Technical Fundamentals & Operational Management of a Low -Load Blower Aeration Basin
1. Txheej txheem cej luam
1.1 Txoj Cai Ua Haujlwm ntawm Blower Aeration Basins
Blower aeration, feem ntau siv hauv Suav teb, feem ntau suav nrog diffused, kauv, thiab microporous aeration hom. Lub aeration phiab feem ntau muaj xws li aeration system, lub phiab qauv, thiab inlet / outlet ports, ua ib tug tseem ceeb qauv nyob rau hauv activated sludge wastewater kho mob. Cov txheej txheem aeration feem ntau yog mechanical thiab blower aeration. Blower aeration systems feem ntau muaj xws li tshwj xeeb aerators thiab blowers. Cov basins feem ntau muab faib ua ntau qhov chaw, txhua tus muaj peev xwm ua kom muaj kev ywj pheej pub noj. Cov dej khib nyiab nkag mus rau hauv lub phiab thiab tawm ntawm qhov kawg. Thaum lub sij hawm tus txheej txheem no, huab cua yog xa los ntawm compressors rau diffusers ntawm lub phiab hauv qab thiab tso tawm raws li npuas.
1.2 Kev tshawb fawb ntsig txog ntawm Blower Aeration Basins
Kev tshawb fawb los ntawm Cheng Dandan et al. pom tias nyob rau hauv Tuam Tshoj lub nroog qhov chaw kho dej khib nyiab (WWTPs), aeration blowers siv kwv yees li 60% ntawm tag nrho cov zog. Kev koom ua ke ntawm lub tshuab aeration nrog ntse PID kaw- voj tswj rau cov pa oxygen (DO) thiab kev siv lub tshuab hluav taws xob-txuag cov tswv yim tuaj yeem hais txog kev siv hluav taws xob siab hauv WWTP aeration systems, txo qis dua 30%.
Liu Xiaoqi et al. ua hauj lwm dispersed flow aerators kom muaj cov pa oxygen hauv cov dej khib nyiab thaum kho thaum txo kev siv hluav taws xob. Qhov no kuj ua tiav cov dej tsis sib xws - huab cua sib xyaw thiab kev faib tawm, txo qhov kev xav tau ntawm lub tshuab aerator installation leveling.
Chang Kai et al. txhim kho cov pa aeration basin system kev ua tau zoo los ntawm kev hloov kho qhov qub huab cua sau hom. Lawv hloov cov tshuaj microporous aerators nrog cov pa oxygen siab -hloov efficiency silicone phaj microporous aerators thiab hloov ib zaug - hla ncaj- ntws aeration basins nrog peb - dhau serpentine flow basins. Incorporating precise aeration tswj ntxiv txhim khu kev qha system, hais txog cov teeb meem ntawm siab zog noj, tsis muaj efficiency, thiab tsis zoo huab hwm coj hloov nyob rau hauv ib txwm blower aeration txoj kev.
1.3 Kev Tswj Xyuas Kev Ua Haujlwm ntawm Blower Aeration Basins
Blower aeration basins yog dav siv hauv kev kho dej khib nyiab. Ua raws li lub hauv paus ntsiab lus ntawm "kev kho cais rau cov dej khib nyiab sib txawv," ib qho tshwj xeeb WWTP's saline wastewater kho chav ua haujlwm feem ntau yog siv hluav taws xob desalination wastewater los ntawm atmospheric-nqus distillation, stripped purified dej, alkylation neutralization wastewater, thiab ib co supernatant thiab siab -salinity. Chav tsev no nta peb -theem kev kho kab mob lom, nrog rau lub tshuab nqus cua tshuab ua rau theem nrab. Nws qhov nruab nrab muaj zog Chemical Oxygen Demand (COD) tsis tu ncua qis dua 100 mg / L, faib nws raws li qis -load activated sludge process. Tshaj li cov cuab yeej hloov kho dua tshiab, kev tswj xyuas kev ua haujlwm kom zoo yuav tsum tau ceev faj tswj thiab kho cov txheej txheem tsis ua haujlwm.
