Cov kub txias yog cov yeeb ncuab ntawm kev tshem tawm cov nitrogen lom. Raws li cov dej kub poob qis dua 15 degree, nitrifying cov kab mob ua rau lawv cov metabolic qeeb heev - thiab ntawm qhov siab siab, cov huab cua nyias nyias ua rau qhov teeb meem los ntawm kev txo cov pa oxygen hloov mus txog 22%. Cov ntaub ntawv kawm no tshuaj xyuas yuav ua li cas 85,000 m³ / d kev kho dej khib nyiab cog rau ntawm Qinghai-Tibet Plateau ntawm 2,200 m qhov siab tau siv MBBR thev naus laus zis los txhawb nqa93-96% ammonia tshem tawm txawm nyob ntawm 9 degree, ua tau raws li Tuam Tshoj Qib 1A effluent qauv xyoo -round.
Qhov project Background
Nyob rau hauv ib cheeb tsam nroog uas muaj neeg coob coob ntawm Qinghai-Tibet Plateau, WWTP no tau pib ua haujlwm rau xyoo 2010 nrog cov txheej txheem "biological disc + aeration tank" txheej txheem tsim los rau COD thiab ammonia tshem tawm. Thaum lub sijhawm ntawd, cov dej ntws tawm yuav tsum ua kom tau raws li Qib 1B cov qauv hauv qab GB 18918-2002 - lub hom phiaj tseem ceeb. Txawm li cas los xij, nrog kev loj hlob sai, kev tso tawm ntau zuj zus, thiab kev nruj dua ib puag ncig cov cai tswj hwm kev tshem tawm tag nrho cov nitrogen mus rau Qib 1A (NH₃-N Tsawg dua lossis sib npaug li 5 mg / L, TN Tsawg dua lossis sib npaug li 15 mg / L), cov nroj tsuag tau ntsib qhov tseem ceeb rov ua dua tshiab. The challenge was not just technical but physical: the existing tank volume was fixed, and expanding the footprint was not feasible given the dense surrounding infrastructure.
Lub tswv yim retrofit maximized tshem tawm nitrogen nyob rau hauv lub constrained tank geometry. Channels 1 thiab thawj ib nrab ntawm Channel 2 tau hloov mus rau hauv ib qho chaw anoxic rau denitrification, thaum lub sij hawm ib nrab ntawm Channel 2 thiab Channels 3 thiab 4 tau raug xaiv raws li aerobic MBBR cheeb tsam rau nitrification. Ntau dua li hloov cov aeration discs uas twb muaj lawm, pab pawg engineering tau khaws lawv thiab qhia MBBR cov xov xwm ncaj qha rau hauv aerobic channels - hloov lub kaw lus rau hauvhybrid integrated fixed -film activated sludge (IFAS) txheej txheem. Txoj kev no txo qis cov nqi rov qab thaum siv cov peev txheej uas twb muaj lawm.
Key Tsim Parameters
| Parameter | Tus nqi |
| Tsim kev khiav | 85,000 m³/d |
| Dej kub ntau yam | 9-26℃(lub caij ntuj no yam tsawg kawg nkaus 9 degree) |
| Influent COD | 350-500 mg / L |
| Influent NH₃-N | 35-55 mg / L |
| Influent TN | 45-70 mg / L |
| Aerobic Tank HRT | 8,2h ua |
| MBBR media filling ratio | 30% (media ntim / tank ntim) |
| Media specification | PE cylindrical cab kuj, Φ15 mm × 15 mm, 800 m² / m³, ceev 0.96 g / cm³ |
| Lub hom phiaj dej (Qib 1A) | COD Tsawg dua lossis sib npaug rau 50, NH₃-N Tsawg dua lossis sib npaug rau 5, TN Tsawg dua lossis sib npaug rau 15, SS Tsawg dua lossis sib npaug 10, BOD₅ Tsawg dua lossis sib npaug li 10 mg / L |
Carrier thiab Biofilm Science
Qhov kev xaiv ntawm cov khoom siv xov xwm yog qhov kev txiav txim siab tsim qauv tseem ceeb tshaj plaws nyob rau hauv txias - huab cua MBBR daim ntawv thov. Qhov phiaj xwm no tau xaiv cov neeg nqa khoom siab tshaj -density polyethylene (HDPE) cylindrical carriers, thiab qhov laj thawj qhia tias vim li cas cov cab kuj tseem ceeb tshaj li cov neeg ua haujlwm feem ntau paub.
