Kawm txog Nitrogen Tshem Tawm Kev Ua Haujlwm ntawm MBBR rau Quasi-IV Kev Txhim Kho Cov Kev Kho Dej Ncua Dej Hauv Suav Teb Sab Hnub Tuaj Thaum Lub Caij Ntuj No

Kawm txog Nitrogen Tshem Tawm Kev Ua Haujlwm ntawm MBBR rau Quasi-IV Kev Txhim Kho Cov Kev Kho Dej Ncua Dej Hauv Tuam Tshoj Sab Qab Teb Sab Hnub Tuaj Thaum Lub Caij Ntuj No

Lub cheeb tsam sab qab teb sab hnub poob ntawm Tuam Tshoj yog qhov loj, nrog qhov sib txawv tseem ceeb hauv kev nyab xeeb thiab geological tej yam kev mob. Qhov chaw dav ntawm cov dej khib nyiab ua rau muaj kev hloov pauv loj hauv dej zoo. Txawm hais tias thaj av no nyob rau sab qab teb, vim tias tag nrho qhov siab thiab thaj av, qhov dej khib nyiab tuaj yeem poob qis dua 10℃thaum lub caij ntuj no txias. Ua ke nrog thaj av nyuaj ntawm thaj av, nrog cov roob sib sib zog nqus thiab hav tob, toj thiab cov tiaj, thiab qhov kub thiab txias sib txawv ntawm nruab hnub thiab hmo ntuj, qhov kev hloov pauv ntawm cov dej khib nyiab txhua hnub kuj pom tseeb. Cov yam ntxwv muaj zog thiab tsis tshua muaj dej kub hauv lub caij ntuj no ua rau muaj kev xav tau ntau dua rau kev tsim thiab kev ua haujlwm ntawm cov dej khib nyiab hauv cheeb tsam no. Tawm tsam keeb kwm yav dhau los ntawm kev txhim kho thiab rov tsim kho cov chaw kho dej khib nyiab hauv tsev, nws tseem ceeb dua los xaiv cov txheej txheem kho kom tsim nyog rau kev kho dua tshiab hauv cov nroj tsuag sab hnub poob kom ntseeg tau tias muaj kev ruaj khov thaum lub caij ntuj sov tsawg -.

