活(huo)(huo)性(xing)(xing)(xing)炭(tan),是黑(hei)色粉(fen)末狀(zhuang)或塊狀(zhuang)、顆粒狀(zhuang)、蜂窩狀(zhuang)的(de)(de)無定形碳(tan)(tan),也有(you)排列規整的(de)(de)晶體碳(tan)(tan)。活(huo)(huo)性(xing)(xing)(xing)炭(tan)中(zhong)(zhong)除碳(tan)(tan)元(yuan)素外(wai),還(huan)包(bao)含兩(liang)類(lei)(lei)摻(chan)和物:一類(lei)(lei)是化(hua)學(xue)結合的(de)(de)元(yuan)素,主要是氧和氫,這些元(yuan)素是由于未完全炭(tan)化(hua)而(er)殘(can)留在(zai)炭(tan)中(zhong)(zhong),或者在(zai)活(huo)(huo)化(hua)過程中(zhong)(zhong),外(wai)來的(de)(de)非碳(tan)(tan)元(yuan)素與活(huo)(huo)性(xing)(xing)(xing)炭(tan)表面化(hua)學(xue)結合;另一類(lei)(lei)摻(chan)和物是灰分(fen),它(ta)是活(huo)(huo)性(xing)(xing)(xing)炭(tan)的(de)(de)無機部分(fen),灰分(fen)在(zai)活(huo)(huo)性(xing)(xing)(xing)碳(tan)(tan)中(zhong)(zhong)易造成二次污染(ran)。活(huo)(huo)性(xing)(xing)(xing)炭(tan)由于具有(you)較(jiao)強的(de)(de)吸附性(xing)(xing)(xing),廣(guang)泛(fan)應用(yong)于生(sheng)產、生(sheng)活(huo)(huo)中(zhong)(zhong)。
活(huo)性(xing)(xing)(xing)(xing)(xing)炭(tan)材(cai)料(liao)是(shi)經過加(jia)工(gong)(gong)(gong)處理所(suo)得(de)的(de)無定(ding)形碳,具有(you)很大的(de)比表(biao)面積,對氣(qi)體、溶(rong)液中的(de)無機或有(you)機物(wu)質(zhi)(zhi)及膠體顆粒等(deng)都有(you)良(liang)好(hao)的(de)吸(xi)(xi)附(fu)能(neng)力。活(huo)性(xing)(xing)(xing)(xing)(xing)炭(tan)材(cai)料(liao)主(zhu)要包括(kuo)活(huo)性(xing)(xing)(xing)(xing)(xing)炭(tan)(Activated Carbon , A C )和活(huo)性(xing)(xing)(xing)(xing)(xing)炭(tan)纖維(wei)(Activated Carbon Fibers, ACF )等(deng)。活(huo)性(xing)(xing)(xing)(xing)(xing)炭(tan)材(cai)料(liao)作(zuo)為一種(zhong)性(xing)(xing)(xing)(xing)(xing)能(neng)優良(liang)的(de)吸(xi)(xi)附(fu)劑,主(zhu)要是(shi)由于其(qi)具有(you)獨特(te)的(de)吸(xi)(xi)附(fu)表(biao)面結構特(te)性(xing)(xing)(xing)(xing)(xing)和表(biao)面化(hua)(hua)學(xue)性(xing)(xing)(xing)(xing)(xing)能(neng)所(suo)決定(ding)的(de)。活(huo)性(xing)(xing)(xing)(xing)(xing)炭(tan)材(cai)料(liao)的(de)化(hua)(hua)學(xue)性(xing)(xing)(xing)(xing)(xing)質(zhi)(zhi)穩定(ding),機械強(qiang)度高,耐(nai)(nai)酸(suan)、耐(nai)(nai)堿、耐(nai)(nai)熱(re),不溶(rong)于水(shui)與有(you)機溶(rong)劑,可以再生使用,已經廣泛地應用于化(hua)(hua)工(gong)(gong)(gong)、環(huan)保、食品加(jia)工(gong)(gong)(gong)、冶(ye)金、藥物(wu)精制、軍事化(hua)(hua)學(xue)防護(hu)等(deng)各個領域 。目(mu)前,改性(xing)(xing)(xing)(xing)(xing)活(huo)性(xing)(xing)(xing)(xing)(xing)炭(tan)材(cai)料(liao)被廣泛用于污水(shui)處理、大氣(qi)污染防治等(deng)領域,在治理環(huan)境污染方面越來越顯示出其(qi)誘人的(de)美(mei)好(hao)前景。
