Cov ntsiab lus dej phwj peb yuav txheeb xyuas hnub no yog qhov zoo - paub thiab paub rau txhua tus. Ib tug hu ua COD, thiab ib tug hu ua BOD. Ntau tus neeg yuav tsis coj lawv tiag tiag thiab xav tias lawv tsuas yog ua qhov loj ntawm lub molehill.
Raws li cov neeg koom nrog hauv kev kho dej phwj tuaj, thawj yam uas peb tau ntsib yog COD, BOD, ammonia nitrogen, tag nrho phosphorus, thiab cov khib nyiab tshem tawm. Qhov thib peb tom kawg yog qhov tsis txaus ntseeg, ammonia nitrogen, tag nrho phosphorus, thiab cov khib nyiab tshem tawm, uas tuaj yeem nkag siab los ntawm lawv cov npe. Tab sis COD thiab BOD txawv heev.
Ib qho yog hu ua chemical oxygen xav tau, thiab lwm qhov yog hu ua biochemical oxygen xav tau. Ntau tus neeg tshiab rau kev kho dej phwj tuaj muaj lus nug: ob qhov ntsuas ntsuas no yog dab tsi? Vim li cas lawv nyob ib txhij?
Hauv kev ua haujlwm dej phwj tiag tiag, lawv tsis yog cov cim tseem ceeb rau kev txiav txim siab qib ntawm cov dej phwj tuaj, tab sis kuj tseem ceeb rau kev txiav txim siab seb cov dej phwj puas haum rau kev kho biochemical. Kab lus no piav txog ob lub ntsiab lus no kom meej.
1, COD: Tag nrho cov organic teeb meem hauv dej uas tuaj yeem oxidized
Hauv kev kho dej khib nyiab, lub npe tag nrho ntawm COD yog Chemical Oxygen Demand
Hauv Suav, nws yog hu ua chemical oxygen xav tau.
Qhov ntsuas no piav qhia seb yuav tsum muaj oxygen npaum li cas rau txhua yam oxidizable hauv dej.
Cias muab, yog tias tag nrho cov organic teeb meem nyob rau hauv cov dej phwj yog 'kub', theoretically npaum li cas oxygen xav tau.
Cov txheej txheem ntawm "hlawv" tsis yog ua tiav nrog hluav taws hauv chav kuaj, tab sis nrog cov oxidants muaj zog.
Txoj kev siv feem ntau tam sim no yog txoj kev potassium dichromate.
Nyob rau hauv qhov kub thiab muaj zog acid, poov tshuaj dichromate tuaj yeem oxidize organic teeb meem hauv dej khib nyiab. Tus nqi ntawm cov pa siv thaum lub sij hawm oxidation yog hloov mus rau COD tus nqi.
COD feem ntau yog qhia hauv mg/L.
Piv txwv li, yog tias COD ntawm qee cov dej phwj tuaj yog 300 mg / L, nws txhais tau hais tias yog tias tag nrho cov pa phem hauv dej raug oxidized, kwv yees li 300 milligrams oxygen xav tau.
Yog li, COD tuaj yeem nkag siab tias yog "tag nrho qhov ntsuas" ntawm cov pa phem hauv dej.
Txawm hais tias cov organic tebchaw no tuaj yeem siv los ntawm cov kab mob los yog tsis, tsuav yog lawv tuaj yeem oxidized, lawv yuav suav nrog hauv kev suav. Qhov no kuj yog vim li cas COD tau siv dav hauv engineering.
2, BOD: Organic teeb meem uas microorganisms tau tiag tiag 'noj'
Piv rau COD, BOD tsom mus rau lwm yam.
Lub npe tag nrho ntawm BOD yog Biochemical Oxygen Demand
Hauv Suav, nws yog hu ua biochemical oxygen xav tau.
Qhov ntsuas no piav qhia seb yuav tsum muaj oxygen npaum li cas rau cov kab mob kom decompose organic teeb meem.
Uas yog hais tias, thaum lub sij hawm cov txheej txheem ntawm cov organic teeb meem nyob rau hauv dej yog "noj" los ntawm cov kab mob, yaj oxygen yog noj.
Cov pa oxygen noj yog BOD.
Hauv kev sim tiag tiag, feem ntau yog: BOD ₅
Lub ntsiab lus: 5-hnub biochemical oxygen xav tau.
Cov txheej txheem kev sim feem ntau mus zoo li no:
Nqa ib lub raj mis dej thiab ntsuas qhov pib yaj oxygen.
Tom qab ntawd muab cov qauv dej tso rau hauv 20℃qhov kub thiab txias incubator rau 5 hnub ntawm kev cog qoob loo.
Ntsuas cov pa oxygen dua hauv 5 hnub.
Qhov sib txawv ntawm cov pa oxygen ua ntej thiab tom qab yog BOD ₅.
Qhov ntsuas no ua tau qhia txog feem ntawm cov organic teeb meem hauv cov dej khib nyiab uas tuaj yeem siv los ntawm cov kab mob.
Yog li, BOD feem ntau suav hais tias yog qhov ntsuas ntawm biodegradable organic teeb meem.
3, Qhov sib txawv tseem ceeb ntawm COD thiab BOD
Ntau tus neeg nyiam sib xyaw COD thiab BOD ua ke, tab sis lawv txoj kev xav txawv kiag li. Nws tuaj yeem nkag siab hauv kab lus yooj yim:
COD hais txog tag nrho cov organic teeb meem.
BOD hais txog cov khoom organic uas tuaj yeem noj tau los ntawm cov kab mob.
Muab piv txwv yooj yim.
