Ntau tus neeg ua haujlwm hauv kev kho dej khib nyiab muaj qhov kev xav: "Cov kab mob microorganisms yog lub zog tseem ceeb, yog li ntau cov sludge txhais tau tias muaj peev xwm kho tau zoo dua." Qhov no zoo li tsim nyog, tab sis hauv kev ua haujlwm tiag tiag, qhov no feem ntau ua rau muaj teeb meem.
Cov neeg uas tau koom nrog hauv - qhov chaw ua haujlwm tau zoo yuav pom qhov xwm txheej no: hloov pauv cov dej ntws tawm, qee zaus ammonia nitrogen tshaj cov qauv, thiab tus neeg teb xov tooj thawj cov tshuaj tiv thaiv yog "tsis txaus sludge concentration," ua rau txo qis lossis txawm tias tsis muaj sludge tawm. MLSS maj mam nce los ntawm 3000 mus rau 4000, 5000, thiab 6000 mg / L.
Qhov txawv, thaum cov sludge concentration ntau dua daws qhov teeb meem, nws tsim cov teeb meem tshiab -sludge overflows los ntawm lub thib ob sedimentation tank, SS effluent tshaj cov qauv, lub blower zaus twb nyob rau hauv siab tshaj plaws, thiab DO nyob rau hauv lub aerobic tank yuav tsis tau nce.
Yog li qhov teeb meem nyob qhov twg?
Kev sib raug zoo ntawm sludge concentration thiab system muaj peev xwm tsis yog ib qho linear, tab sis yog parabola.
Oxygen Supply Bottleneck: Lub "Mail Kawg" ntawm Kev Hloov Pa oxygen
Ua ntej, xav txog aeration: Rau txhua txhua 1000 mg / L nce hauv sludge concentration, oxygen noj tus nqi hauv lub tank spikes. Ua kom cov metabolism hauv ib hnub ntawm 1 kg ntawm cov activated sludge yuav tsum kwv yees li 0.8-1.2 kg ntawm oxygen. Thaum MLSS nce los ntawm 3000 txog 5000, tag nrho cov biomass nyob rau hauv lub tank nce ze li ntawm 70%, ua rau muaj kev nce rau tag nrho cov pa oxygen xav tau.
Ib qho teeb meem tob dua nyob rau hauv cov kev txwv ntawm kev hloov oxygen ntawm microscale. Thaum MLSS tshaj ib qho nqi, qhov loj me thiab qhov ceev ntawm cov sludge flocs nce ntau. Qhov no ua rau cov pa oxygen hloov mus rau qhov nce ntxiv, tsim qhov "mile kawg" teeb meem ntawm kev hloov pauv oxygen yaj.
Nyob rau ntawm lub sijhawm no, txawm hais tias DO hauv lub tank aerobic yuav nyob twj ywm ntawm 2.0-3.0 mg / L, kwv yees li 60% ntawm qhov ntim hauv flocs tuaj yeem nyob rau hauv lub xeev ntawm anoxic mob. Cov kab mob Nitrifying zoo li cov neeg nyob hauv qhov nyem rau hauv "chaw tsis muaj qhov rai hauv tsev," qhov twg oxygen tau noj los ntawm cov kab mob heterotrophic sab nrauv ua ntej mus txog lawv thaj chaw. DO (Dissolved Organic Carbon) kev siv tus nqi poob qis, kev ua haujlwm ntawm cov kab mob nitrifying yog suppressed, thiab ammonia nitrogen pib nce. Nyob rau tib lub sijhawm, qhov chaw nyob ib puag ncig anoxic ua rau nws yooj yim dua rau cov kab mob filamentous kom proliferate, loosening cov sludge qauv thiab deteriorating settling kev ua tau zoo.
Kev Txiav Txim Siab: Qhov "Overload" Crisis ntawm Secondary Settling Tank
Saib ntawm lub tank thib ob: qhov siab dua cov sludge concentration, cov teeb meem ntau dua nkag mus rau hauv lub tank thib ob. Qhov chaw thau khoom tsim tus nqi rau qhov nruab nrab qhov chaw tso dej tank nrog lub hauv nruab nrab thiab qhov hluav taws xob ib puag ncig yog 0.8 ~ 1.2 m³ / m²·h, thiab cov khoom khib nyiab feem ntau yog tswj ntawm 4 ~ 6 kg / m²·h.
Ib qho kev nce ntxiv hauv MLSS (Mixed Liquor Suspended Solids) yuav ncaj qha ua rau muaj kev nce ntxiv hauv cov khib nyiab thauj khoom ntawm lub tank thib ob, tshaj nws cov peev txheej tsim. Thaum overloaded, cov sludge - dej sib cais cov nyhuv tsis muaj zog, lub supernatant yuav turbid, thiab cov SS sluent tshaj tus qauv. Qee lub sij hawm, ib txheej ntawm cov sludge zoo ntab rau ntawm tag nrho saum npoo ntawm lub tank thib ob, thiab kho qhov rov qab ntws piv tsis zoo. Muaj ntau cov effluent tshem tawm cov khib nyiab ntau tshaj tus qauv tsis yog hauv paus hauv kev kho kab mob lom, tab sis yog nyob rau hauv cov sludge concentration tshaj qhov tsim peev xwm ntawm lub tank thib ob.
