Hauv kev kho dej, cov txheej txheem A²O (Anaerobic-Anoxic-Aerobic)), nrog rau nws lub peev xwm zoo tshaj plaws kom tshem tawm nitrogen thiab phosphorus ib txhij, tau dhau los ua qhov kev xaiv tseem ceeb rau cov dej khib nyiab hauv nroog thiab cov chaw kho dej khib nyiab. Txawm li cas los xij, kev paub txog cov txheej txheem no tiag tiag thiab ua tiav qhov zoo tshaj plaws nyob rau hauv "kev ua si daim duab peb sab" ntawm carbon, nitrogen, thiab phosphorus tsis yog ib txoj haujlwm yooj yim.
Kab lus no yuav pib los ntawm lub hauv paus ntawm cov txheej txheem, kev tshuaj xyuas cov ntsiab lus tseem ceeb rau nws cov qauv tsim, thiab muab cov tswv yim daws teeb meem rau cov teeb meem kev ua haujlwm rau kev siv thiab sib pauv ntawm cov npoj yaig.
I. Core of the Process: A "Relay Race" coj los ntawm cov kab mob
Lub ntsiab lus ntawm cov txheej txheem A²O yog los tsim peb qhov chaw sib txawv, tso cai rau cov kab mob uas muaj cov haujlwm tshwj xeeb los "ua lawv lub luag haujlwm," thaum kawg ua kom muaj kev sib koom ua ke ntawm kev tshem tawm cov pa phem. Nws lub zog tsav tsheb tseem ceeb los ntawm ob lub tshuab xa rov qab loj:
Sludge Return: Cov sludge concentrated los ntawm cov sedimentation tank yog thauj rov qab mus rau pem hauv ntej kawg ntawm anaerobic cheeb tsam, uas yog ib qho tseem ceeb los xyuas kom meej txaus "troops" (biomass) rau lub system.
Nitrification cawv recirculation: Cov nitrate - nplua nuj sib tov los ntawm aerobic cheeb tsam yog pumped mus rau pem hauv ntej ntawm lub anoxic cheeb tsam, muab "mos mos txwv" rau cov tshuaj tiv thaiv denitrification.
Nyob rau hauv pem hauv ntej no, peb hom microorganisms tau qhia meej meej lub luag haujlwm:
Anaerobic Zone-"Phosphorus Release Pioneers": Nyob rau hauv nruj me ntsis anaerobic tej yam kev mob (DO <0.2 mg/L), polyphosphate-sau cov kab mob (PAOs) raug yuam kom decompose polyphosphates nyob rau hauv lawv lub cev kom tau txais lub zog thiab absorbs ntau yam ntawm cov volatile FArel fatty acids thaum lub sij hawm volatile fatty acids. dej. Qhov no yog qhov yuav tsum tau ua ua ntej rau cov phosphorus ntau dhau los ntawm cov kab mob aerobic.
Anoxic Zone-"Denitrification Main Force": Cov kab mob denitrifying siv cov pa roj carbon monoxide hauv cov dej nyoos ua cov khoom siv hluav taws xob los txo cov nitrate nitrogen hauv cov cawv rov qab rau cov roj nitrogen, uas tawm mus rau hauv qhov chaw, ua kom tiav denitrification.
Aerobic Zone-"Txhua-Round Terminator": Qhov no yog qhov kawg ntawm kev sib ntaus sib tua ntawm cov tshuaj tiv thaiv. Nitrifying kab mob oxidize ammonia nitrogen rau nitrate nitrogen; polyphosphate- khaws cov kab mob, ntawm qhov tod tes, dhau- nqus phosphates los ntawm dej, ua kom siab -phosphorus sludge; tib lub sijhawm, cov kab mob aerobic heterotrophic ua kom puas BOD tag nrho.
II. Cov ntsiab lus tseem ceeb ntawm zoning tsim: Cov ntsiab lus txiav txim siab ua tiav
1. Anaerobic Zone: Tiv thaiv qhov ntshiab "Nqus Zone"
Lub hom phiaj tseem ceeb: Ua kom muaj txiaj ntsig zoo ntawm phosphorus tso tawm los ntawm polyphosphate- khaws cov kab mob, txhim kho lub peev xwm rau kev tshem tawm phosphorus tom ntej.
HRT (Hydraulic Retention Time): Feem ntau tswj tau ntawm 1-2 teev. Lub sijhawm luv dhau ua rau tsis txaus phosphorus tso tawm; Lub sijhawm ntev dhau los yooj yim ua rau sludge fermentation thiab roj ntau lawm, ua rau sludge ntab.
