活(huo)性炭改(gai)性后處理磺胺廢水

　　磺胺廢水經活(huo)(huo)性(xing)炭(tan)改性(xing)后處理，活(huo)(huo)性(xing)炭(tan)經氯(lv)(lv)化鐵改性(xing)。并進行批(pi)量實(shi)驗(yan)以評估廢水中的磺胺二甲嘧啶吸(xi)附到(dao)(dao)活(huo)(huo)性(xing)炭(tan)和(he)(he)改性(xing)活(huo)(huo)性(xing)炭(tan)上(shang)的平衡，分別分析動力(li)學(xue)和(he)(he)熱力(li)學(xue)特征。結果表(biao)(biao)明，氯(lv)(lv)化鐵處理后，活(huo)(huo)性(xing)炭(tan)改變了(le)表(biao)(biao)面積(ji)、孔隙(xi)體(ti)積(ji)和(he)(he)表(biao)(biao)面zeta電位還增加了(le)表(biao)(biao)面含氧官能團的數量。經試驗(yan)發(fa)現，磺胺二甲啶在改性(xing)活(huo)(huo)性(xing)炭(tan)上(shang)的吸(xi)附得到(dao)(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(neng)有效去除顏色(se)、氣味(wei)、無機(ji)化合(he)物(wu)和(he)大多數有機(ji)污(wu)染(ran)物(wu)。但其在實際應用(yong)中(zhong)(zhong)(zhong)的(de)使用(yong)受其吸(xi)(xi)附(fu)(fu)效率和(he)成本(ben)低(di)的(de)限制(zhi)。金(jin)屬離(li)子(zi)改性(xing)后的(de)活(huo)性(xing)炭(tan)生(sheng)產簡單(dan)便宜，能(neng)顯著(zhu)提高活(huo)性(xing)炭(tan)的(de)吸(xi)(xi)附(fu)(fu)性(xing)能(neng)。然(ran)而，活(huo)性(xing)炭(tan)中(zhong)(zhong)(zhong)磺胺(an)(an)(an)類(lei)廢水的(de)吸(xi)(xi)附(fu)(fu)機(ji)制(zhi)尚(shang)不(bu)清楚，對(dui)磺胺(an)(an)(an)類(lei)的(de)吸(xi)(xi)附(fu)(fu)能(neng)力(li)及其理化性(xing)質知之甚少。本(ben)研究(jiu)采用(yong)鐵離(li)子(zi)改性(xing)活(huo)性(xing)炭(tan)。用(yong)于探索吸(xi)(xi)附(fu)(fu)機(ji)制(zhi)的(de)批(pi)量吸(xi)(xi)附(fu)(fu)實驗。磺胺(an)(an)(an)二甲啶(ding)對(dui)活(huo)性(xing)炭(tan)和(he)改性(xing)活(huo)性(xing)炭(tan)的(de)吸(xi)(xi)附(fu)(fu)特性(xing)通過吸(xi)(xi)附(fu)(fu)動力(li)學(xue)(xue)(xue)、吸(xi)(xi)附(fu)(fu)熱力(li)學(xue)(xue)(xue)和(he)吸(xi)(xi)附(fu)(fu)等溫線進行了(le)研究(jiu)，為去除廢水中(zhong)(zhong)(zhong)的(de)磺胺(an)(an)(an)污(wu)染(ran)物(wu)提供了(le)科學(xue)(xue)(xue)依(yi)據。

