Pilot-Txoj Kev Kawm ntawm Ntau-theem A/O-MBBR System rau Nitrogen Tshem Tawm ntawm Nruab Nrab-Tsuas Kub
Txheej txheem cej luam
Nyob rau hauv xyoo tas los no, Tuam Tshoj tau ua tiav cov txiaj ntsig tseem ceeb hauv kev tswj hwm ib puag ncig dej, tab sis tseem ntsib teeb meem xws li dej tsis txaus, dej ib puag ncig muaj kuab lom, thiab dej ecological puas tsuaj. Los ntawm qhov kev xav ntawm kev tiv thaiv cov peev txheej dej, tiv thaiv dej paug, thiab kho dej ecology, txuas ntxiv txhim kho kev kho dej khib nyiab thiab kev ua tau zoo yog qhov tseem ceeb rau kev nce cov peev txheej siv dej, txhim kho dej ib puag ncig zoo, txhim kho lub teb chaws zoo ntawm lub neej, ua kom muaj kev nyab xeeb ib puag ncig, thiab yeej kev sib ntaus sib tua rau dej huv. Tam sim no, raws li lub teb chaws uas twb muaj lawm "Pollutant Discharge Standard for Urban Wastewater Treatment Plants" (GB18918-2002), tsoom fwv hauv zos tau ua tiav cov kev xav tau tshiab rau cov dej khib nyiab hauv nroog, nrog rau kev xav tau nruj dua ntawm cov ntsuas xws li cov organic teeb meem, ammonia nitrogen, thiab tag nrho cov nitrogen. Cov thev naus laus zis kho dej ib txwm sawv cev los ntawm cov txheej txheem sludge activated fim fwj zoo li txwv tsis pub lom nitrification ntawm qhov kub thiab txias. Ntau qhov kev tshawb fawb tau pom tias qhov kev ua tau zoo ntawm nitrification ntawm cov txheej txheem sludge tau txo qis hauv qis- qhov kub thiab txias, nrog rau cov teeb meem xws li cov sludge loj heev thiab cov kab mob lom. Yog li ntawd, kev rhuav tshem los ntawm qhov tsis tshua muaj kub hauv lub fwj dej thiab ua kom muaj kev ruaj ntseg thiab muaj txiaj ntsig ntawm kev tshem tawm cov roj ntsha nitrogen tau dhau los ua qhov teeb meem ceev uas yuav tsum tau daws hauv kev kho dej khib nyiab. Lub Moving Bed Biofilm Reactor (MBBR) thev naus laus zis tau siv rau ntau pua lub chaw kho dej khib nyiab thoob ntiaj teb. Vim yog qhov txuas nrog kev loj hlob ntawm biofilm nyob rau hauv lub reactor thiab nws lub peev xwm txuas ntxiv txuas ntxiv, nws tsis tsuas yog muaj biomass siab tab sis kuj tswj hwm kev ua haujlwm siab. Daim ntawv thov tshwm sim nyob rau hauv Nordic lub teb chaws kuj qhia tau hais tias nws muaj zog adaptability rau qis kub piv rau cov txheej txheem activated sludge.
Vim li no, qhov kev tshawb fawb no, tsom rau cov yam ntxwv ntawm cov dej khib nyiab hauv nroog hauv Suav teb, siv qhov zoo ntawm MBBR thiab ntau -theem Anoxic/Oxic (A/O) txheej txheem rau kev tshem tawm cov nitrogen lom los tsim.peb -theem A/O-MBBR pilot-scale system. Lub kaw lus tshem tawm lub peev xwm rau cov organic teeb meem, ammonia nitrogen, thiab tag nrho cov inorganic nitrogen nyob rau hauv nruab nrab - qhov kub thiab txias tau raug soj ntsuam. Lub peev xwm nitrification thiab morphological hloov pauv ntawm biofilm nyob rau hauv qhov kev sim zoo li qub tau raug tshuaj xyuas, muab kev txhawb nqa rau kev ua tiav qhov ruaj khov thiab muaj txiaj ntsig nitrogen tshem tawm ntawm cov dej khib nyiab hauv nroog hauv qis- qhov kub thiab txias thiab rau kev tsim kho thiab kev tswj hwm ntawm ntau-theem A / O-MBBR systems.
