Qhov xwm txheej ntawm "siab COD, qis TP, thiab siab TN" sawv cev rau cov xwm txheej qub ntawm cov pa roj carbon hnyav heev -Nitrogen- Phosphorus imbalance. Kab lus no piav qhia luv luv txog kev kuaj mob thiab hais txog qhov teeb meem no (cov ntsiab lus thiab cov duab qhia txog tus kheej kev xav raws li kev ua tau zoo thiab tsuas yog siv rau kev siv xwb).
Lub hom phiaj tseem ceeb ntawm kev hloov kho cov txheej txheem tuaj yeem ua tiav raws li hauv qab no:
1. Tam sim ntawd daws qhov "phosphorus txwv"-lub fwj rau microbial proliferation;
2. Siv tau cov pa roj carbon ntau dhau -hloov siab -concentration COD rau hauv kev tsav tsheb rau denitrification;
3. Ua tiav qhov kev tshem tawm cov nitrogen sib sib zog nqus- kom ntseeg tau tias qhov siab - TN effluent tsis tu ncua raws li cov qauv tso tawm.
Cov kev hloov kho tshwj xeeb yog cov ncauj lus kom ntxaws hauv qab no, tawg raws li kev xav tau ntawm kev siv engineering.
I. "Lub neej-txuag" yuav tsum tau kho tam sim ntawd: Precise phosphorus supplementation
Qhov no yog qhov yuav tsum tau ua ua ntej rau tag nrho lwm yam kev ntsuas. Nyob rau hauv phosphorus-cov kev mob tsis txaus, txawm tias muaj cov pa roj carbon ntau thiab cov pa, cov sludge qhib tsis tuaj yeem tsim cov flocs noj qab haus huv; Es tsis txhob, nws zoo li disintegrate thiab ntxuav tawm.
Txheeb xyuas thiab xam qhov ntau npaum li cas
Txiav txim siab tus nqi ntxiv raws li qhov piv ntawm kwv yees li BOD₅:P=100:1. Yog tias tsuas yog COD cov ntaub ntawv muaj, siv BOD₅/COD piv rau kev hloov pauv (xws li, yog BOD₅/COD ≈ 0.5, kwv yees raws li COD:P ≈ 200:1). Nco ntsoov xam qhov ntau npaum li cas dynamically raws li qhov tseeb txaus txaus tus nqi thiab phosphorus concentrations.
Xaiv qhov chaw phosphorus thiab dosing point
Phosphorus qhov chaw: Ua ntej yooj yim absorbable orthophosphates xws li ammonium dihydrogen phosphate los yog sodium dihydrogen phosphate. Thaum diammonium hydrogen phosphate tuaj yeem siv yog tias nitrogen tseem tsis txaus, qhov xwm txheej tam sim no suav nrog qib nitrogen siab; Yog li ntawd, phosphoric acid los yog sodium dihydrogen phosphate yog pom zoo kom tsis txhob ntxiv nitrogen ntxiv.
Dosing point: Tso lub dosing point ntawm qhov kawg ntawm thaj chaw anoxic lossis pib ntawm thaj chaw aerobic hauv lub tank lom, tso cai rau cov kab mob coj mus rau phosphorus ncaj qha thaum nkag mus rau hauv thaj chaw aerobic. Tsis txhob muab pov tseg tag nrho cov koob tshuaj rau hauv thaj chaw anaerobic, vim qhov no tuaj yeem ua rau muaj ntau dhau los ntawm phosphorus- cov kab mob sib sau ua ke (vim tias kev tshem tawm phosphorus tsis yog lub hom phiaj ntawm no) lossis tsim cov dej nag tsis zoo.
Kev saib xyuas thaum lub sijhawm hloov pauv
Tsis pub dhau 2-3 hnub ntawm phosphorus supplementation, sludge settling ratio (SV) yuav pib txo qis thaum floc zoo txhim kho, tom qab ntawd maj mam nce raws li cov neeg microbial proliferates. Synchronously saib xyuas tag nrho cov phosphorus effluent kom ntseeg tau tias theem nyob rau hauv cov kev txwv tom qab supplementation (zoo tshaj plaws tswj ntawm 0.3-0.5 mg / L kom tau raws li microbial xav tau thaum tswj kev ruaj ntseg paj).