　　活性炭改性后的特(te)性

　　活(huo)(huo)(huo)(huo)(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)和(he)(he)(he)改(gai)(gai)(gai)性(xing)(xing)(xing)(xing)(xing)活(huo)(huo)(huo)(huo)(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)的(de)(de)(de)化(hua)學結(jie)(jie)(jie)構(gou)和(he)(he)(he)物(wu)理化(hua)學性(xing)(xing)(xing)(xing)(xing)質差異很(hen)大(da)。鐵離子改(gai)(gai)(gai)性(xing)(xing)(xing)(xing)(xing)后，活(huo)(huo)(huo)(huo)(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)的(de)(de)(de)表(biao)面(mian)積(ji)、總孔(kong)(kong)(kong)容量、微(wei)孔(kong)(kong)(kong)體(ti)積(ji)和(he)(he)(he)中孔(kong)(kong)(kong)體(ti)積(ji)都(dou)有(you)一(yi)定(ding)程度(du)的(de)(de)(de)增(zeng)加，可(ke)以為磺胺二甲(jia)(jia)(jia)啶提供更(geng)多(duo)的(de)(de)(de)吸附(fu)點。由(you)于(yu)改(gai)(gai)(gai)性(xing)(xing)(xing)(xing)(xing)，活(huo)(huo)(huo)(huo)(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)的(de)(de)(de)微(wei)孔(kong)(kong)(kong)結(jie)(jie)(jie)構(gou)可(ke)能會產生較(jiao)大(da)的(de)(de)(de)比(bi)表(biao)面(mian)積(ji)。在活(huo)(huo)(huo)(huo)(huo)(huo)(huo)(huo)化(hua)過程中，鐵離子主(zhu)要(yao)沉積(ji)在介(jie)孔(kong)(kong)(kong)中，擴大(da)孔(kong)(kong)(kong)徑(jing)并(bing)進(jin)入微(wei)孔(kong)(kong)(kong)。將金屬鹽釋放的(de)(de)(de)氧(yang)(yang)化(hua)氣體(ti)引入微(wei)孔(kong)(kong)(kong)，并(bing)與(yu)(yu)微(wei)孔(kong)(kong)(kong)碳壁反(fan)應。活(huo)(huo)(huo)(huo)(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)和(he)(he)(he)改(gai)(gai)(gai)性(xing)(xing)(xing)(xing)(xing)活(huo)(huo)(huo)(huo)(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)SEM圖(tu)(tu)1顯(xian)示圖(tu)(tu)像(a)和(he)(he)(he)(b)中。活(huo)(huo)(huo)(huo)(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)的(de)(de)(de)形(xing)狀表(biao)明(ming)(ming)具(ju)有(you)規(gui)則(ze)孔(kong)(kong)(kong)結(jie)(jie)(jie)構(gou)的(de)(de)(de)光滑(hua)表(biao)面(mian)。與(yu)(yu)活(huo)(huo)(huo)(huo)(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)相比(bi)，改(gai)(gai)(gai)性(xing)(xing)(xing)(xing)(xing)活(huo)(huo)(huo)(huo)(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)表(biao)面(mian)粗糙不(bu)規(gui)則(ze)。孔(kong)(kong)(kong)隙(xi)結(jie)(jie)(jie)構(gou)受損，孔(kong)(kong)(kong)隙(xi)率(lv)增(zeng)加。這可(ke)能是(shi)由(you)于(yu)鐵離子引入活(huo)(huo)(huo)(huo)(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)內孔(kong)(kong)(kong)，導致碳壁氧(yang)(yang)化(hua)和(he)(he)(he)孔(kong)(kong)(kong)徑(jing)增(zeng)加。活(huo)(huo)(huo)(huo)(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)中磺胺二甲(jia)(jia)(jia)啶的(de)(de)(de)擴散有(you)利于(yu)粗糙的(de)(de)(de)表(biao)面(mian)結(jie)(jie)(jie)構(gou)和(he)(he)(he)多(duo)孔(kong)(kong)(kong)特性(xing)(xing)(xing)(xing)(xing)。活(huo)(huo)(huo)(huo)(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)和(he)(he)(he)改(gai)(gai)(gai)性(xing)(xing)(xing)(xing)(xing)活(huo)(huo)(huo)(huo)(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)TEM圖(tu)(tu)像如(ru)圖(tu)(tu)1(c)和(he)(he)(he)(d)所示。這些圖(tu)(tu)片表(biao)明(ming)(ming)活(huo)(huo)(huo)(huo)(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)是(shi)無(wu)定(ding)形(xing)的(de)(de)(de)。與(yu)(yu)活(huo)(huo)(huo)(huo)(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)相比(bi)，改(gai)(gai)(gai)性(xing)(xing)(xing)(xing)(xing)活(huo)(huo)(huo)(huo)(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)表(biao)現出許多(duo)孔(kong)(kong)(kong)隙(xi)和(he)(he)(he)透明(ming)(ming)點，進(jin)一(yi)步表(biao)明(ming)(ming)表(biao)面(mian)積(ji)增(zeng)加。活(huo)(huo)(huo)(huo)(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)和(he)(he)(he)改(gai)(gai)(gai)性(xing)(xing)(xing)(xing)(xing)活(huo)(huo)(huo)(huo)(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)EDS圖(tu)(tu)像如(ru)圖(tu)(tu)1(e)和(he)(he)(he)(f)所示。與(yu)(yu)活(huo)(huo)(huo)(huo)(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)相比(bi)，改(gai)(gai)(gai)性(xing)(xing)(xing)(xing)(xing)活(huo)(huo)(huo)(huo)(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)的(de)(de)(de)元素O和(he)(he)(he)Fe含量顯(xian)著增(zeng)加，C活(huo)(huo)(huo)(huo)(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)上鐵離子負荷(he)的(de)(de)(de)含量降低。此外，進(jin)一(yi)步證明(ming)(ming)表(biao)面(mian)含氧(yang)(yang)量增(zeng)加，有(you)利于(yu)磺胺二甲(jia)(jia)(jia)啶的(de)(de)(de)吸附(fu)。活(huo)(huo)(huo)(huo)(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)和(he)(he)(he)改(gai)(gai)(gai)性(xing)(xing)(xing)(xing)(xing)活(huo)(huo)(huo)(huo)(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)XRD圖(tu)(tu)如(ru)圖(tu)(tu)1(g)和(he)(he)(he)(h)所示。而(er)且(qie)沒有(you)活(huo)(huo)(huo)(huo)(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)和(he)(he)(he)改(gai)(gai)(gai)性(xing)(xing)(xing)(xing)(xing)活(huo)(huo)(huo)(huo)(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)的(de)(de)(de)明(ming)(ming)顯(xian)特征(zheng)峰值，說(shuo)明(ming)(ming)它們是(shi)無(wu)形(xing)的(de)(de)(de)。這與(yu)(yu)TEM照(zhao)片結(jie)(jie)(jie)果(guo)一(yi)致。

