在(zai)用多孔(kong)性固體(ti)物(wu)質(zhi)處理流體(ti)混(hun)合物(wu)時,流體(ti)中的(de)某一組(zu)分或某些組(zu)分可被吸(xi)表(biao)面并(bing)濃(nong)集其上,此現象(xiang)稱為吸(xi)附。吸(xi)附處理廢氣(qi)(qi)時,吸(xi)附的(de)對象(xiang)是氣(qi)(qi)態(tai)污(wu)染物(wu),氣(qi)(qi)固吸(xi)附。被吸(xi)附的(de)氣(qi)(qi)體(ti)組(zu)分稱為吸(xi)附質(zhi),多孔(kong)固體(ti)物(wu)質(zhi)稱為吸(xi)附劑。
固體表(biao)面(mian)吸(xi)(xi)(xi)(xi)(xi)附(fu)(fu)(fu)(fu)了吸(xi)(xi)(xi)(xi)(xi)附(fu)(fu)(fu)(fu)質(zhi)(zhi)后,一部被吸(xi)(xi)(xi)(xi)(xi)附(fu)(fu)(fu)(fu)的(de)吸(xi)(xi)(xi)(xi)(xi)附(fu)(fu)(fu)(fu)質(zhi)(zhi)可從吸(xi)(xi)(xi)(xi)(xi)附(fu)(fu)(fu)(fu)劑表(biao)面(mian)脫(tuo)離,此(ci)現附(fu)(fu)(fu)(fu)。而當吸(xi)(xi)(xi)(xi)(xi)附(fu)(fu)(fu)(fu)進(jin)行一段時間后,由于(yu)表(biao)面(mian)吸(xi)(xi)(xi)(xi)(xi)附(fu)(fu)(fu)(fu)質(zhi)(zhi)的(de)濃集(ji),使(shi)其吸(xi)(xi)(xi)(xi)(xi)附(fu)(fu)(fu)(fu)能(neng)力明顯下(xia)降而吸(xi)(xi)(xi)(xi)(xi)附(fu)(fu)(fu)(fu)凈化的(de)要(yao)(yao)求,此(ci)時需要(yao)(yao)采用(yong)一定(ding)的(de)措(cuo)施使(shi)吸(xi)(xi)(xi)(xi)(xi)附(fu)(fu)(fu)(fu)劑上(shang)已(yi)吸(xi)(xi)(xi)(xi)(xi)附(fu)(fu)(fu)(fu)的(de)吸(xi)(xi)(xi)(xi)(xi)附(fu)(fu)(fu)(fu)質(zhi)(zhi)脫(tuo)附(fu)(fu)(fu)(fu),以協的(de)吸(xi)(xi)(xi)(xi)(xi)附(fu)(fu)(fu)(fu)能(neng)力,這個過程稱為吸(xi)(xi)(xi)(xi)(xi)附(fu)(fu)(fu)(fu)劑的(de)再(zai)(zai)生。因此(ci)在實(shi)際吸(xi)(xi)(xi)(xi)(xi)附(fu)(fu)(fu)(fu)工程中(zhong),正是(shi)利用(yong)吸(xi)(xi)(xi)(xi)(xi)附(fu)(fu)(fu)(fu)一再(zai)(zai)生一再(zai)(zai)吸(xi)(xi)(xi)(xi)(xi)附(fu)(fu)(fu)(fu)的(de)循環過程,達到除去廢氣中(zhong)污染物(wu)質(zhi)(zhi)并回收(shou)廢氣中(zhong)有用(yong)組分。