Kev ua haujlwm ntawm cov txheej txheem activated sludge yuav tsum muaj kev tswj xyuas kom zoo ntawm ntau qhov tsis zoo, suav nrog kev tswj hwm ntawm MLSS, yog ib qho kev qhia siv ntau tshaj plaws hauv kev ua haujlwm niaj hnub ntawm cov dej khib nyiab.
1. Kev txhais ntawm MLSS
Activated sludge concentration yog hais txog cov ntsiab lus ntawm cov khoom raug tshem tawm hauv cov cawv sib xyaw ntawm qhov hluav taws xob ntawm lub tank aeration, qhia los ntawm lub cim MLSS, nrog cov units ntawm mg / L. Nws yog siv los ntsuas tus nqi ntawm cov activated sludge nyob rau hauv lub aeration tank. Tag nrho cov nyiaj ntawm MLSS suav nrog plaub yam hauv qab no:
Active kab mob;
Tsis yog- biodegradable organic teeb meem adsorbed rau ntawm cov activated sludge;
Cov seem ntawm microbial tus kheej -oxidation;
Inorganic teeb meem.
Thaum lub sijhawm ua haujlwm, nws yog ib qho tseem ceeb uas yuav tsum nco ntsoov tias MLSS tsuas yog hais txog qhov concentration ntawm cov cawv sib xyaw hauv lub tank aeration, tsis suav nrog cov concentration ntawm cov cawv sib xyaw hauv lub tank thib ob. Tsis tas li ntawd, thaum saib xyuas cov dej cawv sib xyaw hauv lub tank aeration, nws yog ib qho tseem ceeb uas yuav tsum tau siv cov concentration ntawm cov cawv sib xyaw ntawm qhov hluav taws xob ntawm lub tank aeration raws li tus qauv ntsuas cov activated sludge concentration thoob plaws hauv lub tank aeration.
2. Kev sib raug zoo ntawm Sludge Concentration thiab lwm yam kev ntsuas ntsuas
1. Kev sib raug zoo ntawm Activated Sludge Concentration thiab Sludge Age
Sludge age yog ib txoj kev ua haujlwm ntawm kev ua tiav lub hnub nyoog sludge los ntawm kev tshem tawm cov sludge activated. Qhov ntau yam tsim nyog rau kev tswj cov activated sludge concentration tuaj yeem muab los ntawm lub hnub nyoog tsim nyog sludge thiab cov zaub mov - rau - microbe ratio. Qhov tseeb, yog tias cov activated sludge concentration yog nce ntau dhau, lub hnub nyoog sludge yuav ntev tshwj xeeb, tshaj li qhov qub tswj cov sludge hnub nyoog tus nqi, txawm tias thaum cov organic teeb meem concentration tsis siab. Qhov no qhia meej meej tias cov activated sludge concentration tau raug tswj siab dhau lawm, uas yog qhov tseeb ntau dua li kev txiav txim siab seb qhov activated sludge concentration yuav tsum tau tswj raws li nws tus nqi kiag li.
2. Kev sib raug zoo ntawm Activated Sludge Concentration thiab Dej Kub
Kev loj hlob, kev loj hlob, thiab cov metabolism hauv cov activated sludge nyob rau hauv lub tank kev kho mob yog ze ze rau dej kub. Rau txhua txhua 10℃txo qis hauv dej kub, kev ua haujlwm ntawm activated sludge yuav txo qis ib nrab; Thaum cov dej kub qis dua 10 degree, cov nyhuv kho tau pom tseeb tsis zoo. Yuav kom daws tau qhov no, cov activated sludge concentration tuaj yeem hloov kho kom tiv thaiv cov dej kub hloov pauv:
Thaum cov dej kub qis, cov activated sludge concentration tuaj yeem nce ntxiv los cuam tshuam qhov cuam tshuam tsis zoo ntawm kev ua kom cov sludge txo qis, yog li ua tiav kev tshem tawm ntau dua ntawm cov dej kub tsawg.