1. Cov ntaub ntawv thiab cov txheej txheem
1.1 Pilot-Size System Experimental Setup and Operation Mode
Cov txheej txheem khiav ntawm peb lub tsev -theem A/O-MBBR pilot- nplai qhov system tau qhia hauvDaim duab 1. Tus kws tsav dav hlau- ntsuas qhov ntsuas muaj peb theem ntawm anoxic/oxic (A/O), muab faib ua 10 qhov chaw tshuaj tiv thaiv hauv tag nrho.Thawj -theemA/O-MBBR subsystem muaj cov tshuaj tiv thaiv anoxic (A1, A2) thiab aerobic cov tshuaj tiv thaiv (O3, O4).Qhov thib ob -theemA/O-MBBR subsystem muaj cov tshuaj tiv thaiv anoxic (A5, A6) thiab aerobic cov tshuaj tiv thaiv (O7, O8).Qhov thib peb -theemA/O-MBBR subsystem muaj thaj tsam anoxic reaction (A9) thiab aerobic reaction zone (O10). Qhov zoo ntim ntawmTxhua thaj tsam uas tau hais tseg saum toj no yog 1.4 m³ (1m * 1m * 1.4m), nrog rau qhov dej tob ntawm 1.4 m. Tshem tawm cov khoom siv biofilm (media) nrog rau thaj chaw tshwj xeeb ntawm 500 m² / m³ tau ntxiv rau txhua qhov kev tawm tsam thaj tsam ntu, nrog rau tus neeg nqa khoom ntim ntawm 35% rau txhua tus. Kev sib xyaw tshuab tau siv nyob rau hauv thaj chaw anoxic cov tshuaj tiv thaiv kom cov neeg nqa khoom muaj kuab lom, thaum cov yeeb nkab perforated aeration tau siv nyob rau hauv cov cheeb tsam aerobic, tswj covyaj oxygen concentration ntawm 3-9 mg / L.
Qhov tseeb inflow tus nqi ntawm tus tsav- ntsuas qhov system yog (23.6 + 5.4) m³ / d, siv ob - taw tes kev faib tawm, nrog cov ntsiab lus nkag tau teeb tsa ntawm thaj chaw tshuaj tiv thaiv A1 thiab O5, thiab qhov sib piv ntawm 1: 1. Tus tsav- teev qhov system muaj ob txheej ntawm nitrified kua recirculation (los ntawm O4 mus rau A1, thiab los ntawm O8 mus rau A5), nrog ib tug recirculation ratio ntawm 100% mus rau 200% (raws li inflow tus nqi ntawm txhua theem). Txhawm rau kom muaj kev tshaj tawm zoo tshaj plaws, 50-90 mg / L ntawm sodium acetate (xws li COD) tau ntxiv los ua cov pa roj carbon monoxide sab nraud hauv thaj tsam A9 cov tshuaj tiv thaiv. Tag nrho cov kev tshawb fawb tau muab faib ua 2 theem: Phase I - Qhov kub thiab txias (18-29 degree); Theem II - Nruab nrab-tsawg kub (10-16 degree).
1.2 Test Dej
Kev sim ntsuas tau ua nyob rau ntawm - qhov chaw ntawm lub nroog cov chaw kho dej khib nyiab hauv Qingdao City. Cov dej kuaj tau raug coj los ntawm cov dej ntws tawm ntawm lub hauv paus sedimentation tank ntawm cov nroj tsuag no thiab nkag mus rau hauv kev tsav tsheb tom qab txhim kho pretreatment los ntawm flotation. Cov dej tsis zoo tom qab txhim kho flotation pretreatment tau qhia hauvTable 1.
1.3 Kev Ntsuas Ntsuas thiab Cov Txheej Txheem
1.3.1 Cov Lus Qhia Raws Cai
Cov cim qhia ib txwm muaj xws li SCOD, NH₄⁺-N, NO₂⁻-N, NO₃⁻-N, SS, MLSS, thiab MLVSS raug ntsuas los ntawm cov qauv txheej txheem los ntawm "Kev Saib Xyuas Dej thiab Dej Num thiab Kev Tshawb Fawb". Cov pa oxygen dissolved, kub, pH, thiab ORP tau ntsuas los ntawm aPortable yaj oxygen meter (HACH HQ40d). Biofilm thickness yog ntsuas los ntawm ib tugInverted fluorescence microscope (Olympus, IX71).
1.3.2 Nitrification Static Experiment
Thaum lub sijhawm ua haujlwm, cov neeg nqa khoom los ntawm thaj chaw aerobic tau ua ntu zus los ntsuas lub peev xwm nitrification ntawm biofilm nyob rau hauv cov xwm txheej zoo li qub. Cov neeg nqa khoom los ntawm txhua cheeb tsam aerobic cov tshuaj tiv thaiv tau muab tso rau hauv 5L reactor, nrog rau qhov sib xyaw ua ke zoo ib yam rau kev tsav tsheb ntawm 35%. Cov dej kuaj tau tsim kho NH₄Cl tov nrog qhov loj ntawm 20-25 mg/L (xws li N). Thaum lub sij hawm sim, ib lub twj tso kua mis me me tau siv rau kev ua kom lub cev muaj zog kom cov neeg nqa khoom muaj kuab paug thaum tswj cov pa oxygen yaj ntawm 7-11 mg / L. Lub sijhawm ntsuas yog 2 teev, nrog rau qhov piv txwv ntawm 30 feeb, ntsuas qhov kev hloov pauv hauv NH₄⁺-N concentration los xam cov peev txheej nitrification ntawm biofilm nyob rau hauv cov xwm txheej zoo li qub.