　　兩(liang)種(zhong)吸附劑(ji)的(de)代表(biao)性(xing)(xing)SEM，TEM和(he)EDS圖像。(a)活(huo)性(xing)(xing)炭(tan)(tan)(tan)的(de)SEM(比例尺(chi)為(wei)2μm)，(b)活(huo)性(xing)(xing)炭(tan)(tan)(tan)的(de)TEM(比例尺(chi)為(wei)100nm)，(c)活(huo)性(xing)(xing)炭(tan)(tan)(tan)的(de)EDS，(d)改(gai)(gai)性(xing)(xing)活(huo)性(xing)(xing)炭(tan)(tan)(tan)SEM(比例尺(chi)為(wei)2μm)，(e)改(gai)(gai)性(xing)(xing)活(huo)性(xing)(xing)炭(tan)(tan)(tan)TEM(比例尺(chi)為(wei)100nm)，(f)改(gai)(gai)性(xing)(xing)活(huo)性(xing)(xing)炭(tan)(tan)(tan)EDS，(g)活(huo)性(xing)(xing)炭(tan)(tan)(tan)的(de)XRD，(h)改(gai)(gai)性(xing)(xing)活(huo)性(xing)(xing)炭(tan)(tan)(tan)XRD。

　　活(huo)性(xing)炭吸(xi)附磺胺的三個階段(duan)