Thaum cov dej kub siab, qhov kev ua haujlwm sludge muaj zog heev. Kev kub siab activated sludge concentration ntau dhau ua rau muaj kev puas tsuaj rau cov activated sludge daws. Nyob rau hauv cov ntaub ntawv no, txo cov activated sludge concentration tuaj yeem tiv thaiv kev tsim cov flocs tsis muaj zog thiab turbid supernatant.
3. Kev sib raug zoo ntawm Kev Ua Haujlwm Sludge Concentration thiab Activated Sludge Settling Ratio
Activated sludge concentration cuam tshuam rau qhov sib piv zaum kawg. Qhov siab dua activated sludge concentration ua rau qhov sib piv siab dua zaum kawg, thiab rov ua dua. Qhov no yog vim hais tias ib tug ntau dua activated sludge concentration ua rau ib tug loj biological quantity, ua rau ib tug ntau dua settling piv tom qab compression thiab sedimentation. Ib qho tseem ceeb sib txawv los ntawm lwm yam uas yuav ua rau kom qhov kev sib piv yog soj ntsuam seb lub compressed activated sludge yog ntom thiab seb nws cov xim yog xim av tsaus. Nyob rau hauv rooj plaub uas tsis muaj ntau ntxiv - ua kom cov sludge concentration ua rau ntau dua qhov sib piv, nws feem ntau yog vim tsis zoo compaction thiab xim duller.
Ntawm chav kawm, ntau dhau qis activated sludge concentration kuj tseem cuam tshuam rau qhov sib piv. Txawm li cas los xij, qhov no feem ntau tsis yog tshwm sim los ntawm cov neeg ua haujlwm txhob txwm txo qis cov activated sludge concentration, tab sis yog los ntawm qhov tsis muaj zog ntawm cov organic teeb meem ntau dhau. Nyob rau hauv tas li ntawd, cov neeg ua hauj lwm, xav tias lub activated sludge concentration yog tsawg heev, sim ua kom nws, ua rau activated sludge laus. Kev soj ntsuam qhov sib piv zaum kawg yuav nthuav tawm cov cim qhia ntawm kev ua kom cov sludge aging: siab compressibility, tsaus xim, thiab ib tug ntshiab supernatant uas muaj nplua flocs.
Yog tias qhov sib piv qis tshwm sim vim qhov txawv txav ntawm cov sludge tawm, kev soj ntsuam kuj tseem qhia tau tias cov activated sludge yog xim daj ntseg, muaj qhov tsis zoo, thiab tsis sib xws.
3. Qhov cuam tshuam ntawm Sludge Concentration ntawm Nitrification thiab Denitrification
1. Qhov cuam tshuam ntawm Sludge Concentration ntawm Nitrification
Ntau yam ntawm ib puag ncig cuam tshuam rau nitrification, suav nrog pH, kub, SRT, DO, BOD / TKN, sludge concentration, thiab tshuaj lom. Hauv cov dej khib nyiab tiag tiag, tsuas yog qhov tsis xws li SRT, DO, BOD / TKN, thiab sludge concentration tuaj yeem tswj tau thaum lub sijhawm ua haujlwm.
a. Hauv aerobic nitrification, cov sludge ntau dua ua rau muaj cov kab mob nitrifying ntau dua, yog li ua rau muaj tus nqi siab dua ntawm aerobic nitrification nyob rau hauv siab sludge concentration.
b. Ib lub hnub nyoog sludge yog tsim nyog los xyuas kom meej tias muaj cov kab mob nitrifying hauv cov sludge lom. Tsim kom muaj kev noj qab nyob zoo rau cov kab mob nitrifying ntxiv ua rau lawv cov kev faib ua feem hauv cov zej zog microbial, yog li ua rau lawv cov concentration. Ntawm cov sludge concentrations ntau, ntau BOD tau noj nyob rau hauv theem anaerobic, ua rau muaj qhov qis BOD / TKN piv rau theem aerobic.
