中(zhong)(zhong)水(shui)(shui)(shui)(shui)(shui)(shui)回(hui)(hui)用(yong)(yong)系(xi)統(tong)是對生活(huo)污(wu)水(shui)(shui)(shui)(shui)(shui)(shui)或工業廢水(shui)(shui)(shui)(shui)(shui)(shui)經過深度技術處理，從(cong)而去除污(wu)水(shui)(shui)(shui)(shui)(shui)(shui)中(zhong)(zhong)各種(zhong)有(you)毒(du)、有(you)害成分(fen)及部分(fen)重金屬分(fen)離分(fen)子，最(zui)終出水(shui)(shui)(shui)(shui)(shui)(shui)進行消毒(du)殺菌，直到水(shui)(shui)(shui)(shui)(shui)(shui)質符合(he)國家規定后，在(zai)重新運(yun)用(yong)(yong)于農業灌溉、景觀用(yong)(yong)水(shui)(shui)(shui)(shui)(shui)(shui)，工業循環(huan)用(yong)(yong)水(shui)(shui)(shui)(shui)(shui)(shui)，地下水(shui)(shui)(shui)(shui)(shui)(shui)回(hui)(hui)罐等非飲用(yong)(yong)途徑。中(zhong)(zhong)水(shui)(shui)(shui)(shui)(shui)(shui)回(hui)(hui)用(yong)(yong)系(xi)統(tong)對現如今水(shui)(shui)(shui)(shui)(shui)(shui)資源越來(lai)越緊(jin)張(zhang)的情況下，可以暫緩用(yong)(yong)水(shui)(shui)(shui)(shui)(shui)(shui)不足的壓(ya)力，帶來(lai)可觀的經濟(ji)利益(yi)，以及很(hen)好的社會效益(yi)。

中(zhong)水(shui)(shui)回用系統(tong)一(yi)(yi)般包括一(yi)(yi)級(ji)處(chu)(chu)理(li)(li)(li)、二(er)級(ji)處(chu)(chu)理(li)(li)(li)和三級(ji)處(chu)(chu)理(li)(li)(li)。初級(ji)處(chu)(chu)理(li)(li)(li)通常是(shi)一(yi)(yi)個格(ge)柵（小孔毛(mao)發收集(ji)器(qi)也用于攔(lan)截大顆粒(li)，如(ru)原水(shui)(shui)中(zhong)的毛(mao)發）和一(yi)(yi)個調(diao)節池，以去除(chu)水(shui)(shui)中(zhong)的大懸浮顆粒(li)和均勻的水(shui)(shui)質，從而保(bao)護后續系統(tong)的正常運行。二(er)級(ji)處(chu)(chu)理(li)(li)(li)是(shi)處(chu)(chu)理(li)(li)(li)原水(shui)(shui)可溶(rong)性污染物的主(zhu)要處(chu)(chu)理(li)(li)(li)設備。深度處(chu)(chu)理(li)(li)(li)主(zhu)要包括過濾和消毒(du)，以確保(bao)污水(shui)(shui)符合標準。

中(zhong)水回用(yong)系統主要(yao)包(bao)括(kuo)生化法、物化法和(he)膜處(chu)(chu)理法。生化法是利用(yong)水中(zhong)的好氧(yang)或厭氧(yang)微(wei)生物來分解(jie)水中(zhong)的有(you)機物。有(you)時它也用(yong)于凈化水質(zhi)。活性污泥法和(he)生物接觸氧(yang)化法是主要(yao)方法。物化法主要(yao)包(bao)括(kuo)混凝沉淀(dian)、過濾、活性炭(tan)吸附(fu)和(he)離子(zi)交換等。主要(yao)處(chu)(chu)理優質(zhi)雜排水。膜處(chu)(chu)理技術一般采用(yong)超濾（微(wei)濾）或反滲透膜處(chu)(chu)理，具有(you)除懸浮物率(lv)高(gao)、占(zhan)地(di)面積(ji)小等優點(dian)，但(dan)成本較高(gao)。目前常用(yong)的是膜生物反應器。處(chu)(chu)理效率(lv)高(gao)，出水水質(zhi)好，設備緊湊，占(zhan)地(di)面積(ji)小，易(yi)于自(zi)動化。