II. Hloov "High COD" rau hauv "Denitrification Asset": Ua ntej- qhov chaw thiab theem ua kom tau txais cov pa roj carbon
Txij li thaum cov pa roj carbon ntau ntau, nws yuav tsum tau siv tag nrho rau denitrification es tsis yog dej nyab ntawm thaj chaw aerobic thiab khib nyiab los ntawm kev siv oxygen.
Siv ntau-point influent lossis carbon diversion
Faib ib feem ntawm cov dej nyoos (COD siab)- hla lub hauv paus sedimentation tank - ncaj qha mus rau hauv thaj chaw anoxic los ua cov pa roj carbon rau denitrification. Tom qab kev tshuaj xyuas thiab tshem tawm grit, cov dej nyoos tuaj yeem "dhia" ncaj nraim mus rau lub tank anoxic, tiv thaiv cov pa roj carbon monoxide los ntawm oxidized thiab nkim hauv thawj lub tank los yog aerobic cheeb tsam. Tswj tus nqi ntawm biodegradable COD nkag mus rau thaj tsam anoxic raws li tag nrho cov hom phiaj tshem tawm nitrogen.
Txhim kho hydrolysis-acidification los txhim kho cov pa roj carbon zoo
Yog tias COD siab tab sis qhov piv txwv BOD₅ / COD tsawg, nws qhia tau tias muaj kev cuam tshuam ntau dua (nyuaj-rau-degrade) organics. Lub hydrolysis-acidification tank tuaj yeem ntsia tau rau hauv theem ua ntej- kho kom tawg loj, refractory organic molecules mus rau hauv biodegradable VFAs (volatile fatty acids), yog li txhim kho cov txiaj ntsig ntawm carbon qhov kev siv rau denitrification.
Siv thaj chaw aerobic kom haus cov pa roj carbon seem
Inevitably, qee qhov chaw carbon yuav nkag mus rau aerobic cheeb tsam; Nyob rau hauv cov ntaub ntawv no, xyuas kom meej cov pa yaj (DO) thaum kawg ntawm lub aerobic theem yog tsawg kawg yog 2 mg / L kom tag oxidize residual BOD thiab tiv thaiv effluent COD los ntawm ntau tshaj qhov txwv. Tsis tas li ntawd, vim tias cov pa roj carbon ntau dhau tuaj yeem ua rau muaj cov kab mob heterotrophic ntau dua - muaj peev xwm ua rau cov kab mob nitrifying ntau ntau - cov hnub nyoog sludge thiab cov organic loading yuav tsum tau ua tib zoo tswj.
III. Targeting qhov "High Tag Nrho Nitrogen" Kev Sib Tw: Ua kom muaj Nitrification-Denitrification Potential
High tag nrho cov nitrogen theem yuav tsum optimizing ob theem nitrification thiab denitrification kom lawv muaj peev xwm.
Nitrification theem: Tsim qhov chaw thiab sijhawm rau nitrifying kab mob
Sludge hnub nyoog tswj: Nitrifying kab mob muaj lub sij hawm ntev tiam; Lub hnub nyoog sludge yuav tsum tau khaws cia tsawg kawg ntawm 15 hnub (tshaj 20 hnub nyob rau lub caij ntuj no) los tiv thaiv lawv los ntawm "poob tawm" los ntawm cov kab mob heterotrophic proliferating sai. DO Kev Saib Xyuas: Khaws DO hauv thaj chaw aerobic ntawm 2–3 mg / L tas li; tsis txhob txo qis nws ntau dhau hauv kev sim txuag lub zog.
Alkalinity Monitoring thiab Supplementation: Nitrification siv alkalinity (kwv yees li 7.14 g ntawm CaCO₃ noj ib gram ntawm NH₄⁺-N oxidized). Nitrification tus nqi poob qis heev thaum pH poob qis dua 7.0; Yog li ntawd, Na₂CO₃ lossis kua alkali yuav tsum tau noj kom tswj tau cov cawv sib xyaw pH ntawm 7.5 thiab 8.0.
Denitrification Zone: Ua kom muaj kev siv ntau tshaj plaws ntawm ob qho tib si sab hauv thiab sab nrauv carbon.
