城市污水(shui)按來(lai)源可分為生活污水(shui)、工業廢水(shui)和徑流(liu)污水(shui)。

生活污水

生活污水主(zhu)(zhu)要(yao)來自家(jia)庭(ting)、機關、商業和城(cheng)市公用設施。其(qi)中主(zhu)(zhu)要(yao)是糞便和洗滌污水，集中排入城(cheng)市下水道管網系統，輸送至污水處(chu)理(li)(li)廠(chang)進(jin)行處(chu)理(li)(li)后排放。其(qi)水量水質(zhi)明顯(xian)具(ju)有晝夜(ye)周期(qi)(qi)性(xing)和季(ji)節周期(qi)(qi)變化的特點。

工業廢水

工(gong)(gong)(gong)業(ye)(ye)廢水(shui)(shui)(shui)在城市污(wu)(wu)水(shui)(shui)(shui)中(zhong)的比(bi)重，因城市工(gong)(gong)(gong)業(ye)(ye)生(sheng)(sheng)產規模和水(shui)(shui)(shui)平而(er)不同，可從百分之幾(ji)到(dao)百分之幾(ji)十。其(qi)中(zhong)往往含有(you)腐(fu)蝕性、有(you)毒、有(you)害、難以生(sheng)(sheng)物(wu)降解的污(wu)(wu)染物(wu)。因此,工(gong)(gong)(gong)業(ye)(ye)廢水(shui)(shui)(shui)必須進行處(chu)理(li)，達到(dao)一定(ding)標準后方(fang)能排入生(sheng)(sheng)活污(wu)(wu)水(shui)(shui)(shui)系(xi)統(tong)。生(sheng)(sheng)活污(wu)(wu)水(shui)(shui)(shui)和工(gong)(gong)(gong)業(ye)(ye)廢水(shui)(shui)(shui)的水(shui)(shui)(shui)量(liang)以及兩者的比(bi)例決定(ding)著城市污(wu)(wu)水(shui)(shui)(shui)處(chu)理(li)的方(fang)法、技術(shu)和處(chu)理(li)程度。

城市徑(jing)流(liu)污水

城市(shi)(shi)徑流污(wu)(wu)水(shui)(shui)是雨雪淋洗城市(shi)(shi)大氣(qi)污(wu)(wu)染(ran)物和(he)沖洗建筑物、地面、廢渣(zha)、垃圾(ji)而形成的。這種污(wu)(wu)水(shui)(shui)具有季節變化和(he)成分復(fu)雜的特點，在降(jiang)雨初期(qi)所含污(wu)(wu)染(ran)物甚至會高出生(sheng)活污(wu)(wu)水(shui)(shui)多(duo)倍。