Qee qhov kev tshawb fawb tau pom tias muaj kev sib raug zoo ntawm qhov sib npaug ntawm cov kab mob nitrifying hauv cov activated sludge thiab BOD / TKN. Txij li cov kab mob nitrifying yog autotrophic, qhov concentration ntawm cov organic substrate tsis yog qhov txwv rau lawv txoj kev loj hlob. Txawm li cas los xij, yog tias cov organic substrate concentration siab dhau lawm, nws yuav ua rau siab - loj hlob - cov kab mob heterotrophic kom proliferate sai, sib tw rau cov pa oxygen. Qhov no ua rau qeeb ntawm kev loj hlob ntawm cov kab mob autotrophic thiab tiv thaiv cov kab mob aerobic nitrifying kom tau txais txiaj ntsig zoo, ua rau txo qis nitrification.
c. Dissolved oxygen (DO) feem ntau yog qhov taw qhia tseem ceeb hauv theem nitrification ntawm cov nroj tsuag dej khib nyiab, feem ntau siab dua 2 mg / L. Hauv feem ntau cov txheej txheem oxidation ditch, qhov nruab nrab DO tus nqi hauv qhov kwj dej yog qhov nyuaj kom ncav cuag 2 mg / L, feem ntau tshuav ntawm 1 mg / L lossis qis dua. Txawm li cas los xij, cov nyhuv nitrification tseem zoo. Yog vim li cas rau qhov no yog tias cov sludge siab concentration tshwj xeeb rau oxidation ditches, txawm tias ua rau qis dua tus nqi DO, txhim kho lwm yam zoo rau nitrification.
Ntxiv sludge concentration nce qhov ntim ntawm cov tshuaj lom neeg lub tank thaum txo cov load. Los ntawm lwm qhov kev xav, nce sludge concentration kuj ua rau muaj peev xwm aerobic ntawm cov kab mob. Nyob rau hauv tib lub aeration tej yam kev mob, lub yaj oxygen meter nyeem ntawv yuav tsum tau qis dua. Cov ntsiab lus saum toj no piav qhia tias kev nce cov sludge concentration tuaj yeem tsim nyog txo qis cov pa oxygen (DO) hauv cov khoom siv tshuaj lom neeg thaum tswj hwm qib nitrification zoo.
d. Txhawm rau kom muaj kev loj hlob zoo thiab kev tsim tawm ntawm cov kab mob nitrifying nyob rau hauv cov sludge activated, lub hnub nyoog sludge feem ntau yuav tsum tau tswj ntau tshaj 8 hnub. Txawm li cas los xij, txhawm rau kom muaj kev sib tw sib luag zoo rau cov kab mob nitrifying tiv thaiv lwm cov kab mob heterotrophic, lub hnub nyoog sludge yuav tsum tau nce ntxiv yam tsis ua rau muaj kev laus loj ntawm cov sludge, uas sib txuas ua rau cov sludge concentration hauv cov kab mob lom.
2. Qhov cuam tshuam ntawm Sludge Concentration ntawm Denitrification
Biological denitrification yog txheej txheem los ntawm cov kab mob denitrifying siv cov ionic oxygen hauv nitrates kom decompose organic teeb meem nyob rau hauv anoxic tej yam kev mob. Nitrate raug txo rau N2, ua tiav cov txheej txheem denitrification. Cov kab mob denitrifying yog cov kab mob heterotrophic facultative muaj ntau nyob rau hauv cov dej khib nyiab. Nyob rau hauv cov xwm txheej aerobic, lawv siv oxygen rau kev ua pa thiab oxidative decomposition ntawm cov organic teeb meem.
