Nyob rau hauv cov txheej txheem kev kho mob lom ntawm cov dej khib nyiab, lub aeration tank yog qhov tseem ceeb ntawm cov tshuaj tiv thaiv. Nws lub luag haujlwm tseem ceeb yog hloov cov pa oxygen mus rau cov cawv sib xyaw los ntawm cov khoom siv aeration kom tau raws li qhov xav tau ntawm microbial metabolism thiab degradation ntawm cov pa phem. Cov pa oxygen xav tau (O₂ xav tau) hais txog tag nrho cov pa oxygen xav tau los ntawm cov kab mob kom txo qis cov organic teeb meem thiab oxidize ammonia nitrogen, thaum aeration tus nqi yog qhov tseeb tso tawm ntawm cov cuab yeej aeration xam raws li cov pa oxygen xav tau thiab tsis xws li oxygen hloov efficiency. Kev xam qhov tseeb ntawm cov pa oxygen xav tau thiab aeration tus nqi tsis tsuas yog ua kom cov dej khib nyiab muaj txiaj ntsig zoo xwb tab sis kuj ua rau kev siv hluav taws xob zoo thiab txo cov nqi khiav lag luam. Tsab ntawv xov xwm no yuav rhuav tshem cov kev xam pom, cov qauv tseem ceeb, thiab cov ntsiab lus tseem ceeb cuam tshuam ntawm ob qhov kev nthuav dav no, muab cov ntaub ntawv siv rau kev tsim engineering thiab kev hloov kho kev ua haujlwm.
I. Oxygen Demand Calculation (O₂ₙₑₑₙₑₙₜ)
Kev ntsuas cov pa oxygen yog ua raws li cov tshuaj microbial metabolic, suav nrog carbonization oxygen xav tau (degradation ntawm cov organic teeb meem) thiab nitrification oxygen xav tau (oxidation ntawm ammonia nitrogen). Nws tseem yuav tsum tau txiav tawm cov pa oxygen uas siv los ntawm endogenous respiration attenuation thiab cov pa oxygen nqa tawm los ntawm cov pa oxygen yaj hauv cov dej ntws tawm, thaum kawg ua rau tag nrho cov pa oxygen xav tau.
1. Lub hauv paus ntawm kev xam thiab cov qauv
Kev suav ntawm cov pa oxygen xav tau (OD) yog ua raws li qhov tseem ceeb xws li dej tsis zoo (BOD₅, COD, NH₄⁺-N), kev kho kom zoo, thiab cov sludge concentration. Lub ntsiab formula yog raws li nram no:
Tag Nrho Oxygen Demand (O₂ₜₒₜₐₗ)=Carbonization Oxygen Demand (O₂₍ₙ₎) + Nitrification Oxygen Demand (O₂₍ₙᵢₜ₎) - Oxygenous Respiration (O₂₍ₑₙₐₐ₎) - Cov pa nqa tawm los ntawm DO hauv cov dej ntws tawm (O₂₍ₒᵤₜ₎)
(1) Carbonation oxygen xav tau (O₂₍ₙ₎)
Carbonation oxygen xav tau yog cov pa oxygen xav tau rau microbial degradation ntawm biodegradable organic teeb meem. Siv BOD₅ ua qhov taw qhia tseem ceeb, cov qauv kev suav yog:
O₂₍ₙ₎ = a' × Q × (Sᵢₙ - Sₒᵤₜ) - b' × V × X
Kev piav qhia ntawm parameter hauv cov qauv:
1a': Oxygen xav tau coefficient rau cov organic teeb meem degradation (kg O₂ / kg) BOD₅: Rau cov dej khib nyiab hauv tsev, a' raug muab li 0.42 ~ 0.53; rau cov dej khib nyiab hauv kev lag luam, tus nqi yuav tsum tau kho raws li biodegradability (tus nqi siab dua rau biodegradability tsis zoo, tus nqi qis dua rau biodegradability zoo);
1Q: Kev kho ntim (m³ / d);
1Sᵢₙ,Sₒᵤₜ: Influent thiab effluent BOD₅ concentrations (kg / m³, piv txwv li, g / L);
1b': Sludge endogenous respiration oxygen noj coefficient (kg O₂ / (kg MLSS·d)), rau cov dej khib nyiab hauv tsev, b' yog muab li 0.10 ~ 0.15;
1V: Siv tau ntim ntawm aeration tank (m³);
1X: Mixed cawv suspended solids concentration nyob rau hauv lub aeration tank (MLSS, kg / m³).
Nco tseg: Yog tias COD siv los ua qhov ntsuas ntsuas, COD yuav tsum tau hloov mus rau BOD₅ ua ntej (rau cov dej khib nyiab hauv tsev, BOD₅ / COD≈0.5; rau cov dej khib nyiab, yuav tsum ntsuas qhov tseeb).
