低(di)濃(nong)(nong)度(du)(du)生(sheng)(sheng)活污(wu)(wu)水(shui)(shui)會影(ying)響(xiang)微生(sheng)(sheng)物的生(sheng)(sheng)長和(he)繁(fan)殖。活性(xing)(xing)(xing)污(wu)(wu)泥(ni)(ni)長期處(chu)于(yu)(yu)饑餓狀態，將導(dao)致(zhi)(zhi)微生(sheng)(sheng)物的活性(xing)(xing)(xing)下(xia)(xia)降，甚(shen)至因微生(sheng)(sheng)物的內(nei)源呼(hu)吸作用，反(fan)應(ying)器內(nei)活性(xing)(xing)(xing)污(wu)(wu)泥(ni)(ni)出現負增長。2) 低(di)濃(nong)(nong)度(du)(du)生(sheng)(sheng)活污(wu)(wu)水(shui)(shui)會影(ying)響(xiang)污(wu)(wu)水(shui)(shui)廠(chang)二級生(sheng)(sheng)物處(chu)理工藝的脫氮除(chu)磷效果。反(fan)硝化(hua)(hua)和(he)生(sheng)(sheng)物除(chu)磷均需(xu)有(you)機(ji)碳源，因低(di)濃(nong)(nong)度(du)(du)生(sheng)(sheng)活污(wu)(wu)水(shui)(shui)中可(ke)被微生(sheng)(sheng)物利用的有(you)機(ji)碳源較少，反(fan)硝化(hua)(hua)菌和(he)聚磷菌對有(you)機(ji)碳源的競爭更(geng)加(jia)激烈，往往導(dao)致(zhi)(zhi)出水(shui)(shui) TN 和(he) TP 無法達標(biao)。解決出水(shui)(shui) TP 超(chao)標(biao)的問題(ti)尚可(ke)通(tong)過輔助化(hua)(hua)學除(chu)磷的方(fang)式，但要實現出水(shui)(shui) TN 達標(biao)不(bu)易(yi)(yi)，有(you)時甚(shen)至NH+-N 也無法滿足排放標(biao)準。3) 低(di)濃(nong)(nong)度(du)(du)生(sheng)(sheng)活污(wu)(wu)水(shui)(shui)容(rong)易(yi)(yi)導(dao)致(zhi)(zhi)污(wu)(wu)泥(ni)(ni)膨脹。有(you)機(ji)物濃(nong)(nong)度(du)(du)較低(di)的條件下(xia)(xia)，菌膠團的生(sheng)(sheng)長速(su)(su)率(lv)低(di)于(yu)(yu)絲狀菌的生(sheng)(sheng)長速(su)(su)率(lv)，此時傳統活性(xing)(xing)(xing)污(wu)(wu)泥(ni)(ni)法容(rong)易(yi)(yi)發(fa)生(sheng)(sheng)污(wu)(wu)泥(ni)(ni)膨脹，使出水(shui)(shui)水(shui)(shui)質惡(e)化(hua)(hua)。

　　低濃(nong)度(du)生活污(wu)水的(de)成因是多方面的(de)，可歸結為兩大類: 1) 有機(ji)污(wu)染物濃(nong)度(du)較低的(de)水進入污(wu)水管道，起到了一定的(de)稀釋作用。