
活性炭(tan)吸附在(zai)幾種土壤(rang)中
活性炭吸附(fu)在(zai)幾種(zhong)(zhong)(zhong)(zhong)土壤(rang)(rang)(rang)中(zhong),在(zai)土壤(rang)(rang)(rang)污染的(de)(de)(de)情況下(xia),土壤(rang)(rang)(rang)改(gai)良劑可用于固定有機污染物(wu),同時(shi)保持(chi)土壤(rang)(rang)(rang)功能(neng),活(huo)性(xing)炭是一種(zhong)(zhong)(zhong)(zhong)有前(qian)景的(de)(de)(de)土壤(rang)(rang)(rang)修復(fu)材(cai)料。在(zai)本期實驗(yan)中(zhong),菲(fei)(fei)烯(Phe)用于污染土壤(rang)(rang)(rang)的(de)(de)(de)污染物(wu),我們(men)(men)研究(jiu)了三種(zhong)(zhong)(zhong)(zhong)活(huo)性(xing)炭研究(jiu)了三種(zhong)(zhong)(zhong)(zhong)活(huo)性(xing)炭對三種(zhong)(zhong)(zhong)(zhong)不同基(ji)質、兩種(zhong)(zhong)(zhong)(zhong)農業表土和(he)(he)純砂的(de)(de)(de)影響(xiang)。我們(men)(men)對土壤(rang)(rang)(rang)性(xing)質的(de)(de)(de)變化、菲(fei)(fei)律賓的(de)(de)(de)吸附(fu)-解吸和(he)(he)菲(fei)(fei)律賓在(zai)所有治療中(zhong)的(de)(de)(de)礦(kuang)化進行(xing)了評估。
石油碳(tan)氫化(hua)合物(wu)(wu)(wu)污(wu)染是(shi)土(tu)(tu)(tu)(tu)(tu)壤(rang)和(he)沉(chen)積物(wu)(wu)(wu)中(zhong)*常見的問題之一。菲律賓是(shi)一種廣泛存在(zai)(zai)的三(san)環芳烴,存在(zai)(zai)時(shi)間長,難以從環境中(zhong)去除(chu)。活性(xing)炭吸(xi)附是(shi)控制土(tu)(tu)(tu)(tu)(tu)壤(rang)和(he)水生系統(tong)中(zhong)有(you)(you)機(ji)污(wu)染物(wu)(wu)(wu)流動性(xing)、可用性(xing)和(he)目的地(di)的關(guan)鍵過(guo)(guo)程(cheng)。多環芳烴的吸(xi)附行為(wei)(wei)主要由土(tu)(tu)(tu)(tu)(tu)壤(rang)有(you)(you)機(ji)質含量(liang)調節(jie),土(tu)(tu)(tu)(tu)(tu)壤(rang)有(you)(you)機(ji)質是(shi)一種通過(guo)(guo)含碳(tan)產(chan)品修復的參(can)數。在(zai)(zai)過(guo)(guo)去的幾(ji)十年里,人們努力(li)探(tan)索和(he)生產(chan)新(xin)材料作為(wei)(wei)一種有(you)(you)效、低成本的土(tu)(tu)(tu)(tu)(tu)壤(rang)修復工具,并深入研究(jiu)了活性(xing)炭在(zai)(zai)土(tu)(tu)(tu)(tu)(tu)壤(rang)中(zhong)的應用。活性(xing)炭是(shi)一種富含碳(tan)的固體有(you)(you)機(ji)物(wu)(wu)(wu)熱(re)分(fen)解產(chan)物(wu)(wu)(wu)。熱(re)解有(you)(you)機(ji)物(wu)(wu)(wu)(木(mu)炭、生物(wu)(wu)(wu)炭、活性(xing)炭)的行為(wei)(wei)明(ming)顯不同于土(tu)(tu)(tu)(tu)(tu)壤(rang)中(zhong)所含的無熱(re)原有(you)(you)機(ji)物(wu)(wu)(wu)。活性(xing)炭的強吸(xi)附性(xing)能可以通過(guo)(guo)改變土(tu)(tu)(tu)(tu)(tu)壤(rang)性(xing)質來調節(jie)土(tu)(tu)(tu)(tu)(tu)壤(rang)中(zhong)芳烴的降解過(guo)(guo)程(cheng),但也可以通過(guo)(guo)降低有(you)(you)機(ji)污(wu)染物(wu)(wu)(wu)的可用性(xing)來調節(jie)。
土壤(rang)、沙(sha)子(zi)和活(huo)性炭(tan)(tan)的來(lai)(lai)源來(lai)(lai)自(zi)兩個(ge)農田(tian)(土壤(rang)1、土壤(rang)2)。沙(sha)子(zi)用10%HCl洗滌40-100μm低鐵(tie)砂粒度,然后(hou)用去離子(zi)水(shui)沖洗10次(ci),直到pH上(shang)升并穩定到5.5。三種(zhong)來(lai)(lai)自(zi)不同來(lai)(lai)源的活(huo)性炭(tan)(tan)用于實驗:(1)木質活(huo)性炭(tan)(tan)(AC(2)根系活(huo)性炭(tan)(tan)(AC和(3)農作物活(huo)性炭(tan)(tan)(AC3)。
土壤修復的方法
