活性(xing)炭(tan)改性(xing)后處理磺胺廢水

　　磺(huang)胺(an)廢(fei)水(shui)經活(huo)性(xing)(xing)(xing)炭(tan)改(gai)(gai)性(xing)(xing)(xing)后處(chu)理，活(huo)性(xing)(xing)(xing)炭(tan)經氯(lv)化鐵(tie)改(gai)(gai)性(xing)(xing)(xing)。并進行批量實驗以(yi)評估(gu)廢(fei)水(shui)中的磺(huang)胺(an)二甲嘧啶吸附到活(huo)性(xing)(xing)(xing)炭(tan)和(he)(he)改(gai)(gai)性(xing)(xing)(xing)活(huo)性(xing)(xing)(xing)炭(tan)上的平衡，分別(bie)分析動力學和(he)(he)熱(re)力學特(te)征(zheng)。結果(guo)表(biao)明，氯(lv)化鐵(tie)處(chu)理后，活(huo)性(xing)(xing)(xing)炭(tan)改(gai)(gai)變了表(biao)面(mian)(mian)積(ji)、孔(kong)隙體積(ji)和(he)(he)表(biao)面(mian)(mian)zeta電位還增(zeng)加了表(biao)面(mian)(mian)含氧官能團的數量。經試驗發(fa)現，磺(huang)胺(an)二甲啶在(zai)改(gai)(gai)性(xing)(xing)(xing)活(huo)性(xing)(xing)(xing)炭(tan)上的吸附得到了顯著(zhu)改(gai)(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，活性炭能有效去除顏色(se)、氣(qi)味、無機(ji)(ji)化合物和(he)(he)大多數(shu)有機(ji)(ji)污染物。但其在實(shi)際應用(yong)中的(de)使用(yong)受其吸附(fu)(fu)效率和(he)(he)成本低的(de)限制(zhi)。金(jin)屬(shu)離子改性(xing)(xing)(xing)(xing)后的(de)活(huo)性(xing)(xing)(xing)(xing)炭(tan)(tan)生(sheng)產簡單便宜，能顯著提高活(huo)性(xing)(xing)(xing)(xing)炭(tan)(tan)的(de)吸附(fu)(fu)性(xing)(xing)(xing)(xing)能。然而(er)，活(huo)性(xing)(xing)(xing)(xing)炭(tan)(tan)中磺胺(an)類(lei)廢(fei)水的(de)吸附(fu)(fu)機(ji)(ji)制(zhi)尚(shang)不清楚(chu)，對(dui)磺胺(an)類(lei)的(de)吸附(fu)(fu)能力及其理(li)化性(xing)(xing)(xing)(xing)質知(zhi)之(zhi)甚少。本研(yan)究(jiu)采用(yong)鐵離子改性(xing)(xing)(xing)(xing)活(huo)性(xing)(xing)(xing)(xing)炭(tan)(tan)。用(yong)于探索吸附(fu)(fu)機(ji)(ji)制(zhi)的(de)批量吸附(fu)(fu)實(shi)驗。磺胺(an)二(er)甲(jia)啶(ding)對(dui)活(huo)性(xing)(xing)(xing)(xing)炭(tan)(tan)和(he)(he)改性(xing)(xing)(xing)(xing)活(huo)性(xing)(xing)(xing)(xing)炭(tan)(tan)的(de)吸附(fu)(fu)特(te)性(xing)(xing)(xing)(xing)通(tong)過吸附(fu)(fu)動力學、吸附(fu)(fu)熱力學和(he)(he)吸附(fu)(fu)等溫線(xian)進行了研(yan)究(jiu)，為去除廢(fei)水中的(de)磺胺(an)污染物提供了科學依(yi)據(ju)。