Nyob rau hauv cov xwm txheej uas tsis muaj cov pa oxygen molecular, thaum nitrate thiab nitrite ions tshwm sim ib txhij, lawv tuaj yeem siv cov pa oxygen hauv cov ions no rau kev ua pa, oxidizing thiab decomposing organic teeb meem. Cov kab mob denitrifying tuaj yeem siv ntau yam ntawm cov organic substrates raws li cov khoom siv hluav taws xob hauv cov txheej txheem denitrification, suav nrog cov carbohydrates, organic acids, cawv, thiab txawm tias cov tebchaw xws li alkanes, benzoates, thiab lwm yam benzene derivatives, uas feem ntau yog cov ntsiab lus ntawm cov dej khib nyiab. Ntau yam cuam tshuam rau tus nqi denitrification, suav nrog pH, kub, yaj oxygen (DO), carbon-rau-nitrogen piv (C / N ratio), thiab sludge concentration. Hauv cov chaw kho dej khib nyiab tiag tiag, tsuas yog qhov tsis xws li DO thiab sludge concentration tuaj yeem tswj tau thaum lub sijhawm ua haujlwm. Txawm hais tias C / N piv yog qhov tseem ceeb tshaj plaws cuam tshuam rau hauv cov tshuaj tiv thaiv denitrification, nws yog nyob ntawm cov dej zoo thiab feem ntau nyuaj rau kev tswj hauv kev xyaum.
a. Denitrification yuav tsum tsis muaj molecular oxygen kom tso cai rau cov kab mob denitrifying siv cov ionic oxygen hauv nitrates thiab nitrites kom decompose organic teeb meem. Raws li tau hais ua ntej, cov kab ke lom neeg nrog cov sludge siab tuaj yeem tsim nyog txo cov pa oxygen (DO) thaum lub sij hawm nitrification thaum tswj kev ua haujlwm nitrification. Yog li ntawd, txo qis DO thaum kawg ntawm nitrification zoo txo cov DO cov ntsiab lus nqa hauv cov kua nitrate rov qab los, txo qhov cuam tshuam ntawm molecular oxygen ntawm cov txheej txheem denitrification hauv thaj chaw anoxic thiab txhim kho cov kab mob denitrifying lub peev xwm los siv cov pa roj carbon monoxide.
Tib lub sijhawm, cov sludge siab ntau kuj ua rau muaj zog endogenous metabolic aerobic muaj peev xwm, ntxiv cov pa oxygen yaj hauv qhov rov qab thiab thaj chaw anoxic. Tsis tas li ntawd, cov sludge siab heev hloov cov viscosity ntawm cov cawv sib xyaw, ua kom muaj kev sib txawv thiab yog li txo cov DO nqa hauv cov kua rov qab. Hauv qee cov txheej txheem kev kho mob siv cov kev qhib raws li cov xa rov qab, qhov no tuaj yeem txo cov pa oxygenation xav tau rau kev rov qab los. Hauv cov ntsiab lus, cov sludge siab concentrations ua lub luag haujlwm tseem ceeb hauv kev txo DO thaum lub sijhawm denitrification hauv cov txheej txheem ua haujlwm.
b. Txij li cov kab mob denitrifying yog cov kab mob heterotrophic facultative thiab muaj ntau nyob rau hauv cov dej khib nyiab, ua kom cov sludge concentration nyob rau hauv lub cev muaj peev xwm ua tau kom cov concentration ntawm denitrifying kab mob. Tus nqi ntawm denitrification yog feem ntau ywj siab ntawm nitrate thiab nitrite concentrations, tab sis pom ib tug thawj - txiav txim cov tshuaj tiv thaiv nrog concentration ntawm denitrifying kab mob.
Yog li ntawd, nyob rau hauv cov txheej txheem tiag tiag, cov sludge concentrations yuav txo tau lub sij hawm denitrification thiab txo qhov ntim zoo ntawm thaj tsam anoxic. Muab qhov ntim tau zoo nyob rau hauv thaj chaw anoxic, cov sludge siab ntau tso cai rau kev siv tau zoo dua ntawm kev nyuaj heev - rau - degrade organic teeb meem hauv cov organic matrix ua cov pa roj carbon monoxide. Qhov no tseem ceeb tshwj xeeb rau cov txheej txheem tshem tawm nitrogen thiab phosphorus, tshwj xeeb tshaj yog thaum cov pa roj carbon tsis txaus.
c. High sludge concentrations ua rau qhov loj dua microbial floc diameters. Thaum lub sij hawm nitrification, qib qis cov pa oxygen ua rau me me oxygen siab gradient, ua kom yooj yim rau cov cheeb tsam anoxic tsim nyob rau hauv flocs, yog li txhawb denitrification. Yog li ntawd, siab sludge concentrations yuav txhawb ib txhij denitrification.