　　活(huo)性(xing)(xing)炭(tan)(tan)和(he)改(gai)性(xing)(xing)活(huo)性(xing)(xing)炭(tan)(tan)和(he)改(gai)性(xing)(xing)活(huo)性(xing)(xing)炭(tan)(tan)上(shang)的吸(xi)(xi)附(fu)和(he)擴(kuo)散過程(cheng)(cheng)可分三(san)個(ge)階(jie)段(duan)描述，如圖(tu)2所(suo)示。由(you)于**階(jie)段(duan)吸(xi)(xi)附(fu)在活(huo)性(xing)(xing)炭(tan)(tan)表面，吸(xi)(xi)附(fu)率*初很高(gao)。然后，在顆粒(li)內(nei)快速(su)擴(kuo)散的過程(cheng)(cheng)中，磺胺二甲啶逐漸吸(xi)(xi)附(fu)在活(huo)性(xing)(xing)炭(tan)(tan)上(shang)，吸(xi)(xi)附(fu)率常數逐漸降低。在第三(san)階(jie)段(duan)，邊界層和(he)傳質阻力的影響(xiang)增(zeng)加(jia)，導致顆粒(li)擴(kuo)散減慢。所(suo)有(you)三(san)個(ge)階(jie)段(duan)的擬合(he)方程(cheng)(cheng)都沒有(you)通過坐標的原點，這表明顆粒(li)的擴(kuo)散并(bing)不是控(kong)制吸(xi)(xi)附(fu)率的**步(bu)驟。因此，吸(xi)(xi)附(fu)過程(cheng)(cheng)也受(shou)膜擴(kuo)散和(he)表面吸(xi)(xi)附(fu)的影響(xiang)。

　　磺胺(an)二甲啶在活性炭上吸附(fu)的顆(ke)粒中(zhong)擴(kuo)散。

　　改性(xing)活性(xing)炭的表面顯示出(chu)許(xu)多孔隙和透明(ming)度(du)，大量含氧官能團被改性(xing)，導致磺(huang)胺二甲啶(ding)吸附機制的變(bian)化。根據本研究(jiu)的相關研究(jiu)結(jie)果，活性(xing)炭表面磺(huang)胺二甲啶(ding)的吸附機制總結(jie)如下（圖3）：

　　1.微孔捕獲

　　SEM圖像顯(xian)示，活(huo)性炭(tan)的規則孔(kong)(kong)(kong)結構受損(sun)，孔(kong)(kong)(kong)隙率增加。TEM圖像顯(xian)示，改性活(huo)性炭(tan)表(biao)面(mian)含有(you)許多透明點，表(biao)明孔(kong)(kong)(kong)結構更發達，修(xiu)改后可獲(huo)得更多的吸(xi)(xi)附(fu)點。這有(you)利于磺(huang)胺二甲啶吸(xi)(xi)附(fu)到黑碳分子(zi)層的孔(kong)(kong)(kong)中(zhong)。此外，經(jing)鐵離子(zi)改性后，活(huo)性炭(tan)的表(biao)面(mian)積(ji)、總孔(kong)(kong)(kong)容量、微孔(kong)(kong)(kong)體積(ji)和(he)中(zhong)孔(kong)(kong)(kong)體積(ji)都有(you)一(yi)定程(cheng)度的增加。

　　2.氫鍵相(xiang)互(hu)作用(yong)

　　通過FTIR通過促(cu)進(jin)改(gai)性活性炭(tan)表面與(yu)(yu)磺胺(an)二甲(jia)(jia)啶(ding)之(zhi)間氫鍵的(de)相互(hu)作用(yong)，促(cu)進(jin)磺胺(an)二甲(jia)(jia)啶(ding)的(de)吸(xi)附。從數據圖中發現，3400和(he)(he)2850cm-1處寬(kuan)吸(xi)收峰表明改(gai)性活性炭(tan)表面存在-OH。這些(xie)分子間氫鍵增(zeng)強了磺胺(an)二甲(jia)(jia)啶(ding)與(yu)(yu)活性炭(tan)的(de)表面相互(hu)作用(yong)，預計將有助于活性炭(tan)與(yu)(yu)異磺胺(an)二甲(jia)(jia)啶(ding)之(zhi)間的(de)親和(he)(he)力吸(xi)附。

　　3.π-π電子供(gong)體(ti)(ti)-受體(ti)(ti)(EDA)相互作用。

　　磺胺二甲啶與(yu)改性活(huo)性炭合理(li)相(xiang)(xiang)互作(zuo)用(yong)的示意圖。1.微(wei)孔捕(bu)獲(huo)。2.氫鍵相(xiang)(xiang)互作(zuo)用(yong)。.π-πEDA相(xiang)(xiang)互作(zuo)用(yong)。4.靜電相(xiang)(xiang)互作(zuo)用(yong)。5.配位相(xiang)(xiang)互作(zuo)用(yong)。