將活性炭(尺(chi)寸<1mm)以(yi)1%(w/w)的比(bi)率(lv)摻(chan)入測試的土壤和(he)沙子(zi)中(zhong),這是(shi)一(yi)個模擬自然環境的修復(fu)過程,考慮到30 cm的土壤深度(du)(du)和(he)約1.6t m-3的土壤密度(du)(du)。將混(hun)合物均化(hua)后,將每個樣品潤(run)濕至60%的保水能力,并在(zai)(zai)室溫(20-25℃)下在(zai)(zai)聚乙烯袋中(zhong)平衡15天。所(suo)有程序和(he)實(shi)驗(基本表征(zheng),批次(ci)相互(hu)作用(yong)和(he)土壤培養)進行3-4次(ci)重復(fu)。
菲的吸附實驗
在(zai)(zai)玻(bo)璃(li)離心(xin)管和7ml不同濃度的(de)菲烯(xi)溶液(ye)中(zhong)放入(ru)0.7g摻入(ru)活(huo)性(xing)炭的(de)干燥土壤。通過(guo)在(zai)(zai)10mm CaCl 2和1.5的(de)背景(jing)溶液(ye)中(zhong)保(bao)持乙醇的(de)比例<0.1%,將試(shi)(shi)管在(zai)(zai)頂置振蕩器中(zhong)以(yi)100rpm搖動24小時,然后將它們以(yi)2700g離心(xin)15分(fen)鐘,取1ml上清液(ye)的(de)等分(fen)試(shi)(shi)樣(yang)。在(zai)(zai)β計(ji)(ji)數(shu)器中(zhong)通過(guo)液(ye)體(ti)閃爍(shuo)計(ji)(ji)數(shu)進行處理和分(fen)析,并在(zai)(zai)相互作用的(de)7,24和48小時取上清液(ye)的(de)等分(fen)試(shi)(shi)樣(yang)。
菲的解吸實驗
對于該實(shi)驗,我們選擇在相互作用后從(cong)吸附(fu)實(shi)驗中獲取(qu)活(huo)性(xing)炭土壤菲的樣品。我們在吸附(fu)實(shi)驗中提取(qu)了保留在土壤中的菲,劑量(liang)為(wei)1μg菲g-1土壤有六個(ge)表(biao)示。
熱化(hua)合物在高重(zhong)力(li)下改性
高重力環境下活(huo)(huo)(huo)(huo)(huo)性(xing)(xing)炭(tan)(tan)的熱化合物改性(xing)(xing)。將100g以活(huo)(huo)(huo)(huo)(huo)性(xing)(xing)炭(tan)(tan)為填料層,9000r/min速(su)度(du)操作300分鐘,99%氮氣通過入口(kou)。活(huo)(huo)(huo)(huo)(huo)性(xing)(xing)炭(tan)(tan)表示活(huo)(huo)(huo)(huo)(huo)性(xing)(xing)炭(tan)(tan)-RPB-N。原(yuan)始活(huo)(huo)(huo)(huo)(huo)性(xing)(xing)炭(tan)(tan)和活(huo)(huo)(huo)(huo)(huo)性(xing)(xing)炭(tan)(tan)-RPB-N用1mol·L-1HNO 3在70攝氏度(du),流速(su)40L·min-1,轉(zhuan)速(su)36.3Hz改性(xing)(xing)。處理后,用去離子水沖洗后,將兩(liang)個樣品在110℃的真空烘箱中干燥(zao)24小時,并分別表示為活(huo)(huo)(huo)(huo)(huo)性(xing)(xing)炭(tan)(tan)-RPB-HNO和活(huo)(huo)(huo)(huo)(huo)性(xing)(xing)炭(tan)(tan)-RPB-N-HNO。
在高重力(li)物(wu)理(li)改性(xing)過程中,氮分(fen)布不(bu)再是從(cong)頂部到底部的(de)單(dan)一流動,而是通過各(ge)個方向的(de)對流輸送(song)到活性(xing)炭。與(yu)活性(xing)炭接觸后,氮產生新的(de)微(wei)孔(kong),挖掘現(xian)有的(de)吸附通道。因(yin)此,它增加了(le)它們(men)的(de)表面積(ji)和(he)孔(kong)容(rong)量(liang)。簡化(hua)原(yuan)理(li)圖(tu)如圖(tu)1所示。
氮和硝(xiao)酸改性(xing)在正常和高(gao)重力環境(jing)中(zhong)的示(shi)意圖。
實驗研究(jiu)活性炭吸附性能
研究(jiu)了活性炭(tan)在(zai)吸(xi)(xi)(xi)(xi)附(fu)(fu)柱中吸(xi)(xi)(xi)(xi)附(fu)(fu)甲(jia)(jia)苯(ben)(ben)(ben)的(de)(de)(de)能(neng)力。活性炭(tan)用量為10g,氣(qi)(qi)(qi)體發(fa)生器產生吸(xi)(xi)(xi)(xi)附(fu)(fu)質甲(jia)(jia)苯(ben)(ben)(ben)氣(qi)(qi)(qi)體。活性炭(tan)吸(xi)(xi)(xi)(xi)附(fu)(fu)性能(neng)的(de)(de)(de)數據是通(tong)(tong)過(guo)測(ce)量吸(xi)(xi)(xi)(xi)附(fu)(fu)前(qian)后甲(jia)(jia)苯(ben)(ben)(ben)的(de)(de)(de)濃(nong)度(du)來獲得的(de)(de)(de)。