2. Cov txiaj ntsig thiab kev tshuaj xyuas
2.1 Kev Ua Haujlwm Kev Ua Haujlwm ntawm Peb -theem A/O-MBBR Pilot System
Kev ua haujlwm ntawm peb -theem A/O-MBBR pilot system tau qhia hauvDaim duab 2. Nyob rau theem kub ib txwm (Phase I), nrog rau qhov ntsuas kub ntawm 18-29 degree, kev kho tus nqi ntawm (23.6+5.4) m³ / d, thiab cov pa roj carbon ntau npaum li 50 mg / L (xws li COD, tib yam hauv qab no) hauv thaj tsam anoxic ntawm qhov thib peb -theem A/O-MBluent system, SCOD, NH₄⁺-N, thiab TIN concentrations yog (160 ± 31), (35.0 ± 7.2), thiab (35.8 ± 7.0) mg / L, raws li, thiab kev kho cov kua dej ntau yog (27 ± 8), (0.6 ± 0.5), thiab (2.7 ± 2.2), ntsig txog mg / L.Qhov nruab nrab tshem tawm mus txog 83.1%, 98.3%, thiab 92.5%. Hauv nruab nrab- theem kub qis (Phase II), nrog qhov ntsuas kub ntawm 10-16 degree, tib txoj kev kho tus nqi ntawm (23.6+5.4) m³ / d, thiab cov pa roj carbon ntau npaum li cas ntawm 50-90 mg / L hauv thaj tsam anoxic ntawm qhov thib peb -theem A/O-MBBRs subsystem, Influent SCOD, NH₄⁺-N, thiab TIN concentrations yog (147 ± 30), (38.3 ± 2.1), thiab (39.6 ± 2.3) mg / L, raws li, thiab cov concentrations yog (26 ± 6), (0.4 ± 0.6), thiab (6.8 ± 3.6), ntsig txog.Qhov nruab nrab tshem tawm mus txog 82.3%, 99.0%, thiab 82.8%. Tsis tas li ntawd, nyob rau hnub 56-62 ntawm kev ua haujlwm, thaum cov pa roj carbon ntau npaum li 50 mg / L, qhov tseem ceeb NO₂⁻-N tsub zuj zuj tshwm sim hauv thaj tsam A9. Txawm li cas los xij, tom qab maj mam nce cov pa roj carbon ntau npaum li 90 mg / L, NO₂⁻-N tsub zuj zuj hauv thaj tsam A9 cov tshuaj tiv thaiv maj mam ploj mus, thiab TIN concentration txo qis mus rau theem tsim nyog.
2.2 Kev hloov pauv hauv Biofilm Nitrification Peev Xwm nyob rau hauv txhua qhov chaw Aerobic Reaction nyob rau hauv qhov sib txawv ntawm qhov kub thiab txias
Txhawm rau ntsuas qhov kev hloov pauv hauv nitrification muaj peev xwm ntawm peb -theem A/O-MBBR system los ntawm tag nrho cov kev xav, NH₄⁺-N nitrification contribution npaum li cas thiab lub peev xwm nitrification ntawm biofilm nyob rau hauv txhua cheeb tsam aerobic tshuaj tiv thaiv nyob rau hauv cov tshuaj tiv thaiv kub sib txawv, nrog rau cov txiaj ntsig tau pom nyob rau hauvCov duab 3 thiab 4, raws.
Daim duab 4 Nitrification tshem tawm load thiab haum curves nyob rau hauv aerobic aav ntawm theem 1 thiab 2nd theem A/O-MBBR subsystems nyob rau hauv sib txawv cov tshuaj tiv thaiv kub
Los ntawmDaim duab 3, nws tuaj yeem pom tau tias nyob rau hauv peb -theem A/O-MBBR system, vim yog ob qho - taw tes muaj zog, O3 thiab O4 cov tshuaj tiv thaiv thaj tsam ntawm thawj -theem A/O-MBBR subsystem thiab O7 thiab O8 cov tshuaj tiv thaiv thaj tsam ntawm thib ob-stage A/O-MBBR subsystem tho lub ntsiab nitrification load ntawm lub system. Nyob rau hauv ob qho tib si ib txwm thiab nruab nrab- qhov kub thiab txias, qhovNH₄⁺ -N nitrification tus nqi ntawm ob lub subsystems yog 43.1%, 49.6% thiab 33.8%, 54.0%, feem. Qhov no qhia tau hais tias nyob rau hauv nruab nrab- qhov kub thiab txias, NH₄⁺-N nitrification tus nqi ntawm qhov thib ob -theem subsystem yog 20.2% siab dua li ntawm thawj -theem subsystem.
