則。孔(kong)(kong)(kong)(kong)(kong)隙結(jie)構(gou)受損，孔(kong)(kong)(kong)(kong)(kong)隙率(lv)增(zeng)加。這(zhe)可(ke)能是由(you)于鐵離(li)子引(yin)入(ru)活(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)內孔(kong)(kong)(kong)(kong)(kong)，導致碳壁(bi)氧化(hua)(hua)(hua)和(he)(he)孔(kong)(kong)(kong)(kong)(kong)徑增(zeng)加。活(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)中(zhong)(zhong)磺胺(an)二(er)甲啶(ding)的(de)(de)(de)(de)(de)擴散有利于粗糙的(de)(de)(de)(de)(de)表(biao)(biao)(biao)(biao)(biao)面結(jie)構(gou)和(he)(he)多(duo)(duo)孔(kong)(kong)(kong)(kong)(kong)特性(xing)(xing)(xing)(xing)(xing)(xing)。活(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)和(he)(he)改(gai)(gai)(gai)(gai)性(xing)(xing)(xing)(xing)(xing)(xing)活(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)TEM圖像(xiang)如圖1(c)和(he)(he)(d)所示(shi)(shi)。這(zhe)些圖片(pian)表(biao)(biao)(biao)(biao)(biao)明(ming)活(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)是無(wu)(wu)定(ding)(ding)形(xing)的(de)(de)(de)(de)(de)。與(yu)活(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)相比，改(gai)(gai)(gai)(gai)性(xing)(xing)(xing)(xing)(xing)(xing)活(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)表(biao)(biao)(biao)(biao)(biao)現出許多(duo)(duo)孔(kong)(kong)(kong)(kong)(kong)隙和(he)(he)透明(ming)點，進一步表(biao)(biao)(biao)(biao)(biao)明(ming)表(biao)(biao)(biao)(biao)(biao)面積(ji)(ji)增(zeng)加。活(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)和(he)(he)改(gai)(gai)(gai)(gai)性(xing)(xing)(xing)(xing)(xing)(xing)活(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)EDS圖像(xiang)如圖1(e)和(he)(he)(f)所示(shi)(shi)。與(yu)活(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)相比，改(gai)(gai)(gai)(gai)性(xing)(xing)(xing)(xing)(xing)(xing)活(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)的(de)(de)(de)(de)(de)元素O和(he)(he)Fe含量(liang)顯(xian)著增(zeng)加，C活(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)上(shang)鐵離(li)子負荷的(de)(de)(de)(de)(de)含量(liang)降(jiang)低。此外，進一步證(zheng)明(ming)表(biao)(biao)(biao)(biao)(biao)面含氧量(liang)增(zeng)加，有利于磺胺(an)二(er)甲啶(ding)的(de)(de)(de)(de)(de)吸附。活(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)和(he)(he)改(gai)(gai)(gai)(gai)性(xing)(xing)(xing)(xing)(xing)(xing)活(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)XRD圖如圖1(g)和(he)(he)(h)所示(shi)(shi)。而且沒有活(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)和(he)(he)改(gai)(gai)(gai)(gai)性(xing)(xing)(xing)(xing)(xing)(xing)活(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)的(de)(de)(de)(de)(de)明(ming)顯(xian)特征峰值(zhi)，說明(ming)它們(men)是無(wu)(wu)形(xing)的(de)(de)(de)(de)(de)。這(zhe)與(yu)TEM照片(pian)結(jie)果一致。

　　兩種吸附劑的(de)(de)代(dai)表性(xing)(xing)SEM，TEM和EDS圖像(xiang)。(a)活(huo)性(xing)(xing)炭(tan)的(de)(de)SEM(比(bi)例(li)尺為(wei)2μm)，(b)活(huo)性(xing)(xing)炭(tan)的(de)(de)TEM(比(bi)例(li)尺為(wei)100nm)，(c)活(huo)性(xing)(xing)炭(tan)的(de)(de)EDS，(d)改(gai)(gai)性(xing)(xing)活(huo)性(xing)(xing)炭(tan)SEM(比(bi)例(li)尺為(wei)2μm)，(e)改(gai)(gai)性(xing)(xing)活(huo)性(xing)(xing)炭(tan)TEM(比(bi)例(li)尺為(wei)100nm)，(f)改(gai)(gai)性(xing)(xing)活(huo)性(xing)(xing)炭(tan)EDS，(g)活(huo)性(xing)(xing)炭(tan)的(de)(de)XRD，(h)改(gai)(gai)性(xing)(xing)活(huo)性(xing)(xing)炭(tan)XRD。