Internal Recirculation Ratio Optimization: Xyuas kom txaus recirculation ntawm siab -nitrate tov cawv los ntawm qhov kawg ntawm aerobic cheeb tsam rov qab mus rau thaj tsam anoxic; Internal recirculation ratio yog feem ntau teem ntawm 200% thiab 400%. Kev rov ua haujlwm ntau dhau qhia ntau dhau DO, cuam tshuam rau qhov chaw anoxic. Kev tuav tswj cov xwm txheej Anoxic: DO hauv thaj chaw anoxic yuav tsum tau tswj nruj me ntsis hauv qab 0.5 mg / L; siv cov khoom sib xyaw kom ntseeg tau cov sludge- dej sib cuag thaum tsis txhob muaj qhov aeration.
Kev Tswj Xyuas Ib Ntus ntawm Carbon Sources: Yog tias cov pa roj carbon monoxide sab nraud (COD) txaus, tus nqi denitrification tuaj yeem ncav cuag 0.03-0.06 kg NO₃⁻-N / (kg MLVSS·d). Yog tias cov pa roj carbon deficiency tshwm sim (piv txwv li, nce effluent nitrate-nitrogen), xav txog cov pa roj carbon thaum muaj xwm ceev xws li sodium acetate, tab sis cov no tsis yog thawj qhov kev xaiv; ua ntej siv tag nrho cov dej nyoos cov ntsiab lus carbon.
Xav txog ib nrab Nitrification-Denitrification los yog Anammox (tsim rau C / N ratios tsawg heev; thaum qhov xwm txheej no muaj ntau cov pa roj carbon ntau- ua ib feem ntawm txoj kev tsis tsim nyog- cov thev naus laus zis no tuaj yeem ua cov kev xaiv yav tom ntej).
Yog tias tag nrho cov nitrogen siab heev thiab cov pa roj carbon ntau-txawm tias muaj ntau- tseem ua tsis tau raws li qhov xav tau ntawm denitrification (qhov xwm txheej hnyav), ib tus tuaj yeem sim ib nrab nitrification (nitrite tsub zuj zuj) ua ke nrog Anammox rau kev tshem tawm nitrogen. Txawm li cas los xij, qhov no yog qhov nyuaj rau kev siv hauv kev xyaum, xav tau kev saib xyuas online thiab kev tswj xyuas kom meej, thiab yuav tsum tau saib ua lub sijhawm ntev - lub tswv yim optimization.
IV. Hais txog Cov Ntaub Ntawv Tshwj Xeeb ntawm "High COD tab sis Poor Biodegradability"
Yog tias kev soj ntsuam pom tau hais tias BOD₅ / COD piv <0.2, qhov siab COD yog qhov nyuaj rau kev siv ncaj qha los ntawm cov txheej txheem lom neeg, thiab cov tswv yim hais txog kev siv cov pa roj carbon monoxide yuav ua haujlwm tsawg dua. Hauv theem no, cov kev ntsuas hauv qab no yuav tsum tau:
1. Physicochemical pretreatment rau load txo: Nruab coagulation - sedimentation, tshuaj oxidation (Fenton, O₃), los yog activated carbon adsorption units upstream ntawm cov kab mob lom kom txo recalcitrant COD los ntawm 30% -50% thawj zaug, yog li txhim kho cov tom ntej / COD ratio.
2. Bio-augmentation: Siv cov kab mob tshwj xeeb los yog cov enzymes lom rau hauv hydrolysis-acidification tank, los yog siv cov txheej txheem PACT (Powdered Activated Carbon-Activated Sludge) rau adsorb recalcitrant tshuaj thiab txuas ntxiv lawv lub sijhawm nyob.
3. Membrane sib cais raws li kev tiv thaiv zaum kawg: Siv MBR lossis NF / RO systems thaum kawg ntawm theem biochemical mus ntes cov seem COD, kom ntseeg tau tias cov txiaj ntsig tau txais kev kho mob sib cais.
V. "Safety Net" rau Kev Tswj Xyuas Kev Ua Haujlwm
Kev soj ntsuam tas li ntawm phosphorus tshuav nyiaj li cas: Kev Ntsuas Tag Nrho Phosphorus (TP) qib hauv qhov muaj zog, thaum kawg ntawm thaj chaw anaerobic, thiab qhov kawg ntawm thaj chaw aerobic thaum txhua qhov kev hloov pauv; Qhov no tiv thaiv sludge disintegration vim tsis txaus supplementation thiab tsis txhob effluent txwv kev ua txhaum cai los ntawm ntau phosphorus dosing.