4. Qhov cuam tshuam ntawm Sludge Concentration ntawm Biological Phosphorus Tshem Tawm
Tus yuam sij rau kev tshem tawm cov phosphorus lom yog nce qhov feem ntawm polyphosphate- khaws cov kab mob hauv cov kab mob activated sludge, thaum tib lub sij hawm txhawb lawv txoj kev loj hlob sai thiab kev tsim tawm thaum lub sij hawm ua haujlwm, tswj cov phosphorus siab hauv cov polyphosphate- khaws cov kab mob thaum tso tawm.
Txhawm rau nce qhov feem pua ntawm cov kab mob polyphosphate-accumulating (PAC) cov kab mob hauv cov kab mob activated sludge, nws yog ib qho tsim nyog yuav tsum tsim kom muaj ib puag ncig zoo dua thiab hydraulic tej yam kev mob rau lawv txoj kev loj hlob thiab kev loj hlob. Qhov no txhais tau tias muaj qhov zoo anaerobic thiab aerobic ib puag ncig hauv cov txheej txheem ntws. Kev tswj hwm ib puag ncig hauv cheeb tsam anaerobic yog qhov tseem ceeb tshwj xeeb rau kev loj hlob thiab kev loj hlob ntawm PAC cov kab mob thiab kev ua tiav ntawm kev tshem tawm phosphorus. Qhov siab sludge concentration nyob rau hauv cheeb tsam anaerobic yog qhov zoo dua rau cov kab mob PAC.
Qhov ua tau zoo ntawm kev tshem tawm cov phosphorus lom muaj feem cuam tshuam nrog cov hnub nyoog sludge. Tsuas yog nrog qee lub hnub nyoog sludge (nyob ib ncig ntawm 3 hnub) tuaj yeem tshaj phosphorus tshem tawm tau zoo, ua tiav cov haujlwm tshem tawm phosphorus. Muab cov khib nyiab ruaj khov (SS), txij li cov sludge concentration yog ncaj qha proportional rau cov hnub nyoog sludge, qhov siab dua cov sludge concentration dhau ib qho, qhov phem tshaj qhov phosphorus tshem tawm.
a. Thaum tuav lub hnub nyoog sludge txaus rau kev tshem tawm phosphorus efficiency, ua kom cov sludge concentration nyob rau hauv anaerobic cheeb tsam ua rau ib tug sib raug zoo concentration ntawm PAC cov kab mob. Qhov no ua rau kom cov phosphorus ntau dua - tso tawm cov kab mob, uas ua rau nce ntxiv ntawm aerobic phosphorus tom ntej- nqus cov kab mob, yog li txhim kho tag nrho cov phosphorus tshem tawm ntawm lub cev.
b. Hauv thaj chaw anaerobic, polyphosphate- cov kab mob sib xyaw nqus VFA thiab tso tawm phosphorus. Ib txhij, nyob rau hauv tej yam kev mob ntawm siab sludge concentration, anaerobic cheeb tsam yuav ua hauj lwm raws li anaerobic acidification seem ntawm lub system, anaerobically hydrolyzing siab -molecular- hnyav, recalcitrant organic teeb meem nyob rau hauv dej. Lub zog tso tawm thaum lub sij hawm phosphorus tso tawm los ntawm polyphosphate- cov kab mob sib xyaw tuaj yeem siv los ua kom nquag plias acetic acid, H +, thiab lwm yam, tsim PHB thiab khaws cia rau hauv cov kab mob. Qhov no txhawb cov txheej txheem acidification ntawm cov organic teeb meem, txhim kho biodegradability ntawm cov dej khib nyiab, thiab nce cov pa roj carbon monoxide siv rau cov tshuaj denitrification hauv cov txheej txheem tom ntej.