(2) Nitrification Oxygen Demand (O₂₍ₙᵢₜ₎)
Yog hais tias tus txheej txheem yuav tsum tau nitrification (oxidation ntawm ammonia nitrogen rau nitrate nitrogen), cov nitrification oxygen thov yuav tsum tau xam cais. Cov mis yog:
O₂₍ₙᵢₜ₎=4.57 × Q × (NH₄⁺-Nᵢₙ - NH₄⁺-Nₒᵤₜ) - 0.12 × Q × (NO₃⁂ₜ) {{5} NO₃⁻-Nᵢₙ)
Kev piav qhia ntawm parameter hauv cov qauv:
14.57: Theoretical oxygen thov coefficient rau oxidation ntawm ammonia nitrogen rau nitrate nitrogen (kg O₂/kg) NH₄⁺-N);
10.12: Oxygen noj offset coefficient rau nitrate denitrification (qhov no tuaj yeem tsis quav ntsej yog tias tsis muaj denitrification);
1NH₄⁺-Nᵢₙ, NH₄⁺-Nₒᵤₜ: Ammonia nitrogen concentration hauv influent thiab effluent (kg/m³);
1NO₃⁻-Nᵢₙ, NO₃⁻-Nₒᵤₜ: Nitrate nitrogen concentration hauv influent thiab effluent (kg/m³).
(3) Oxygen Consumption los ntawm Endogenous Respiration thiab Oxygen Carryover los ntawm DO hauv Effluent
Kev siv cov pa oxygen los ntawm kev ua pa endogenous twb tau tshwm sim hauv carbonation oxygen thov mis los ntawm b' parameter thiab tsis tas yuav suav rov qab; Cov qauv rau kev suav cov pa oxygen nqa los ntawm DO hauv effluent yog:
O₂₍ₒᵤₜ₎=8.33 × Q × (DOₒᵤₜ - DOᵢₙ)
Qhov twg: 8.33 yog cov pa oxygen density conversion factor (kg O₂/(m³·mg/L)), DOᵢₙ thiab DOₒᵤₜ yog cov yaj oxygen concentrations ntawm influent thiab effluent (mg/L), feem. Hauv cov xwm txheej ib txwm muaj, DO hauv cov neeg muaj peev xwm tuaj yeem tsis quav ntsej (ntau npaum li 0), thiab DO hauv cov dej ntws yog tswj ntawm 2 ~ 3 mg / L.
2. Piv txwv ntawm Oxygen Demand (OD) Xam Xaj Muab ib qho chaw kho dej khib nyiab hauv tsev uas muaj peev xwm kho tau ntawm Q=1000 m³ / d, muaj txiaj ntsig zoo aeration tank ntim ntawm V=300 m³, muaj txiaj ntsig BOD₅=200 mg/L, effluent BOD₅=20 mg / L, MLSS influent NH₄⁺-N=30 mg/L, effluent NH₄⁺-N=1 mg/L, thiab effluent DO=2 mg/L, noj a'=0.5 thiab b'=0.12.
(1) Carbonation oxygen xav tau: O₂₍ₙ₎=0.5 × 1000 × (0.2 - 0.02) - 0.12 × 300 × 3=90 - 108=-18 (Tus nqi tsis zoo qhia tias endogenous respiration oxygen xav tau ntau dua carbonation oxygen xav tau, yog li peb noj 0);
(2) Nitrification oxygen xav tau: O₂₍ₙᵢₜ₎=4.57 × 1000 × (0.03 - 0.001)=4.57 × 29 ≈ 132.53 kg O₂/d;
(3) Cov pa nqa tawm los ntawm DO hauv cov dej ntws tawm: O₂₍ₒᵤₜ₎=8.33 × 1000 × (2 - 0)=16.66 kg O₂/d;
(4) Tag Nrho Cov Pa oxygen: O₂ₜₒₜₐₗ=0 + 132.53 - 16.66≈115.87kg O₂/d.
II. Kev suav ntawm Aeration Volume (Gₛ)
Aeration ntim yog hais txog cov huab cua uas cov khoom siv aeration yuav tsum tau nkag mus rau hauv lub tank aeration. Nws yuav tsum tau muab xam raws li tag nrho cov pa oxygen xav tau, ua ke nrog cov tsis xws li oxygen hloov efficiency thiab cov pa oxygen cov ntsiab lus. Kev kho rau kev hloov pauv oxygen vim yog yam xws li dej kub thiab huab cua siab kuj yuav tsum tau xav txog.