　　活性炭改性后的特性

　　活(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)和(he)改(gai)(gai)(gai)(gai)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)活(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)的(de)(de)(de)化(hua)學結(jie)(jie)構(gou)(gou)和(he)物理(li)化(hua)學性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)質差異很大。鐵(tie)離子改(gai)(gai)(gai)(gai)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)后，活(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)的(de)(de)(de)表面積(ji)、總孔(kong)(kong)容(rong)量(liang)、微孔(kong)(kong)體積(ji)和(he)中孔(kong)(kong)體積(ji)都有一(yi)(yi)定程(cheng)度的(de)(de)(de)增加，可以為磺胺(an)二甲(jia)啶(ding)提(ti)供更多(duo)的(de)(de)(de)吸(xi)附(fu)點。由(you)(you)于改(gai)(gai)(gai)(gai)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)，活(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)的(de)(de)(de)微孔(kong)(kong)結(jie)(jie)構(gou)(gou)可能(neng)會產生(sheng)較大的(de)(de)(de)比(bi)表面積(ji)。在(zai)活(huo)(huo)(huo)(huo)化(hua)過程(cheng)中，鐵(tie)離子主要沉積(ji)在(zai)介孔(kong)(kong)中，擴大孔(kong)(kong)徑(jing)并(bing)(bing)進入(ru)微孔(kong)(kong)。將金屬鹽釋(shi)放的(de)(de)(de)氧(yang)化(hua)氣體引入(ru)微孔(kong)(kong)，并(bing)(bing)與(yu)微孔(kong)(kong)碳(tan)壁反應。活(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)和(he)改(gai)(gai)(gai)(gai)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)活(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)SEM圖(tu)(tu)1顯示(shi)圖(tu)(tu)像(xiang)(a)和(he)(b)中。活(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)的(de)(de)(de)形(xing)(xing)狀(zhuang)表明(ming)具有規(gui)則(ze)孔(kong)(kong)結(jie)(jie)構(gou)(gou)的(de)(de)(de)光滑表面。與(yu)活(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)相(xiang)比(bi)，改(gai)(gai)(gai)(gai)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)活(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)表面粗糙(cao)不規(gui)則(ze)。孔(kong)(kong)隙(xi)結(jie)(jie)構(gou)(gou)受損，孔(kong)(kong)隙(xi)率增加。這可能(neng)是由(you)(you)于鐵(tie)離子引入(ru)活(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)內孔(kong)(kong)，導(dao)致(zhi)碳(tan)壁氧(yang)化(hua)和(he)孔(kong)(kong)徑(jing)增加。活(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)中磺胺(an)二甲(jia)啶(ding)的(de)(de)(de)擴散有利于粗糙(cao)的(de)(de)(de)表面結(jie)(jie)構(gou)(gou)和(he)多(duo)孔(kong)(kong)特性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)。活(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)和(he)改(gai)(gai)(gai)(gai)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)活(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)TEM圖(tu)(tu)像(xiang)如(ru)圖(tu)(tu)1(c)和(he)(d)所(suo)示(shi)。這些圖(tu)(tu)片表明(ming)活(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)是無定形(xing)(xing)的(de)(de)(de)。與(yu)活(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)相(xiang)比(bi)，改(gai)(gai)(gai)(gai)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)活(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)表現出(chu)許多(duo)孔(kong)(kong)隙(xi)和(he)透明(ming)點，進一(yi)(yi)步(bu)表明(ming)表面積(ji)增加。活(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)和(he)改(gai)(gai)(gai)(gai)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)活(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)EDS圖(tu)(tu)像(xiang)如(ru)圖(tu)(tu)1(e)和(he)(f)所(suo)示(shi)。與(yu)活(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)相(xiang)比(bi)，改(gai)(gai)(gai)(gai)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)活(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)的(de)(de)(de)元素O和(he)Fe含量(liang)顯著增加，C活(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)上鐵(tie)離子負荷(he)的(de)(de)(de)含量(liang)降低。此外，進一(yi)(yi)步(bu)證明(ming)表面含氧(yang)量(liang)增加，有利于磺胺(an)二甲(jia)啶(ding)的(de)(de)(de)吸(xi)附(fu)。活(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)和(he)改(gai)(gai)(gai)(gai)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)活(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)XRD圖(tu)(tu)如(ru)圖(tu)(tu)1(g)和(he)(h)所(suo)示(shi)。而且沒有活(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)和(he)改(gai)(gai)(gai)(gai)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)活(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)(tan)的(de)(de)(de)明(ming)顯特征峰(feng)值，說明(ming)它們是無形(xing)(xing)的(de)(de)(de)。這與(yu)TEM照片結(jie)(jie)果一(yi)(yi)致(zhi)。

　　兩(liang)種吸附劑的代(dai)表(biao)性(xing)SEM，TEM和(he)EDS圖像。(a)活性(xing)炭(tan)(tan)(tan)(tan)的SEM(比例(li)尺(chi)為(wei)2μm)，(b)活性(xing)炭(tan)(tan)(tan)(tan)的TEM(比例(li)尺(chi)為(wei)100nm)，(c)活性(xing)炭(tan)(tan)(tan)(tan)的EDS，(d)改(gai)性(xing)活性(xing)炭(tan)(tan)(tan)(tan)SEM(比例(li)尺(chi)為(wei)2μm)，(e)改(gai)性(xing)活性(xing)炭(tan)(tan)(tan)(tan)TEM(比例(li)尺(chi)為(wei)100nm)，(f)改(gai)性(xing)活性(xing)炭(tan)(tan)(tan)(tan)EDS，(g)活性(xing)炭(tan)(tan)(tan)(tan)的XRD，(h)改(gai)性(xing)活性(xing)炭(tan)(tan)(tan)(tan)XRD。