Cov txheej txheem Moving Bed Biofilm Reactor (MBBR), los ntawm kev ntxiv cov cab kuj raug tshem tawm hauv thaj chaw ruaj khov, txhim kho cov kab mob ua haujlwm zoo dua qub thiab txhim kho qis -kub tsis kam. Nws tau siv dav hauv kev txhim kho cov haujlwm ntawm cov chaw kho dej khib nyiab. Tam sim no, daim ntawv thov teev ntawm MBBR txheej txheem hauv Suav teb tau tshaj 2.5 × 10⁷ m³·d⁻¹, thiab MBBR tau suav nrog "txoj kev siv dav thiab muaj kev nyab xeeb thiab txhim khu kev qha" hauv qhov kev hloov kho tshiab "Sab nraum zoov Drainage Design Standard" (GB 50014-2021). Kev siv dav dav ntawm cov txheej txheem kuj tau txhawb kev ua raws li sai sai -kev tshawb fawb. Kev tshawb fawb hotspots ntawm cov txheej txheem MBBR feem ntau yog tsom rau cov txheej txheem tsim qauv, kev tshawb fawb txog kev tshawb fawb, thiab kev tshawb nrhiav engineering. Cov lus xaus feem ntau suav nrog MBBR txhim kho biochemical efficiency, biofilm txhim kho qhov cuam tshuam thiab txhim kho qis-kub tsis kam, MBBR txhim kho cov kab mob ua kom zoo dua qub, thiab biofilm SND txhim kho kev tshem tawm nitrogen. Piv txwv li, Huang Qing et al. pom tias tom qab kev kho dua tshiab nrog cov txheej txheem MBBR, qhov cuam tshuam tsis zoo ntawm cov dej khib nyiab kho tau zoo dua qub, thiab cov dej ntws tawm tseem tuaj yeem ua tau raws li cov qauv ruaj khov txawm tias nyob rau lub sijhawm ntev BOD thiab TN tshaj. Liu Qiang et al. pom tias cov txheej txheem MBBR tau ua kom muaj peev xwm kho tau zoo ntawm cov nroj tsuag ntawm qhov kub thiab txias, thiab cov dej ntws tawm tuaj yeem ua tau raws li cov qauv tsim ntawm qhov kub qis ntawm 9-11 degree. Luan Zhixiang et al. pom tias tom qab kev txhim kho cov dej khib nyiab sab qaum teb nrog cov txheej txheem MBBR, thaj chaw aerobic MBBR tuaj yeem tshem tawm 20.12% ntawm TN los ntawm SND ntawm cov neeg nqa khoom raug tshem tawm. Han Wenjie et al. piv rau tsib lub nroog cov chaw kho dej khib nyiab nrog cov txheej txheem MBBR hybrid hauv cheeb tsam Yangtze River Delta nyob rau lub caij ntuj no qis thiab pom tias qhov sib ntxiv ntawm cov neeg nqa khoom raug tshem tawm tau nce cov kab mob nitrifying biomass hauv lub cev, nrog rau cov cab cab uas raug tshem tawm ntxiv 86.12% -95.36% ntawm cov kab mob nitrifying. Txawm li cas los xij, kev tshawb fawb tam sim no tseem muaj qee qhov kev txwv. Piv txwv li, ntau cov kev tshawb fawb cais MBBR tsim los ntawm kev ua haujlwm ntawm kev ua haujlwm, tsis muaj kev sib piv ntawm kev tsim qauv thiab kev ua haujlwm rau tib qhov project. Hais txog qhov cuam tshuam ntawm MBBR, tsuas yog "zoo tab sis tsis muaj ntau" cov lus xaus, tsis muaj ntau qhov kev txiav txim siab ntawm qhov siab tshaj qhov siab. Hais txog qhov tshwm sim SND, nws tsuas yog " ntsuas tau tab sis tsis tswj tau," tsis muaj kev txheeb xyuas ncaj qha ntawm qhov chaw ntawm nitrogen tshem tawm los ntawm kev sim macro tsim, lossis cov lus qhia ua haujlwm muaj txiaj ntsig los ntawm kev xav ntawm kev tswj xyuas engineering.

Raws li cov kev txwv ntawm cov kev tshawb fawb uas twb muaj lawm, txoj kev tshawb no yuav siv kev kho dua tshiab ntawm CASS cov dej khib nyiab hauv Suav teb sab hnub poob ua piv txwv los piav qhia cov qauv tsim thiab cov laj thawj ntawm MBBR txheej txheem. Ua ke nrog cov kev ua haujlwm tiag tiag hauv lub caij ntuj no tsis zoo tshaj plaws, qhov laj thawj ntawm MBBR tsim tau raug tshuaj xyuas. Cov txheej txheem kev kho mob muaj peev xwm raug txheeb xyuas ntau los ntawm kev hloov pauv hauv cov dej zoo raws li lub tank lom thiab siab - cov kev sim hauv substrate. Kev kuaj denitrification kuaj siv aerobic biofilm tau tsim los tshawb xyuas qhov tseeb ntawm SND tshwm sim hauv hybrid MBBR system. Cov kev cuam tshuam ntawm engineering kev ua haujlwm tsis ua haujlwm ntawm SND cuam tshuam ntawm MBBR system tau kawm, thiab ua ke nrog cov ntaub ntawv haum, kev ua haujlwm zoo tshaj plaws rau SND tau thov. Qhov sib txawv ntawm microbial kev faib tawm ntawm cov sludge thiab biofilm tau soj ntsuam los ntawm qhov pom ntawm cov kab mob muaj pes tsawg leeg, thiab cov kab mob microscopic cuam tshuam ntawm SND tau txheeb xyuas los ntawm hom thiab cov txheeb ze ntawm cov kab mob aerobic denitrifying. Nws cia siab tias qhov kev tshawb fawb no tuaj yeem muab cov ntaub ntawv siv rau MBBR txheej txheem tsim ntawm lwm cov chaw kho dej khib nyiab zoo sib xws, muab cov ntaub ntawv yooj yim rau kev ua haujlwm ruaj khov ntawm MBBR cov nroj tsuag, thiab muab cov lus qhia ua haujlwm rau kev ua haujlwm zoo ntawm SND hauv MBBR systems.