2. Kev Saib Xyuas Qhov Chaw
2.1 Saline Wastewater Treatment Unit Process Flow
Chav tsev ntiav cov txheej txheem "Equalization + Oil Separation + Ob-Stage Flotation + Three-Stage Biological Treatment" txheej txheem, nrog rau kev kho cov dej xa mus rau chav polishing. Cov roj separator siv kev sib xyaw ua ke kab rov tav thiab inclined phaj tsim. Ob theem flotation siv Vortex Cavitation Air Flotation (CAF) thiab Partial Reflux Pressurized Dissolved Air Flotation (DAF), feem. Peb theem kev lom neeg muaj raws li nram no: Pure Oxygen Aeration Tank III, Blower Aeration Tank, thiab Secondary Biochemical Tank (EM-BAF). Cov txheej txheem ntws tau qhia hauvDaim duab 1.
2.2 Blower Aeration Basin Description
Lub tshuab nqus dej aeration phiab yog qhov chaw rov tsim dua qub tsim hauv xyoo 1995 ua ib feem ntawm chav kho dej khib nyiab oily. Nws siv ib txwm ntsaws- ntws aeration tsim nrog lub ntim zoo ntawm 3,888 m³ thiab lub sijhawm hydraulic tuav tam sim no (HRT) kwv yees li 17.6 teev. Lub phiab ua haujlwm nyob rau hauv ob lub tsheb ciav hlau sib txuas, txhua qhov muaj plaub qhov chaw. Aerators yog ntsia rau hauv qab, muab los ntawm centrifugal blowers los muab oxygen rau activated sludge metabolism. Nws kuj tau nruab nrog ob lub ntsiab lus meej (Φ18m x 5m).
Hauv peb -theem biological system:
- Theem 1 (Ntshiab Oxygen Aeration Tank III): Lub luag haujlwm tseem ceeb yog COD tshem tawm.
- Theem 2 (Blower Aeration Tank): Lub luag haujlwm tseem ceeb yog ammonia nitrogen (NH₃-N) tshem tawm, kev ua haujlwm thib ob yog ntxiv COD tshem tawm.
- Theem 3 (Secondary Biochemical Tank - EM-BAF): Muaj nuj nqi ntxiv rau polish effluent COD thiab NH₃-N, ua kom cov dej zoo kawg nkaus.
2.3 Blower Aeration Basin Influent thiab Effluent Quality
Kev cuam tshuam rau lub tshuab nqus cua tshuab los ntawm Pure Oxygen Aeration Tank III, nrog cov pa phem txwv: CODcr Tsawg dua lossis sib npaug li 300 mg / L, NH₃-N Tsawg dua lossis sib npaug li 30 mg / L, Suspended Solids (SS) Tsawg dua lossis sib npaug li 50 mg
Nws cov effluent pub rau Secondary Biochemical Tank, nrog txwv: CODcr Tsawg dua lossis sib npaug rau 120 mg / L, NH₃-N Tsawg dua lossis sib npaug li 30 mg / L, SS Tsawg dua lossis sib npaug li 50 mg / L.
Qhov kawg effluent los ntawm Secondary Biochemical Tank yuav tsum tau raws li: CODcr Tsawg dua los yog sib npaug rau 70 mg/L, Petroleum Tsawg dua los yog sib npaug rau 5 mg/L, NH₃-N Tsawg dua los yog sib npaug rau 3 mg/L.
Thoob plaws xyoo 2021, lub phiab qhov nruab nrab muaj CODcr yog 67.094 mg/L, thiab qhov nruab nrab NH₃-N yog 23.098 mg/L, ob qho tib si raws li kev tsim qauv. Txawm li cas los xij, qhov tsis txaus ntseeg COD ua rau cov pa roj carbon tsis txaus rau cov activated sludge, cuam tshuam nws cov metabolism. Conversely, txaus ammonia nitrogen thiab tsis tshua muaj kuab paug concentration nyob rau hauv cov cawv sib tov nyiam nitrification, uas ua tau zoo.