　　活性炭(tan)吸附磺胺的三(san)個階段

　　活性炭(tan)(tan)和(he)改(gai)性活性炭(tan)(tan)和(he)改(gai)性活性炭(tan)(tan)上(shang)的吸(xi)(xi)附(fu)(fu)和(he)擴(kuo)(kuo)(kuo)散(san)(san)過(guo)(guo)程(cheng)可分(fen)三個階段(duan)描述，如圖2所(suo)示(shi)。由于**階段(duan)吸(xi)(xi)附(fu)(fu)在(zai)(zai)活性炭(tan)(tan)表(biao)面，吸(xi)(xi)附(fu)(fu)率*初很高(gao)。然后，在(zai)(zai)顆(ke)粒(li)內快速擴(kuo)(kuo)(kuo)散(san)(san)的過(guo)(guo)程(cheng)中，磺(huang)胺二甲啶逐(zhu)漸吸(xi)(xi)附(fu)(fu)在(zai)(zai)活性炭(tan)(tan)上(shang)，吸(xi)(xi)附(fu)(fu)率常數逐(zhu)漸降低。在(zai)(zai)第(di)三階段(duan)，邊界層(ceng)和(he)傳(chuan)質阻力的影響增加，導致顆(ke)粒(li)擴(kuo)(kuo)(kuo)散(san)(san)減慢(man)。所(suo)有三個階段(duan)的擬合方程(cheng)都沒(mei)有通過(guo)(guo)坐(zuo)標的原(yuan)點，這表(biao)明顆(ke)粒(li)的擴(kuo)(kuo)(kuo)散(san)(san)并不是控制吸(xi)(xi)附(fu)(fu)率的**步驟。因此，吸(xi)(xi)附(fu)(fu)過(guo)(guo)程(cheng)也受(shou)膜擴(kuo)(kuo)(kuo)散(san)(san)和(he)表(biao)面吸(xi)(xi)附(fu)(fu)的影響。

　　磺胺二(er)甲啶在(zai)活(huo)性炭上吸附的顆粒(li)中(zhong)擴散。

　　改(gai)(gai)性(xing)(xing)活(huo)性(xing)(xing)炭的表面(mian)顯示出許(xu)多孔隙和透(tou)明度，大量含氧官(guan)能團被改(gai)(gai)性(xing)(xing)，導致(zhi)磺(huang)(huang)胺二甲(jia)啶吸(xi)(xi)附機制的變化。根據本研(yan)究的相(xiang)關研(yan)究結(jie)果，活(huo)性(xing)(xing)炭表面(mian)磺(huang)(huang)胺二甲(jia)啶的吸(xi)(xi)附機制總(zong)結(jie)如下（圖3）：

　　1.微孔捕獲

　　SEM圖(tu)像顯(xian)示，活(huo)性(xing)炭的(de)規則孔(kong)結構(gou)受損，孔(kong)隙率(lv)增加。TEM圖(tu)像顯(xian)示，改性(xing)活(huo)性(xing)炭表面(mian)含(han)有(you)許多(duo)透明(ming)點(dian)，表明(ming)孔(kong)結構(gou)更(geng)發(fa)達，修(xiu)改后(hou)(hou)可獲得(de)更(geng)多(duo)的(de)吸(xi)附(fu)點(dian)。這有(you)利于磺胺二甲啶吸(xi)附(fu)到黑碳分(fen)子層的(de)孔(kong)中。此外，經鐵(tie)離子改性(xing)后(hou)(hou)，活(huo)性(xing)炭的(de)表面(mian)積、總孔(kong)容量、微孔(kong)體(ti)積和中孔(kong)體(ti)積都有(you)一定程度的(de)增加。

　　2.氫鍵相互(hu)作用

　　通(tong)過FTIR通(tong)過促(cu)(cu)進(jin)改(gai)性(xing)活(huo)性(xing)炭表(biao)(biao)面(mian)與磺胺二(er)(er)甲(jia)啶(ding)(ding)之間氫(qing)(qing)鍵的相互作用，促(cu)(cu)進(jin)磺胺二(er)(er)甲(jia)啶(ding)(ding)的吸附。從(cong)數據圖(tu)中發現，3400和(he)2850cm-1處寬(kuan)吸收峰表(biao)(biao)明改(gai)性(xing)活(huo)性(xing)炭表(biao)(biao)面(mian)存(cun)在-OH。這(zhe)些分子間氫(qing)(qing)鍵增強(qiang)了(le)磺胺二(er)(er)甲(jia)啶(ding)(ding)與活(huo)性(xing)炭的表(biao)(biao)面(mian)相互作用，預計將有(you)助(zhu)于活(huo)性(xing)炭與異磺胺二(er)(er)甲(jia)啶(ding)(ding)之間的親和(he)力吸附。

