活性炭(tan)改性后處理磺胺廢水

　　磺胺(an)廢水經(jing)活(huo)(huo)性(xing)(xing)炭(tan)改(gai)性(xing)(xing)后處理(li)，活(huo)(huo)性(xing)(xing)炭(tan)經(jing)氯(lv)化(hua)鐵改(gai)性(xing)(xing)。并進(jin)行批量實驗(yan)以評估廢水中的(de)磺胺(an)二(er)甲(jia)嘧啶吸附到(dao)活(huo)(huo)性(xing)(xing)炭(tan)和(he)改(gai)性(xing)(xing)活(huo)(huo)性(xing)(xing)炭(tan)上的(de)平衡(heng)，分(fen)(fen)別(bie)分(fen)(fen)析動力學和(he)熱(re)力學特征。結果表(biao)明，氯(lv)化(hua)鐵處理(li)后，活(huo)(huo)性(xing)(xing)炭(tan)改(gai)變了(le)表(biao)面積、孔隙體積和(he)表(biao)面zeta電位(wei)還增加(jia)了(le)表(biao)面含氧官(guan)能團(tuan)的(de)數量。經(jing)試驗(yan)發現，磺胺(an)二(er)甲(jia)啶在改(gai)性(xing)(xing)活(huo)(huo)性(xing)(xing)炭(tan)上的(de)吸附得到(dao)了(le)顯著(zhu)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，活性炭能有(you)效(xiao)去(qu)除顏色(se)、氣味、無機化合物(wu)和(he)大多數有(you)機污染物(wu)。但其在實際應用中(zhong)的使用受其吸(xi)(xi)(xi)附(fu)(fu)(fu)效(xiao)率和(he)成本低的限制。金屬離(li)子(zi)改性(xing)(xing)后的活(huo)性(xing)(xing)炭(tan)生產(chan)簡單便宜，能顯著(zhu)提高活(huo)性(xing)(xing)炭(tan)的吸(xi)(xi)(xi)附(fu)(fu)(fu)性(xing)(xing)能。然(ran)而，活(huo)性(xing)(xing)炭(tan)中(zhong)磺胺(an)類廢水(shui)(shui)的吸(xi)(xi)(xi)附(fu)(fu)(fu)機制尚(shang)不清楚，對磺胺(an)類的吸(xi)(xi)(xi)附(fu)(fu)(fu)能力及其理化性(xing)(xing)質知之(zhi)甚少。本研(yan)究(jiu)采用鐵離(li)子(zi)改性(xing)(xing)活(huo)性(xing)(xing)炭(tan)。用于探索吸(xi)(xi)(xi)附(fu)(fu)(fu)機制的批量(liang)吸(xi)(xi)(xi)附(fu)(fu)(fu)實驗。磺胺(an)二甲啶對活(huo)性(xing)(xing)炭(tan)和(he)改性(xing)(xing)活(huo)性(xing)(xing)炭(tan)的吸(xi)(xi)(xi)附(fu)(fu)(fu)特(te)性(xing)(xing)通(tong)過吸(xi)(xi)(xi)附(fu)(fu)(fu)動力學(xue)(xue)、吸(xi)(xi)(xi)附(fu)(fu)(fu)熱力學(xue)(xue)和(he)吸(xi)(xi)(xi)附(fu)(fu)(fu)等溫線(xian)進(jin)行(xing)了研(yan)究(jiu)，為去(qu)除廢水(shui)(shui)中(zhong)的磺胺(an)污染物(wu)提供了科學(xue)(xue)依據。