Los ntawmDaim duab 4(a) thiab (c), nws tuaj yeem pom tau tias rau cov biofilms hauv O3 thiab O7 aerobic cov tshuaj tiv thaiv aerobic nyob rau hauv ib txwm kub, lawv yog cov tshuaj tiv thaiv tseem ceeb hauv peb -theem A/O-MBBR system rau organic teeb meem degradation ua ke nrog nitrification muaj nuj nqi. Thaum SCOD tshem tawm load rau ib cheeb tsam ntawm tus neeg nqa khoom (cov ntawv luv li "SCOD tshem tawm load", xam raws li COD) tsawg dua 2.0 g / (m²·d) thiab cov khoom siv nitrification rau ib cheeb tsam ntawm cov cab kuj (ua luv li "nitrification load", xam raws li N) tsawg dua 1.6 g / (m²·d), qhov kev sib raug zoo ntawm lub tsheb thauj khoom (m²·d). "Nitrification tshem tawm load", xam raws li N) thiab cov nitrification load ua raws thawj - txiav txim linear cov tshuaj tiv thaiv, nrog nqes hav ntawm 0.83 thiab 0.84, feem. Thaum cov nitrification load nce mus rau 1.6-6.0 g / (m²·d), kev sib raug zoo ntawm nitrification tshem tawm load thiab nitrification load ua raws li ib tug xoom- txiav txim cov tshuaj tiv thaiv, nrog coj nruab nrab nitrification tshem tawm loads ntawm 1.31 thiab 1.34 g / (m²·d), feem. Thaum SCOD tshem tawm load yog 2.0-4.0 g/(m²·d) thiab nitrification load yog 1.6-6.0 g/(m²·d), txawm hais tias xoom-txiav txim siab kev sib raug zoo ntawm nitrification tshem tawm load thiab nitrification load tseem tsis hloov, qhov sib thooj nruab nrab nitrification tshem tawm 7 thiab 09. g/(m²·d), raws. Rau cov biofilms nyob rau hauv O3 thiab O7 aerobic cov tshuaj tiv thaiv zones nyob rau hauv nruab nrab-tsawg kub, thaum lub SCOD tshem tawm load tsawg tshaj li 2.0 g / (m²·d) thiab cov nitrification load yog tsawg tshaj li 1.1 g / (m²·d), cov linear slopes ntawm nitrification tshem tawm load piv nrog nitrive load poob mus rau 0.81, thiab 0.81. Thaum cov nitrification load nce mus rau 1.1-6.0 g / (m²·d), qhov sib thooj nruab nrab nitrification tshem tawm loads txo mus rau 0.78 thiab 0.94 g / (m²·d), feem, sawv cev txo qis ntawm 40.4% thiab 19.4% piv rau qhov kub thiab txias. Thaum SCOD tshem tawm load nce mus rau 2.0-4.0 g / (m²·d), qhov nruab nrab nitrification tshem tawm cov loads tau txo qis rau 0.66 thiab 0.91 g / (m²·d), feem, sawv cev txo qis ntawm 30.5% thiab 6.2% piv rau qhov kub thiab txias. Lub peev xwm nitrification ntawm biofilm hauv thaj tsam O3 cov tshuaj tiv thaiv tau ua raws li kev tshawb fawb ntawm HEM li al. nyob rau hauv cov xwm txheej zoo sib xws. Txawm li cas los xij, nws yog ib qho tseem ceeb uas nyob rau hauv nruab nrab-tsawg kub tej yam kev mob, piv rau O3 tshuaj tiv thaiv cheeb tsam biofilm, O7 tshuaj tiv thaiv cheeb tsam biofilm pom muaj zog nitrification muaj peev xwm.
Los ntawmCov duab 4(b) thiab (d), nws tuaj yeem pom tau tias rau cov biofilms hauv O4 thiab O8 aerobic cov tshuaj tiv thaiv aerobic nyob rau hauv ib txwm kub, lawv yog cov tshuaj tiv thaiv cheeb tsam hauv peb -theem A/O-MBBR system feem ntau ua haujlwm ntxiv nitrification muaj nuj nqi. Thaum SCOD tshem tawm load tsawg dua 1.0 g / (m²·d) thiab nitrification load tsawg dua 1.3 g / (m²·d), kev sib raug zoo ntawm nitrification tshem tawm load thiab nitrification load ua raws li thawj - txiav txim linear cov tshuaj tiv thaiv, nrog nqes ntawm 0.86 thiab 0.88, raws li. Thaum cov nitrification load nce mus rau 1.3-3.0 g/(m²·d), kev sib raug zoo ntawm nitrification tshem tawm load thiab nitrification load ua raws li ib tug xoom- txiav txim cov tshuaj tiv thaiv, nrog coj nruab nrab nitrification tshem tawm loads ntawm 1.11 thiab 1.13 g/(m²·d), feem. Nyob rau hauv nruab nrab-tsawg kub tej yam kev mob, thaum lub SCOD tshem tawm load tsawg tshaj li 1.0 g / (m²·d) thiab cov nitrification load yog tsawg tshaj li 1.0 g / (m²·d), cov linear slopes ntawm nitrification tshem tawm load piv rau nitrification load poob mus rau 0.72 thiab 0.84, feem. Thaum cov nitrification load nce mus rau 1.0-3.0 g / (m²·d), qhov sib npaug nruab nrab nitrification tshem tawm loads yog 0.72 thiab 0.86 g / (m²·d), feem, sawv cev txo qis ntawm 35.1% thiab 23.9% piv rau ib txwm kub.