　　活性炭吸附磺(huang)胺的三個階段

　　活(huo)性(xing)炭和(he)改(gai)性(xing)活(huo)性(xing)炭和(he)改(gai)性(xing)活(huo)性(xing)炭上(shang)的(de)(de)吸(xi)(xi)附(fu)(fu)和(he)擴(kuo)散(san)(san)過(guo)程可分(fen)三(san)(san)個(ge)階(jie)段描述(shu)，如圖2所(suo)示。由于**階(jie)段吸(xi)(xi)附(fu)(fu)在活(huo)性(xing)炭表(biao)面，吸(xi)(xi)附(fu)(fu)率(lv)*初很高。然后，在顆(ke)(ke)粒內快速擴(kuo)散(san)(san)的(de)(de)過(guo)程中，磺胺(an)二(er)甲啶逐(zhu)漸吸(xi)(xi)附(fu)(fu)在活(huo)性(xing)炭上(shang)，吸(xi)(xi)附(fu)(fu)率(lv)常數逐(zhu)漸降低。在第(di)三(san)(san)階(jie)段，邊界層和(he)傳(chuan)質(zhi)阻力的(de)(de)影(ying)響增加(jia)，導致顆(ke)(ke)粒擴(kuo)散(san)(san)減慢。所(suo)有三(san)(san)個(ge)階(jie)段的(de)(de)擬合(he)方程都沒有通過(guo)坐標的(de)(de)原點，這(zhe)表(biao)明顆(ke)(ke)粒的(de)(de)擴(kuo)散(san)(san)并不(bu)是控制吸(xi)(xi)附(fu)(fu)率(lv)的(de)(de)**步驟。因(yin)此，吸(xi)(xi)附(fu)(fu)過(guo)程也受膜擴(kuo)散(san)(san)和(he)表(biao)面吸(xi)(xi)附(fu)(fu)的(de)(de)影(ying)響。

　　磺胺(an)二甲(jia)啶(ding)在活性炭上吸附(fu)的顆粒中擴散(san)。

　　改性(xing)活性(xing)炭的表(biao)面(mian)顯示(shi)出許多孔隙和透明度，大量含氧官能團被改性(xing)，導致磺(huang)胺二甲(jia)啶吸附機制的變(bian)化。根據本研究的相關研究結(jie)果，活性(xing)炭表(biao)面(mian)磺(huang)胺二甲(jia)啶的吸附機制總結(jie)如(ru)下（圖3）：

　　1.微孔捕獲

　　SEM圖像顯(xian)示，活性(xing)炭(tan)(tan)的(de)(de)規則(ze)孔(kong)(kong)(kong)結(jie)構受損，孔(kong)(kong)(kong)隙(xi)率(lv)增(zeng)加。TEM圖像顯(xian)示，改性(xing)活性(xing)炭(tan)(tan)表(biao)面含有(you)許(xu)多透明點(dian)，表(biao)明孔(kong)(kong)(kong)結(jie)構更(geng)發達，修改后可獲得更(geng)多的(de)(de)吸(xi)附點(dian)。這有(you)利(li)于磺胺(an)二甲(jia)啶吸(xi)附到黑碳分子層的(de)(de)孔(kong)(kong)(kong)中。此外，經鐵離子改性(xing)后，活性(xing)炭(tan)(tan)的(de)(de)表(biao)面積、總孔(kong)(kong)(kong)容(rong)量(liang)、微孔(kong)(kong)(kong)體積和中孔(kong)(kong)(kong)體積都有(you)一定(ding)程度的(de)(de)增(zeng)加。

　　2.氫(qing)鍵相互作用(yong)

　　通過(guo)FTIR通過(guo)促進(jin)(jin)改性(xing)(xing)活性(xing)(xing)炭表面(mian)與磺胺(an)二(er)甲啶(ding)之間氫(qing)鍵的(de)相(xiang)互作用(yong)，促進(jin)(jin)磺胺(an)二(er)甲啶(ding)的(de)吸附(fu)。從數據圖中發現(xian)，3400和2850cm-1處寬吸收峰表明(ming)改性(xing)(xing)活性(xing)(xing)炭表面(mian)存在-OH。這些分(fen)子間氫(qing)鍵增(zeng)強了磺胺(an)二(er)甲啶(ding)與活性(xing)(xing)炭的(de)表面(mian)相(xiang)互作用(yong)，預計(ji)將(jiang)有助于活性(xing)(xing)炭與異磺胺(an)二(er)甲啶(ding)之間的(de)親和力吸附(fu)。