實(shi)驗(yan)吸(xi)(xi)(xi)(xi)附(fu)(fu)裝置的(de)(de)(de)流程圖(tu)如圖(tu)2所示(shi)。甲(jia)(jia)苯(ben)(ben)(ben)氣(qi)(qi)(qi)體與氮氣(qi)(qi)(qi)混合,然(ran)后吸(xi)(xi)(xi)(xi)附(fu)(fu)在(zai)恒溫吸(xi)(xi)(xi)(xi)附(fu)(fu)塔中。通(tong)(tong)過(guo)在(zai)線(xian)FID檢測(ce)器測(ce)量吸(xi)(xi)(xi)(xi)附(fu)(fu)前(qian)后的(de)(de)(de)甲(jia)(jia)苯(ben)(ben)(ben)含量,并通(tong)(tong)過(guo)流量計控制甲(jia)(jia)苯(ben)(ben)(ben)流量。當脫氣(qi)(qi)(qi)和入口濃(nong)度(du)在(zai)30分鐘內保(bao)持(chi)一致時,認(ren)為吸(xi)(xi)(xi)(xi)附(fu)(fu)平衡已(yi)經達到。通(tong)(tong)過(guo)廢氣(qi)(qi)(qi)出口排出吸(xi)(xi)(xi)(xi)附(fu)(fu)氣(qi)(qi)(qi)體。
實(shi)驗吸附流(liu)動圖。
幾種(zhong)活性(xing)(xing)炭(tan)對(dui)甲苯(ben)的吸附性(xing)(xing)能比較
不(bu)同(tong)活(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)上甲苯的(de)(de)(de)(de)(de)穿透曲線和(he)(he)吸(xi)(xi)附(fu)(fu)等(deng)溫曲線如圖3所(suo)示和(he)(he)4所(suo)示。不(bu)同(tong)活(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)的(de)(de)(de)(de)(de)吸(xi)(xi)附(fu)(fu)率(lv)(lv)(lv)從(cong)高到低依次為(wei):活(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)-RPB-N-HNO>活(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)-RPB-HNO>活(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)-HNO>活(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)-RPB-N>活(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)-N>原始活(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)。吸(xi)(xi)附(fu)(fu)率(lv)(lv)(lv)越(yue)大(da),滲透時間(jian)越(yue)長,這與活(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)的(de)(de)(de)(de)(de)復(fu)雜孔徑分布(bu)和(he)(he)表(biao)面(mian)(mian)官能(neng)團的(de)(de)(de)(de)(de)數(shu)量有關。高溫氮氣(qi)中活(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)的(de)(de)(de)(de)(de)微孔體(ti)積(ji)(ji)增(zeng)加(jia)(jia)(jia)(jia),增(zeng)加(jia)(jia)(jia)(jia)了(le)活(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)通道的(de)(de)(de)(de)(de)內孔體(ti)積(ji)(ji)。在(zai)(zai)高重(zhong)(zhong)力氮氣(qi)環境中,不(bu)利(li)于(yu)甲苯吸(xi)(xi)收的(de)(de)(de)(de)(de)原始活(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)的(de)(de)(de)(de)(de)內部(bu)結構(gou)被重(zhong)(zhong)新(xin)分配并(bing)分裂成新(xin)的(de)(de)(de)(de)(de)空間(jian)結構(gou),進(jin)一步增(zeng)加(jia)(jia)(jia)(jia)了(le)突(tu)破(po)時間(jian)。HNO 在(zai)(zai)高重(zhong)(zhong)力環境下,3處理活(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)的(de)(de)(de)(de)(de)突(tu)破(po)時間(jian)大(da)于(yu)改(gai)性(xing)(xing)(xing)(xing)(xing)HNO 改(gai)性(xing)(xing)(xing)(xing)(xing)活(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)浸泡。