3. Kev ua haujlwm muaj feem cuam tshuam thiab tswj kev ntsuas
3.1 Kev cuam tshuam ntawm Kev Ua Phem Tsawg thiab Sludge Aging
Nrog COD influent ntawm 67.094 mg/L-hauv qab ob qho tib si tsim txwv (tsawg dua lossis sib npaug li 300 mg/L) thiab cov microbial carbon xav tau (kwv yees . 100 mg/L BOD₅)- cov activated sludge ntsib cov pa roj carbon deficiency. Qhov qis load ua rau qeeb sludge txoj kev loj hlob, ua rau nws yooj yim rau kev laus thiab tsim cov qauv xoob. Laus, tuag sludge tsim scum floating nyob rau theem nrab clarifier nto. Tsis muaj cov khoom siv khib nyiab pov tseg, cov khoom siv khib nyiab no ntws tawm nrog cov dej ntws tawm, ua rau muaj kev kub ntxhov, dhau COD thiab SS txwv, thiab tom qab ntawd overloading downstream Secondary Biochemical Tank, cuam tshuam nws qhov kawg effluent zoo.
Kev ntsuas ntsuas: Pab neeg ua haujlwm tau tswj xyuas qhov sib xyaw ua kua dej Suspended Solids (MLSS) concentration. Siv 1000 mL kawm tiav lub tog raj kheej rau 30-feeb Sludge Volume Index (SVI), lawv khaws SVI nyob ib ncig ntawm 20%, sib npaug rau MLSS ntawm kwv yees li 2 g / L. Qhov kev sib npaug ntawm kev tshem tawm cov pa phem no nrog kev tiv thaiv sludge aging, ntab, thiab dej tsis zoo. Qhov kev loj hlob qeeb qeeb txhais tau tias tsawg thiab tsis tshua muaj sludge nkim, tso cai rau cov kab mob nitrifying lub sij hawm nyob tshaj lawv lub sij hawm tsawg kawg nkaus, ntxiv kev txhawb nqa nitrification.
3.2 Qhov cuam tshuam ntawm Kev Tswj Xyuas Cov Pa oxygen (DO)
Cov kab mob hauv cov activated sludge feem ntau yog aerobic, feem ntau xav tau DO ntawm 1-3 mg / L. Cov qauv kev lag luam tau teeb tsa DO ntau rau cov tsoos plug-flow aeration basins ntawm 2-4 mg / L, nrog nitrification xav tau DO feem ntau tsis qis dua 2.0 mg / L. Tam sim no tsis tshua muaj hluav taws xob load thiab ntxiv txo MLSS concentration txo qis DO thov, ua rau kev tswj nyuaj. Kev tuav tag nrho kev sib xyaw feem ntau tau tsa DO saum toj 4 mg / L, thaum tswj DO nyob rau hauv cov phiaj xwm qee zaum ua rau kev sib xyaw tsis txaus hauv qee qhov chaw, ua rau sludge nyob.
Tsis tas li ntawd, siab DO accelerates organic teeb meem decomposition, exacerbating sludge aging. Yog li, nyob rau hauv kev xyaum, DO yog tswj nyob ib ncig ntawm 3 mg / L. Tsis tas li ntawd, tag nrho cov huab cua li qub tau hloov kho kwv yees li ib hlis los txhim kho kev sib xyaw ua ke, rov ua kom tsis muaj zog flocs, thiab tswj cov khoom siv biomass.
3.3 Kev cuam tshuam ntawm dej kub
Qhov kub thiab txias cuam tshuam rau kev ua haujlwm ntawm microbial. Qhov ntsuas kub tsim nyog txhawb kev ua haujlwm, thaum qhov kub tsis tshua muaj cuam tshuam los yog txo qis, thiab qhov kub siab tuaj yeem hloov kho lub cev lossis ua rau tuag taus. Hauv qhov system no, cov kab mob thermophilic yog cov pab pawg ua haujlwm tseem ceeb. Rau kev nyab xeeb ntawm lub cev, qhov kub thiab txias feem ntau yog nyob nruab nrab ntawm 15-35 degree, txawm tias qhov haum yog 10-45 degree. Tshaj 30℃tuaj yeem denature nitrifier proteins, txo lawv cov haujlwm. Cov activated sludge muaj ob qho COD-degrading thiab nitrifying kab mob, nrog nitrification muaj qhov nqaim dua qhov zoo ntawm 5-30 degree.
