Cov teebmeem ntawm pH ntawm Simultaneous Nitrogen thiab Manganese Tshem Tawm hauv MBBR
Kev cuam tshuam ntawm pH ntawm MBBR Performance
pH ua lub luag haujlwm tseem ceeb hauv kev ua haujlwm ntawm Moving Bed Biofilm Reactors (MBBR) los ntawm kev cuam tshuam ncaj qha rau kev ua haujlwm microbial thiab cov tshuaj tiv thaiv biochemical. Raws li qhov tseem ceeb ntawm ib puag ncig, pH variations cuam tshuam rau:
- Biofilm zej zog qauv- Hloov pauv hauv pH hloov qhov kev tswj hwm ntawm nitrifying/denitrifying kab mob thiab manganese- oxidizing kab mob.
- Kev ua haujlwm enzyme- Cov pH zoo tshaj plaws tswj kev ua haujlwm ntawm nitrite oxidoreductase (pH 7-8) thiab manganese oxidase (pH 6-7).
- Redox tshuaj tiv thaiv kinetics- pH txiav txim siab qhov sib npaug ntawm Mn²⁺/Mn⁴⁺ transformations thiab nitrogen conversion pathways.
- Tej zaum dej nag - Higher pH (>8) txhawb Mn²⁺ oxidation thiab phosphate nag lossis daus, thaum acidic tej yam kev mob (pH<6) may inhibit these processes.
Lub kaw lus pom tau tias muaj kev hloov pauv tau zoo, nrog qee cov kab mob microbial tswj kev ua haujlwm thoob plaws pH ntau yam (5-9), txawm hais tias qhov kev tshem tawm zoo tshaj plaws rau cov kab mob sib txawv tshwm sim ntawm cov pH tshwj xeeb.
MBBR Kev Ua Haujlwm Raws li qhov sib txawv pH
Ib txoj kev tshawb fawb tsis ntev los no los ntawm ib lub tsev kawm ntawv hauv Suav teb tau tshawb xyuas qhov ua tau zoo ntawm Moving Bed Biofilm Reactor (MBBR) cov tshuab nyob rau hauv cov pH sib txawv (pH 5-9), thiab nyob rau hauv cov xwm txheej ntawm ib qho muaj zog Mn²⁺ concentration ntawm 10 mg·L⁻¹. Qhov muaj txiaj ntsig thiab muaj txiaj ntsig ntawm NH₄⁺-N, TN, TP, COD, Mn²⁺, NO₂⁻-N, thiab NO₃⁻-N thaum lub sijhawm ua haujlwm IV yog cov ntsiab lus hauv qab no.
(1)NH₄⁺-N tshem tawm Efficiency
The MBBR demonstrated consistently high NH₄⁺-N removal across all pH levels, with average efficiencies of 96.22% (pH 5), 98.89% (pH 6), 98.70% (pH 7), 98.65% (pH 8), and 96.69% (pH 9). These results indicate robust nitrification performance (>96% efficiency) tsis hais pH variation. Thaum qhov kev tshem tawm tau pib nce los ntawm pH 5 mus rau 6 (ntaus ntawm 98.89%) ua ntej maj mam txo qis ntawm pH siab dua, tag nrho cov kev cuam tshuam ntawm pH ntawm NH₄⁺-N tshem tawm tsawg heev. Qhov no qhia tau hais tias muaj zog adaptability ntawm nitrifying kab mob nyob rau hauv biofilm rau pH hloov pauv.
(2) TN tshem tawm Efficiency
Tag nrho cov nitrogen tshem tawm pom qhov tseem ceeb pH dependence:
- PH 5: 40.13%
- PH 6: 42.66%
- PH 7: 49.20%
- PH 8: 52.74%
- pH 9:69.79%(Peak Performance)
Qhov 29.66% kev txhim kho los ntawm pH 5 mus rau 9 qhia txog kev txhim kho denitrifying microbial kev ua haujlwm nyob rau hauv alkaline tej yam kev mob.
(3) COD tshem tawm Efficiency
Kev tshem tawm COD ua raws lub tswb -zoo li tus nkhaus:
- Optimal nruab nrab pH94.27% ntawm pH 7
- Txo thaum kawg:
- pH 5: 90.85%
- pH 9: 53.81%
The sharp drop at pH>7 qhia tias inhibition ntawm cov kab mob heterotrophic hauv alkaline ib puag ncig.
(4)Mn²⁺ Tshem Tawm Ua Haujlwm
Mn²⁺ tshem tawm tau zoo tshaj plaws nyob ze -pH nruab nrab:
- pH 695.74% (zoo rau Mn²⁺ → MnOx oxidation)
- pH 5/9: <60% efficiency
Qhov no cuam tshuam nrog manganese-oxidizing microbial kev ua ub no.
