活性炭改性后處理磺胺廢水

　　磺(huang)胺廢水經活性(xing)炭改(gai)性(xing)后處(chu)理(li)(li)，活性(xing)炭經氯(lv)化鐵改(gai)性(xing)。并(bing)進行批(pi)量實驗以評(ping)估廢水中的(de)(de)磺(huang)胺二甲嘧啶吸附(fu)到活性(xing)炭和改(gai)性(xing)活性(xing)炭上的(de)(de)平衡(heng)，分別分析動(dong)力學和熱力學特征。結果表(biao)明，氯(lv)化鐵處(chu)理(li)(li)后，活性(xing)炭改(gai)變了(le)表(biao)面積(ji)、孔(kong)隙體(ti)積(ji)和表(biao)面zeta電位還(huan)增加了(le)表(biao)面含(han)氧官(guan)能團的(de)(de)數(shu)量。經試驗發現(xian)，磺(huang)胺二甲啶在改(gai)性(xing)活性(xing)炭上的(de)(de)吸附(fu)得(de)到了(le)顯(xian)著改(gai)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)(neng)有(you)(you)效去(qu)除(chu)顏(yan)色、氣味(wei)、無機化(hua)合物和(he)大多數(shu)有(you)(you)機污(wu)染(ran)物。但其(qi)在實際應用中的(de)(de)使用受(shou)其(qi)吸(xi)(xi)(xi)(xi)附效率和(he)成本低的(de)(de)限制。金屬離子改(gai)性(xing)(xing)后(hou)的(de)(de)活(huo)(huo)(huo)性(xing)(xing)炭(tan)生產(chan)簡單便宜，能(neng)(neng)顯著提高(gao)活(huo)(huo)(huo)性(xing)(xing)炭(tan)的(de)(de)吸(xi)(xi)(xi)(xi)附性(xing)(xing)能(neng)(neng)。然而，活(huo)(huo)(huo)性(xing)(xing)炭(tan)中磺(huang)胺(an)類廢(fei)水(shui)的(de)(de)吸(xi)(xi)(xi)(xi)附機制尚不清(qing)楚，對磺(huang)胺(an)類的(de)(de)吸(xi)(xi)(xi)(xi)附能(neng)(neng)力及其(qi)理化(hua)性(xing)(xing)質(zhi)知之甚少。本研究采用鐵離子改(gai)性(xing)(xing)活(huo)(huo)(huo)性(xing)(xing)炭(tan)。用于(yu)探(tan)索吸(xi)(xi)(xi)(xi)附機制的(de)(de)批量吸(xi)(xi)(xi)(xi)附實驗。磺(huang)胺(an)二甲啶對活(huo)(huo)(huo)性(xing)(xing)炭(tan)和(he)改(gai)性(xing)(xing)活(huo)(huo)(huo)性(xing)(xing)炭(tan)的(de)(de)吸(xi)(xi)(xi)(xi)附特性(xing)(xing)通過吸(xi)(xi)(xi)(xi)附動力學、吸(xi)(xi)(xi)(xi)附熱力學和(he)吸(xi)(xi)(xi)(xi)附等溫線進行了(le)研究，為去(qu)除(chu)廢(fei)水(shui)中的(de)(de)磺(huang)胺(an)污(wu)染(ran)物提供了(le)科學依據(ju)。

　　活性(xing)炭改性(xing)后的特性(xing)