　　3.π-π電子供體-受體(EDA)相互作(zuo)用。

　　磺胺(an)二甲啶與(yu)改性活性炭合理相(xiang)互(hu)作用(yong)(yong)的示意圖。1.微(wei)孔(kong)捕獲。2.氫鍵(jian)相(xiang)互(hu)作用(yong)(yong)。.π-πEDA相(xiang)互(hu)作用(yong)(yong)。4.靜電相(xiang)互(hu)作用(yong)(yong)。5.配位相(xiang)互(hu)作用(yong)(yong)。

　　鐵離子改(gai)性(xing)后，活(huo)(huo)性(xing)炭(tan)活(huo)(huo)性(xing)炭(tan)的(de)表面積(ji)、總孔容量、微孔體積(ji)和(he)(he)中(zhong)孔體積(ji)。含氧加(jia)(jia)了(le)活(huo)(huo)性(xing)炭(tan)表面含氧官(guan)能團的(de)數量，可(ke)以(yi)大(da)大(da)提高吸(xi)(xi)(xi)附(fu)(fu)(fu)能力。磺(huang)胺(an)(an)二(er)(er)(er)(er)甲(jia)(jia)(jia)嘧(mi)啶(ding)在(zai)改(gai)性(xing)活(huo)(huo)性(xing)炭(tan)上(shang)去除磺(huang)胺(an)(an)廢水中(zhong)顯(xian)著增加(jia)(jia)，并在(zai)25℃下磺(huang)胺(an)(an)二(er)(er)(er)(er)甲(jia)(jia)(jia)嘧(mi)啶(ding)在(zai)改(gai)性(xing)活(huo)(huo)性(xing)炭(tan)上(shang)的(de)*大(da)吸(xi)(xi)(xi)附(fu)(fu)(fu)量為17.261mg/g。然而，吸(xi)(xi)(xi)附(fu)(fu)(fu)平衡時間(jian)幾(ji)乎保持(chi)不變。磺(huang)胺(an)(an)二(er)(er)(er)(er)甲(jia)(jia)(jia)啶(ding)在(zai)原始和(he)(he)改(gai)性(xing)活(huo)(huo)性(xing)炭(tan)上(shang)的(de)吸(xi)(xi)(xi)附(fu)(fu)(fu)動力學(xue)分(fen)為快(kuai)(kuai)速和(he)(he)慢速吸(xi)(xi)(xi)附(fu)(fu)(fu)階段(duan)，磺(huang)胺(an)(an)二(er)(er)(er)(er)甲(jia)(jia)(jia)啶(ding)吸(xi)(xi)(xi)附(fu)(fu)(fu)在(zai)12小時內快(kuai)(kuai)速完成。pH該值(zhi)對(dui)(dui)磺(huang)胺(an)(an)二(er)(er)(er)(er)甲(jia)(jia)(jia)啶(ding)的(de)吸(xi)(xi)(xi)附(fu)(fu)(fu)有顯(xian)著影響。當pH磺(huang)胺(an)(an)二(er)(er)(er)(er)甲(jia)(jia)(jia)啶(ding)的(de)吸(xi)(xi)(xi)附(fu)(fu)(fu)量在(zai)3-10之間(jian)增加(jia)(jia)，然后減少。微孔捕獲，靜電(dian)相(xiang)互作(zuo)用，氫鍵(jian)相(xiang)互作(zuo)用，π-πEDA相(xiang)互作(zuo)用和(he)(he)配位相(xiang)互作(zuo)用是吸(xi)(xi)(xi)附(fu)(fu)(fu)的(de)可(ke)能機制。降低溫(wen)度促進吸(xi)(xi)(xi)附(fu)(fu)(fu)反應(ying)。pH該值(zhi)對(dui)(dui)磺(huang)胺(an)(an)二(er)(er)(er)(er)甲(jia)(jia)(jia)啶(ding)的(de)吸(xi)(xi)(xi)附(fu)(fu)(fu)有顯(xian)著影響。當pH磺(huang)胺(an)(an)二(er)(er)(er)(er)甲(jia)(jia)(jia)啶(ding)的(de)吸(xi)(xi)(xi)附(fu)(fu)(fu)量在(zai)3-10之間(jian)增加(jia)(jia)，然后減少。