　　活性炭改性后的特性

　　活(huo)(huo)(huo)(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)和(he)改(gai)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)活(huo)(huo)(huo)(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)的(de)(de)(de)化(hua)學結構(gou)和(he)物理化(hua)學性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)質(zhi)差異(yi)很大(da)。鐵離(li)子(zi)(zi)改(gai)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)后(hou)，活(huo)(huo)(huo)(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)的(de)(de)(de)表(biao)(biao)(biao)面(mian)積(ji)(ji)、總(zong)孔(kong)(kong)(kong)(kong)(kong)(kong)容量(liang)(liang)、微(wei)孔(kong)(kong)(kong)(kong)(kong)(kong)體(ti)(ti)積(ji)(ji)和(he)中(zhong)孔(kong)(kong)(kong)(kong)(kong)(kong)體(ti)(ti)積(ji)(ji)都有一(yi)定(ding)程度的(de)(de)(de)增(zeng)加(jia)，可(ke)以為磺胺(an)二甲啶(ding)(ding)提供更多的(de)(de)(de)吸附點。由于改(gai)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)，活(huo)(huo)(huo)(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)的(de)(de)(de)微(wei)孔(kong)(kong)(kong)(kong)(kong)(kong)結構(gou)可(ke)能會產生較大(da)的(de)(de)(de)比(bi)表(biao)(biao)(biao)面(mian)積(ji)(ji)。在活(huo)(huo)(huo)(huo)(huo)(huo)(huo)化(hua)過程中(zhong)，鐵離(li)子(zi)(zi)主要沉積(ji)(ji)在介孔(kong)(kong)(kong)(kong)(kong)(kong)中(zhong)，擴(kuo)(kuo)大(da)孔(kong)(kong)(kong)(kong)(kong)(kong)徑(jing)并進(jin)入微(wei)孔(kong)(kong)(kong)(kong)(kong)(kong)。將金屬鹽釋放的(de)(de)(de)氧化(hua)氣體(ti)(ti)引(yin)入微(wei)孔(kong)(kong)(kong)(kong)(kong)(kong)，并與(yu)微(wei)孔(kong)(kong)(kong)(kong)(kong)(kong)碳(tan)壁反應。活(huo)(huo)(huo)(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)和(he)改(gai)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)活(huo)(huo)(huo)(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)SEM圖(tu)1顯示圖(tu)像(xiang)(xiang)(a)和(he)(b)中(zhong)。活(huo)(huo)(huo)(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)的(de)(de)(de)形狀表(biao)(biao)(biao)明(ming)(ming)(ming)具有規則孔(kong)(kong)(kong)(kong)(kong)(kong)結構(gou)的(de)(de)(de)光滑表(biao)(biao)(biao)面(mian)。與(yu)活(huo)(huo)(huo)(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)相比(bi)，改(gai)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)活(huo)(huo)(huo)(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)表(biao)(biao)(biao)面(mian)粗糙不規則。孔(kong)(kong)(kong)(kong)(kong)(kong)隙結構(gou)受(shou)損(sun)，孔(kong)(kong)(kong)(kong)(kong)(kong)隙率(lv)增(zeng)加(jia)。這可(ke)能是由于鐵離(li)子(zi)(zi)引(yin)入活(huo)(huo)(huo)(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)內孔(kong)(kong)(kong)(kong)(kong)(kong)，導致碳(tan)壁氧化(hua)和(he)孔(kong)(kong)(kong)(kong)(kong)(kong)徑(jing)增(zeng)加(jia)。活(huo)(huo)(huo)(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)中(zhong)磺胺(an)二甲啶(ding)(ding)的(de)(de)(de)擴(kuo)(kuo)散(san)有利(li)于粗糙的(de)(de)(de)表(biao)(biao)(biao)面(mian)結構(gou)和(he)多孔(kong)(kong)(kong)(kong)(kong)(kong)特(te)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)。活(huo)(huo)(huo)(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)和(he)改(gai)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)活(huo)(huo)(huo)(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)TEM圖(tu)像(xiang)(xiang)如圖(tu)1(c)和(he)(d)所(suo)示。這些圖(tu)片表(biao)(biao)(biao)明(ming)(ming)(ming)活(huo)(huo)(huo)(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)是無定(ding)形的(de)(de)(de)。與(yu)活(huo)(huo)(huo)(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)相比(bi)，改(gai)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)活(huo)(huo)(huo)(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)表(biao)(biao)(biao)現出許多孔(kong)(kong)(kong)(kong)(kong)(kong)隙和(he)透明(ming)(ming)(ming)點，進(jin)一(yi)步表(biao)(biao)(biao)明(ming)(ming)(ming)表(biao)(biao)(biao)面(mian)積(ji)(ji)增(zeng)加(jia)。活(huo)(huo)(huo)(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)和(he)改(gai)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)活(huo)(huo)(huo)(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)EDS圖(tu)像(xiang)(xiang)如圖(tu)1(e)和(he)(f)所(suo)示。與(yu)活(huo)(huo)(huo)(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)相比(bi)，改(gai)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)活(huo)(huo)(huo)(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)的(de)(de)(de)元素O和(he)Fe含量(liang)(liang)顯著增(zeng)加(jia)，C活(huo)(huo)(huo)(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)上鐵離(li)子(zi)(zi)負荷的(de)(de)(de)含量(liang)(liang)降低(di)。此(ci)外(wai)，進(jin)一(yi)步證明(ming)(ming)(ming)表(biao)(biao)(biao)面(mian)含氧量(liang)(liang)增(zeng)加(jia)，有利(li)于磺胺(an)二甲啶(ding)(ding)的(de)(de)(de)吸附。活(huo)(huo)(huo)(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)和(he)改(gai)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)活(huo)(huo)(huo)(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)XRD圖(tu)如圖(tu)1(g)和(he)(h)所(suo)示。而(er)且沒有活(huo)(huo)(huo)(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)和(he)改(gai)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)活(huo)(huo)(huo)(huo)(huo)(huo)(huo)性(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)炭(tan)的(de)(de)(de)明(ming)(ming)(ming)顯特(te)征峰(feng)值，說明(ming)(ming)(ming)它們是無形的(de)(de)(de)。這與(yu)TEM照(zhao)片結果一(yi)致。