　　鐵(tie)離子改(gai)性(xing)(xing)(xing)(xing)后，活性(xing)(xing)(xing)(xing)炭(tan)活性(xing)(xing)(xing)(xing)炭(tan)的(de)表面積(ji)(ji)、總(zong)孔容(rong)量(liang)(liang)、微孔體(ti)積(ji)(ji)和中(zhong)孔體(ti)積(ji)(ji)。含氧加(jia)了活性(xing)(xing)(xing)(xing)炭(tan)表面含氧官(guan)能(neng)團的(de)數(shu)量(liang)(liang)，可以大大提高吸(xi)(xi)(xi)附(fu)(fu)(fu)(fu)能(neng)力(li)。磺(huang)(huang)(huang)(huang)胺(an)(an)(an)二甲(jia)(jia)嘧啶在改(gai)性(xing)(xing)(xing)(xing)活性(xing)(xing)(xing)(xing)炭(tan)上(shang)去(qu)除磺(huang)(huang)(huang)(huang)胺(an)(an)(an)廢(fei)水中(zhong)顯著(zhu)(zhu)(zhu)增(zeng)加(jia)，并在25℃下磺(huang)(huang)(huang)(huang)胺(an)(an)(an)二甲(jia)(jia)嘧啶在改(gai)性(xing)(xing)(xing)(xing)活性(xing)(xing)(xing)(xing)炭(tan)上(shang)的(de)*大吸(xi)(xi)(xi)附(fu)(fu)(fu)(fu)量(liang)(liang)為17.261mg/g。然(ran)而，吸(xi)(xi)(xi)附(fu)(fu)(fu)(fu)平衡時間(jian)幾(ji)乎保持不變。磺(huang)(huang)(huang)(huang)胺(an)(an)(an)二甲(jia)(jia)啶在原始(shi)和改(gai)性(xing)(xing)(xing)(xing)活性(xing)(xing)(xing)(xing)炭(tan)上(shang)的(de)吸(xi)(xi)(xi)附(fu)(fu)(fu)(fu)動力(li)學分為快速(su)和慢速(su)吸(xi)(xi)(xi)附(fu)(fu)(fu)(fu)階段，磺(huang)(huang)(huang)(huang)胺(an)(an)(an)二甲(jia)(jia)啶吸(xi)(xi)(xi)附(fu)(fu)(fu)(fu)在12小時內快速(su)完成。pH該(gai)值對磺(huang)(huang)(huang)(huang)胺(an)(an)(an)二甲(jia)(jia)啶的(de)吸(xi)(xi)(xi)附(fu)(fu)(fu)(fu)有顯著(zhu)(zhu)(zhu)影(ying)響(xiang)。當pH磺(huang)(huang)(huang)(huang)胺(an)(an)(an)二甲(jia)(jia)啶的(de)吸(xi)(xi)(xi)附(fu)(fu)(fu)(fu)量(liang)(liang)在3-10之間(jian)增(zeng)加(jia)，然(ran)后減(jian)少(shao)。微孔捕(bu)獲，靜電相互作(zuo)用(yong)，氫鍵相互作(zuo)用(yong)，π-πEDA相互作(zuo)用(yong)和配位相互作(zuo)用(yong)是吸(xi)(xi)(xi)附(fu)(fu)(fu)(fu)的(de)可能(neng)機制。降低溫度(du)促進吸(xi)(xi)(xi)附(fu)(fu)(fu)(fu)反應。pH該(gai)值對磺(huang)(huang)(huang)(huang)胺(an)(an)(an)二甲(jia)(jia)啶的(de)吸(xi)(xi)(xi)附(fu)(fu)(fu)(fu)有顯著(zhu)(zhu)(zhu)影(ying)響(xiang)。當pH磺(huang)(huang)(huang)(huang)胺(an)(an)(an)二甲(jia)(jia)啶的(de)吸(xi)(xi)(xi)附(fu)(fu)(fu)(fu)量(liang)(liang)在3-10之間(jian)增(zeng)加(jia)，然(ran)后減(jian)少(shao)。