Kev kho dej khib nyiab yog qhov tseem ceeb ntawm kev txhim kho hauv nroog, cuam tshuam rau pej xeem kev noj qab haus huv- thiab kev txhim kho tib neeg kom ruaj khov. Nws yog ib qho kev xav tau ntawm ib puag ncig, lub hauv paus rau dej zoo, thiab tus yuam sij rau kev siv dej khib nyiab. Tam sim no, cov dej khib nyiab tau sau los ntawm cov kav dej hauv nroog (suav ua ke lossis cais) thiab tso tawm mus rau cov chaw kho dej khib nyiab. Cov nroj tsuag no tom qab ntawd ua kev kho mob tertiary kom ua tau raws li cov qauv kev tso tawm hauv lub tebchaws ua ntej tso tawm mus rau hauv cov dej reservoirs raug xaiv. Cov dej rov qab tau raug thauj mus rau qhov chaw ntsuab thiab cov dej ntws los ntawm cov dej siv rov qab, ua tiav cov dej khib nyiab ntau dua.
Kev kho dej khib nyiab Tertiary yog cov txheej txheem kho dej khib nyiab tiav uas txuas nrog thiab nce qib kev kho thawj zaug thiab theem nrab. Cov chaw kho dej khib nyiab sib txawv hauv cheeb tsam sib txawv xaiv cov kev kho mob sib txawv raws li cov kev cai hauv cheeb tsam ib puag ncig thiab kev npaj siv. Ua ntej, kev kho thawj zaug siv cov tshuaj ntxhib thiab zoo tshem tawm cov khib nyiab loj, cov khib nyiab, thiab lwm yam. Tom qab ntawd, grit chambers cais cov khoom loj loj xws li xuab zeb thiab gravel, ua raws li lub hauv paus sedimentation tank los daws cov khoom tshem tawm. Feem ntau cov khib nyiab thiab impurities raug tshem tawm, tab sis theem no feem ntau yog siv txoj kev kho lub cev, tawm hauv cov organic teeb meem thiab lwm yam impurities uas tsis tuaj yeem tawm ncaj qha mus rau ib puag ncig thiab xav tau kev kho mob ntxiv.
Kev kho mob thib ob feem ntau suav nrog cov txheej txheem lom neeg, siv cov cuab yeej siv hluav taws xob siv hluav taws xob thiab cov txheej txheem biofilm, ua ke nrog cov tso tsheb hlau luam thib ob rau cov khoom sib cais -kua kua, tshem tawm biodegradable organic teeb meem los ntawm cov dej khib nyiab. Tom qab theem no, feem ntau tshem tawm cov khib nyiab thiab cov organic teeb meem hauv cov dej tuaj yeem raug tshem tawm, nrog rau cov ntsiab lus nitrogen thiab phosphorus txo qis dua 30%, qhov tseem ceeb ua tau raws li cov qauv B tso tawm rau hauv nroog thawj qhov chaw kho dej khib nyiab. Ntau qhov chaw kho dej khib nyiab tau nruab nrog qhov kev teeb tsa no. Txawm li cas los xij, nyob rau xyoo tas los no, nrog cov kev cai tiv thaiv ib puag ncig nruj zuj zus, qhov kev kho dej khib nyiab no tsis txaus, yuav tsum tau kho ntau dua.
Tertiary kev kho mob yog qhov kev kho mob siab tshaj ntawm cov dej khib nyiab, siv txoj hauv kev zoo sib xyaw ua ke ntawm lub cev, tshuaj, thiab cov txheej txheem lom neeg kom tshem tawm cov impurities xws li nitrogen thiab phosphorus, cov hlau hnyav, thiab cov kab mob pathogenic uas tuaj yeem ua rau eutrophication. Tam sim no, feem ntau cov chaw kho dej khib nyiab feem ntau siv thev naus laus zis xws li nitrogen thiab phosphorus tshem tawm, sib sib zog nqus pom, thiab tshuaj tua kab mob. Cov dej kho thib ob yog tawm mus rau hauv denitrification thiab nitrification lim rau kev tshem tawm nitrogen, tom qab ntawd mus rau hauv phosphorus tshem tawm tso tsheb hlau luam qhov chaw tshuaj reagents xws li PAC thiab PFS ntxiv rau kev tshem tawm phosphorus, tom qab ntawd mus rau hauv cov dej tob tob kom lim tawm cov khib nyiab me me, thiab thaum kawg muab tshuaj tua kab mob chlorine dioxide los yog ultraviolet.