1 Cov ntaub ntawv thiab cov txheej txheem

1.1 Project Overview

Ib lub chaw kho dej khib nyiab nyob rau sab hnub poob Suav teb, nrog lub peev xwm tsim ntawm 1 × 10⁵ m³·d⁻¹, cov dej khib nyiab yuav tsum tau ua kom tau raws li Chav Kawm A tus qauv ntawm "Kev Tso Tawm Ntawm Cov Kabmob rau Kev Kho Dej Hauv Nroog" (GB 18918-2002). Vim muaj kev txwv kev siv av thaum lub sij hawm tsim kho thaum ntxov, cov txheej txheem CASS uas tsis muaj ib txwm siv cov twj tso kua mis thib ob tau txais yuav. Txawm li cas los xij, thaum lub sijhawm ua haujlwm, cov teeb meem xws li nitrification tsis txaus thaum lub caij ntuj no txias, tsis zoo sludge settleability, thiab txo cov kev kho mob tau tshwm sim. Hauv 2019, cov nroj tsuag tau hloov kho mus rau quasi-Class IV cov qauv. Kev kho dua tshiab yuav tsum tau xav txog ob qho tib si qhov nce hauv qhov muaj zog nitrogen concentration thiab txhim kho cov qauv effluent. Tus tsim muaj zog thiab effluent zoo ua ntej thiab tom qab reconstruction yog qhia nyob rau hauvTable 1. Raws li qhov muaj txiaj ntsig NH₃-N thiab TN loads tau nce 66.67% thiab 62.16% feem, cov pa roj carbon monoxide, nitrogen, phosphorus, thiab lwm yam, yuav tsum tau hloov kho los ntawm Chav Kawm A ntawm GB 18918-2002 mus rau Chav Kawm Zoo Tshaj Plaws IV" 3838-2002), uas yog sib npaug rau nce nitrification thiab denitrification loads los ntawm 127.27% thiab 94%, feem. Qhov phiaj xwm no tau txais cov txheej txheem Bardenpho-MBBR, hloov pauv tus qub CASS tank rau hauv lub tank lom thiab lub tank sedimentation.

Tom qab kev tsim kho dua tshiab, rau kev tshem tawm nitrogen, qhib cov sludge txuas ntxiv mus ua lub luag haujlwm tseem ceeb. Lub sij hawm denitrification retention ntawm tus thawj CASS tank tau txuas ntxiv los ntawm 3.78 h txog 6.35 h, thiab denitrification volumetric load ntawm cov activated sludge tau nce los ntawm 0.140 mus rau 0.189 kg·(m³·d)⁻¹. Txhawm rau txhim kho activated sludge denitrification, pre-anoxic thiab post-anoxic aav tau teeb tsa nrog lub sijhawm khaws cia ntawm 4.23 h thiab 2.12 h, raws li. Cov ncej-anoxic cheeb tsam siv cov pa roj carbon ntau ntxiv los txhim kho denitrification los daws cov teeb meem ntawm cov pa roj carbon tsis txaus hauv cov dej nyoos. Rau nitrification, lub sij hawm cia nitrification ntawm tus qub CASS tank raug txo los ntawm 7.55 h mus rau 4.23 h, thaum lub nitrification load yuav tsum tau zoo heev los ntawm 0.079 mus rau 0.275 kg·(m³·d)⁻¹. Txhawm rau txhim kho cov txiaj ntsig nitrification, cov neeg nqa khoom raug tshem tawm tau ntxiv rau hauv thaj chaw aerobic los tsim ib qho chaw aerobic MBBR. Cov neeg nqa khoom siv yog SPR- hom III, nrog txoj kab uas hla ntawm (25 ± 0.5) hli thiab tuab ntawm (10 ± 1) hli. After biofilm attachment, the density was close to that of water, and the effective specific surface area was greater than 800 m²·m⁻³, meeting the industry standard "High-density polyethylene suspended carrier for water treatment" (CJ/T461-2014). Cov biofilm ntawm cov cab cab uas raug tshem tawm tau tshwm sim tsaus grey tom qab txuas (Daim duab 1). MBBR cheeb tsam siv tsuas yog perforated aeration los muab hydraulic shear, tswj cov biofilm tuab ntawm (208.82 ± 37.57) μm, muab cov kev mob zoo rau kev hloov pauv huab cua thiab oxygen.

