活(huo)(huo)性(xing)(xing)炭(tan),是(shi)黑(hei)色粉末(mo)狀(zhuang)或塊狀(zhuang)、顆粒狀(zhuang)、蜂窩狀(zhuang)的(de)(de)無定形(xing)碳(tan),也有(you)排(pai)列規整的(de)(de)晶體碳(tan)。活(huo)(huo)性(xing)(xing)炭(tan)中(zhong)除碳(tan)元(yuan)素(su)(su)外,還包含兩類摻和物(wu):一類是(shi)化(hua)學結合的(de)(de)元(yuan)素(su)(su),主要(yao)是(shi)氧和氫,這些(xie)元(yuan)素(su)(su)是(shi)由(you)于未完全炭(tan)化(hua)而(er)殘留在(zai)炭(tan)中(zhong),或者在(zai)活(huo)(huo)化(hua)過程中(zhong),外來(lai)的(de)(de)非碳(tan)元(yuan)素(su)(su)與活(huo)(huo)性(xing)(xing)炭(tan)表面化(hua)學結合;另一類摻和物(wu)是(shi)灰分,它是(shi)活(huo)(huo)性(xing)(xing)炭(tan)的(de)(de)無機部分,灰分在(zai)活(huo)(huo)性(xing)(xing)碳(tan)中(zhong)易造成二次(ci)污染。活(huo)(huo)性(xing)(xing)炭(tan)由(you)于具有(you)較強的(de)(de)吸附性(xing)(xing),廣泛(fan)應用(yong)于生(sheng)產、生(sheng)活(huo)(huo)中(zhong)。
活(huo)(huo)性(xing)(xing)炭材料是(shi)經過加(jia)工(gong)處理(li)(li)所得(de)的無定形碳(tan),具(ju)有很大的比表面積,對氣體、溶液中的無機(ji)或有機(ji)物(wu)質及膠體顆粒等(deng)都(dou)有良好的吸附能(neng)力(li)。活(huo)(huo)性(xing)(xing)炭材料主要(yao)包括活(huo)(huo)性(xing)(xing)炭(Activated Carbon , A C )和(he)(he)活(huo)(huo)性(xing)(xing)炭纖(xian)維(Activated Carbon Fibers, ACF )等(deng)。活(huo)(huo)性(xing)(xing)炭材料作為(wei)一種(zhong)性(xing)(xing)能(neng)優良的吸附劑,主要(yao)是(shi)由(you)于其具(ju)有獨(du)特(te)的吸附表面結構特(te)性(xing)(xing)和(he)(he)表面化學性(xing)(xing)能(neng)所決定的。活(huo)(huo)性(xing)(xing)炭材料的化學性(xing)(xing)質穩定,機(ji)械強(qiang)度高,耐酸、耐堿、耐熱(re),不(bu)溶于水(shui)與有機(ji)溶劑,可以再生(sheng)使用(yong),已(yi)經廣(guang)泛地應用(yong)于化工(gong)、環保、食(shi)品加(jia)工(gong)、冶金、藥物(wu)精制、軍事化學防護等(deng)各個(ge)領(ling)域 。目前,改性(xing)(xing)活(huo)(huo)性(xing)(xing)炭材料被廣(guang)泛用(yong)于污(wu)(wu)水(shui)處理(li)(li)、大氣污(wu)(wu)染防治(zhi)(zhi)等(deng)領(ling)域,在治(zhi)(zhi)理(li)(li)環境(jing)污(wu)(wu)染方面越來越顯(xian)示出(chu)其誘(you)人的美好前景。
活(huo)(huo)性(xing)炭80%-90%以上由碳(tan)元素(su)(su)組成,這(zhe)(zhe)也是(shi)(shi)活(huo)(huo)性(xing)炭為疏水(shui)性(xing)吸附劑(ji)的(de)原因。除(chu)了碳(tan)元素(su)(su)外(wai),還包含有兩類(lei)摻和物:一類(lei)是(shi)(shi)化(hua)(hua)(hua)學結合的(de)元素(su)(su),主要是(shi)(shi)氧和氫(qing),這(zhe)(zhe)些元素(su)(su)是(shi)(shi)由于未完全炭化(hua)(hua)(hua)而殘留在(zai)炭中,或者(zhe)在(zai)活(huo)(huo)化(hua)(hua)(hua)過(guo)程中,外(wai)來的(de)非碳(tan)元素(su)(su)與活(huo)(huo)性(xing)炭表面(mian)化(hua)(hua)(hua)學結合,如用水(shui)蒸氣活(huo)(huo)化(hua)(hua)(hua)時,活(huo)(huo)性(xing)炭表面(mian)被氧化(hua)(hua)(hua)或水(shui)蒸氣氧化(hua)(hua)(hua);另一類(lei)摻和物是(shi)(shi)灰分,它是(shi)(shi)活(huo)(huo)性(xing)炭的(de)無(wu)機部分。
活(huo)性(xing)炭的(de)(de)主(zhu)要原料幾(ji)乎可(ke)(ke)以是(shi)(shi)所(suo)有(you)(you)富含(han)碳的(de)(de)有(you)(you)機材料,如煤、木材、果(guo)殼(ke)(ke)、椰殼(ke)(ke)、核桃殼(ke)(ke)、杏殼(ke)(ke)、棗殼(ke)(ke)等。這些(xie)含(han)碳材料在(zai)活(huo)化(hua)(hua)爐中(zhong),在(zai)高溫(wen)和(he)一定壓力下通過(guo)(guo)熱解作(zuo)(zuo)用(yong)(yong)被轉換成活(huo)性(xing)炭。在(zai)此活(huo)化(hua)(hua)過(guo)(guo)程中(zhong),巨(ju)大(da)的(de)(de)表面積(ji)和(he)復(fu)雜(za)的(de)(de)孔(kong)(kong)(kong)隙(xi)結構(gou)逐漸形成, 而所(suo)謂(wei)的(de)(de)吸(xi)附過(guo)(guo)程正是(shi)(shi)在(zai)這些(xie)孔(kong)(kong)(kong)隙(xi)中(zhong)和(he)表面上進(jin)行的(de)(de),活(huo)性(xing)炭中(zhong)孔(kong)(kong)(kong)隙(xi)的(de)(de)大(da)小(xiao)(xiao)對吸(xi)附質(zhi)有(you)(you)選擇(ze)吸(xi)附的(de)(de)作(zuo)(zuo)用(yong)(yong),這是(shi)(shi)由于大(da)分子(zi)不能進(jin)入比它孔(kong)(kong)(kong)隙(xi)小(xiao)(xiao)的(de)(de)活(huo)性(xing)炭孔(kong)(kong)(kong)徑內的(de)(de)緣故。活(huo)性(xing)炭是(shi)(shi)由含(han)炭為主(zhu)的(de)(de)物(wu)質(zhi)作(zuo)(zuo)原料,經高溫(wen)炭化(hua)(hua)和(he)活(huo)化(hua)(hua)制得的(de)(de)疏水性(xing)吸(xi)附劑(ji)。活(huo)性(xing)炭含(han)有(you)(you)大(da)量微孔(kong)(kong)(kong),具(ju)有(you)(you)巨(ju)大(da)無(wu)(wu)比的(de)(de)表面積(ji),能有(you)(you)效地(di)去除(chu)色度、臭味(wei),可(ke)(ke)去除(chu)二級出水中(zhong)大(da)多數有(you)(you)機污染物(wu)和(he)某些(xie)無(wu)(wu)機物(wu),包含(han)某些(xie)有(you)(you)毒的(de)(de)重金(jin)屬。