Cov dej qab ntsev uas muaj kuab lom muaj qhov kub siab -kub ntws. Cov xwm txheej dhau los cuam tshuam nrog cov hnub sib law liag ntawm qhov kub siab tshaj 40 degree, ua rau sludge disintegration, tuag ntawm COD-degraders thiab nitrifiers, thiab lub cev qhuav dej. Tom qab ntawd, tus pas ntsuas kub tau muab tso rau ntawm qhov sib npaug ntawm lub tank effluent kab kom nruj tswj qhov ntsuas kub kom tsis txhob siab tshaj 40 degree, ua tau raws li qhov yuav tsum tau ua ntawm sludge kub. Tsis muaj qhov xwm txheej zoo sib xws cuam tshuam rau nitrification tshwm sim hauv 2021.
3.4 Kev cuam tshuam ntawm Alkalinity
Raws li cov qauv kev lag luam cuam tshuam, thaum siv cov activated sludge rau kev tshem tawm ammonia, qhov cuam tshuam tag nrho alkalinity rau ammonia nitrogen piv yuav tsum tsis pub tsawg dua 7.14; Txwv tsis pub, alkalinity yuav tsum tau ntxiv. Nrog rau tus qauv tsim muaj txiaj ntsig NH₃-N ntawm 30 mg / L thiab qhov tseeb nruab nrab ntawm 23.098 mg / L, tag nrho cov alkalinity yuav tsum tsis pub tsawg dua 214.2 mg / L. Tam sim no, lub zog alkalinity tsis txaus, xav tau cov dej qab ntsev txhua hnub (Na₂CO₃) ntxiv kom tau raws li cov txheej txheem xav tau.
3.5 Kev cuam tshuam ntawm pH thiab tshuaj lom
Activated sludge microorganisms thrive in a pH range of 6.5–8.5. Below pH 4.5, protozoa largely disappear, most microbial activity is inhibited, fungi become dominant, floc structure is destroyed, and sludge bulking can occur. Above pH 9, metabolism is severely affected, causing floc disintegration and bulking. Wastewater with pH >10 lub<5 should be neutralized before entering the aeration basin.
Aerobic microbial metabolism tuaj yeem hloov pauv pH tsis txaus. Piv txwv li, kev siv nitrogen compound tuaj yeem txo pH thaum lub sij hawm nitrification, thaum decarboxylation tsim alkaline amines, nce pH. Qhov no tso cai rau ntev - lub sij hawm acclimation rau me ntsis acidic/alkaline khib nyiab. Lub hauv paus alkalinity ntawm cov dej khib nyiab kuj pab inhibit pH poob.
Txawm li cas los xij, kev hloov pauv pH (piv txwv li, tam sim ntawd alkaline nkag mus rau hauv cov kua qaub) cuam tshuam rau microbes thiab tuaj yeem cuam tshuam kev ua haujlwm. Yog li ntawd, neutralization yuav tsum tau nyob ntawm qhov xwm txheej tshwj xeeb. Cov me me, zoo ib yam pH hloov pauv, tshwj xeeb tshaj yog nrog cov acids tsis muaj zog / cov hauv paus, yuav tsis xav tau qhov nruab nrab. Kev hloov pauv loj dua yuav tsum hloov pH mus rau nruab nrab.