Online ammonia nitrogen / nitrate nitrogen profileing: Ntsuam xyuas qhov ua tiav ntawm nitrification thiab qhov tsim nyog ntawm cov khoom siv rov ua dua tshiab los ntawm kev taug qab kev hloov pauv hauv ammonia nitrogen thiab nitrate nitrogen concentrations raws thaj tsam aerobic.
Kev kuaj xyuas me me ntawm cov yam ntxwv sludge: Tam sim ntawd tshawb xyuas qhov cuam tshuam ntawm cov phosphorus qhov chaw lossis kev siv tshuaj tsis txaus yog tias cov kab mob floc ua zoo, cov kab mob filamentous proliferate, los yog dawb- cov kab mob ua luam dej.
Kev npaj cov tshuaj tiv thaiv thaum muaj xwm txheej ceev: Khaws cov khoom tsim nyog ntawm phosphoric acid, carbon qhov chaw (sodium acetate), thiab alkalinity agents (kua alkali) kom tsis txhob muaj kev cuam tshuam ntawm cov saw hlau.
Kev cuam tshuam ntawm chloride ions ntawm cov kev ntsuas no:
I. Core Correlation: Yuav ua li cas Chloride Ions Ua rau Ammonia Nitrogen Qib nce (Nitrification System Collapse)
Qhov no yog qhov txuas ncaj qha thiab tseem ceeb tshaj plaws. Cov qib siab Tag Nrho Nitrogen feem ntau suav nrog feem ntau ntawm ammonia nitrogen. Cov ntsiab lus siab ntawm chloride ions tuaj yeem raug "tua" cov kab mob ua lub luag haujlwm rau kev ua cov ammonia nitrogen.
Osmotic shock: Nitrifying kab mob yog thawj zaug raug tshem tawm
Nitrifying kab mob (tshwj xeeb tshaj yog ammonia- cov kab mob oxidizing) yog qhov nkag siab heev rau kev hloov pauv hauv osmotic siab-ntau tshaj li cov kab mob heterotrophic uas degrade COD. Thaum cov tshuaj chloride ion concentrations nce siab (piv txwv li, ntau tshaj 5,000-10,000 mg / L), lawv cov hlwb poob dej, ua rau kev ua haujlwm metabolic tsis ua haujlwm lossis tseem ua rau cov cell tuag. Qhov tshwm sim tam sim no: Nitrification hauv thaj chaw aerobic; ammonia nitrogen tsis tuaj yeem hloov mus rau hauv nitrite thiab nitrate, ua rau cov dej ammonia nce siab. Koj yuav pom cov ntaub ntawv no: lub siab muaj zog ammonia, nrog cov dej ammonia tawm ntawm cov qib ze li zoo ib yam rau cov neeg muaj zog.
Kev txiav txim tsis raug vim "pseudo-COD" cuam tshuam: Raws li tau hais dhau los, chloride ions cuam tshuam nrog COD ntsuas. Yog tias qhov "COD siab" koj pom yog qhov kev tsis pom tseeb- txhais tau tias qhov tseeb COD qis dua- thiab koj nce rov ua dua lossis aeration raws li qhov kev nyeem tsis tseeb no, koj tsuas yog ua rau lub cev tsis ruaj khov. Txawm li cas los xij, cov tshuaj chloride siab tiv thaiv cov kab mob nitrifying nws tus kheej ntawm seb qhov kev nyeem ntawv COD puas yog.
II. Cov txiaj ntsig sib xyaw: "Tuag Kauv" Ua los ntawm High Ammonia, High Chloride, thiab Phosphorus Deficiency
Synergy ntawm ammonia toxicity thiab salinity toxicity:
High concentrations ntawm ammonia nitrogen (tshwj xeeb tshaj yog dawb ammonia, los yog FA) yog inherently inhibitory rau cov kab mob. Ib txhij, high salinity (chloride ions) cuam tshuam qhov sib npaug ntawm cov cell sab hauv thiab sab nrauv. Cov kev ntxhov siab ob no ua rau muaj kev cuam tshuam loj rau kev ua haujlwm ntawm microbial.
Cov ntsiab lus tseem ceeb: Cov kab mob uas muaj kev ntxhov siab yuav tsum haus ntau lub zog (ATP) kom tswj tau qhov sib npaug ntawm ionic los ntawm kev siv cov sodium thiab chloride ions tawm ntawm lub cell. Lub zog no - cov txheej txheem siv zog siv phosphorus ntau heev. Txawm li cas los xij, txij li thaum koj lub cev muaj phosphorus loj heev - tsis txaus, cov kab mob tsis muaj peev txheej los tiv thaiv kev sib xyaw ua ke ntawm cov ntsev thiab ammonia siab, ua rau kom ceev cell tuag thiab autolysis.
