Lub simultaneous nitrification thiab denitrification ntawm MBBR pom tau li cas?
(1) Lub tswv yim ntawm simultaneous nitrification thiab denitrification lom nitrogen tshem tawm (SND)
Simultaneous nitrification, denitrification thiab denitrification (SND) yog ib txhij ntawm nitrification, denitrification thiab carbon tshem tawm hauv tib lub reactor. Nws tawg los ntawm kev pom ib txwm muaj tias nitrification thiab denitrification tsis tuaj yeem tshwm sim tib lub sijhawm, tshwj xeeb tshaj yog nyob rau hauv cov xwm txheej aerobic, denitrification tuaj yeem tshwm sim, ua rau tib lub sijhawm nitrification thiab denitrification ua tau.
Cov txheej txheem nitrification siv cov alkalinity, thiab cov txheej txheem denitrification tsim alkalinity, yog li SND tuaj yeem ua kom tus nqi pH hauv lub reactor ruaj khov, tsis tas yuav muaj cov kua qaub-base neutralization, thiab tsis tas yuav tsum muaj cov pa roj carbon monoxide sab nraud; nws txuag lub ntim ntawm lub reactor, shortens lub sij hawm cov tshuaj tiv thaiv, thiab txo cov nitrate lub xeev. Nitrogen concentration tuaj yeem txo cov sludge floating nyob rau hauv cov sedimentation tank theem nrab, yog li SND tau dhau los ua qhov kev tshawb fawb hotspot ntawm bio denitrification. Rau qhov ua tau ntawm SND biological denitrification, tam sim no muaj peb lub ntsiab lus los ntawm ntau qhov kev xav:
Macro-environmental foundations: Qhov kev xav no ntseeg tias tsis muaj qhov sib xyaw ua ke ntawm lub xeev, thiab qhov tsis sib xws ntawm DO nyob rau hauv lub reactor tuaj yeem tsim cov cheeb tsam aerobic, anoxic, thiab anaerobic, uas tuaj yeem tshwm sim hauv tib lub bioreactor nyob rau hauv anoxic / anaerobic. ib puag ncig tej yam kev mob Denitrification cov tshuaj tiv thaiv, ua ke nrog kev tshem tawm cov organic teeb meem nyob rau hauv lub aerobic ib puag ncig thiab cov nitrification ntawm ammonia nitrogen nyob rau hauv seem, SND yuav ua tau tiav.
Los ntawm qhov kev xav ntawm microenvironment: Qhov kev pom no tuav tau tias qhov anoxic microenvironment hauv microbial floc yog qhov laj thawj tseem ceeb rau kev tsim SND, uas yog, vim muaj kev txwv ntawm oxygen diffusion (kev xa mus), muaj cov pa oxygen gradient hauv cov microbial. floc, uas yog conducive rau lub realization ntawm ib txhij nitrification thiab denitrification Microenvironment.
Biological point of view: Qhov kev pom no tuav tau tias qhov muaj nyob ntawm cov neeg tshwj xeeb microbial yog suav tias yog qhov laj thawj tseem ceeb rau qhov tshwm sim ntawm SND. Qee cov kab mob nitrifying tuaj yeem ua tau denitrification ntxiv rau cov nitrification ib txwm, thiab qee cov kws tshawb fawb Dutch tau cais tawm aerobic nitrification. , thiab tuaj yeem nqa tawm aerobic denitrification ntawm Thiococcus pantrophicus; Qee cov kab mob koom tes nrog kev sib koom ua ke los ua cov tshuaj tiv thaiv kab mob los hloov cov ammonia rau hauv nitrogen, uas muaj peev xwm ua kom tiav cov tshuaj lom neeg lom neeg hauv tib lub reactor nyob rau tib lub sijhawm.