Piv txwv tias muaj ob yam hauv ib khob dej:
Ib qho yog qab zib
Ib hom yog cov khoom tawg yooj yim
Qab Zib yog yooj yim decomposed los ntawm cov kab mob, thaum yas tsis yog siv los ntawm cov kab mob.
Yog tias ntsuas COD, ob yam khoom yuav raug suav nrog hauv kev suav.
Yog tias ntsuas BOD, nws feem ntau cuam tshuam txog cov piam thaj.
Yog li ntawd, nyob rau hauv feem ntau ntawm cov dej khib nyiab, muaj qhov xwm txheej uas COD ib txwm muaj ntau dua BOD.
4, Kev sib raug zoo ntawm COD thiab BOD
Hauv kev kho dej phwj tuaj, COD thiab BOD feem ntau siv ua ke.
Vim tias lawv tuaj yeem cuam tshuam cov ntaub ntawv tseem ceeb ntawm lawv: biodegradability ntawm cov dej khib nyiab.
Hauv engineering, ib qho piv txwv yooj yim feem ntau siv los txiav txim siab BOD / COD
Qhov ntawd yog hais, B / C piv.
Qhov siab dua qhov sib piv, ntau cov organic teeb meem hauv cov dej phwj tuaj yeem siv tau los ntawm cov kab mob.
Generally speaking, B/C ratio with biodegradability>0.45 zoo heev, 0.3-0.45 zoo dua, 0.2-0.3 yog qhov nruab nrab, thiab<0.2 is poor
Yog tias qhov sib piv B / C tsawg heev, nws feem ntau qhia tau tias muaj ntau qhov nyuaj rau degrade cov organic tebchaw hauv dej.
Piv txwv li:
Dye dej khib nyiab
tshuaj dej khib nyiab
Cov dej khib nyiab
Hauv qhov no, kev cia siab rau kev kho mob biochemical feem ntau nyuaj. Yuav tsum tau koom tes nrog: txheej txheem oxidation, txheej txheem adsorption, thiab txheej txheem sib sib zog nqus.
5, Kev ntsuas kev ntsuas rau COD thiab BOD
Hauv kev sim tiag tiag, muaj qhov sib txawv tseem ceeb hauv kev ntsuas ntawm COD thiab BOD.
COD nrhiav pom
Kev kuaj COD feem ntau yog siv txoj kev potassium dichromate.
Cov kauj ruam sim yog kwv yees li hauv qab no:
Ntxiv poov tshuaj dichromate
Ntxiv sulfuric acid thiab catalyst
Kub kub digestion
Tom qab cov tshuaj tiv thaiv, COD tuaj yeem txiav txim siab los ntawm titration lossis photometry. Tag nrho cov txheej txheem xeem feem ntau yuav siv li 2 teev kom tiav. Yog li, COD yog ib qho kev soj ntsuam ntau heev hauv kev ua haujlwm ntawm cov chaw kho dej phwj. Ntau qhov chaw kho dej phwj tuaj txawm nruab nrog online COD meters.
Kev kuaj BOD
Kev kuaj BOD yog txawv kiag li. Nws tso siab rau cov kab mob microorganisms kom decompose organic teeb meem.
Kev sim xav tau: cog rau 5 hnub.
Tag nrho cov txheej txheem suav nrog:
dej qauv dilution
Inoculate cov kab mob
qhov kub thiab txias cultivation
Kev txiav txim siab ntawm kev hloov pauv oxygen yaj
Yog li, lub sijhawm tshawb nrhiav BOD yog qhov ntev. Hauv kev ua haujlwm txhua hnub, BOD feem ntau tsis pom txhua hnub. Feem ntau siv rau cov txheej txheem tsim, kev ntsuas dej zoo, thiab kev txheeb xyuas biodegradability.
6, Qee qhov kev paub hauv engineering ua haujlwm
COD feem ntau yog qhov taw qhia kev tswj ntau tshaj plaws hauv kev ua haujlwm ntawm cov chaw kho dej phwj.
Qhov laj thawj yog qhov yooj yim: kev tshawb nrhiav ceev ceev thiab cov ntaub ntawv tawm tswv yim raws sijhawm.
Piv txwv li, kev hloov pauv hauv COD muaj peev xwm tuaj yeem cuam tshuam sai sai ntawm cov dej tsis zoo.
Thiab BOD yog ntau dua li 'reference indicator'.
BOD tuaj yeem siv los txiav txim seb lub kaw lus puas haum rau kev kho mob lom.
Thaum lub sij hawm tsim qauv, engineers feem ntau tsom rau B / C piv.
Yog tias qhov sib piv B / C tsawg dhau, nws yuav tsum tau txiav txim siab seb puas tsim nyog ua ntej.
Tsis tas li ntawd, BOD feem ntau yog siv los xam sludge load nyob rau hauv activated sludge systems.
Piv txwv li, F hauv F / M piv feem ntau yog raws li BOD.
Hauv kev xaus
COD thiab BOD yog ob qho kev ntsuas tseem ceeb tshaj plaws hauv kev kho dej khib nyiab.
COD qhia txog tag nrho cov kuab paug organic hauv dej.
BOD qhia txog ib feem ntawm cov organic teeb meem uas cov kab mob tuaj yeem degrade.
Cias muab:
COD hais txog 'tag nrho cov pa phem'.
BOD hais txog 'degradable pollution'.
Kev sib xyaw ua ke ob feem ntau tuaj yeem muab kev ntsuas ntau dua ntawm cov dej phwj tuaj. Hauv ntau qhov kev paub txog engineering, tus tsim qauv thiab cov neeg ua haujlwm tuaj yeem txiav txim siab txog qhov nyuaj ntawm kev kho cov dej khib nyiab ntev npaum li lawv pom ob tus lej COD thiab BOD.