Tshaj tag nrho cov phosphorus hauv cov dej ntws tawm yog ib qho teeb meem nyuaj tshaj plaws hauv AAO systems. Thaum daws teeb meem, tib neeg feem ntau xav txog: Puas yog cov pa roj carbon txaus txaus? Puas yog cov sludge nyob rau hauv zoo? Yuav tsum tau ntxiv cov tshuaj phosphorus tshem tawm?
Cov lus qhia no yog tag nrho, tab sis muaj ib qho yooj yim overlooked ua rau -ntev - lub sij hawm dhau aeration.
Muaj ib qho kev nkag siab zoo hauv kev lag luam: qhov ntau dua qhov aeration thiab siab dua cov pa oxygen (DO), lub zog aerobic phosphorus uptake, thiab qhov ruaj khov dua cov phosphorus tshem tawm. Qhov no tsis yog qhov tseeb tiag -Aeration ntau dhau tuaj yeem ua rau ntsiag to tsis muaj zog ntawm kev tshem tawm phosphorus lom, ua rau nws yog "tus neeg tua tsis pom." Nws yuav tsis ua rau lub cev qhuav dej tam sim ntawd, tab sis nws yuav maj mam ua kom tsis muaj zog "qhov tseem ceeb" ntawm polyphosphate- cov kab mob sib sau ua ke, nws thiaj li ua rau muaj qhov tsis meej pem tshwj xeeb: ntu anaerobic yog qhov qub, tab sis tag nrho cov phosphorus hauv cov dej ntws txuas ntxiv mus dhau tus qauv.
I. Dab tsi yog qhov kev tshem tawm phosphorus lom?
Cov txheej txheem AAO tso siab rau ib hom kab mob hu ua polyphosphate- khaws cov kab mob kom tshem tawm phosphorus. Lawv ua ob txoj kev hloov pauv nyob rau hauv anaerobic thiab aerobic ib puag ncig:
Qib anaerobic: Polyphosphate- cov kab mob sib sau ua ke (PABs) thawj zaug decompose polyphosphates hauv lawv lub hlwb, tso cov phosphates rau hauv dej thiab tau txais lub zog. Tom qab ntawd lawv siv lub zog no kom nqus tau luv luv - cov roj ntsha fatty acids (xws li acetic acid) los ntawm cov dej khib nyiab, hloov mus rau PHB rau khaws cia.
Aerobic Theem: PPBs decompose PHB hauv lawv lub hlwb kom tau txais lub zog. Tom qab ntawd lawv siv lub zog no los nqus cov phosphates ntau ntawm cov dej, tsim cov polyphosphates thiab khaws cia rau hauv lawv cov hlwb.
Thaum kawg, kev tshem tawm phosphorus yog ua tiav los ntawm kev tshem tawm cov sludge: Phosphorus - nplua nuj PPBs yog nqa tawm ntawm lub cev los ntawm kev tawm ntawm cov sludge ntau dhau, yog li tshem tawm phosphorus los ntawm dej.
Lub ntsiab lus tseem ceeb ntawm tag nrho cov txheej txheem yog qhov tseeb: Tus nqi ntawm PHB synthesized nyob rau hauv lub anaerobic theem ncaj qha txiav txim siab npaum li cas ntawm phosphorus uas yuav absorbed nyob rau hauv lub aerobic theem. Txaus PHB reserves ua rau txaus phosphorus nqus; Tsis txaus PHB reserves txo phosphorus absorption muaj peev xwm.
II. Dab tsi yog kev puas tsuaj los ntawm ntau dhau aeration?
Nyob rau hauv ib txwm aeration tej yam kev mob, yaj oxygen nyob rau hauv lub aerobic tank yog tswj nyob rau hauv ib tug tsim nyog ntau yam. PPBs yuav haus PHB raws li qhov xav tau, ua ntej nws siv rau kev nqus phosphorus, ua rau muaj kev tshem tawm phosphorus ruaj khov.
Txawm li cas los xij, cov teeb meem tshwm sim thaum aeration ntau dhau thiab yaj cov pa oxygen hauv thaj chaw aerobic tseem siab: Thaum cov pa oxygen yaj ntau dhau, polyphosphate- cov kab mob sib txuas (PABs) tsis tsuas yog siv PHB los nqus phosphorus xwb tab sis kuj haus ntau ntawm PHB rau "tswj lawv tus kheej cov metabolism hauv paus." Qhov no yog qhov tshwm sim tsis txaus ntseeg tshaj plaws tau pom ntawm - qhov chaw: phosphorus tso tawm hauv thaj chaw anaerobic yog qhov qub, tab sis tag nrho cov phosphorus hauv cov dej ntws yuav tsis txo qis.
