活(huo)(huo)性(xing)炭,是(shi)黑(hei)色粉末狀或(huo)塊(kuai)狀、顆粒狀、蜂(feng)窩(wo)狀的(de)無定形碳(tan),也有排列規整的(de)晶(jing)體(ti)碳(tan)。活(huo)(huo)性(xing)炭中(zhong)除碳(tan)元(yuan)(yuan)素外(wai),還包含兩類摻和(he)物(wu):一(yi)類是(shi)化學結合(he)的(de)元(yuan)(yuan)素,主要(yao)是(shi)氧(yang)和(he)氫(qing),這些元(yuan)(yuan)素是(shi)由于(yu)(yu)未完全炭化而殘留在(zai)炭中(zhong),或(huo)者在(zai)活(huo)(huo)化過程中(zhong),外(wai)來的(de)非(fei)碳(tan)元(yuan)(yuan)素與活(huo)(huo)性(xing)炭表面化學結合(he);另(ling)一(yi)類摻和(he)物(wu)是(shi)灰(hui)(hui)分(fen),它是(shi)活(huo)(huo)性(xing)炭的(de)無機部分(fen),灰(hui)(hui)分(fen)在(zai)活(huo)(huo)性(xing)碳(tan)中(zhong)易(yi)造(zao)成二(er)次污染。活(huo)(huo)性(xing)炭由于(yu)(yu)具有較強(qiang)的(de)吸附性(xing),廣泛(fan)應用于(yu)(yu)生產、生活(huo)(huo)中(zhong)。
活(huo)性(xing)(xing)(xing)炭(tan)材料是經(jing)過(guo)加工(gong)(gong)處理所得(de)的(de)(de)(de)無定(ding)形碳,具有(you)很(hen)大(da)的(de)(de)(de)比表(biao)面(mian)積(ji),對氣體(ti)、溶液中(zhong)的(de)(de)(de)無機(ji)或有(you)機(ji)物(wu)質(zhi)及膠體(ti)顆粒等都有(you)良好的(de)(de)(de)吸(xi)附能力。活(huo)性(xing)(xing)(xing)炭(tan)材料主(zhu)要包括活(huo)性(xing)(xing)(xing)炭(tan)(Activated Carbon , A C )和活(huo)性(xing)(xing)(xing)炭(tan)纖維(Activated Carbon Fibers, ACF )等。活(huo)性(xing)(xing)(xing)炭(tan)材料作為(wei)一種(zhong)性(xing)(xing)(xing)能優良的(de)(de)(de)吸(xi)附劑,主(zhu)要是由于其(qi)具有(you)獨(du)特(te)的(de)(de)(de)吸(xi)附表(biao)面(mian)結構(gou)特(te)性(xing)(xing)(xing)和表(biao)面(mian)化(hua)學性(xing)(xing)(xing)能所決定(ding)的(de)(de)(de)。活(huo)性(xing)(xing)(xing)炭(tan)材料的(de)(de)(de)化(hua)學性(xing)(xing)(xing)質(zhi)穩定(ding),機(ji)械強度(du)高,耐酸、耐堿、耐熱,不溶于水與有(you)機(ji)溶劑,可以再生使用,已經(jing)廣(guang)泛地應用于化(hua)工(gong)(gong)、環(huan)保、食品加工(gong)(gong)、冶金、藥物(wu)精制、軍事(shi)化(hua)學防(fang)護(hu)等各個領(ling)域 。目(mu)前,改性(xing)(xing)(xing)活(huo)性(xing)(xing)(xing)炭(tan)材料被(bei)廣(guang)泛用于污(wu)水處理、大(da)氣污(wu)染(ran)防(fang)治等領(ling)域,在(zai)治理環(huan)境污(wu)染(ran)方面(mian)越來(lai)越顯示出其(qi)誘人的(de)(de)(de)美好前景。