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

　　活性炭吸附磺胺的三個階段

　　活(huo)(huo)性(xing)炭(tan)和(he)改性(xing)活(huo)(huo)性(xing)炭(tan)和(he)改性(xing)活(huo)(huo)性(xing)炭(tan)上(shang)的(de)吸(xi)附(fu)(fu)和(he)擴(kuo)散(san)(san)過程可分三(san)個(ge)(ge)階(jie)段(duan)描述，如圖2所示。由于**階(jie)段(duan)吸(xi)附(fu)(fu)在活(huo)(huo)性(xing)炭(tan)表(biao)面，吸(xi)附(fu)(fu)率(lv)*初很高。然后，在顆粒(li)內快(kuai)速擴(kuo)散(san)(san)的(de)過程中，磺(huang)胺二甲(jia)啶(ding)逐漸(jian)吸(xi)附(fu)(fu)在活(huo)(huo)性(xing)炭(tan)上(shang)，吸(xi)附(fu)(fu)率(lv)常(chang)數逐漸(jian)降低。在第三(san)階(jie)段(duan)，邊界層和(he)傳質阻力的(de)影響(xiang)增加，導(dao)致顆粒(li)擴(kuo)散(san)(san)減慢。所有三(san)個(ge)(ge)階(jie)段(duan)的(de)擬合方程都沒有通(tong)過坐標的(de)原點(dian)，這表(biao)明顆粒(li)的(de)擴(kuo)散(san)(san)并(bing)不(bu)是控制吸(xi)附(fu)(fu)率(lv)的(de)**步驟。因此，吸(xi)附(fu)(fu)過程也受膜(mo)擴(kuo)散(san)(san)和(he)表(biao)面吸(xi)附(fu)(fu)的(de)影響(xiang)。

　　磺胺二甲(jia)啶(ding)在活性炭上吸附的顆粒中擴散。

　　改性活性炭的(de)表面顯示出許多孔(kong)隙(xi)和(he)透明度，大量含氧官能團被改性，導(dao)致(zhi)磺胺(an)二(er)甲啶(ding)吸附機(ji)制的(de)變(bian)化。根(gen)據本研究的(de)相關研究結果，活性炭表面磺胺(an)二(er)甲啶(ding)的(de)吸附機(ji)制總結如下（圖(tu)3）：

　　1.微孔捕獲

　　SEM圖(tu)像顯示，活(huo)性炭(tan)的(de)(de)規(gui)則孔(kong)結構受損，孔(kong)隙率增加。TEM圖(tu)像顯示，改性活(huo)性炭(tan)表面含有(you)(you)許(xu)多(duo)透明(ming)(ming)點(dian)，表明(ming)(ming)孔(kong)結構更發(fa)達，修改后可獲得更多(duo)的(de)(de)吸附點(dian)。這有(you)(you)利于(yu)磺胺(an)二甲啶吸附到黑碳分子層的(de)(de)孔(kong)中(zhong)。此外，經鐵離子改性后，活(huo)性炭(tan)的(de)(de)表面積(ji)、總孔(kong)容量、微孔(kong)體(ti)積(ji)和中(zhong)孔(kong)體(ti)積(ji)都有(you)(you)一定程度的(de)(de)增加。

　　2.氫鍵相互作用

　　通過FTIR通過促進改(gai)性(xing)(xing)活性(xing)(xing)炭(tan)表(biao)(biao)面與磺(huang)胺(an)二(er)甲(jia)啶之(zhi)間(jian)(jian)氫鍵(jian)的相(xiang)互作用，促進磺(huang)胺(an)二(er)甲(jia)啶的吸(xi)(xi)附(fu)。從(cong)數據圖中發現，3400和2850cm-1處寬吸(xi)(xi)收峰表(biao)(biao)明改(gai)性(xing)(xing)活性(xing)(xing)炭(tan)表(biao)(biao)面存在(zai)-OH。這(zhe)些分子間(jian)(jian)氫鍵(jian)增強了磺(huang)胺(an)二(er)甲(jia)啶與活性(xing)(xing)炭(tan)的表(biao)(biao)面相(xiang)互作用，預(yu)計將(jiang)有助(zhu)于活性(xing)(xing)炭(tan)與異磺(huang)胺(an)二(er)甲(jia)啶之(zhi)間(jian)(jian)的親(qin)和力吸(xi)(xi)附(fu)。