Yog vim li cas tiag tiag tsis nyuaj: cov txheej txheem "khoom noj khoom haus" hauv thaj chaw anaerobic tsis cuam tshuam, tab sis nyob rau hauv thaj chaw aerobic, PHBs ntawm PPAs tau noj ntau dhau, tawm hauv lub zog tsis txaus rau loj - nplai phosphorus nqus. Tsis tuaj yeem nqus phosphorus los ntawm cov dej, qee qhov PPAs tseem yuav tso phosphorus hauv cov txheej txheem thim rov qab, thaum kawg ua rau cov phosphate ntau dhau hauv cov dej ntws tawm.
III. Cov ntaub ntawv tiag tiag: Uncontrolled Aeration, Plummeting Phosphorus Tshem Tawm Ua Haujlwm
Ib txheej ntawm - cov ntaub ntawv ntsuas qhov chaw qhia meej qhia qhov teeb meem: Ntawm qhov chaw kho dej khib nyiab, DO nyob rau pem hauv ntej kawg ntawm lub tank aerobic tau tswj nyob ib ncig ntawm 2 mg / L (hauv qhov tsim nyog), tab sis tsis muaj kev tswj tshwj xeeb ntawm qhov kawg, thiab ntau dhau aeration ua rau DO thaum kawg nce mus txog 5 mg / L.
Raws li qhov tshwm sim, lub cev muaj peev xwm tshem tawm phosphorus deteriorated sai: Effluent phosphate theem nce los ntawm ib txwm 0.37 mg / L txog 5.7 mg / L; Kev tshem tawm cov phosphorus lom tau poob qis, yuav luag ua tsis tiav.
Tom qab ntawd, cov neeg ua haujlwm saib xyuas kom ruaj khov rau cov pa oxygen (DO) hauv tag nrho lub tank aerobic ntawm 2-3 mg / L, thiab lub kaw lus maj mam rov zoo. Tom qab kwv yees li ob lub lis piam ntawm kev ua haujlwm ruaj khov, cov phosphorus effluent poob mus rau 0.89 mg / L, thiab phosphorus tshem tawm efficiency rov qab mus rau tus nqi tsim.
Kev tshem tawm phosphorus degradation tshwm sim los ntawm ntau dhau aeration tsis tuaj yeem kho tam sim ntawd tom qab kho qhov ntsuas.
Thaum PHB noj ntau dhau lawm, polyphosphate- cov kab mob sib sau nkag mus rau hauv lub xeev "endogenous respiration"-lawv pib decompose lawv tus kheej cov khoom siv cellular kom ciaj sia, ua rau tag nrho cov kev ua ntawm cov kab mob hauv zej zog. Txhawm rau rov- tsim kom muaj peev xwm tshem tawm cov phosphorus ruaj khov, lub kaw lus xav tau sijhawm txaus rau polyphosphate- khaws cov kab mob kom rov tsim dua thiab rov ua dua - PHB. Cov txheej txheem no feem ntau siv sijhawm ob peb hnub mus rau ob peb lub lis piam, nyob ntawm seb qhov kev puas tsuaj. Qhov no kuj yog qhov laj thawj tseem ceeb vim li cas ntau cov nroj tsuag tsis pom cov txiaj ntsig tom qab kho aeration - nws tsis yog qhov kev hloov kho tsis raug, tab sis lub sijhawm tsis raug.
IV. 3 Qhov xwm txheej no feem ntau yuav ua rau tsis pom zoo dua -Aeration
1. Hnub los nag los yog qis-Load Influent: Thaum nws los nag los yog cov dej khib nyiab hauv kev lag luam tsawg dua li niaj zaus, qhov concentration ntawm cov organic teeb meem hauv lub zog poob qis heev. Cov sludge siv cov pa oxygen tsawg dua, yog li cov pa oxygen xav tau qis dua. Yog tias tus nqi aeration tseem zoo li qub, cov pa oxygen yuav tsis siv, ua rau cov pa oxygen yaj (DO) nce mus tas li thiab depleting PHB ntawm polyphosphate accumulating bacteria. Yog tias tus nqi aeration tsis hloov tam sim ntawd tom qab lub zog muaj zog poob qis, thiab cov aeration siab tau khaws cia rau lub sijhawm ntev, qhov "qav boiling" tshwm sim dhau - aeration yog qhov tsis txaus ntseeg tshaj plaws. Phosphorus tshem tawm efficiency yuav maj mam poob nyob rau ob peb lub hlis mus txog thaum nws mam li nco dheev tshaj tus qauv.