1. Core Calculation Logic thiab Formula
Cov ntsiab lus ntawm cov pa oxygen hauv huab cua yog kwv yees li 21% (feem ntau seem). Oxygen transfer efficiency (Eₚ) yog hais txog qhov kev faib ua feem ntawm cov pa uas tau kis los ntawm huab cua mus rau cov cawv sib xyaw. Tus nqi aeration yog xam los ntawm cov qauv hauv qab no:
Qhov tseeb Aeration Rate (Gₛ)=Tag Nrho Oxygen Demand (O₂ₜₒₜₐₗ) / (Air Oxygen Content × Oxygen Transfer Efficiency × Correction Factor)
Specific Decomposition Formula:
Gₛ = O₂ₜₒₜₐₗ × 1000 / (0.21 × 1.205 × Eₚ × Kₜ × ... Kₚ)
Kev piav qhia ntawm parameter hauv cov qauv:
10.21: Volume feem ntawm cov pa oxygen hauv huab cua (%);
11.205: Cua ceev (kg / m³, raws li tus qauv, 20 degree, 1 atm);
1Eₚ: Oxygen hloov efficiency (%), Eₚ txawv heev nyob ntawm cov khoom siv aeration: blower aeration (microporous aerator) Eₚ=15% ~ 25%, nto aeration ( impeller aerator) Eₚ=8% ~ 15%;
1Kₜ: Dej kub kho qhov tseem ceeb, Kₜ=1.024^(T-20), qhov twg T yog qhov tseeb dej kub hauv lub tank aeration (degree). Raws li dej kub nce, oxygen solubility txo, thiab Kₜ nce.
1Kₚ: Gas pressure correction factor, Kₚ=P/1.013, qhov twg P yog lub zos atmospheric siab (atm). Raws li atmospheric siab nce, oxygen solubility nce, thiab Kₚ nce.
11000: Unit conversion factor (hloov kg O₂ to g O₂).
2. Piv txwv ntawm aeration tus nqi xam (raws li cov pa oxygen xav tau piv txwv saum toj no) Muab tag nrho cov pa oxygen xav tau O₂ₜₒₜₐₗ=115.87kg O₂/d, siv microporous aerators, Eₚ=20%, aeration tank dej kub T=25℃4 ric , thiab hauv zos siab ntawm P
(1) Xam qhov kho kom raug: Kₜ=1.024^(25-20)=1.024⁵≈1.127, Kₚ=1.0/1.013≈0.987;
(2) xam tus nqi aeration: Gₛ=115.87 × 1000 / (0.21 × 1.205 × 20% × 1.127 × 0.987)≈115870 / (0.21 × 1.205 × 0.2 × 1.127 × 0.987)≈ 1. 0.056≈2069109 m³/d? Kev suav ntawm no tsis raug thiab yuav tsum tau kho raws li hauv qab no:
Recalculate (units ib yam): O₂ₜₒₜₐₗ=115.87 kg/d=115870 g/d;
Tus lej: 0.21 (oxygen ntim feem) × 1.205 (air density kg/m³) × Eₚ (20%=0.2) × Kₜ (1.127) × Kₚ (0.987)=0.21 × 1.205 × 0.27 × 20.1 1.205 ≈ 0.253, 0.253 × 0.2 ≈ 0.0506, 0.0506 × 1.127 ≈ 0.057, 0.057 × 0.987 ≈ 0.056 kg O₂/m³ Cua;
Yog li ntawd, Gₛ=115.87 kg/d / 0.056 kg O₂/m³ cua ≈ 2069 m³/d (kwv yees 86.2 m³/h).
III. Cov yam tseem ceeb cuam tshuam thiab kev hloov kho kom zoo
1. Cov dej tsis zoo
Cov concentration ntawm cov organic teeb meem (BOD₅, COD) thiab ammonia nitrogen ncaj qha txiav txim siab cov pa oxygen: qhov siab dua, qhov xav tau oxygen ntau dua, thiab aeration tus nqi yuav tsum tau nce ntxiv; Yog tias cov dej khib nyiab muaj cov khoom siv hluav taws xob tsis zoo lossis cov tshuaj lom neeg, nws yuav cuam tshuam cov kev ua haujlwm ntawm microbial, yuav tsum tau nce qhov tsim nyog ntawm aeration (nce DO concentration kom txo tau cov tshuaj toxicity inhibition).
2. Kev ua haujlwm tsis zoo
MLSS siab heev yuav ua rau kom cov pa oxygen noj endogenous thiab txo cov pa oxygen hloov mus rau qhov ua tau zoo (ntau ntxiv cov cawv sib xyaw), yuav tsum muaj qhov sib npaug ntawm MLSS thiab aeration rate; sludge tuav lub sij hawm (SRT) cuam tshuam rau nitrification efficiency, cov txheej txheem nitrification yuav tsum tau tswj SRT Ntau tshaj los yog sib npaug rau 10 hnub (20 degree) thiab phim txaus nitrification oxygen xav tau.