Tam sim no, muaj ntau yam kev tshawb fawb txog microbiological thiab kev piav qhia txog kev lom neeg denitrification, tab sis lawv tsis zoo tag nrho, thiab kev nkag siab ntawm SND phenomenon tseem tab tom txhim kho thiab tshawb nrhiav. Lub microenvironment txoj kev xav feem ntau lees txais. Vim tias muaj cov pa oxygen gradient, cov pa oxygen concentration nyob rau sab nrauv ntawm microbial flocs lossis biofilms yog siab, feem ntau aerobic nitrifying kab mob thiab cov kab mob ammonia; sib sib zog nqus nyob rau hauv, oxygen hloov yog thaiv thiab sab nraud Ib tug loj npaum li cas ntawm yaj oxygen yog noj los tsim anoxic cheeb tsam, thiab denitrifying cov kab mob yog cov tseem ceeb hom, uas yuav ua rau tshwm sim ntawm ib txhij nitrification thiab denitrification. Qhov kev xav no piav qhia txog qhov teeb meem ntawm cov kab mob sib txawv hauv tib lub reactor, tab sis kuj muaj qhov tsis xws luag, uas yog, qhov teeb meem ntawm cov organic carbon. Cov organic carbon qhov chaw tsis yog tsuas yog cov khoom siv hluav taws xob ntawm heterotrophic denitrification, tab sis kuj yog tus inhibitor ntawm cov txheej txheem nitrification. Thaum cov pa roj carbon monoxide hauv cov dej phwj tuaj dhau los ntawm txheej aerobic, nws yog thawj oxidized los ntawm aerobic oxidation. Cov kab mob denitrifying nyob rau hauv thaj tsam anoxic yog vim qhov tsis muaj hluav taws xob pub dawb txo tus nqi denitrification, uas yuav cuam tshuam rau kev ua haujlwm ntawm denitrification ntawm SND. Yog li ntawd, lub mechanism ntawm ib txhij nitrification thiab denitrification tseem yuav tsum tau txhim kho ntxiv.
(2) Cov txheej txheem ntawm ib txhij nitrification, denitrification thiab denitrification hauv MBBR lom lub txaj
MBBR yog ib hom tshiab ntawm cov reactor uas ua ke nrog cov txheej txheem activated sludge ntawm kev ncua kev loj hlob thiab cov txheej txheem biofilm ntawm txuas nrog kev loj hlob. Lub hauv paus ntsiab lus tsim qauv yog ncaj qha ntxiv cov tshuaj tshem tawm nrog ib qho tshwj xeeb nqus ze rau dej thiab tuaj yeem raug tshem tawm hauv dej rau hauv cov tshuaj tiv thaiv tank raws li kev ua haujlwm ntawm cov kab mob. Cov neeg nqa khoom, cov muab tub lim tshem tawm tuaj yeem nyob rau hauv kev sib cuag nrog cov dej phwj tuaj, thiab cov biofilm (zaj duab xis dai) maj mam loj tuaj rau ntawm qhov chaw muab tub lim, uas ntxiv dag zog rau kev hloov pauv huab cua ntawm cov pa phem, yaj oxygen thiab biofilm, uas yog MBBR. hu ua "mobile biological film". Raws li kev tshawb fawb ntawm SND mechanism kom deb li deb, ua ke nrog microenvironment thiab biological txoj kev xav, qhov ua tau cov tshuaj tiv thaiv hom SND hauv MBBR biofilm yog aerobic ammonia oxidizing kab mob, nitrite oxidizing kab mob thiab aerobic denitrification faib nyob rau hauv aerobic txheej ntawm biofilm. Cov kab mob koom tes nrog cov kab mob anammox, cov kab mob autotrophic nitrite thiab cov kab mob denitrifying faib rau hauv cov txheej txheem biological anoxic, thiab thaum kawg ua tiav lub hom phiaj ntawm denitrification.
MBBR tso siab rau lub aeration hauv lub aeration tank thiab lifting nyhuv ntawm cov dej ntws los ua tus cab kuj nyob rau hauv ib tug fluidized lub xeev, yog li tsim suspended activated sludge thiab txuas biofilm, muab tag nrho cov kev ua si rau qhov zoo ntawm ob qho tib si txuas thiab tshem tawm cov kab mob. Nws tsis tsuas yog muab macroscopic thiab microscopic aerobic thiab anaerobic ib puag ncig, tab sis kuj daws cov kev tsis sib haum xeeb ntawm DO thiab carbon qhov kev tsis sib haum xeeb ntawm cov kab mob autotrophic nitrifying, heterotrophic denitrifying kab mob thiab cov kab mob heterotrophic. Yog li ntawd, MBBR tuaj yeem paub qhov sib npaug ntawm ob txoj haujlwm ntawm nitrification thiab denitrification, thiab muaj cov xwm txheej zoo heev rau kev sib xyaw nitrification thiab denitrification, thiab tuaj yeem paub MBBR ib txhij nitrification, denitrification thiab denitrification.
Influencing yam ntawm MBBR ib txhij nitrification thiab denitrification
Lub thev naus laus zis tseem ceeb kom ua tiav ib txhij nitrification thiab denitrification hauv MBBR yog los tswj cov kinetic tshuav ntawm nitrification thiab denitrification hauv MBBR, thiab daws qhov kev tsis sib haum xeeb ntawm cov kab mob autotrophic nitrifying thiab cov kab mob heterotrophic, thiab cov pa roj carbon qhov tsis sib haum xeeb ntawm cov kab mob denitrifying thiab cov kab mob heterotrophic, thiab lwm yam, yog li lub ntsiab tswj hwm yog: carbon-nitrogen piv, yaj oxygen concentration, kub thiab pH.