2. Tsom ntsoov rau hauv pem hauv ntej kawg nkaus xwb, tsis quav ntsej qhov Back End: Ntau cov nroj tsuag tsuas yog nruab DO probes nyob rau pem hauv ntej kawg ntawm lub tank aerobic. Lawv xav tias muaj kev ntseeg siab thaum DO nyob rau hauv pem hauv ntej kawg zoo li qub, tab sis dhau - aeration nquag tshwm sim nyob rau hauv qab kawg compartments. Nyob rau hauv qhov tseeb, thaum tag nrho cov aeration tus nqi siab dhau lawm, qhov kawg ntawm lub aerobic tank yog qhov twg DO feem ntau yuav siab, thiab nws kuj yog qhov twg PHB yog "thaum kawg depleted."
V. Cov lus qhia siv tau
1. Hloov tus cwj pwm ntawm "qhov siab dua qhov aeration, qhov zoo dua"
Qhov pom zoo ua kom yaj cov pa oxygen (DO) hauv lub tank aerobic yog nyob nruab nrab ntawm 2-3 mg / L, thiab zam dhau 4 mg / L rau lub sijhawm ntev. Ua tib zoo saib xyuas cov pa oxygen hauv qhov kawg ntawm lub tank aerobic, tsis yog theem dej ntws xwb.
2. Ua kom txo qis aeration thaum lub sij hawm qis -load
Nyob rau hauv cov ntaub ntawv ntawm los nag los yog tsis muaj influent concentration, tam sim ntawd txo lub aeration tus nqi kom tswj PHB cia ntawm polyphosphate- accumulating kab mob.
3. Muaj lwm txoj hauv kev thaum tshawb xyuas cov phosphorus ntau dhau
Yog hais tias phosphorus tso tawm nyob rau hauv lub anaerobic theem yog ib txwm, tab sis cov phosphorus effluent tseem yog siab, xyuas kom ntau aeration. Tsis tas li xyuas lub sij hawm khaws cia ntawm cov sedimentation tank, DO nqa los ntawm cov reflux, ntau nitrate nitrogen, thiab txaus sludge tawm. Tsis txhob ntxiv ntau cov tshuaj phosphorus tshem tawm tam sim ntawd- qhov no ua rau cov nqi nce ntxiv thiab tuaj yeem npog qhov teeb meem tiag tiag.
4. Ua siab ntev tom qab kho DO
Tom qab paub meej tias qhov ntau dhau aeration ua rau cov phosphorus tshem tawm tsis zoo, txo qis DO thiab tso cai rau qee lub sijhawm. Kev hloov pauv tsis tu ncua tuaj yeem cuam tshuam cov kab mob hauv zej zog ntau zaus, ua rau nws rov qab los.
5. Tiv thaiv "Oxygen Backflow" Yog tias siab -DO dej los ntawm lub tank aerobic nkag mus rau hauv lub tank anaerobic lossis anoxic los ntawm sludge recirculation los yog cov dej cawv sib xyaw ua ke, nws yuav cuam tshuam rau ib puag ncig anaerobic thiab cuam tshuam ncaj qha rau PHB synthesis los ntawm polyphosphate - cov kab mob sib xyaw. Lub recirculation system yuav tsum muaj qhov zoo tshaj plaws muaj qhov chaw tsis muaj anoxic los yog tswj qhov sib piv kom txo tau cov pa oxygen.
Thaum kawg, tus yuam sij rau AAO lom phosphorus tshem tawm tsis yog ua kom aeration lossis tsuas yog ntxiv cov pa roj carbon monoxide, tab sis ua kom muaj qhov sib npaug ntawm PHB "zog nyiaj" rau polyphosphate- khaws cov kab mob.
Tsis txaus aeration ua rau tsis txaus phosphorus uptake; ntau dhau aeration depletes cov polyphosphate - accumulating cov kab mob "deposits" ntxov ntxov, ho txo los yog txawm tshem tawm cov hauj lwm zoo ntawm lom phosphorus tshem tawm. Rau kev ua haujlwm thiab kev saib xyuas, tswj cov pa oxygen hauv lub tank aerobic yog qhov tseem ceeb. Thaum tag nrho cov phosphorus qib siab tshaj tus qauv, xav txog ntau txheej txheej thiab kev ntsuas ntxiv feem ntau ua tau zoo dua li qhov kho qhov muag tsis pom lossis ntxiv cov tshuaj.
Faj seeb: PHB yog ib lub npe luv rau poly- -hydroxybutyric acid, uas yog ib qho khoom siv hluav taws xob khaws cia hauv cov kab mob polyphosphate.