　　活(huo)(huo)(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)和(he)(he)改(gai)(gai)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)活(huo)(huo)(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)的(de)(de)化(hua)(hua)學結(jie)(jie)構(gou)和(he)(he)物理化(hua)(hua)學性(xing)(xing)(xing)(xing)(xing)(xing)(xing)質差異很大。鐵離(li)子改(gai)(gai)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)后(hou)，活(huo)(huo)(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)的(de)(de)表(biao)(biao)面(mian)積、總孔(kong)(kong)(kong)容量、微(wei)(wei)(wei)孔(kong)(kong)(kong)體積和(he)(he)中孔(kong)(kong)(kong)體積都(dou)有(you)(you)(you)一(yi)定程(cheng)度的(de)(de)增(zeng)加(jia)，可以(yi)為磺(huang)胺(an)二(er)(er)(er)甲啶提供更多(duo)的(de)(de)吸附(fu)點(dian)。由(you)于改(gai)(gai)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)，活(huo)(huo)(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)的(de)(de)微(wei)(wei)(wei)孔(kong)(kong)(kong)結(jie)(jie)構(gou)可能會產生較大的(de)(de)比(bi)表(biao)(biao)面(mian)積。在活(huo)(huo)(huo)(huo)(huo)(huo)化(hua)(hua)過(guo)程(cheng)中，鐵離(li)子主要(yao)沉積在介孔(kong)(kong)(kong)中，擴大孔(kong)(kong)(kong)徑(jing)并(bing)進入微(wei)(wei)(wei)孔(kong)(kong)(kong)。將金屬鹽(yan)釋放的(de)(de)氧(yang)化(hua)(hua)氣(qi)體引入微(wei)(wei)(wei)孔(kong)(kong)(kong)，并(bing)與(yu)(yu)微(wei)(wei)(wei)孔(kong)(kong)(kong)碳壁反應。活(huo)(huo)(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)和(he)(he)改(gai)(gai)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)活(huo)(huo)(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)SEM圖(tu)1顯示(shi)(shi)圖(tu)像(a)和(he)(he)(b)中。活(huo)(huo)(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)的(de)(de)形(xing)狀表(biao)(biao)明(ming)(ming)(ming)具(ju)有(you)(you)(you)規則(ze)孔(kong)(kong)(kong)結(jie)(jie)構(gou)的(de)(de)光滑表(biao)(biao)面(mian)。與(yu)(yu)活(huo)(huo)(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)相比(bi)，改(gai)(gai)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)活(huo)(huo)(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)表(biao)(biao)面(mian)粗(cu)糙(cao)不(bu)規則(ze)。孔(kong)(kong)(kong)隙結(jie)(jie)構(gou)受損，孔(kong)(kong)(kong)隙率增(zeng)加(jia)。這(zhe)可能是由(you)于鐵離(li)子引入活(huo)(huo)(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)內孔(kong)(kong)(kong)，導致(zhi)碳壁氧(yang)化(hua)(hua)和(he)(he)孔(kong)(kong)(kong)徑(jing)增(zeng)加(jia)。活(huo)(huo)(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)中磺(huang)胺(an)二(er)(er)(er)甲啶的(de)(de)擴散(san)有(you)(you)(you)利于粗(cu)糙(cao)的(de)(de)表(biao)(biao)面(mian)結(jie)(jie)構(gou)和(he)(he)多(duo)孔(kong)(kong)(kong)特性(xing)(xing)(xing)(xing)(xing)(xing)(xing)。活(huo)(huo)(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)和(he)(he)改(gai)(gai)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)活(huo)(huo)(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)TEM圖(tu)像如圖(tu)1(c)和(he)(he)(d)所(suo)示(shi)(shi)。這(zhe)些圖(tu)片表(biao)(biao)明(ming)(ming)(ming)活(huo)(huo)(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)是無定形(xing)的(de)(de)。與(yu)(yu)活(huo)(huo)(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)相比(bi)，改(gai)(gai)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)活(huo)(huo)(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)表(biao)(biao)現(xian)出許多(duo)孔(kong)(kong)(kong)隙和(he)(he)透明(ming)(ming)(ming)點(dian)，進一(yi)步(bu)表(biao)(biao)明(ming)(ming)(ming)表(biao)(biao)面(mian)積增(zeng)加(jia)。活(huo)(huo)(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)和(he)(he)改(gai)(gai)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)活(huo)(huo)(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)EDS圖(tu)像如圖(tu)1(e)和(he)(he)(f)所(suo)示(shi)(shi)。與(yu)(yu)活(huo)(huo)(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)相比(bi)，改(gai)(gai)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)活(huo)(huo)(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)的(de)(de)元素O和(he)(he)Fe含量顯著增(zeng)加(jia)，C活(huo)(huo)(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)上(shang)鐵離(li)子負荷的(de)(de)含量降低。此外，進一(yi)步(bu)證明(ming)(ming)(ming)表(biao)(biao)面(mian)含氧(yang)量增(zeng)加(jia)，有(you)(you)(you)利于磺(huang)胺(an)二(er)(er)(er)甲啶的(de)(de)吸附(fu)。活(huo)(huo)(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)和(he)(he)改(gai)(gai)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)活(huo)(huo)(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)XRD圖(tu)如圖(tu)1(g)和(he)(he)(h)所(suo)示(shi)(shi)。而且沒有(you)(you)(you)活(huo)(huo)(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)和(he)(he)改(gai)(gai)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)活(huo)(huo)(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)的(de)(de)明(ming)(ming)(ming)顯特征(zheng)峰值(zhi)，說明(ming)(ming)(ming)它們是無形(xing)的(de)(de)。這(zhe)與(yu)(yu)TEM照片結(jie)(jie)果一(yi)致(zhi)。