1.2 Kev txiav txim siab ntawm kev tshem tawm Nitrogen hauv Biological Tank

Txhawm rau nkag siab txog txoj hauv kev tshem tawm nitrogen hauv txhua qhov chaw ua haujlwm ntawm lub tank lom nyob rau hauv lub caij ntuj no qis tom qab kev tsim kho, cov dej zoo nyob hauv lub tank lom tau raug saib xyuas txhua hnub txij lub Kaum Ob Hlis 15, 2020, txog rau Lub Kaum Ob Hlis 22, 2020. Lub sijhawm no, cov dej kub hauv lub tank lom yog 9.5-10.2 degree. Cov qauv no suav nrog cov khoom siv hluav taws xob hauv lub tank, cov dej ntws tawm ntawm thaj chaw anaerobic, cov dej ntws ntawm thaj chaw anoxic, cov dej ntws ntawm MBBR cheeb tsam, cov dej ntws tawm ntawm cov ncej - anoxic zone, effluent ntawm post-aerobic cheeb tsam, thiab effluent ntawm lub tank. Cov qauv raug coj txhua txhua 2-3 teev. Tom qab sau, cov qauv tau pretreated tam sim ntawd. Tom qab sedimentation, cov supernatant tau sau, thiab peb cov qauv tau muab sib xyaw ua ke los txiav txim siab NH₃-N, NO₃-N, TN, thiab COD, txheeb xyuas txoj kev tshem tawm cov pa phem thiab nitrification / denitrification load ntawm txhua qhov chaw ua haujlwm.

1.3 Kev txiav txim siab ntawm Nitrification muaj peev xwm ntawm MBBR System thiab kev koom tes tus nqi ntawm cov neeg nqa khoom raug tshem tawm

Txhawm rau txheeb xyuas qhov kev ua siab ntev siab tshaj plaws ntawm MBBR system uas twb muaj lawm, kev sim tshuaj nitrification tau ua thaum Lub Ob Hlis 27 thiab 28, 2021. Cov neeg nqa khoom raug tshem tawm thiab qhib cov sludge los ntawm thaj chaw aerobic ntawm cov nroj tsuag tau sau txhua hnub los simulate qhov cuam tshuam ntawm MBBR system thaum lub caij ntuj no muaj zog ntxiv. Lub chaw kuaj sim simulated qhov muaj peev xwm ntawm MBBR cheeb tsam raws txoj kev ntws. Lub supernatant ntawm thaj chaw anoxic effluent tom qab siv sedimentation, thiab NH₃-N thiab alkalinity tau ntxiv los ntawm kev ntxiv ammonium chloride thiab sodium bicarbonate raws li lub zog rau kev kuaj. Cov cuab yeej ntsuas nitrification tau qhia hauvDaim duab 2. Ntshiab-biofilm, ntshiab-sludge, thiab hybrid systems tau teeb tsa ua ntu zus. Cov sludge concentration thiab carrier filling ratio tau ua raws li cov xwm txheej ntawm lub tank lom. Txhawm rau kom siv tag nrho cov peev txheej nitrification ntawm MBBR system thiab txhim kho huab hwm coj hloov pauv thiab hloov pauv oxygen, lub zog NH₃-N concentration tau nce los ntawm kwv yees li 10 mg·L⁻¹ raws txoj kev ntws mus txog li 25 mg·L⁻¹, thiab DO tau nce los ntawm 2–4 mg·L⁻¹ raws txoj kev ntws mus txog 7 mg⁻¹. Thaum lub sij hawm ntsuas, cov dej kub yog 9.7-10.4 degree. Cov twj tso kua mis aeration thiab yoj tsim tau siv los tswj cov txheej txheem oxygenation thiab cov kua dej hauv lub cev. Cov qauv raug coj txhua txhua 30 feeb thiab pretreated los txiav txim qhov kev hloov ntawm ammonia nitrogen concentration. Raws li cov txheej txheem qhia, cov txheej txheem biofilm load suav nrog hauv hybrid MBBR system yog qhia hauv qhov sib npaug (1) thiab (2).