Nitrifying kab mob yog pH siab heev -sensitive, nrog rau kev pom zoo nitrification ntawm pH 7.2-8.0, thaum cov microbes dav nyiam 6.5-8.5. Rau cov dej khib nyiab tshwj xeeb, hom tshuaj lom neeg feem ntau raug kho, tab sis cov concentrations thiab cov paug tawm hloov pauv. Ntxiv nrog rau kev sib npaug, cov tshuaj lom neeg muaj suab npe yuav tsum tau saib xyuas thiab tswj. Tom qab sludge acclimation, lub siab tshaj plaws concentration txwv yuav tsum tau tsim raws li acclimation℃thiab kev ua hauj lwm. Kev ncua ntev yuav tsum tau ntsuas xws li txo cov dej ntws, ua kom cov sludge rov ua dua, lossis txhim kho cov pa oxygen kom tiv thaiv microbial lom thiab kho tsis ua haujlwm. Tam sim no, tsis muaj cov tshuaj lom uas ua rau muaj kab mob microbial lom nyob rau hauv lub phiab lub zog.
3.6 Kev cuam tshuam ntawm kev cuam tshuam ntawm kev poob siab
Lub zog COD tseem nyob qis qis nrog kev hloov pauv me me, thiab NH₃-N thiab Tag Nrho Nitrogen (TN) kuj tseem nyob hauv qhov chaw ruaj khov nyob rau lub sijhawm ntev. Cov neeg nitrifier tseem nyob ruaj. Txawm li cas los xij, vim tias lawv qhov kev loj hlob qeeb, ib qho kev nce ntxiv ntawm NH₃-N lossis TN tuaj yeem ua rau cov dej ntws tawm ntawm lub phiab, cuam tshuam cov dej ntws NH₃-N thiab TN zoo.
Raws li kev xav, microbial N thiab P xav tau ua raws li BOD₅: N:P piv ntawm 100: 5: 1. Txawm li cas los xij, N thiab P cov ntsiab lus sib txawv heev nrog hom dej khib nyiab. Qee cov dej khib nyiab siab hauv N thiab P, yuav tsum tau tshem tawm kom tau raws li cov qauv. Lwm tus tsis txaus, xav tau kev pab ntxiv kom tsis txhob txwv cov metabolism. Rau kev khiav dej num kho cov dej khib nyiab uas tsis tshua muaj N/P, muaj kev cuam tshuam txog li 10 mg/L NH₃-N thiab 5 mg/L phosphate tuaj yeem ua tau raws li cov kev xav tau ntawm microbial. Kev ncua ntev hauv qab no yuav tsum tau nce N / P koob tshuaj.
Kev ua haujlwm txhua hnub yuav tsum tau ua tib zoo saib xyuas ntawm NH₃-N thiab TN nyob rau hauv tag nrho cov kwj dej uas muaj zog thiab cov dej sib npaug ntawm lub tank, nrog rau cov khoom siv rov ua dua tshiab los ntawm cov tso tsheb hlau luam hloov kho, txhawm rau tiv thaiv overloading downstream polishing unit thiab hem qhov kev nyab xeeb ntawm cov dej xau zaum kawg.
4. Cov lus xaus
Raws li cov tub ntxhais nitrification reactor nyob rau hauv lub saline wastewater kho chav tsev, lub blower aeration phiab yuav tsum tau kaw txhua hnub kev saib xyuas ntawm dej kub, influent NH₃-N, thiab TN. Kev tswj hwm nruj ntawm MLSS concentration, tswj DO nyob ib ncig ntawm 3 mg / L, thiab ua kom muaj cov alkalinity txaus ntxiv yog qhov tseem ceeb. Raws li cov kev ntsuas tau zoo no, lub kaw lus ua haujlwm ruaj khov nrog cov dej ntws zoo: nruab nrab COD ntawm 54.213 mg / L, NH₃-N ntawm 9.678 mg / L, thiab SS ntawm 23.849 mg / L, ua tau raws li Secondary Biochemical Tank cov kev xav tau muaj zog. Kev sim tsis tu ncua, kev sib sau ua ke, thiab kev ua kom zoo los ntawm ntau yam kuj tseem ceeb heev los xyuas kom meej cov cuab yeej kev ntseeg siab thiab kev ua haujlwm zoo.