3. Cov xwm txheej ib puag ncig
Cov dej kub nce ntxiv txo cov pa oxygen solubility thiab txo cov pa oxygen hloov mus rau qhov ua tau zoo, yuav tsum tau nce aeration. Txo cov huab cua siab (xws li, nyob rau hauv siab- thaj chaw siab) ntxiv txo cov pa solubility, yuav tsum tau nce aeration los them. Cov pH ntawm cov cawv sib xyaw cuam tshuam rau nitrification (pH zoo tshaj=7.5~ 8.5); pH txawv txav yuav tsum tau ua qhov tseem ceeb ntawm kev hloov kho dej ua ntej optimizing aeration.
4. Kev xaiv cov khoom siv aeration
Cov khoom siv aeration sib txawv muaj qhov sib txawv ntawm cov pa oxygen hloov pauv tau zoo. Microporous aerators muaj lub siab tshaj plaws kev hloov pauv cov pa oxygen thiab tsim nyog rau lub tank loj aeration. Surface aerators yog ib qho yooj yim rau nruab thiab tsim nyog rau cov chaw kho dej me me. Thaum xaiv cov cuab yeej siv, nws yog ib qho tseem ceeb uas yuav tsum xav txog kev xav tau oxygen thiab lub tank hom, ua qhov tseem ceeb ntawm -kev ua tau zoo, qis- zog- cov khoom siv los txo cov ntim ntim thiab cov nqi khiav lag luam.
IV. Lus Ceeb Toom
1. Precise Parameter Values: Coefficients xws li a', b', thiab Eₚ yuav tsum tau hloov kho raws li hom dej khib nyiab (cov dej phwj hauv tsev / cov dej khib nyiab hauv tsev), cov qauv khoom siv aeration, thiab cov ntaub ntawv ntsuas kom tsis txhob suav cov kev sib txawv los ntawm kev siv ncaj qha rau qhov muaj nuj nqis.
2. Unit Consistency yog Qhov Tseem Ceeb: Ua ntej muab xam, tag nrho cov parameter units yuav tsum zoo ib yam (piv txwv li, mg/L rau kg/m³, m³/d rau m³/h) kom tsis txhob muaj kev tsis sib haum xeeb ntawm chav tsev uas ua rau yuam kev.
3. Tsim Margin: Hauv cov haujlwm tiag tiag, qhov kev nyab xeeb ntawm 1.1 ~ 1.2 yuav tsum tau muab sib npaug los ntawm kev suav aeration tus nqi los hais txog qhov txo qis hauv cov pa xa mus los ntawm cov khoom xws li dej tsis zoo thiab cov khoom siv laus.
4. Kev hloov kho raws li kev ua haujlwm tiag tiag: suav cov txiaj ntsig yog cov txiaj ntsig theoretical. Hauv kev ua haujlwm tiag tiag, tus nqi aeration yuav tsum tau hloov kho raws li cov cawv sib xyaw ua ke DO concentration (tswj ntawm 2 ~ 3 mg / L) thiab cov dej ntws zoo (BOD₅, NH₄⁺-N) kom ua tiav qhov sib npaug ntawm kev ua haujlwm thiab kev siv zog.
V. Xaus
Kev suav cov pa oxygen thov thiab aeration tus nqi hauv lub tank aeration yog ib qho tseem ceeb ntawm kev kho dej khib nyiab engineering tsim thiab kev ua haujlwm kom zoo. Qhov tseem ceeb, nws suav nrog kev ntsuas qhov kev xav tau ntawm cov kab mob metabolic ntawm cov kab mob thiab cov pa oxygen hloov mus ua kom tiav "ntawm-xav tau cov pa oxygen." Kev ntsuas cov pa oxygen yuav tsum tau ua raws li cov dej tsis zoo thiab cov qauv microbial metabolic, thaum kev xam cov nqi aeration yuav tsum tau kho nrog rau cov khoom ua tau zoo thiab ib puag ncig. Hauv kev siv cov tswv yim, lub hauv paus ntsiab lus yuav tsum tau tsim los ntawm kev suav theoretical, ua raws li kev hloov pauv hloov pauv raws li cov ntaub ntawv ntsuas. Qhov no ua kom ntseeg tau tias kev kho cov dej khib nyiab ua tau raws li cov qauv thaum txo qis aeration zog siv, ua tiav cov txheej txheem kev lag luam thiab kev lag luam.