Kev Tswj Ib puag ncig: DO yuav tsum qis dua 0.2 mg / L. Ib qho qis - ceev agitator yuav tsum tau siv, ua haujlwm tsuas yog ncua kev ua haujlwm; aeration yog txwv tsis pub. Lub tank yuav tsum tau npog los yog kaw kom tsis txhob nto reoxygenation los ntawm kev cuam tshuam qhov chaw anaerobic.
2. Anoxic Cheeb Tsam: Ib qho Precisely Control "Denitrification Reactor"
Lub hom phiaj tseem ceeb: tshem tawm cov nitrogen kom zoo thiab haus qee cov organic teeb meem kom txo tau cov khoom aerobic.
HRT thiab Carbon Source: Feem ntau tsim rau 2-4 teev, lub sijhawm tshwj xeeb yuav tsum tau kuaj xyuas raws li qhov muaj txiaj ntsig C / N piv (carbon-nitrogen ratio) thiab dej kub. Thaum cov pa roj carbon muaj txiaj ntsig tsis txaus los txhawb kev denitrification, nws yuav tsum xav txog kev ntxiv sodium acetate lossis methanol los ntxiv cov pa roj carbon.
Internal Recirculation Ratio (R): Qhov no yog ib qho tseem ceeb parameter txiav txim siab cov nitrogen tshem tawm efficiency. Tus nqi tsim feem ntau yog 100% ~ 300%, thiab tus nqi tshwj xeeb yuav tsum tau suav kom raug raws li lub hom phiaj tag nrho nitrogen (TN) tshem tawm tus nqi. Tsis txhob ua qhov muag tsis pom kev ua kom muaj qhov sib npaug ntau dhau (tsis li ntawd, nws yuav ua rau kom muaj zog noj thiab nqa ntau dhau DO).
3. Aerobic Zone: Lub "Main Battlefield" ntawm Nitrification thiab Phosphorus Uptake
Lub hom phiaj tseem ceeb: Ua kom tiav cov tshuaj tiv thaiv nitrification, degrade BOD, thiab ua tiav superphosphate uptake los ntawm polyphosphate- cov kab mob sib sau.
HRT thiab DO: Thaj chaw no muaj lub sijhawm nyob ntev tshaj plaws, feem ntau yog 4-8 teev. Dissolved oxygen (DO) yuav tsum khaws cia ntawm 2.0 ~ 3.0 mg / L. Tsis tshua muaj DO yuav txwv tsis pub cov kab mob nitrifying, thaum siab dhau DO yuav ua rau lub cev rov ua haujlwm sab hauv kom nqa cov pa oxygen ntau ntau, cuam tshuam qhov chaw anoxic / anaerobic nyob rau pem hauv ntej kawg.
Sludge Retention Time (SRT): Qhov no yog cov hlab ntshav ntawm tag nrho cov kab ke. Txhawm rau kom muaj txiaj ntsig zoo ntawm cov kab mob nitrifying (ntev lub voj voog ntev), SRT feem ntau xav tau 10-15 hnub lossis ntau dua (ntxiv txuas ntxiv ntawm qhov kub thiab txias). Txawm li cas los xij, qhov tsis sib haum xeeb nyob rau hauv qhov tseeb tias phosphorus tsub zuj zuj los ntawm cov kab mob polyphosphate (PAP) tso siab rau kev tshem tawm cov sludge, yuav tsum tau siv sijhawm luv dua sludge. Qhov zoo tshaj qhov sib npaug ntawm qhov no yuav tsum pom thaum lub sij hawm tsim qauv.
III. Key Design Parameters (Ib qho -Stop Solution)
Nutrient Ratio: Qhov zoo tshaj plaws influent BOD₅ : TN : TP ratio yuav tsum yog 100 : (20-25): (1-5). Cov pa roj carbon monoxide yog cov "khoom noj" rau kev tshem tawm nitrogen thiab phosphorus; thaum qhov piv tsis sib npaug, ob txoj kev yuav sib tw hnyav.
MLSS Concentration: Tus nqi tsim qauv yog khaws cia ntawm 2500-4000 mg / L.
Sludge Return Ratio: Feem ntau yog teem rau ntawm 50% -100%, siv los tswj qhov system concentration thiab kho lub sijhawm khaws cia hauv thaj chaw anaerobic.
Dej Kub thiab pH: Nitrification yog kub -sensitive; Tus nqi txo qis qis dua 15 degree. Cov pH hauv thaj chaw aerobic yuav tsum tau tswj xyuas ntawm 7.0 thiab 8.0. Nitrification siv alkalinity; Yog tias pH tsawg dhau, sodium carbonate lossis cov khoom siv zoo sib xws yog xav tau.