Los ntawm kev soj ntsuam saum toj no, nws tuaj yeem pom tau tias nyob rau hauv nruab nrab - qhov kub thiab txias, cov ntsiab lus inflection ntawm kev sib raug zoo ntawm nitrification tshem tawm load thiab nitrification load rau biofilm nyob rau hauv txhua cheeb tsam cov tshuaj tiv thaiv tshwm sim ua ntej piv rau ib txwm kub. Qhov tshwm sim no zoo ib yam nrog cov txiaj ntsig kev tshawb fawb ntawm SAFWAT. Zuag qhia tag nrho, txawm hais tias lub peev xwm nitrification ntawm biofilm nyob rau hauv txhua qhov chaw aerobic ntawm lub cev tau pom qhov kev poob qis hauv nruab nrab- qhov kub thiab txias,Lub peev xwm nitrification ntawm biofilm nyob rau hauv O7 cov tshuaj tiv thaiv cheeb tsam ntawm qhov thib ob -theem A/O-MBBR subsystem tau nce los ntawm 20.5%-37.9% piv rau O3 cov tshuaj tiv thaiv, thiab lub peev xwm nitrification ntawm biofilm nyob rau hauv O8 cov tshuaj tiv thaiv cheeb tsam tau nce li ntawm 19.4% piv rau O4 cov tshuaj tiv thaiv cheeb tsam.. Qhov no qhia tau hais tias qhov kev teeb tsa thib ob - theem cov tshuaj tiv thaiv cheeb tsam hauv peb -theem A/O-MBBR system yog qhov zoo rau kev txhim kho tag nrho cov peev txheej nitrification ntawm lub cev.
2.3 Kev hloov pauv hauv Biofilm Denitrification Peev Xwm nyob rau hauv Txhua Qhov Kev Tiv Thaiv Kab Mob Anoxic nyob rau hauv qhov ntsuas kub sib txawv
Txhawm rau ntsuas qhov kev hloov pauv ntawm qhov muaj peev xwm denitrification ntawm peb -theem A/O-MBBR system los ntawm tag nrho cov kev xav, qhov kev tshawb fawb no tau tshuaj xyuas lub peev xwm denitrification ntawm biofilm nyob rau hauv txhua cheeb tsam anoxic tshuaj tiv thaiv nyob rau hauv cov tshuaj tiv thaiv kub sib txawv, nrog rau cov txiaj ntsig tau pom hauvDaim duab 5.
Daim duab 5 Kev tshem tawm denitrification load nyob rau hauv txhua qhov anoxic cheeb tsam ntawm peb -theem A/O-MBBR system nyob rau hauv cov tshuaj tiv thaiv kub sib txawv
Los ntawmCov duab 5(a) thiab (c), nws tuaj yeem pom tau tias rau thaj chaw A1 thiab A5 anoxic cov tshuaj tiv thaiv, lawv yog thaj chaw tseem ceeb denitrification nyob rau hauv peb -theem A/O-MBBR system siv cov dej nyoos carbon raws li substrate. Nyob rau hauv ob qho tib si ib txwm thiab nruab nrab- qhov kub thiab txias tsis tshua muaj, thaum qhov sib thooj anoxic denitrification carbon- rau -nitrogen ratio (ΔCBSCOD / CNOx--N) yog ntau dua 5.0 thiab denitrification load rau ib qho chaw nqa khoom nto (ua luv li "denitrification", xam raws li NOx--N) tsawg dua 0.95 g/(m²·d), kev sib raug zoo ntawm denitrification tshem tawm load ib cheeb tsam ntawm tus cab kuj (ua luv li "denitrification tshem tawm load", xam raws li NOx--N) thiab denitrification load ua raws a thawj- xaj cov tshuaj tiv thaiv kab mob, nrog cov nqes hav ntawm 0.87, 0.88 thiab 0.82, 0.84, raws li. Thaum lub denitrification load nce siab tshaj 0.95 g / (m²·d), kev sib raug zoo ntawm denitrification tshem tawm load thiab denitrification load ua raws li xoom- txiav txim cov tshuaj tiv thaiv, nrog rau qhov nruab nrab denitrification tshem tawm loads ntawm 0.82, 0.82 g / (m²·d) thiab 0.78 g (m²·d), fwm. Raws li ΔCBSCOD / CNOx--N tau txo qis, qhov cuam tshuam ntawm kev sib raug zoo ntawm denitrification tshem tawm load thiab denitrification load hloov mus rau pem hauv ntej, txoj kab nqes hav nyob rau hauv qis-load tej yam kev mob pom ib tug downward trend, thiab ib txhij, qhov nruab nrab denitrification tshem tawm load nyob rau hauv high-load tej yam kev mob kuj pom ib tug downward trend. Cov txiaj ntsig no qhia tau hais tias rau biofilm denitrification nyob rau hauv A1 thiab A5 cov tshuaj tiv thaiv thaj chaw siv cov dej nyoos cov pa roj carbon, cov pa roj carbon-rau-nitrogen piv yog qhov tseem ceeb ntawm kev txiav txim siab denitrification muaj nuj nqi, thiab nyob rau hauv kev ntsuas dej zoo, qhov zoo tshaj plaws carbon-to-nitrogen piv rau A1 thiab A5 anoxic cov tshuaj tiv thaiv cheeb tsam yuav tsum ntau dua 5.