(1) Kev cuam tshuam ntawm cov fillers ntawm MBBR txoj kev
Lub ntsiab tseem ceeb ntawm MBBR txoj kev yog nyob rau hauv cov khoom siv roj ntsha uas nws lub ntiajteb txawj nqus yog ze rau ntawm cov dej, thiab uas yooj yim txav mus los ntawm cov dej hauv qab kev ntxhov siab me ntsis. Feem ntau cov muab tub lim yog ua los ntawm polyethylene yas. Cov duab ntawm txhua tus cab kuj yog ib lub tog raj kheej me me nrog txoj kab uas hla ntawm 10mm thiab qhov siab ntawm 8mm. Muaj kev txhawb nqa ntoo khaub lig hauv lub tog raj kheej thiab cov kab ntsug ntsug ntawm cov phab ntsa sab nrauv. Qhov khoob ntawm qhov muab tub lim rau 0.95 feem pua ntawm tag nrho cov ntim. , uas yog, nyob rau hauv ib lub thawv uas muaj dej thiab muab tub lim, qhov ntim ntawm cov dej hauv txhua qhov muab tub lim yog 95 feem pua. Noj mus rau hauv tus account qhov kev sib hloov ntawm cov muab tub lim thiab tag nrho cov ntim ntawm lub thawv, qhov sib piv ntawm cov muab tub lim yog txhais raws li qhov kev faib ua feem ntawm qhov chaw nyob los ntawm cov cab kuj. Txhawm rau kom ua tiav qhov sib xyaw zoo tshaj plaws, qhov sib piv ntawm cov muab tub lim yog feem ntau 0.7. Raws li txoj cai, tag nrho cov cheeb tsam tshwj xeeb ntawm qhov muab tub lim yog txhais los ntawm tus naj npawb ntawm thaj chaw tshwj xeeb ntawm ib chav tsev ntim ntawm cov khoom siv roj ntsha, uas feem ntau yog 700m2 / m3. Thaum cov biofilm loj hlob hauv cov cab kuj, qhov kev siv tau zoo ntawm thaj chaw tshwj xeeb yog li 500m2 / m3.
Hom khoom siv roj ntsha no yog qhov tsim nyog rau kev loj hlob ntawm cov kab mob ntawm cov kab mob hauv lub cev, tsim cov biofilm ruaj khov, thiab nws yooj yim rau kev tsim cov kua dej hauv lub xeev. Thaum cov kev xav tau pretreatment tsawg tsawg los yog cov dej phwj muaj ntau cov tshuaj fiber ntau, piv txwv li, lub hauv paus sedimentation tank tsis yog siv nyob rau hauv lub nroog cov dej phwj tuaj kho los yog thaum lub papermaking khib nyiab uas muaj ib tug loj npaum li cas ntawm fibers yog kho, cov khoom siv roj ntsha nrog. ib cheeb tsam me me thiab qhov loj me yog siv. Thaum muaj qhov zoo dua pretreatment lossis rau nitrification, cov khoom siv roj ntsha nrog rau thaj chaw loj tshwj xeeb yog siv.
(2) Cov nyhuv ntawm yaj oxygen (DO) ntawm MBBR txoj kev
DO concentration yog ib qho tseem ceeb txwv tsis pub cuam tshuam rau ib txhij nitrification thiab denitrification. Los ntawm kev tswj DO concentration, ntau qhov chaw ntawm biofilm tuaj yeem tsim aerobic zone lossis anoxic zone, uas muaj peev xwm ua tiav ib txhij nitrification thiab denitrification. lub cev tej yam kev mob.
Raws li txoj cai, thaum DO concentration siab dhau lawm, DO tuaj yeem nkag mus rau sab hauv ntawm biofilm, ua rau nws nyuaj rau tsim ib qho chaw anoxic sab hauv, thiab ntau cov ammonia nitrogen yog oxidized rau nitrate thiab nitrite, ua rau TN effluent tseem siab. . Ntawm qhov tsis sib xws, yog tias qhov concentration ntawm DO tsawg heev, qhov loj ntawm thaj chaw anaerobic yuav tsim nyob rau hauv biofilm, thiab lub peev xwm denitrification ntawm biofilm yuav raug txhim kho (cov concentrations ntawm nitrate thiab nitrite hauv cov dej ntws tsawg heev. ), tab sis vim yog cov khoom tsis txaus ntawm DO, MBBR Cov txiaj ntsig nitrification ntawm cov txheej txheem txo qis, yog li cov concentration ntawm ammonia nitrogen nyob rau hauv cov effluent nce, uas ua rau muaj kev nce hauv TN ntawm cov effluent, uas cuam tshuam rau kev kho mob kawg.