活性(xing)炭(tan)(tan)80%-90%以上由碳元(yuan)素組(zu)成,這也是(shi)(shi)活性(xing)炭(tan)(tan)為疏(shu)水性(xing)吸附劑的原因。除了碳元(yuan)素外(wai),還包含(han)有兩(liang)類摻和物:一(yi)類是(shi)(shi)化(hua)(hua)學(xue)(xue)結(jie)合(he)(he)的元(yuan)素,主要(yao)是(shi)(shi)氧和氫,這些元(yuan)素是(shi)(shi)由于(yu)未完全炭(tan)(tan)化(hua)(hua)而殘留在(zai)炭(tan)(tan)中,或(huo)者在(zai)活化(hua)(hua)過程中,外(wai)來的非碳元(yuan)素與活性(xing)炭(tan)(tan)表面化(hua)(hua)學(xue)(xue)結(jie)合(he)(he),如(ru)用水蒸氣活化(hua)(hua)時,活性(xing)炭(tan)(tan)表面被氧化(hua)(hua)或(huo)水蒸氣氧化(hua)(hua);另一(yi)類摻和物是(shi)(shi)灰分(fen),它(ta)是(shi)(shi)活性(xing)炭(tan)(tan)的無機部分(fen)。
活(huo)性(xing)(xing)炭(tan)的(de)(de)(de)(de)主要(yao)原料(liao)幾乎可以(yi)是所有(you)(you)富含碳的(de)(de)(de)(de)有(you)(you)機材料(liao),如煤、木材、果殼、椰殼、核桃殼、杏殼、棗殼等。這些含碳材料(liao)在(zai)(zai)活(huo)化爐中,在(zai)(zai)高(gao)溫和一(yi)定壓力下(xia)通過(guo)熱解作(zuo)(zuo)用被轉換成活(huo)性(xing)(xing)炭(tan)。在(zai)(zai)此活(huo)化過(guo)程中,巨(ju)大的(de)(de)(de)(de)表(biao)面(mian)積和復雜的(de)(de)(de)(de)孔(kong)(kong)隙(xi)(xi)結構(gou)逐漸形成, 而所謂的(de)(de)(de)(de)吸附過(guo)程正是在(zai)(zai)這些孔(kong)(kong)隙(xi)(xi)中和表(biao)面(mian)上進(jin)行(xing)的(de)(de)(de)(de),活(huo)性(xing)(xing)炭(tan)中孔(kong)(kong)隙(xi)(xi)的(de)(de)(de)(de)大小對吸附質(zhi)有(you)(you)選擇吸附的(de)(de)(de)(de)作(zuo)(zuo)用,這是由于大分子不能(neng)進(jin)入(ru)比它孔(kong)(kong)隙(xi)(xi)小的(de)(de)(de)(de)活(huo)性(xing)(xing)炭(tan)孔(kong)(kong)徑(jing)內的(de)(de)(de)(de)緣故。活(huo)性(xing)(xing)炭(tan)是由含炭(tan)為主的(de)(de)(de)(de)物(wu)質(zhi)作(zuo)(zuo)原料(liao),經高(gao)溫炭(tan)化和活(huo)化制得的(de)(de)(de)(de)疏水性(xing)(xing)吸附劑。活(huo)性(xing)(xing)炭(tan)含有(you)(you)大量微孔(kong)(kong),具有(you)(you)巨(ju)大無(wu)比的(de)(de)(de)(de)表(biao)面(mian)積,能(neng)有(you)(you)效(xiao)地去(qu)除色度、臭味,可去(qu)除二(er)級出水中大多數有(you)(you)機污(wu)染物(wu)和某些無(wu)機物(wu),包(bao)含某些有(you)(you)毒的(de)(de)(de)(de)重(zhong)金屬。