HODM-AO系列污水(shui)(shui)處理設備(bei)去除(chu)有(you)(you)(you)機(ji)物(wu)污染(ran)物(wu)及氨氮主要(yao)(yao)依賴于(yu)設備(bei)中(zhong)(zhong)(zhong)(zhong)的的AO生(sheng)物(wu)工(gong)藝。其中(zhong)(zhong)(zhong)(zhong)工(gong)作(zuo)(zuo)原理是在(zai)(zai)A級(ji)(ji)(ji)，由(you)于(yu)污水(shui)(shui)有(you)(you)(you)機(ji)物(wu)濃度很高，微生(sheng)物(wu)處于(yu)缺氧狀態，此時微生(sheng)物(wu)為(wei)兼性微生(sheng)物(wu)，它們將(jiang)污水(shui)(shui)中(zhong)(zhong)(zhong)(zhong)的有(you)(you)(you)機(ji)氮轉(zhuan)化(hua)(hua)分解(jie)成(cheng)(cheng)NH3-N，同時利用(yong)(yong)有(you)(you)(you)機(ji)碳(tan)作(zuo)(zuo)為(wei)電子供體(ti)，將(jiang)NO2-N、NO3-N轉(zhuan)化(hua)(hua)成(cheng)(cheng)N2，而且(qie)還(huan)利用(yong)(yong)部分有(you)(you)(you)機(ji)碳(tan)源和NH3-N合成(cheng)(cheng)新的細胞物(wu)質.所以A級(ji)(ji)(ji)池(chi)不(bu)僅具有(you)(you)(you)一定(ding)的有(you)(you)(you)機(ji)物(wu)去除(chu)功能，減(jian)輕(qing)后(hou)續好(hao)氧池(chi)的有(you)(you)(you)機(ji)負荷，以利于(yu)硝化(hua)(hua)作(zuo)(zuo)用(yong)(yong)的進(jin)行，而且(qie)依靠(kao)原水(shui)(shui)中(zhong)(zhong)(zhong)(zhong)存在(zai)(zai)的較高濃度有(you)(you)(you)機(ji)物(wu)，完(wan)成(cheng)(cheng)反硝化(hua)(hua)作(zuo)(zuo)用(yong)(yong)，消(xiao)除(chu)氮的富營(ying)養化(hua)(hua)污染(ran).在(zai)(zai)O級(ji)(ji)(ji)，由(you)于(yu)有(you)(you)(you)機(ji)物(wu)濃度已大幅度降低(di)，但仍有(you)(you)(you)一定(ding)量的有(you)(you)(you)機(ji)物(wu)及較高NH3-N存在(zai)(zai).為(wei)了使(shi)有(you)(you)(you)機(ji)物(wu)進(jin)一步氧化(hua)(hua)分解(jie)，同時在(zai)(zai)碳(tan)化(hua)(hua)作(zuo)(zuo)用(yong)(yong)處于(yu)完(wan)成(cheng)(cheng)情況下硝化(hua)(hua)作(zuo)(zuo)用(yong)(yong)能順利進(jin)行，在(zai)(zai)O級(ji)(ji)(ji)設置有(you)(you)(you)機(ji)負荷較低(di)的好(hao)氧生(sheng)物(wu)接(jie)觸氧化(hua)(hua)池(chi).在(zai)(zai)O級(ji)(ji)(ji)池(chi)中(zhong)(zhong)(zhong)(zhong)主要(yao)(yao)存在(zai)(zai)好(hao)氧微生(sheng)物(wu)及自氧型細菌（硝化(hua)(hua)菌）利用(yong)(yong)有(you)(you)(you)機(ji)物(wu)分解(jie)產生(sheng)的無機(ji)碳(tan)或(huo)空氣(qi)中(zhong)(zhong)(zhong)(zhong)的CO2作(zuo)(zuo)為(wei)營(ying)養源，將(jiang)污水(shui)(shui)中(zhong)(zhong)(zhong)(zhong)的NH3-N轉(zhuan)化(hua)(hua)成(cheng)(cheng)NO2-N，NO3-N，O級(ji)(ji)(ji)池(chi)的出水(shui)(shui)部分回流到A級(ji)(ji)(ji)池(chi)，為(wei)A級(ji)(ji)(ji)池(chi)提供電子接(jie)受體(ti)，通(tong)過反硝化(hua)(hua)作(zuo)(zuo)用(yong)(yong)消(xiao)除(chu)氮污染(ran)。