　　3.π-π電子供體(ti)-受體(ti)(EDA)相互作用。

　　磺胺二(er)甲啶與改(gai)性活性炭合理相(xiang)(xiang)互作(zuo)用(yong)的示意圖。1.微孔捕獲。2.氫鍵相(xiang)(xiang)互作(zuo)用(yong)。.π-πEDA相(xiang)(xiang)互作(zuo)用(yong)。4.靜電(dian)相(xiang)(xiang)互作(zuo)用(yong)。5.配位相(xiang)(xiang)互作(zuo)用(yong)。

　　鐵離子改(gai)性(xing)(xing)后，活(huo)性(xing)(xing)炭(tan)活(huo)性(xing)(xing)炭(tan)的(de)(de)(de)表(biao)面(mian)積(ji)、總(zong)孔(kong)容(rong)量(liang)(liang)、微(wei)(wei)孔(kong)體(ti)(ti)積(ji)和(he)中孔(kong)體(ti)(ti)積(ji)。含氧加了(le)活(huo)性(xing)(xing)炭(tan)表(biao)面(mian)含氧官能(neng)團的(de)(de)(de)數量(liang)(liang)，可(ke)以大大提高吸(xi)(xi)(xi)(xi)附(fu)(fu)(fu)能(neng)力(li)(li)。磺(huang)胺(an)(an)二(er)(er)(er)甲(jia)嘧啶(ding)(ding)(ding)(ding)在改(gai)性(xing)(xing)活(huo)性(xing)(xing)炭(tan)上去除磺(huang)胺(an)(an)廢水中顯(xian)著增加，并在25℃下磺(huang)胺(an)(an)二(er)(er)(er)甲(jia)嘧啶(ding)(ding)(ding)(ding)在改(gai)性(xing)(xing)活(huo)性(xing)(xing)炭(tan)上的(de)(de)(de)*大吸(xi)(xi)(xi)(xi)附(fu)(fu)(fu)量(liang)(liang)為(wei)17.261mg/g。然(ran)(ran)而，吸(xi)(xi)(xi)(xi)附(fu)(fu)(fu)平衡時間幾乎保持不變(bian)。磺(huang)胺(an)(an)二(er)(er)(er)甲(jia)啶(ding)(ding)(ding)(ding)在原始和(he)改(gai)性(xing)(xing)活(huo)性(xing)(xing)炭(tan)上的(de)(de)(de)吸(xi)(xi)(xi)(xi)附(fu)(fu)(fu)動力(li)(li)學分(fen)為(wei)快速和(he)慢(man)速吸(xi)(xi)(xi)(xi)附(fu)(fu)(fu)階段，磺(huang)胺(an)(an)二(er)(er)(er)甲(jia)啶(ding)(ding)(ding)(ding)吸(xi)(xi)(xi)(xi)附(fu)(fu)(fu)在12小時內快速完成。pH該值(zhi)對磺(huang)胺(an)(an)二(er)(er)(er)甲(jia)啶(ding)(ding)(ding)(ding)的(de)(de)(de)吸(xi)(xi)(xi)(xi)附(fu)(fu)(fu)有顯(xian)著影響(xiang)。當pH磺(huang)胺(an)(an)二(er)(er)(er)甲(jia)啶(ding)(ding)(ding)(ding)的(de)(de)(de)吸(xi)(xi)(xi)(xi)附(fu)(fu)(fu)量(liang)(liang)在3-10之間增加，然(ran)(ran)后減(jian)少。微(wei)(wei)孔(kong)捕(bu)獲，靜電相(xiang)互(hu)作(zuo)用，氫鍵相(xiang)互(hu)作(zuo)用，π-πEDA相(xiang)互(hu)作(zuo)用和(he)配(pei)位相(xiang)互(hu)作(zuo)用是吸(xi)(xi)(xi)(xi)附(fu)(fu)(fu)的(de)(de)(de)可(ke)能(neng)機(ji)制。降低溫度促進吸(xi)(xi)(xi)(xi)附(fu)(fu)(fu)反應(ying)。pH該值(zhi)對磺(huang)胺(an)(an)二(er)(er)(er)甲(jia)啶(ding)(ding)(ding)(ding)的(de)(de)(de)吸(xi)(xi)(xi)(xi)附(fu)(fu)(fu)有顯(xian)著影響(xiang)。當pH磺(huang)胺(an)(an)二(er)(er)(er)甲(jia)啶(ding)(ding)(ding)(ding)的(de)(de)(de)吸(xi)(xi)(xi)(xi)附(fu)(fu)(fu)量(liang)(liang)在3-10之間增加，然(ran)(ran)后減(jian)少。