Los ntawm cov duab 5(b) thiab (d), nws tuaj yeem pom tau tias rau thaj tsam A2 thiab A6 anoxic cov tshuaj tiv thaiv, vim tias A1 thiab A5 anoxic cov tshuaj tiv thaiv thaj chaw tshem tawm thiab siv cov pa roj carbon hauv cov dej khib nyiab thiab feem ntau ntawm cov nitrate nqa los ntawm cov dej ntws rov qab, A2 thiab A6 anoxic cov tshuaj tiv thaiv cheeb tsam tau ntev -lub sij hawm substrate- tsis muaj lub xeev {8}. Yog li ntawd, nyob rau hauv ob qho tib si ib txwm thiab nruab nrab- qhov kub thiab txias, thaum ΔCBSCOD / CNOx--N nyob nruab nrab ntawm 1.0-2.0 thiab qhov denitrification load tsawg dua 0.50 g / (m²·d), txoj kab nqes hav ntawm denitrification tshem tawm load piv rau denitrification load tsuas yog 0.70, 0.4. Ntxiv mus, thaum lub denitrification load nce mus rau 0.50-1.50 g / (m²·d), qhov nruab nrab denitrification tshem tawm tsuas yog 0.25, 0.20 thiab 0.20, 0.17 g / (m²·d), feem. Txawm li cas los xij, qhov kev sim zoo li qub tau tshwm sim hauv txoj kev tshawb fawb no tau pom tias nyob rau hauv cov xwm txheej ntawm cov pa roj carbon txaus thiab nitrate substrate, qhov denitrification tshem tawm ntawm biofilm hauv A2 thiab A6 anoxic cov tshuaj tiv thaiv tuaj yeem ncav cuag (0.66 ± 0.14) thiab (0.68 ± 0.11) g / (m²·d), feem. Qhov tshwm sim no qhia tau hais tias cov biofilm nyob rau hauv A2 thiab A6 anoxic cov tshuaj tiv thaiv zones yeej muaj peev xwm denitrification muaj zog, uas yog txwv los ntawm qhov tsis muaj cov pa roj carbon thiab nitrate substrates hauv qhov kev sim no.
Los ntawmDaim duab 5 (e), nws tuaj yeem pom tau tias rau thaj tsam A9 anoxic tshuaj tiv thaiv, nws dais lub denitrification load rau tag nrho cov nitrate ntws tawm los ntawm thawj ob theem ntawm peb -theem A/O-MBBR system, siv externally ntxiv sodium acetate raws li cov denitrification carbon qhov chaw. Nyob rau hauv ob qho tib si ib txwm thiab nruab nrab- qhov kub thiab txias, thaum ΔCBSCOD / CNOx--N yog ntau dua 5 thiab cov denitrification load tsawg dua 2.5 g / (m²·d), kev sib raug zoo ntawm denitrification tshem tawm load thiab denitrification load ua raws li ib tug thawj - txiav txim linear cov tshuaj tiv thaiv ntawm 0.9 thiab slopes 0,94 ,ua. Txawm li cas los xij, raws li ΔCBSCOD / CNOx{17}}-N txo qis, txoj kab nqes hav ntawm kev sib raug zoo ntawm denitrification tshem tawm load thiab denitrification load pom qhov poob qis. Cov txiaj ntsig no tseem qhia tau tias rau biofilm denitrification hauv thaj tsam A9 cov tshuaj tiv thaiv siv cov pa roj carbon monoxide sab nraud, cov pa roj carbon-rau-nitrogen piv kuj yog qhov tseem ceeb uas txiav txim siab txog kev ua haujlwm denitrification, nrog rau qhov yuav tsum tau denitrification carbon-to-nitrogen piv ntau dua 3. Ib txhij, qhov cuam tshuam ntawm cov tshuaj tiv thaiv kub hloov ntawm nws cov denitrification muaj nuj nqi kuj me me.