　　兩種吸(xi)附(fu)劑的(de)(de)代(dai)表(biao)性(xing)(xing)(xing)(xing)(xing)(xing)SEM，TEM和EDS圖像。(a)活(huo)性(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)的(de)(de)SEM(比(bi)例(li)尺(chi)(chi)為(wei)2μm)，(b)活(huo)性(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)的(de)(de)TEM(比(bi)例(li)尺(chi)(chi)為(wei)100nm)，(c)活(huo)性(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)的(de)(de)EDS，(d)改(gai)性(xing)(xing)(xing)(xing)(xing)(xing)活(huo)性(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)SEM(比(bi)例(li)尺(chi)(chi)為(wei)2μm)，(e)改(gai)性(xing)(xing)(xing)(xing)(xing)(xing)活(huo)性(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)TEM(比(bi)例(li)尺(chi)(chi)為(wei)100nm)，(f)改(gai)性(xing)(xing)(xing)(xing)(xing)(xing)活(huo)性(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)EDS，(g)活(huo)性(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)的(de)(de)XRD，(h)改(gai)性(xing)(xing)(xing)(xing)(xing)(xing)活(huo)性(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)XRD。

　　活性(xing)炭吸附磺胺的(de)三個階段

　　活(huo)(huo)性(xing)(xing)(xing)炭(tan)和改(gai)性(xing)(xing)(xing)活(huo)(huo)性(xing)(xing)(xing)炭(tan)和改(gai)性(xing)(xing)(xing)活(huo)(huo)性(xing)(xing)(xing)炭(tan)上的(de)(de)(de)吸附(fu)和擴(kuo)散(san)(san)(san)過(guo)程可分三(san)(san)個階段(duan)(duan)描述，如圖2所(suo)示。由于**階段(duan)(duan)吸附(fu)在活(huo)(huo)性(xing)(xing)(xing)炭(tan)表(biao)面(mian)，吸附(fu)率*初很高。然后，在顆(ke)(ke)粒(li)內快速擴(kuo)散(san)(san)(san)的(de)(de)(de)過(guo)程中，磺胺二甲(jia)啶(ding)逐漸吸附(fu)在活(huo)(huo)性(xing)(xing)(xing)炭(tan)上，吸附(fu)率常數逐漸降低(di)。在第三(san)(san)階段(duan)(duan)，邊界層和傳質阻力的(de)(de)(de)影(ying)響增加(jia)，導致顆(ke)(ke)粒(li)擴(kuo)散(san)(san)(san)減(jian)慢(man)。所(suo)有三(san)(san)個階段(duan)(duan)的(de)(de)(de)擬合方程都沒有通過(guo)坐標的(de)(de)(de)原(yuan)點，這(zhe)表(biao)明顆(ke)(ke)粒(li)的(de)(de)(de)擴(kuo)散(san)(san)(san)并(bing)不是控制吸附(fu)率的(de)(de)(de)**步驟。因此，吸附(fu)過(guo)程也受膜擴(kuo)散(san)(san)(san)和表(biao)面(mian)吸附(fu)的(de)(de)(de)影(ying)響。

　　磺胺二(er)甲啶在活性(xing)炭上吸附(fu)的(de)顆粒中擴散。

　　改(gai)性(xing)活性(xing)炭(tan)的(de)(de)表(biao)面顯(xian)示出(chu)許多孔(kong)隙和透明度，大量(liang)含氧官能團(tuan)被改(gai)性(xing)，導致磺胺二(er)(er)甲啶吸附(fu)機制的(de)(de)變化。根(gen)據本研究的(de)(de)相關研究結(jie)果，活性(xing)炭(tan)表(biao)面磺胺二(er)(er)甲啶的(de)(de)吸附(fu)機制總結(jie)如(ru)下(xia)（圖3）：

　　1.微孔捕獲

　　SEM圖像(xiang)顯(xian)示，活性(xing)炭(tan)的(de)(de)(de)規則孔(kong)結構受(shou)損(sun)，孔(kong)隙率(lv)增加。TEM圖像(xiang)顯(xian)示，改(gai)性(xing)活性(xing)炭(tan)表(biao)(biao)面含有(you)(you)許多透明點，表(biao)(biao)明孔(kong)結構更發達，修改(gai)后可(ke)獲得更多的(de)(de)(de)吸(xi)附點。這有(you)(you)利于磺胺(an)二甲啶(ding)吸(xi)附到(dao)黑碳分子層的(de)(de)(de)孔(kong)中(zhong)。此外，經(jing)鐵離子改(gai)性(xing)后，活性(xing)炭(tan)的(de)(de)(de)表(biao)(biao)面積(ji)、總孔(kong)容量、微孔(kong)體(ti)(ti)積(ji)和中(zhong)孔(kong)體(ti)(ti)積(ji)都有(you)(you)一定程度(du)的(de)(de)(de)增加。