Lub Hnub Nyoog Tsis Txaus Siab: Qhov "Kev Laus" Nrauj Tom Qab Kev Ntseeg
Lwm qhov yooj yim saib xyuas yog sludge hnub nyoog. Nrog rau qhov ntim tas li sludge tawm, nce MLSS yuav ua rau lub hnub nyoog sludge lengthen.
Lub hnub nyoog sludge ntau dhau ua rau sludge aging: cov kab mob nkag mus rau theem endogenous ua pa, ua rau lawv tus kheej siv cov pa oxygen, tab sis lawv cov kev ua haujlwm zoo hauv cov pa phem txo qis. Kev laus sludge flocs ua zoo thiab tawg, nyob qeeb dua thiab yooj yim ploj nrog cov effluent.
Nrhiav qhov "Balance Point": Dynamic Control yog qhov tseem ceeb
Hauv kev xyaum, "kev tsim nyog concentration" yog ib txwm tseem ceeb tshaj li "siab concentration." Tsis muaj ib qho, universally siv tau zoo sludge concentration; kev khiav hauj lwm tsis yuav tsum tau dynamically hloov raws li cov kev khiav hauj lwm tej yam kev mob:
Influent Load: Nyob rau hauv high organic load tej yam kev mob, nruab nrab ntawm cov sludge concentration tuaj yeem cuam tshuam cov dej tsis zoo; nyob rau hauv ntev - lub sij hawm uas tsis muaj zog loads, ntau sludge concentration yuav tsuas ua rau kom kiv cua zog noj thiab ua rau kom lub siab ntawm sludge tawm tu.
Cov Dej Kub Kub: Nyob rau lub caij ntuj no, qhov kub qis txo qis microbial metabolic kev ua si, tso cai rau kev nce nruab nrab ntawm MLSS (Multi{0}}Layer Sludge Solids) biomass kom muaj nitrification. Nyob rau hauv lub caij ntuj sov, dej kub thiab siab dua microbial kev ua ub no txo sludge concentration, txuag aeration zog thiab txo txoj kev pheej hmoo ntawm sludge bulking.
Core Benchmark: Ua kom pom tseeb ntawm F/M (Pib-rau-Microorganism Ratio)
Qhov kev ntseeg siab tshaj plaws rau kev txiav txim siab seb cov sludge concentration yog qhov tsim nyog yog qhov F / M piv (piv- rau- cov kab mob sib kis), es tsis yog tsom rau ib qho MLSS tus nqi.
Rau cov pa dej khib nyiab hauv nroog, qhov tsim nyog F / M ntau yog feem ntau 0.1 ~ 0.2 kg BOD₅ / kg MLSS·d (qee qhov txheej txheem tuaj yeem so qhov no mus rau 0.2 ~ 0.4).
Qhov sib piv F / M qis dua 0.05 qhia tau hais tias ntev - lub sij hawm tsis muaj microbial substrate; kev tshaib kev nqhis tas mus li yuav ua rau sludge aging.
Qhov F / M piv saum toj no 0.4 qhia tias tsis txaus biomass reserves, ua rau cov effluent cuam tshuam rau ntau tshaj cov qauv thaum muaj dej tsis zoo.
Kev hloov kho txhua hnub rau cov sludge tawm tus nqi kom ruaj khov rau cov khoom noj - rau - cov kab mob kab mob kis tau ntau dua li kev ua raws li cov sludge ruaj khov. Ntau qhov zoo- tau tsim cov chaw kho dej khib nyiab dynamically kho lawv cov sludge concentrations raws li tej yam kev mob: ua kom cov concentration nyob rau lub caij ntuj no kom muaj kev kho mob, thiab txo nws nyob rau lub caij ntuj sov kom txuag tau zog thiab tswj sludge bulking. Cov no yog cov kev paub dhau los uas tau sau tseg los ntawm cov neeg ua haujlwm pem hauv ntej tom qab suav tsis txheeb sim thiab ua yuam kev.
Thaum kawg, sludge concentration tsuas yog ib txoj hauv kev kho cov txheej txheem, tsis yog lub hom phiaj kawg ntawm kev ua haujlwm. Qhov peb xav kom ua tiav yog qhov ntev - lub sij hawm system stability, tsis tu ncua ua raws li cov dej ntws tawm, thiab cov nqi khiav lag luam tswj tau.
Ob qho tib si siab dhau thiab qis qis MLSS yog qhov cuam tshuam rau kev ua haujlwm ruaj khov. Qhov zoo tshaj plaws sludge concentration yog ib qho uas tswj tus nqi ntws (F / M) nyob rau hauv qhov tsim nyog, ua kom ruaj khov thiab tswj tau cov pa oxygen (DO), tiv thaiv cov sludge los ntawm cov sedimentation theem nrab, thiab ua tau raws li cov qauv dej zoo. Tus nqi no yuav siab dua lossis qis dua tus nqi tsim qauv, tab sis siab dua yog qhov tsis zoo ib txwm.