　　3.π-π電子供體-受體(EDA)相互(hu)作(zuo)用。

　　磺胺二甲啶與改(gai)性(xing)活(huo)性(xing)炭(tan)合理相互(hu)作(zuo)(zuo)(zuo)用的(de)示意圖。1.微孔捕(bu)獲。2.氫鍵相互(hu)作(zuo)(zuo)(zuo)用。.π-πEDA相互(hu)作(zuo)(zuo)(zuo)用。4.靜電相互(hu)作(zuo)(zuo)(zuo)用。5.配位相互(hu)作(zuo)(zuo)(zuo)用。

　　鐵(tie)離子改性(xing)(xing)后(hou)(hou)，活(huo)(huo)(huo)性(xing)(xing)炭活(huo)(huo)(huo)性(xing)(xing)炭的(de)表面積、總孔容量(liang)(liang)、微(wei)孔體積和(he)(he)中孔體積。含(han)氧加了活(huo)(huo)(huo)性(xing)(xing)炭表面含(han)氧官能(neng)團的(de)數量(liang)(liang)，可以大(da)大(da)提高吸(xi)(xi)(xi)附(fu)能(neng)力(li)。磺胺(an)(an)二(er)(er)(er)(er)甲嘧啶(ding)(ding)(ding)在(zai)(zai)改性(xing)(xing)活(huo)(huo)(huo)性(xing)(xing)炭上(shang)(shang)去除(chu)磺胺(an)(an)廢水中顯著增加，并在(zai)(zai)25℃下磺胺(an)(an)二(er)(er)(er)(er)甲嘧啶(ding)(ding)(ding)在(zai)(zai)改性(xing)(xing)活(huo)(huo)(huo)性(xing)(xing)炭上(shang)(shang)的(de)*大(da)吸(xi)(xi)(xi)附(fu)量(liang)(liang)為17.261mg/g。然而，吸(xi)(xi)(xi)附(fu)平(ping)衡(heng)時間幾(ji)乎(hu)保持不變。磺胺(an)(an)二(er)(er)(er)(er)甲啶(ding)(ding)(ding)在(zai)(zai)原(yuan)始和(he)(he)改性(xing)(xing)活(huo)(huo)(huo)性(xing)(xing)炭上(shang)(shang)的(de)吸(xi)(xi)(xi)附(fu)動力(li)學(xue)分為快速(su)和(he)(he)慢速(su)吸(xi)(xi)(xi)附(fu)階(jie)段，磺胺(an)(an)二(er)(er)(er)(er)甲啶(ding)(ding)(ding)吸(xi)(xi)(xi)附(fu)在(zai)(zai)12小時內(nei)快速(su)完(wan)成(cheng)。pH該值對(dui)磺胺(an)(an)二(er)(er)(er)(er)甲啶(ding)(ding)(ding)的(de)吸(xi)(xi)(xi)附(fu)有顯著影響(xiang)。當pH磺胺(an)(an)二(er)(er)(er)(er)甲啶(ding)(ding)(ding)的(de)吸(xi)(xi)(xi)附(fu)量(liang)(liang)在(zai)(zai)3-10之間增加，然后(hou)(hou)減少。微(wei)孔捕獲，靜電相(xiang)互(hu)作用，氫鍵相(xiang)互(hu)作用，π-πEDA相(xiang)互(hu)作用和(he)(he)配位相(xiang)互(hu)作用是吸(xi)(xi)(xi)附(fu)的(de)可能(neng)機制。降(jiang)低溫度促(cu)進吸(xi)(xi)(xi)附(fu)反(fan)應。pH該值對(dui)磺胺(an)(an)二(er)(er)(er)(er)甲啶(ding)(ding)(ding)的(de)吸(xi)(xi)(xi)附(fu)有顯著影響(xiang)。當pH磺胺(an)(an)二(er)(er)(er)(er)甲啶(ding)(ding)(ding)的(de)吸(xi)(xi)(xi)附(fu)量(liang)(liang)在(zai)(zai)3-10之間增加，然后(hou)(hou)減少。