　　2.氫鍵相(xiang)互作用

　　通過FTIR通過促進(jin)改性(xing)(xing)(xing)活性(xing)(xing)(xing)炭(tan)表面與磺(huang)胺二(er)甲啶之(zhi)間氫鍵(jian)的相互作用，促進(jin)磺(huang)胺二(er)甲啶的吸附。從數據圖中發現，3400和(he)2850cm-1處寬(kuan)吸收峰表明改性(xing)(xing)(xing)活性(xing)(xing)(xing)炭(tan)表面存在-OH。這些分子間氫鍵(jian)增(zeng)強了磺(huang)胺二(er)甲啶與活性(xing)(xing)(xing)炭(tan)的表面相互作用，預計(ji)將有助于活性(xing)(xing)(xing)炭(tan)與異磺(huang)胺二(er)甲啶之(zhi)間的親(qin)和(he)力吸附。

　　3.π-π電子供體(ti)-受體(ti)(EDA)相互作用。

　　磺胺二甲啶與改性(xing)(xing)活性(xing)(xing)炭(tan)合理相(xiang)互(hu)(hu)作(zuo)用(yong)的(de)示(shi)意圖(tu)。1.微(wei)孔捕(bu)獲(huo)。2.氫鍵相(xiang)互(hu)(hu)作(zuo)用(yong)。.π-πEDA相(xiang)互(hu)(hu)作(zuo)用(yong)。4.靜電相(xiang)互(hu)(hu)作(zuo)用(yong)。5.配位相(xiang)互(hu)(hu)作(zuo)用(yong)。

　　鐵離子改性(xing)(xing)后(hou)(hou)，活性(xing)(xing)炭(tan)活性(xing)(xing)炭(tan)的(de)(de)表面積(ji)、總(zong)孔(kong)容量(liang)、微(wei)孔(kong)體積(ji)和中孔(kong)體積(ji)。含氧加(jia)了活性(xing)(xing)炭(tan)表面含氧官能(neng)團的(de)(de)數(shu)量(liang)，可以大大提高吸(xi)(xi)(xi)附(fu)(fu)(fu)能(neng)力。磺(huang)(huang)胺(an)二(er)甲嘧啶(ding)在(zai)(zai)改性(xing)(xing)活性(xing)(xing)炭(tan)上去除磺(huang)(huang)胺(an)廢水(shui)中顯(xian)(xian)著增(zeng)加(jia)，并在(zai)(zai)25℃下磺(huang)(huang)胺(an)二(er)甲嘧啶(ding)在(zai)(zai)改性(xing)(xing)活性(xing)(xing)炭(tan)上的(de)(de)*大吸(xi)(xi)(xi)附(fu)(fu)(fu)量(liang)為17.261mg/g。然而，吸(xi)(xi)(xi)附(fu)(fu)(fu)平(ping)衡(heng)時(shi)(shi)間幾乎保持不變(bian)。磺(huang)(huang)胺(an)二(er)甲啶(ding)在(zai)(zai)原(yuan)始和改性(xing)(xing)活性(xing)(xing)炭(tan)上的(de)(de)吸(xi)(xi)(xi)附(fu)(fu)(fu)動力學分為快速(su)和慢速(su)吸(xi)(xi)(xi)附(fu)(fu)(fu)階段，磺(huang)(huang)胺(an)二(er)甲啶(ding)吸(xi)(xi)(xi)附(fu)(fu)(fu)在(zai)(zai)12小(xiao)時(shi)(shi)內快速(su)完成。pH該值(zhi)對磺(huang)(huang)胺(an)二(er)甲啶(ding)的(de)(de)吸(xi)(xi)(xi)附(fu)(fu)(fu)有(you)顯(xian)(xian)著影響。當pH磺(huang)(huang)胺(an)二(er)甲啶(ding)的(de)(de)吸(xi)(xi)(xi)附(fu)(fu)(fu)量(liang)在(zai)(zai)3-10之間增(zeng)加(jia)，然后(hou)(hou)減(jian)少。微(wei)孔(kong)捕獲，靜(jing)電相互(hu)(hu)作(zuo)用，氫鍵相互(hu)(hu)作(zuo)用，π-πEDA相互(hu)(hu)作(zuo)用和配位相互(hu)(hu)作(zuo)用是吸(xi)(xi)(xi)附(fu)(fu)(fu)的(de)(de)可能(neng)機制。降(jiang)低溫度促進吸(xi)(xi)(xi)附(fu)(fu)(fu)反應。pH該值(zhi)對磺(huang)(huang)胺(an)二(er)甲啶(ding)的(de)(de)吸(xi)(xi)(xi)附(fu)(fu)(fu)有(you)顯(xian)(xian)著影響。當pH磺(huang)(huang)胺(an)二(er)甲啶(ding)的(de)(de)吸(xi)(xi)(xi)附(fu)(fu)(fu)量(liang)在(zai)(zai)3-10之間增(zeng)加(jia)，然后(hou)(hou)減(jian)少。