活(huo)性(xing)(xing)(xing)(xing)炭(tan)(tan)80%-90%以上由(you)碳(tan)元(yuan)素(su)組(zu)成,這也是(shi)(shi)活(huo)性(xing)(xing)(xing)(xing)炭(tan)(tan)為疏水(shui)性(xing)(xing)(xing)(xing)吸附(fu)劑的(de)原因。除了碳(tan)元(yuan)素(su)外,還包含有兩類摻(chan)和物(wu):一類是(shi)(shi)化(hua)(hua)學(xue)結合(he)(he)的(de)元(yuan)素(su),主要是(shi)(shi)氧(yang)和氫,這些元(yuan)素(su)是(shi)(shi)由(you)于未完全炭(tan)(tan)化(hua)(hua)而殘留在炭(tan)(tan)中(zhong),或者(zhe)在活(huo)化(hua)(hua)過程中(zhong),外來的(de)非碳(tan)元(yuan)素(su)與(yu)活(huo)性(xing)(xing)(xing)(xing)炭(tan)(tan)表(biao)面(mian)(mian)化(hua)(hua)學(xue)結合(he)(he),如用水(shui)蒸氣活(huo)化(hua)(hua)時,活(huo)性(xing)(xing)(xing)(xing)炭(tan)(tan)表(biao)面(mian)(mian)被氧(yang)化(hua)(hua)或水(shui)蒸氣氧(yang)化(hua)(hua);另一類摻(chan)和物(wu)是(shi)(shi)灰分,它是(shi)(shi)活(huo)性(xing)(xing)(xing)(xing)炭(tan)(tan)的(de)無機部分。
活性(xing)炭(tan)(tan)的(de)(de)(de)主要原料(liao)幾乎(hu)可(ke)以是所有(you)(you)(you)富含(han)碳(tan)的(de)(de)(de)有(you)(you)(you)機材(cai)料(liao),如煤、木材(cai)、果殼(ke)、椰殼(ke)、核桃殼(ke)、杏殼(ke)、棗(zao)殼(ke)等。這(zhe)(zhe)些(xie)(xie)含(han)碳(tan)材(cai)料(liao)在活化爐(lu)中(zhong)(zhong),在高溫和一定壓(ya)力下通過(guo)熱解作用被轉換(huan)成(cheng)活性(xing)炭(tan)(tan)。在此(ci)活化過(guo)程(cheng)中(zhong)(zhong),巨大(da)(da)(da)的(de)(de)(de)表面積(ji)和復(fu)雜的(de)(de)(de)孔(kong)(kong)隙(xi)結構逐(zhu)漸形成(cheng), 而所謂的(de)(de)(de)吸附過(guo)程(cheng)正(zheng)是在這(zhe)(zhe)些(xie)(xie)孔(kong)(kong)隙(xi)中(zhong)(zhong)和表面上進行的(de)(de)(de),活性(xing)炭(tan)(tan)中(zhong)(zhong)孔(kong)(kong)隙(xi)的(de)(de)(de)大(da)(da)(da)小對吸附質有(you)(you)(you)選擇吸附的(de)(de)(de)作用,這(zhe)(zhe)是由(you)于大(da)(da)(da)分子不能進入比(bi)它(ta)孔(kong)(kong)隙(xi)小的(de)(de)(de)活性(xing)炭(tan)(tan)孔(kong)(kong)徑內的(de)(de)(de)緣故。活性(xing)炭(tan)(tan)是由(you)含(han)炭(tan)(tan)為主的(de)(de)(de)物(wu)質作原料(liao),經(jing)高溫炭(tan)(tan)化和活化制(zhi)得的(de)(de)(de)疏水性(xing)吸附劑。活性(xing)炭(tan)(tan)含(han)有(you)(you)(you)大(da)(da)(da)量微(wei)孔(kong)(kong),具有(you)(you)(you)巨大(da)(da)(da)無比(bi)的(de)(de)(de)表面積(ji),能有(you)(you)(you)效地去除色度(du)、臭味(wei),可(ke)去除二級出(chu)水中(zhong)(zhong)大(da)(da)(da)多數有(you)(you)(you)機污染物(wu)和某些(xie)(xie)無機物(wu),包(bao)含(han)某些(xie)(xie)有(you)(you)(you)毒的(de)(de)(de)重(zhong)金(jin)屬。