Qhov twg: N₂ yog nitrification volumetric load ntawm biofilm nyob rau hauv hybrid system, kg·(m³·d)⁻¹; N₁ yog tag nrho cov nitrification volumetric load ntawm MBBR hybrid system, kg·(m³·d)⁻¹; N₃ yog nitrification volumetric load ntawm lub tshuab nqus dej sludge, kg·(m³·d)⁻¹; η yog tus nqi nitrification ntawm cov neeg nqa khoom raug tshem tawm, %.

1.4 Kev Tshawb Fawb Txog Kev Tshawb Fawb thiab Kev Tswj Xyuas Kom Zoo ntawm SND hauv MBBR System

Rau qhov tshwm sim ib txhij ntawm nitrification thiab denitrification (SND) hauv MBBR system, txhawm rau txheeb xyuas qhov tseeb ntawm cov nyhuv SND, ib qho kev sim kuaj denitrification siv MBBR biofilm ntshiab tau ua thaum Lub Ob Hlis 28, 2021. Cov neeg nqa khoom raug tshem tawm ntawm thaj chaw aerobic tau sau. Tus cab kuj filling piv tau ua raws li cov xwm txheej ntawm lub tank lom. Qhov cuam tshuam rau qhov kev sim tau npaj los ntawm kev ntxiv cov poov tshuaj nitrate rau cov dej nyoos ntawm cov nroj tsuag. Cov qauv raug coj txhua txhua 20 feeb thiab pretreated los txiav txim siab nitrate nitrogen concentration.

Txij lub Kaum Ob Hlis 1, 2020, txog rau Lub Ob Hlis 28, 2021, cov dej tsis zoo thiab kev ua haujlwm tsis zoo ntawm thaj chaw MBBR tom qab kev tsim kho dua tshiab tau taug qab txhua hnub thoob plaws lub caij ntuj no. Cov qauv no suav nrog cov effluent ntawm thaj chaw anoxic thiab effluent ntawm MBBR cheeb tsam. Cov qauv raug coj txhua txhua 2-3 teev. Tom qab sau, cov qauv tau pretreated tam sim ntawd. Tom qab sedimentation, cov supernatant tau sau, thiab peb cov qauv tau muab sib xyaw ua ke los txiav txim TN, NH₃-N, NO₃-N, thiab COD. Nyob rau tib lub sijhawm, DO qib hauv thaj tsam aerobic MBBR tau ntsuas. Cov ntaub ntawv ntsuas tau raug soj ntsuam los ntawm cov ntsiab lus tseem ceeb (PCA) txhawm rau txheeb xyuas cov lus teb tseem ceeb uas cuam tshuam rau SND cov nyhuv hauv thaj chaw aerobic. Cov kev tswj xyuas qhov zoo tshaj plaws tau txiav txim siab los ntawm kev tsom xam kom haum los muab lub hauv paus rau qhov ntsuas - tswj hwm ntawm SND.