IV. Kev Tswj Xyuas Kev Ua Haujlwm: Kev kos duab ntawm Dynamic Optimization
Carbon Source Addition Strategy: Ua ntej ntxiv cov pa roj carbon monoxide rau thaj tsam anaerobic kom ntseeg tau tias phosphorus tso tawm los ntawm polyphosphate- cov kab mob sib sau ua ke (PAOs). Yog tias tag nrho cov nitrogen tshem tawm siab siab, xav txog ntxiv cov pa roj carbon monoxide rau thaj tsam anoxic.
Intelligent Internal Recirculation Adjustment: Lub recirculation ratio yuav tsum tau dynamically hloov raws li cov nitrate concentration ntawm lub anoxic cheeb tsam qhov hluav taws xob kom tsis txhob ntau recirculation ua rau lub zog pov tseg thiab yaj oxygen (DO) cuam tshuam.
Precise Sludge Discharge: Tshem tawm cov sludge ntau dhau yog tib txoj hauv kev kom tshem tawm phosphorus. Lub sludge paug taw tes yog pom zoo kom nyob rau hauv qhov kawg ntawm aerobic cheeb tsam, qhov twg cov intracellular polyphosphate ntsiab lus ntawm PAOs yog siab tshaj. Los ntawm kev kho cov sludge paug tus nqi, qhov sib npaug ntawm qhov ntev nitrification (ntev) thiab luv phosphorus tshem tawm (luv luv) lub sij hawm rau phosphorus tshem tawm (SRT) tuaj yeem ua tiav.
V. Cov ntsiab lus mob thiab kev daws teeb meem
Qhov "Sludge Age Dispute" Ntawm Nitrogen thiab Phosphorus Tshem Tawm
Phenomenon: Nitrification yuav tsum muaj lub hnub nyoog sludge ntev, thaum tshem tawm phosphorus cia siab rau cov hnub nyoog luv luv rau kev tso tawm.
Kev daws: Ua tib zoo tswj lub hnub nyoog sludge nyob rau hauv qhov nqaim uas tso cai rau ob leeg ua tiav; los yog txo qhov kev tsis sib haum xeeb ncaj qha los ntawm kev txhim kho cov txheej txheem (xws li inverted A²O, ntxiv ib qho ua ntej -anoxic zone).
"Kev tshaib kev nqhis" ntawm Carbon Sources
Phenomenon: Nrog rau cov pa roj carbon tsawg tsawg, cov kab mob denitrifying thiab polyphosphate- cov kab mob sib xyaw ua ke sib tw rau "khoom noj" hauv thaj chaw anaerobic/anoxic.
Kev daws: Optimize lub hydraulic zoning ntim; txais yuav cov txheej txheem A²O inverted (prepositioning thaj tsam anoxic rau qhov tseem ceeb ntawm cov khoom siv denitrification carbon), los yog siv qhov tseeb, tsom ntxiv ntawm cov khoom siv sab nraud.
Qhov "Floating Sludge Crisis" hauv Secondary Settling Tank
Ua rau: Tsis tiav denitrification ua rau cov seem nitrogen nqa sludge mus rau saum npoo hauv lub tank thib ob.
Kev daws: Tshawb xyuas thiab txhim kho cov nyhuv denitrification hauv thaj chaw anoxic, lossis tsim nyog nce cov sludge rov qab los ua kom lub sijhawm khaws cov sludge hauv lub tank thib ob.
Kev daws teeb meem rau "Kev Ua Haujlwm Lub Caij Ntuj Sov" ntawm Cov Kub Kub: Ua kom lub cev muaj zog MLSS thiab tsim nyog txuas ntxiv HRT; nyob rau hauv siab - cheeb tsam latitude, nws yog ib qho tsim nyog yuav tau xav txog cov txheej txheem insulating los yog cua sov lub zog. Xaus: Mastering cov txheej txheem A²O yog qhov tseem ceeb ntawm kev tswj hwm ntawm microbial ecosystem. Los ntawm qhov ntsuas ntsuas hauv theem tsim mus rau kev hloov pauv hloov pauv thaum lub sijhawm ua haujlwm, tsuas yog kev nkag siab tob txog cov txheej txheem biochemical ntawm txhua kauj ruam tuaj yeem ua kom ruaj khov thiab ntev - lub sijhawm nce mus rau kev ua tiav cov dej ntws tawm.