2.4 Nitrification Peev Xwm thiab morphological yam ntxwv ntawm Biofilm nyob rau hauv Txhua Aerobic Reaction Zone nyob rau hauv Static Experimental Conditions
Lub peev xwm nitrification ntawm biofilm nyob rau hauv txhua cheeb tsam aerobic tshuaj tiv thaiv nyob rau hauv cov kev sim zoo li qub tau qhia hauvDaim duab 6. Los ntawm daim duab 6, nws tuaj yeem pom tias nyob rau hauv qhov kub thiab txias, lub peev xwm nitrification ntawm biofilm nyob rau hauv O3, O4, O7, thiab O8 aerobic cov tshuaj tiv thaiv aav yog (1.37 ± 0.21), (1.23 ± 0.15), (1.40 ± 0.20), thiab (1.25 ± 0.13.²) g/(m². Nyob rau hauv nruab nrab- qhov kub thiab txias, qhov muaj peev xwm nitrification ntawm biofilm nyob rau hauv cov cheeb tsam aerobic cov tshuaj tiv thaiv yog (1.07 ± 0.01), (1.00 ± 0.04), (1.08 ± 0.09), thiab (1.03 ± 0.05) g / (m²·d), feem, 21 . 22.9%, thiab 17.6% piv rau qhov kub thiab txias. Cov kev sim zoo li no tau ua raws li qhov sib txawv ntawm qhov ntsuas qhov tseem ceeb hauv qhov kev sim ntsuas. Tsis tas li ntawd, nws tuaj yeem pom tias qhov ntsuas nitrification muaj peev xwm ntawm biofilm nyob rau hauv txhua qhov chaw aerobic nyob rau hauv qhov kev sim zoo li qub yog me ntsis siab dua li qhov tseeb ntawm qhov kev sim. Qhov kev tsom xam ua qhov no rau kev siv ib qho ammonium nitrogen substrate thiab ze rau -saturated siab yaj oxygen tej yam kev mob thaum lub sij hawm static thwmsim, ua rau ib tug ntau dua ntawm biofilm nitrification muaj peev xwm. Nyob rau hauv ib txwm kub, qhov muaj peev xwm nitrification tiag tiag hauv O3, O4, O7, thiab O8 cov tshuaj tiv thaiv thaj tsam ntawm peb -theem A / O-MBBR system yog 95.6%, 90.6%, 95.7%, thiab 90.4% ntawm qhov siab tshaj plaws nitrification peev nyob rau hauv cov kev sim zoo li qub, feem. Nyob rau hauv nruab nrab- qhov kub thiab txias, qhov muaj peev xwm nitrification tiag tiag hauv O3, O4, O7, thiab O8 cov tshuaj tiv thaiv thaj tsam txo qis rau 72.9%, 72.0%, 87.0%, thiab 84.5%, feem.
Kev tshuaj xyuas ntxiv tau pom tias nyob rau hauv qhov kub thiab txias, qhov tshwj xeeb ammonia oxidation tus nqi (nitrification tus nqi ib chav tsev loj MLVSS, xam raws li N) ntawm biofilm hauv O3, O4, O7, thiab O8 aerobic cov tshuaj tiv thaiv yog (0.062 ± 0.0095), (0.059 ± 0.00608), (0. (0.060 ± 0.0063) g/(g·d), raws. Nyob rau hauv nruab nrab- qhov kub thiab txias, qhov tshwj xeeb ammonia oxidation tus nqi ntawm biofilm nyob rau hauv O3 thiab O4 aerobic cov tshuaj tiv thaiv zones tsuas yog (0.046±0.0004) thiab (0.041±0.0016) g/(g·d), feem, txo los ntawm 25.8% thiab 3 li qub. Hauv qhov sib piv, qhov tshwj xeeb ammonia oxidation tus nqi ntawm biofilm nyob rau hauv O7 thiab O8 aerobic cov tshuaj tiv thaiv aav yog (0.062 ± 0.0051) thiab (0.060 ± 0.0029) g / (g·d), feem. Piv nrog rau qhov kub thiab txias, lub peev xwm ammonia oxidation ntawm O8 cov tshuaj tiv thaiv kab mob biofilm tseem tsis hloov pauv, thaum lub peev xwm ammonia oxidation ntawm O7 aerobic tshuaj tiv thaiv cheeb tsam biofilm txawm nce los ntawm 3.3%. Qhov txiaj ntsig no qhia tau tias nyob rau hauv nruab nrab- qhov kub thiab txias, biofilm nyob rau hauv qhov thib ob - theem cov tshuaj tiv thaiv cheeb tsam ntawm lub tshuab tsav tsheb muaj peev xwm nitrification zoo dua thiab qhov laj thawj ntawm qhov thib ob -stage subsystem txoj kev koom tes rau tag nrho cov kab ke nitrification.