這是因(yin)為(wei)HNO 在(zai)(zai)分散的(de)(de)(de)(de)(de)小液滴中,增(zeng)加(jia)(jia)(jia)(jia)了(le)與活(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)表(biao)面(mian)(mian)和(he)(he)內部(bu)接觸(chu)的(de)(de)(de)(de)(de)可(ke)能(neng)性(xing)(xing)(xing)(xing)(xing),進(jin)而(er)增(zeng)加(jia)(jia)(jia)(jia)了(le)活(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)上含(han)氧官能(neng)團的(de)(de)(de)(de)(de)負荷,提高了(le)其吸(xi)(xi)附(fu)(fu)效率(lv)(lv)(lv)。在(zai)(zai)重(zhong)(zhong)力作用下,復(fu)合改(gai)性(xing)(xing)(xing)(xing)(xing)活(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)具有較長的(de)(de)(de)(de)(de)穿透時間(jian)和(he)(he)較大(da)的(de)(de)(de)(de)(de)吸(xi)(xi)附(fu)(fu)率(lv)(lv)(lv),因(yin)為(wei)物理改(gai)性(xing)(xing)(xing)(xing)(xing)增(zeng)加(jia)(jia)(jia)(jia)了(le)比表(biao)面(mian)(mian)積(ji)(ji),增(zeng)加(jia)(jia)(jia)(jia)了(le)孔體(ti)積(ji)(ji)分布(bu),而(er)化學改(gai)性(xing)(xing)(xing)(xing)(xing)增(zeng)加(jia)(jia)(jia)(jia)了(le)表(biao)面(mian)(mian)氧基團的(de)(de)(de)(de)(de)數(shu)量。反過來,這些特(te)性(xing)(xing)(xing)(xing)(xing)增(zeng)強了(le)吸(xi)(xi)附(fu)(fu)性(xing)(xing)(xing)(xing)(xing)。
活(huo)性(xing)炭(tan)的突破曲線(xian)。
等溫曲線吸(xi)附活性炭。
活(huo)性(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)在(zai)常規(gui)和高(gao)(gao)重(zhong)(zhong)力(li)(li)環(huan)境高(gao)(gao)重(zhong)(zhong)力(li)(li)環(huan)境下進(jin)行了物理、化學和化合物改(gai)(gai)性(xing)(xing)(xing)(xing)(xing)。研究(jiu)了甲(jia)苯在(zai)不同活(huo)性(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)上(shang)的(de)(de)(de)吸(xi)附(fu)(fu)。高(gao)(gao)重(zhong)(zhong)力(li)(li)化合物改(gai)(gai)性(xing)(xing)(xing)(xing)(xing)活(huo)性(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)具有*大的(de)(de)(de)吸(xi)附(fu)(fu)率和容量(liang)。還發現,微(wei)孔(kong)結構(gou)在(zai)活(huo)性(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)吸(xi)附(fu)(fu)甲(jia)苯的(de)(de)(de)過程中起著主導作用。由于化合物的(de)(de)(de)改(gai)(gai)性(xing)(xing)(xing)(xing)(xing),活(huo)性(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)的(de)(de)(de)優異吸(xi)附(fu)(fu)能(neng)力(li)(li)增(zeng)加(jia)了有效吸(xi)附(fu)(fu)位點的(de)(de)(de)數量(liang)。活(huo)性(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)-RPB-N-HNO上(shang)甲(jia)苯表面(mian)覆蓋(gai)率為(wei)51.67%。因此(ci),活(huo)性(xing)(xing)(xing)(xing)(xing)炭(tan)(tan)(tan)(tan)在(zai)高(gao)(gao)重(zhong)(zhong)力(li)(li)下的(de)(de)(de)復(fu)合改(gai)(gai)性(xing)(xing)(xing)(xing)(xing)可以大大提高(gao)(gao)吸(xi)附(fu)(fu)性(xing)(xing)(xing)(xing)(xing)能(neng)。
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