Qhov chaw siab tshwj xeeb (800 m² / m³):Ntawm 30% sau piv, qhov zoo ntawm biofilm thaj tsam thaj tsam yog kwv yees li 240 m² ib cubic meter ntawm tank ntim - kwv yees li 8 mus rau 10 npaug ntawm cov pa activated sludge tuaj yeem muab tau. Qhov chaw saum npoo loj no txhais tau hais tias lub reactor tuaj yeem tuav lub nitrifier cov pej xeem ntom ntom uas raug tshem tawm - cov kab ke loj hlob tsis tuaj yeem sib xws, uas yog qhov laj thawj tseem ceeb MBBR ua haujlwm ntawm qhov kub qis. Txawm hais tias qhov txo qis metabolic ntawm 9 degree, qhov ntau npaum li cas ntawm nitrifiers khaws cia ntawm cov neeg nqa khoom them rau qeeb qeeb rau - cell kinetics.
Ze ntawm - nruab nrab buoyancy (0.96 g / cm³):Ntawm qhov siab siab, qhov twg atmospheric oxygen ib nrab siab tsuas yog li ntawm 78% ntawm hiav txwv- theem qhov tseem ceeb, kev hloov pauv oxygen twb cuam tshuam los ntawm physics. Cov cab kuj nyob hauv qab dej ua kom cov xov xwm nyob twj ywm raug ncua thiab nthuav tawm dawb nrog cov khoom siv hluav taws xob tsawg tsawg - kev ua haujlwm tseem ceeb thiab kev lag luam xav txog thaum txhua kWh ntawm lub tshuab hluav taws xob yuav tsum kov yeej ob qho tib si lom neeg xav tau thiab qhov siab siab - ntxias hloov tsis tau.
Kev tiv thaiv sab hauv nto geometry:Cov duab cylindrical nrog tus ntoo khaub lig sab hauv -bracing tsim cov chaw nyob microenvironments uas biofilm yog thaiv los ntawm hydraulic shear rog thaum sib tov. Qhov kev tiv thaiv no tso cai rau cov ntaub ntawv biofilm tuab dua, muaj zog dua los tsim - qhov txiaj ntsig tseem ceeb hauv cov xwm txheej txias uas qhov kev loj hlob ntawm biofilm yog qhov pib qeeb thiab cov zej zog microbial xav tau txhua qhov txiaj ntsig los tsim thiab pheej mus txog lub caij ntuj no ntev.
Txias -Climate Nitrification Mechanism
Ntawm qhov kub thiab txias, bio nitrification ntsib peb qhov teeb meem sib cuam tshuam uas cov pa activated sludge tawm tsam kom kov yeej:
1. Txo tus nqi metabolic:Ammonia-cov kab mob oxidizing (AOB) thiab nitrite- cov kab mob oxidizing (NOB) muaj qhov tshwj xeeb loj hlob qis dua 15 degree. Hauv kev ncua - txoj kev loj hlob, qhov no txhais tau hais tias cov neeg nitrifier tuaj yeem raug ntxuav tawm ntawm lub reactor yog tias lub sij hawm khaws cov khib nyiab (SRT) tsis txaus - ib qho kev ua lej tsis yooj yim thaum qhov kev loj hlob poob qis dua tus nqi nkim. MBBR daws qhov no los ntawm immobilizing nitrifiers hauv biofilm, qhov twg SRT zoo tshaj lub sijhawm tuav hydraulic. Txawm tias nyob rau ntawm 9 degree, cov pejxeem tseem nyob ruaj khov thiab ua haujlwm zoo.