Cov txiaj ntsig kev soj ntsuam ntawm biofilm morphology nyob rau hauv txhua qhov aerobic tshuaj tiv thaiv cheeb tsam ntawm thawj thiab thib ob theem A/O-MBBR subsystems tau qhia hauvDaim duab 7. Nyob rau hauv ib txwm kub, biofilm thicknesses nyob rau hauv O3, O4, O7, thiab O8 aerobic tshuaj tiv thaiv zones yog (217.6 ± 54.6), (175.7 ± 38.7), (168.1 ± 38.2), thiab (152.4 ± 37.8) μm, feem. Nyob rau hauv nruab nrab- qhov kub thiab txias, biofilm thicknesses nyob rau hauv O3 thiab O4 cov tshuaj tiv thaiv zones yog (289.4 ± 59.9) thiab (285.3 ± 61.9) μm, ntsig txog, sawv cev nce ntawm 33.0% thiab 62.4% piv rau biofilm thickness nyob rau hauv ib txwm kub. Piv txwv li, biofilm thicknesses nyob rau hauv O7 thiab O8 cov tshuaj tiv thaiv zones yog (173.1 ± 40.2) thiab (178.3 ± 31.2) μm, feem, nce los ntawm tsuas yog 3.0% thiab 17.0% piv rau ib txwm kub. Qee cov kev tshawb fawb tau pom tias cov biofilms nyias nyias muaj zog ammonia oxidation muaj peev xwm, uas zoo ib yam nrog cov kev sim ntawm txoj kev tshawb no. Kev tsom xam ua qhov no rau qhov tseeb tias nitrifying kab mob hauv biofilm yog vertically faib rau hauv cov txheej txheem txheej ntawm biofilm; ntau biofilm thickness ua rau txo qis substrate loj hloov efficiency thiab substrate affinity. Ntxiv mus, nyob rau hauv nruab nrab- qhov kub thiab txias tsis tshua muaj, cov pa oxygen concentration nyob rau hauv txhua qhov chaw aerobic ntawm lub tshuab tsav tsheb tau qis dua li hauv qhov kev sim ntsuas qhov ntsuas kub (qhov txawv ntawm 3.0-5.0 mg / L). Tshwj xeeb tshaj yog rau cov biofilms thicker nyob rau hauv O3 thiab O4 cov tshuaj tiv thaiv zones, qhov txo qis hauv oxygen huab hwm coj hloov mus rau hauv biofilm ua rau txo qis hauv lawv cov peev xwm nitrification tiag tiag (tsuas yog li 70% ntawm qhov siab tshaj plaws nitrification peev ntsuas nyob rau hauv cov xwm txheej zoo li qub). Yog li ntawd, rau ib tug ntshiab biofilm MBBR, nws yog ib qho tsim nyog los txhim kho biofilm rov ua dua tshiab los ntawm kev ntxiv dag zog rau kev siv zog thiab tsim nyog tswj biofilm thickness kom muaj peev xwm biofilm nitrification.
3. Cov lus xaus
① Nyob rau hauv cov xwm txheej ntawm cov tshuaj tiv thaiv kub ntawm 10-16℃(nruab nrab- tsis kub), kev kho tus nqi ntawm (23.6 ± 5.4) m³ / d, thiab cov pa roj carbon ntau npaum li cas ntawm 50-90 mg / L (xws li COD) hauv thaj tsam anoxic thib peb{{7} A/O-MBBR subsystem, SCOD effluent, NH₄⁺-N, thiab TIN concentrations ntawm peb-theem A/O-MBBR pilot system yog (26 ± 6), (0.4 ± 0.6), thiab (6.8 ± 3.6) mg/L, feem, nrog rauQhov nruab nrab tshem tawm mus txog 82.3%, 99.0%, thiab 82.8%.
② Hauv nruab nrab- qhov kub thiab txias, vim qhov sib txawv ntawm biofilm ntawm thaj chaw aerobic tshuaj tiv thaiv ntawm thawj -theem thiab thib ob-theem A/O-MBBR subsystems, qhov sib txawv ntawm nitrification peev xwm ntawm biofilm ntawm ob lub subsystems tau tsim. Tshwj xeeb tshaj yog rau thawj -theem A/O-MBBR subsystem, lub peev xwm nitrification poob vim muaj zog biofilm thickness. Txhawm rau kom muaj peev xwm biofilm nitrification, nws yog ib qho tsim nyog yuav tsum tswj xyuas qhov biofilm tuab.
③ Hauv peb -theem A/O-MBBR pilot system, cov nyhuv ntawm cov tshuaj tiv thaiv kub hloov ntawm qhov denitrification muaj nuj nqi kuj me me. Nyob rau hauv qhov sib txawv ntawm cov tshuaj tiv thaiv kub, cov denitrification carbon - mus rau -nitrogen piv siv cov dej nyoos raws li cov pa roj carbon monoxide yuav tsum siab dua 5, thiab cov denitrification carbon - mus rau -nitrogen piv siv sab nraud ntxiv sodium acetate raws li cov pa roj carbon monoxide yuav tsum muaj ntau dua 3.