(5) TP Tshem Tawm Ua Haujlwm
Kev tshem tawm phosphorus txhim kho linearly nrog pH:
- pH 5: 20.70% → pH 9:51.76%
Qhov qis tshaj TP (2.80 mg/L ntawm pH 9) qhia tias alkaline-favored PAOs kev ua.
(6)NO₃⁻-N & NO₂⁻-N Dynamics
- NO₃⁻-N txo qis ntawm pH 9: 5.89 mg/L (vs . 11.63 mg/L ntawm pH 5)
- ruaj khov NO₂⁻-N txuam nrog (0.16–0.19 mg/L) thoob plaws txhua theem
Qhov no qhia tau hais tias synergistic nitrification -denitrification ntawm alkaline pH.
Xaus
Nyob rau hauv cov xwm txheej ntawm qhov muaj zog Mn²⁺ concentration ntawm 10 mg·L⁻¹, qhov kev tshawb fawb no tau tshawb xyuas ntxiv txog qhov cuam tshuam ntawm pH sib txawv ntawm MBBR kev ua tau zoo rau kev kho dej khib nyiab. Cov txiaj ntsig tau pom tias thaum lub zog pH tau nce mus rau 9, qhov nruab nrab tshem tawm cov txiaj ntsig ntawm NH₄⁺-N, TN, thiab TP mus txog96.69%, 69.79%, thiab 51.76%, raws. Piv rau Phase I (pH 5), kev tshem tawm cov txiaj ntsig ntawm TN thiab TP tau nce ntau heev los ntawm29.66% thiab 31.06%, raws.
Cov kev tshawb pom tseem ceeb
1. Kev ua tau zoo ntawm pH 9
- Siab tshaj N&P Tshem Tawm: MBBR nthuav tawm nws qhov zoo tshaj plawsdenitrification thiab phosphorus tshem tawmmuaj peev xwm nyob rau hauv alkaline tej yam kev mob (pH 9), nrog tsawg NO₃⁻-N tiam thiab nyob ze- ua tiav NH₄⁺-N hloov dua siab tshiab.
- Enhanced Microbial Activity: CovZoo Tag Nrho Thaj Chaw (ETSA)ntawm biofilm tau nce proportionally nrog pH (7-9), nce siab ntawm pH 9, qhia txog kev ua haujlwm metabolic zoo tshaj hauv cov kab mob alkaline. Qhov no yuav yog vim muaj ntau ntawm cov dawb hydroxide ions (OH⁻), uas txhim khoib txhij nitrification -denitrification (SND) efficiency.
2. Mn²⁺ Tshem Tawm Mechanism
- Extracellular Adsorption Dominance: Hla txhua theem (I-V), dhau75% ntawm Mn²⁺ tshem tawmtau tiav los ntawm extracellular adsorption los ntawm biofilm microorganisms.
3. Microbial Community Dynamics
- Alkaline{0}}Favored Denitrifiers: Qhov tseem ceeb denitrifying genera xws li Comamonas thiab Hyphomicrobium tau pom tias muaj cov txheeb ze ntau ntxiv ntawm cov pH siab dua, paub meej tias lawv hloov mus rau alkaline ib puag ncig.
- Comamonas aquatica LNL3 tau pom qhov tshwj xeeb ntawm cov metabolic versatility, converting NH₄⁺-N → NO₂⁻-N thiab NH₄⁺-N → N₂.
- Txhim kho Biodiversity ntawm pH 9: Unique Operational Taxonomic Units (OTUs) tau nce los ntawm2 (pH 5) txog 13 (pH 9), reflecting ntau dua microbial nplua nuj nyob rau hauv alkaline tej yam kev mob.
4. Muaj nuj nqi cuam tshuam
- Synergistic Nutrient Tshem Tawm: Alkaline pH (9) txhawb kev ua haujlwm ntawmpolyphosphate-cov kab mob sib txuas (PAOs)thiabdenitrifying kab mob(eg, Acinetobacter), optimizing ib txhij N-P tshem tawm.
- Txheej Txheem Stability: The MBBR maintained robust Mn²⁺ adsorption (>75%) tsis hais txog kev hloov pauv ntawm pH, qhov tseem ceeb ntawm qhov system resilience.
Cov kev cuam tshuam
- Pom zoo ua haujlwm pH: 8.5–9.0rau TN/TP tshem tawm ntau tshaj plaws hauv Mn²⁺- hloov kho MBBR systems.
- Microbial Management: Bioaugmentation nrog Comamonas lossis Hyphomicrobium hom tuaj yeem txhim kho denitrification hauv alkaline reactors.