2. Oxygen hloov txwv:Ntawm 2,200 m qhov siab, cov pa oxygen saturation concentration nyob rau hauv dej yog kwv yees li 22% qis dua nyob rau hauv hiav txwv theem, txo tus tsav tsheb rau oxygen loj hloov ntawm cov pa npuas mus rau cov kua. Biofilm architecture mitigates qhov no: cov txheej txheem aerobic sab nrauv siv cov pa oxygen rau nitrification, tswj kom muaj qhov siab siab gradient uas ua kom muaj txiaj ntsig zoo tshaj plaws, thaum sab hauv anoxic cheeb tsam txhawb kev denitrification siv cov nitrate tsim nyob rau hauv txheej txheej.
3. Substrate diffusion txwv:Cov dej txias dua yog khov dua, uas ua rau qeeb cov molecular diffusion ntawm ammonia thiab oxygen rau hauv biofilms. MBBR txoj hauv kev hais txog qhov no los ntawm kev tuav cov txheej nyias nyias, cov txheej txheem metabolically active txheej txheej biofilm (feem ntau yog 150-300 μm) uas txo qhov ntev ntawm txoj kev diffusion, kom ntseeg tau tias substrate ncav cuag nitrifiers txawm nyob rau hauv txias, nkig dej.
Kev ua tau zoo
Cov nroj tsuag retrofitted tau ua haujlwm ruaj khov txij li pib ua haujlwm, thiab cov ntaub ntawv qhia txog zaj dab neeg txaus ntshai. Cov lus hauv qab no nthuav qhia cov cim qhia txog kev ua haujlwm tseem ceeb thoob plaws lub caij ntuj sov - nco ntsoov tshwj xeeb tshaj yog qhov kev puas tsuaj me me tshwm sim ntawm lub caij ntuj sov thiab lub caij ntuj no.
Table 1: MBBR kev ua tau zoo thoob plaws lub caij ntuj sov ntau yam
| Parameter | Lub caij ntuj sov (20-26 degree) | Lub caij ntuj no (9-13 degree) | Qhov nruab nrab txhua xyoo |
| Cov kua dej COD (mg / L) | 28–35 | 32–42 | 33 |
| Kev tshem tawm COD (%) | 91–93 | 89–91 | 91 |
| NH₃{0}}N (mg/L) | 0.8–1.5 | 1.8–3.2 | 1.6 |
| NH₃-N Tshem Tawm (%) | 96–98 | 93–96 | 96 |
| Cov kua dej TN (mg / L) | 9–12 | 11–14 | 10.5 |
| Kev tshem tawm TN (%) | 78–82 | 74–78 | 79 |
Lub caij ntuj no kev ua tau zoo heev: txawm nyob rau ntawm 9 degree,NH₃-N tshem tawm nyob saum 93%nrog cov kua dej tsis tu ncua qis dua 3.2 mg / L - yooj yim hauv 5 mg / L Qib 1A qab nthab. Kev tshem tawm TN tuav ntawm 74-78%, ua tau raws li 15 mg / L tus qauv. Kev tshem tawm COD tseem nyob ruaj khov ntawm 89–91%, lees paub tias kev ua haujlwm heterotrophic yog qhov ntsuas kub tsawg dua -sensitive hauv biofilm systems dua li raug tshem tawm - kev loj hlob kev teeb tsa.
Qhov Tseem Ceeb Ua Tau Zoo
Tsawg-Load Biofilm Acclimation
Ua ntej lub caij ntuj no pib, cov nroj tsuag tau txiav txim siab, maj mam txo cov organic loading npaum li 3-lub lim tiam. Vim li cas qhov no tseem ceeb? Thaum qis qis qis, cov kab mob heterotrophic - uas loj hlob sai dua nitrifiers - tau tshaib plab ntawm lawv cov thawj substrate, ua rau qeeb qeeb - cov kab mob nitrifying loj hlob zoo dua. Lub tswv yim ua ntej no -acclimation lub tswv yim tso cai rau cov neeg nitrifier kom ncav cuag qhov siab tshaj plaws ua ntej qhov kub thiab txias, tsim kom muaj roj ntsha tsis zoo uas ua rau muaj kev ua tau zoo los ntawm lub hli txias tshaj plaws. Yog tsis muaj cov kauj ruam no, nitrifiers nkag mus rau lub caij ntuj no ntawm sub-peak cov pej xeem yuav pom ntau dua kev poob qis.