Los ntawm kev tshawb fawb, qhov txiaj ntsig zoo ntawm MBBR txoj kev kho hauv nroog cov dej phwj tuaj DO thaum kawg tau txais: thaum DO concentration siab dua 2 mg / L, DO muaj kev cuam tshuam me ntsis ntawm cov nyhuv nitrification ntawm MBBR, thiab tshem tawm tus nqi ntawm ammonia nitrogen tuaj yeem ncav cuag 97 feem pua -99 feem pua, cov effluent ammonia nitrogen tuaj yeem khaws cia qis dua 1.0mg/L; Thaum qhov DO loj concentration yog li ntawm 1.0mg / L, ammonia nitrogen tshem tawm tus nqi yog li 84 feem pua, thiab cov effluent ammonia nitrogen concentration tau nce ntau. Tsis tas li ntawd, DO hauv lub aeration tank yuav tsum tsis txhob siab dhau. Cov pa oxygen ntau dhau tuaj yeem ua rau cov organic paug decompose sai heev, kom cov kab mob tsis muaj cov as-ham, cov activated sludge yog ib qho yooj yim rau hnub nyoog, thiab cov qauv yog xoob. Tsis tas li ntawd, DO yog siab dhau lawm thiab kev siv zog ntau dhau tsis haum rau kev lag luam.
Vim tias txoj kev MBBR feem ntau paub txog kev kho dej phwj zaum kawg los ntawm kev tshem tawm cov fillers, qhov cuam tshuam ntawm DO ntawm cov muab tso rau hauv qhov raug tshem tawm kuj yog tus yuam sij rau tag nrho cov txiaj ntsig kev kho mob. Cov kev tshawb fawb tau pom tias lub peev xwm oxygenation ntawm lub reactor nce nrog qhov nce ntawm qhov ntim ntawm cov muab tub lim tshem tawm hauv qee qhov ntau. Nyob rau hauv qhov kev txiav txim ntawm aeration, cov dej yog fluidized ua ke nrog cov muab tub lim, thiab cov turbulence ntawm cov dej ntws yog ntau tshaj qhov uas tsis muaj cov muab tub lim, uas accelerates tus tshiab ntawm cov roj-kua interface thiab cov kev hloov ntawm oxygen, thiab nce tus nqi. kev hloov oxygen. Raws li tus nqi ntawm cov muab tub lim nce, qhov kev txiav txim siab thiab kev ua haujlwm turbulent ntawm cov muab tub lim, cua ntws thiab dej ntws mus ntxiv. Txawm li cas los xij, thaum tus nqi ntawm cov muab tub lim ntxiv yog 60 feem pua, cov nyhuv fluidization ntawm cov muab tub lim hauv dej yuav tsis zoo, thiab cov qib ntawm kev kub ntxhov hauv lub cev dej kuj txo qis, uas txo qis kev sib kis ntawm cov pa thiab kev siv cov pa oxygen. Yog li ntawd, rau ntau hom dej zoo, kev tswj hwm tus nqi ntawm DO yog qhov tseem ceeb rau kev kho qhov kawg ntawm tag nrho cov txheej txheem.
MBBR yog dab tsi?
Cov txheej txheem MBBR yog raws li lub hauv paus ntsiab lus ntawm cov txheej txheem biofilm. Los ntawm kev ntxiv qee qhov kev tshem tawm cov cab kuj mus rau lub reactor, biomass thiab tsiaj txhu hauv reactor tau nce, yog li txhim kho cov kev ua haujlwm ntawm lub reactor. Txij li qhov ceev ntawm cov muab tub lim yog ze rau ntawm cov dej, nws yog tov nrog dej thaum lub sij hawm aeration, thiab ib puag ncig rau microbial kev loj hlob yog roj, kua, thiab khoom peb-theem.
Kev sib tsoo thiab shearing ntawm cov cab kuj nyob rau hauv dej ua rau cov pa npuas me me thiab ua rau kom siv cov pa oxygen. Tsis tas li ntawd, txhua tus cab kuj muaj cov kab mob sib txawv sab hauv thiab sab nraud, nrog qee cov kab mob anaerobic lossis cov kab mob facultative loj hlob sab hauv, thiab cov kab mob aerobic sab nraud, kom txhua tus cab kuj yog microreactor, kom nitrification cov tshuaj tiv thaiv thiab cov tshuaj tiv thaiv denitrification coexist, yog li txhim kho kev ua haujlwm. .