Sludge disintegration tso tawm ntau ammonia nitrogen:
Thaum cov kab mob microbial tuag thiab rupture en masse, intracellular organic nitrogen compounds -xws li cov proteins thiab nucleic acids - raug tso rau hauv dej thiab hloov mus rau hauv ammonia nitrogen los ntawm ammonifying cov kab mob. Qhov no ua rau muaj kev puas tsuaj loj heev:
Phosphorus deficiency → Cov kab mob tuag thiab tawg, tsis tuaj yeem tiv taus siab salinity / ammonia toxicity → Ntau ammonia nitrogen tso tawm → Ammonia toxicity intensifies → Ntau cov kab mob tuag.
Nyob rau theem no, koj tuaj yeem pom tias -txawm tias tsis muaj qhov cuam tshuam ammonia- qhov ammonia concentration ntawm qhov kawg ntawm lub tank aerobic tshaj qhov muaj zog; Qhov tshwm sim no hu ua endogenous ammonia tso tawm.
III. Cov txheej txheem daws teeb meem: Txheeb xyuas cov teeb meem ntawm Ammonia Data Analysis
Muab qhov siab -chloride keeb kwm yav dhau, qhov taw qhia ntawm cov ntawv nitrogen sib txawv tuaj yeem muab cov ntaub ntawv kuaj pom tseeb. Ammonia siab heev-nitrogen; nitrate- qib nitrogen zero
Phenomenon: Ammonia- qib nitrogen hauv qhov hluav taws xob ntawm lub tank aerobic tseem siab npaum li cov neeg muaj zog, tab sis nitrate-nitrogen tsis tshua pom.
Kev kuaj mob: Nitrification muaj nuj nqi tau ploj lawm. Muab lub siab chloride ion keeb kwm yav dhau, salinity inhibition yog thawj tus neeg raug liam.
Kev ntsuas kub ceev: Lub hauv paus ntawm chloride ions yuav tsum raug txheeb xyuas thiab txiav tawm tam sim ntawd. Nyob rau hauv cov xwm txheej ntawm kev poob siab ib ntus (xws li dej hiav txwv nkag), txo cov dej ntws thiab hloov mus rau "kaw-loop aeration" (aeration tsis muaj inflow) kom tso cai rau cov dej qab ntsev ua ntej maj mam rov ua haujlwm ib txwm. Kev hloov kho tus qauv-xws li hloov cov sludge hnub nyoog lossis nce aeration siv-yuav ua tsis tau tiav.
High ammonia-nitrogen thiab siab nitrate-nitrogen
Phenomenon: Nitrification yog ib feem active, tab sis ammonia conversion tsis tiav.
Kev kuaj mob: Chloride ion concentration yuav nyob rau ntawm qhov tseem ceeb (2,000–5,000 mg / L), inhibiting tus nqi nitrification hnyav heev; Tsis tas li ntawd, phosphorus tsis muaj peev xwm yuav txo tau cov kab mob nitrifying cov pejxeem. Kev tsom xam qhov ntev ntev yog yuav tsum tau txheeb xyuas qhov twg ammonia qib tsis txo qis; qhov no yuav tsum tau ua ke nrog peb cov ntaub ntawv (Oxygen Uptake Rate) los ntsuas qhov℃ntawm inhibition.
Qhov "divergence" ntawm ammonia txuam nrog pH
Qhov no yog ib qho yooj yim overlooked thaum ntxov ceeb toom teeb liab. Nitrification yog cov kua qaub- tsim cov txheej txheem (siv alkalinity) uas feem ntau ua rau pH poob. Yog hais tias ammonia concentrations nyob twj ywm siab thoob plaws hauv lub tank aerobic thaum lub pH nce los yog tsis poob, nws qhia tau hais tias nitrification yog tsis tshua muaj zog los yog tau tso tseg tag nrho. Qhov tshwm sim no ua haujlwm ceeb toom ntxov- muab kev ceeb toom ua ntej txij li feeb mus txog ze li ib teev- ntawm qhov yuav tshwm sim nitrification system tawg, muab cov txiaj ntsig kwv yees ntau dua li cov ntaub ntawv ammonia ib leeg.