Carrier Retention Design
Stainless hlau wedge-cov ntxaij vab tshaus hlau nrog qhov tseeb 3 hli qhov qhib tau ntsia ntawm lub qhov hluav taws xob tank. Qhov qhib qhov loj me no tau ua tib zoo xaiv - loj txaus kom tso cai rau cov dej cawv sib xyaw (MLSS) kom dhau los ntawm kev ywj pheej, tab sis me me kom ntseeg tau khaws cov 15 hli txoj kab uas hla. Kev tshuaj ntsuam clogging, ib qho mob taub hau hauv MBBR kev ua haujlwm, tau tiv thaiv los ntawm kev siv cov huab cua sib cuam tshuam uas tshem tawm cov khoom khib nyiab ua ntej lawv tuaj yeem tsim ib daim lev.
Progressive Aeration Strategy
Kev siv aeration tau nce zuj zus los ntawm qhov nkag mus rau qhov chaw qhov hluav taws xob, sib piv cov pa oxygen mus rau qhov sib txawv ntawm qhov xav tau. Nyob rau hauv lub inlet, qhov twg ammonia concentrations siab tshaj, siab aeration tus nqi tsav ceev nitrification. Ntawm qhov hluav taws xob, txo qis aeration txuag lub zog thaum tswj DO ntawm 2-3 mg / L hauv thaj chaw nitrification. Qhov profile tapered no kuj tsim micro-gradients hauv biofilm uas txhawb nqaib txhij nitrification -denitrification (SND)- qhov dawb huv grail ntawm lom nitrogen tshem tawm - qhov twg nitrate tsim nyob rau hauv aerobic txheej txheej biofilm diffuses sab hauv thiab yog denitrified nyob rau hauv lub anoxic core, tag nrho nyob rau hauv ib tug carrier.
Hla -Kev ntsuas huab cua
Qinghai cog li cas piv rau MBBR kev teeb tsa hauv huab cua sov? Table 2 muab cov lus teb - thiab nws muaj kev txhawb zog ntau dua li ntau tus engineers xav tau.
Table 2: MBBR Performance Comparison Across Climate Zones
| Parameter | Qinghai (Cold Plateau 9-26 degree) | Northern China (Tshooj 12-30 degree) | Cov teb chaws Es Xias Qab Teb (Tshooj 25-32 degree) |
| Qhov siab (m) | 2,200 | 50 | 5 |
| Lub caij ntuj no NH₃-N Tshem Tawm (%) | 93–96 | 94–97 | 95–98 |
| HRT (hli) | 8.2 | 6.5 | 5.0 |
| Media Fill Ratio (%) | 30 | 25 | 20 |
| Aeration Zog (kWh / kg COD tshem tawm) | 0.38 | 0.31 | 0.28 |
Cov ntaub ntawv lees paub tus qauv zoo ib yam: txias- huab cua MBBR cov tshuab yuav tsum muaj HRT siab dua (8.2 vs. 5.0 teev) thiab sau qhov sib piv (30% vs. 20}%) los them rau cov kab mob kinetics qeeb, tab sis lawvua tau zoo sib piv kev kho mob rau sov- huab cua systems. Qhov 2–3 feem pua ntawm cov ntsiab lus sib txawv nyob rau lub caij ntuj no NH₃-N tshem tawm ntawm Qinghai thiab tropical systems yog qhov me me uas tau muab qhov sib txawv ntawm 16-23 degrees. Qhov no yog qhov muaj txiaj ntsig zoo ntawm biofilm-raws li nitrogen tshem tawm raws li kev nyab xeeb- thev naus laus zis thev naus laus zis.
Cov Lus Qhia Ua Haujlwm tau kawm
Txias- huab cua pib- nce:Kev ua haujlwm thaum lub caij ntuj no yog qhov nyuaj tab sis ua tau tag nrho nrog cov noob sludge los ntawm cov kab mob nitrifying mature thiab 4-6 lub lis piam ramp- lub sij hawm nce. Lub biofilm siv sijhawm ntev dua los tsim kom muaj qhov kub thiab txias, tab sis ib zaug tsim, nws yog tus kheej - txhawb nqa. Sim ua kom luv luv lub sij hawm acclimation invariably ua rau kev ua haujlwm tsis zoo.
Carrier mixing optimization:Ntawm 30% sau piv, aeration tus nqi ntawm 3-5 Nm³ / m²·h yog txaus rau tag nrho cov cab kuj. Pab neeg no pom tias kev siv aeration ntau dhau ntawm qhov ntau ntawm qhov no nkim lub zog yam tsis muaj kev txhim kho kev sib xyaw - ib qho yuam kev tsis tu ncua hauv MBBR kev ua haujlwm uas cov neeg ua haujlwm xav tias "ntau huab cua sib npaug zoo dua sib xyaw."
Biofilm thickness xyuas:Kev ntsuas ib ntus ntawm biofilm thickness siv cov qauv coj mus kuaj thiab kuaj kab mob - lub hom phiaj 150–300 μm - tau ua pov thawj qhov tseem ceeb rau kev ua kom zoo dua SRT thiab tiv thaiv cov khoom siv biofilm ntau dhau. Biofilms thicker dua 300 μm muaj kev pheej hmoo tsim anaerobic aav uas tuaj yeem ua rau sloughing thiab unpredictable kev ua tau zoo viav vias.
Lub caij ntuj no foaming tswj:Pib-thaum lub hli txias tuaj yeem ua rau me me filamentous foaming vim cov zaub mov tsawg-rau- kab mob (F/M) piv. Cov nroj tsuag tau tswj qhov no nrog kev tswj cov sludge nkim thiab ib ntus tiv thaiv -ua npuas dej - kev ua haujlwm me me uas yuav tsum tsis txhob cuam tshuam cov nroj tsuag los ntawm lub caij ntuj no commissioning.
Xaus
Qhov project Qinghai ua tiav qhia tau hais tias MBBR thev naus laus zis tuaj yeem xa cov khoom siv hluav taws xob txhim khu kev qha, siab -kev tshem tawm nitrogen nyob rau hauv qhov chaw txias toj siab uas cov pa activated sludge yuav tawm tsam kom tau raws li cov qauv tso tawm niaj hnub no. Plaub qhov kev ua haujlwm tseem ceeb - siab- tshwj xeeb-nto- cheeb tsam HDPE cov cab kuj uas khaws qeeb- loj hlob nitrifiers, biofilm architecture txhawb nqa ib txhij nitrification-denitrification, ua ntej-lub caij ntuj no acclimation tapered microbial zog tsim kom zoo dua cov zej zog, tsim kom zoo dua - tsim ib lub moj khaum uas hloov tau uas cov nroj tsuag ntsib cov teeb meem zoo sib xws tuaj yeem txais kev ntseeg siab.
Rau cov kws tsim khoom thiab cov thawj coj ntawm cov nroj tsuag uas cuam tshuam nrog huab cua txias, qhov siab siab, txwv hneev taw, lossis nruj txwv tsis pub tso tawm nitrogen, MBBR muajpov thawj, tus nqi -txoj kev ua haujlwm tau zoouas tsis xav tau kev ua haujlwm loj hauv pej xeem lossis nthuav dav tankage.
Qhia meej siab -Kev Ua Haujlwm MBBR Media rau Koj Qhov Txias-Kev nyab xeeb
Juntai Yas tsim cov neeg nqa khoom HDPE MBBR nrog 800 m² / m³ tiv thaiv thaj chaw, tsim kho kom txias - huab cua thiab siab - qhov siab ntawm qhov dej khib nyiab. Peb cov neeg nqa khoom muaj cov tswv cuab cylindrical geometry nrog cov ntoo khaub lig sab hauv -bracing rau qhov siab tshaj plaws biofilm tuav thiab tsawg kawg shear poob - txhawb nqa los ntawm kev txhawb nqa los ntawm cov txheej txheem tsim los ntawm commissioning.