1.5 Siab -Throughput Sequencing of Microorganisms in the Wastewater Treatment Plant

Txhawm rau txheeb xyuas qhov sib txawv ntawm cov sludge thiab biofilm theem nyob rau hauv MBBR system hais txog microbial ntau haiv neeg, hom tseem ceeb, thiab cov kab mob ua kom muaj txiaj ntsig zoo, thiab txhawm rau txheeb xyuas qhov chaw ntawm SND, qhib cov sludge thiab tshem tawm cov cab kuj los ntawm MBBR system tau sau rau Lub Ob Hlis 28, 2021} rau qhov sib piv, { Kev sib txuas ntawm 16S rDNA amplicons. Lub sijhawm no, lub kaw lus tau ntsib tag nrho lub caij ntuj no, thiab cov kab mob microbial hauv zej zog tuaj yeem cuam tshuam zoo dua qhov xwm txheej nyob rau hauv qis - qhov kub thiab txias. Cov txheej txheem tshwj xeeb rau siab - dhau los ntawm kev txiav txim siab thiab kev tshuaj xyuas xa mus rau cov ntaub ntawv tshaj tawm yav dhau los.

1.6 Cov Txheej Txheem Kev Txiav Txim Dej Zoo

Txhua qhov ntsuas dej tsis zoo uas koom nrog hauv txoj kev tshawb no tau txiav txim siab siv cov txheej txheem txheej txheem. COD tau txiav txim los ntawm lub teb chaws tus qauv qauv; NH₃-N tau txiav txim los ntawm Nessler's reagent spectrophotometric method; NO₃-N tau txiav txim los ntawm txoj kev ultraviolet spectrophotometric; TN tau txiav txim siab los ntawm alkaline potassium persulfate digestion -UV spectrophotometric method; TP tau txiav txim siab los ntawm txoj kev ammonium molybdate spectrophotometric; DO thiab dej kub tau ntsuas los ntawm kev siv lub tshuab nqus pa oxygen meter.

2 Cov txiaj ntsig thiab kev sib tham

2.1 Tag Nrho Cov Kev Kho Mob Hauv Qab Qis-Qhov Kub Kub Ua Ntej thiab Tom Qab Kev Tsim Kho

Ua ntej, tag nrho cov kev kho mob ntawm lub cev nyob rau hauv qis lub caij ntuj no kub ua ntej thiab tom qab reconstruction (2018-12-01 txog 2019-02-28, 2020-12-01 txog 2021-02-28) tau muab piv. Ua ntej thiab tom qab kev tsim kho, lub caij ntuj no cov dej kub tau tswj hwm ntawm 9-13 degree. Ua ntej rov tsim kho, lub caij ntuj no ntws yog (9.12 ± 0.58) × 10⁴ m³·d⁻¹, thiab tom qab kev tsim kho, nws nce mus rau (9.42 ± 0.44) × 10⁴ m³·d⁻¹. Raws li qhia hauvDaim duab 3(a)-(d), tom qab kev tsim kho dua tshiab, qhov nruab nrab muaj zog COD thiab BOD₅ loads nce 16.82% thiab 26.97%, feem, piv rau ua ntej kev tsim kho, tab sis cov effluent poob mus rau (20.04 ± 2.38) thiab (4.47 ± 0.84, mg·L. Tom qab kev tsim kho dua tshiab, qhov nruab nrab muaj zog TP load tau nce los ntawm 23.40% piv rau ua ntej kev tsim kho dua tshiab, tab sis cov dej ntws TP tseem tuaj yeem qis li (0.26±0.02) mg·L⁻¹. Tom qab kev tsim kho dua tshiab, qhov muaj zog SS thauj khoom tau qis dua ua ntej, tab sis cov dej ntws SS poob ntau dua 17.51% piv rau ua ntej, mus rau (3.44 ± 1.17) mg·L⁻¹, nrog qhov siab tshaj plaws tsuas yog 4.75 mg·L⁻¹.

Lub ntsiab tseem ceeb ntawm txoj haujlwm no tom qab kev tsim kho dua tshiab yog kev txhim kho cov peev txheej tshem tawm nitrogen. Tom qab kev tsim kho dua tshiab, qhov nruab nrab muaj zog NH₃-N thiab TN loads nce 21.56% thiab 19.79%, feem, piv rau ua ntej rov tsim kho, tab sis cov dej ntws tau txo qis rau (0.94±0.22) thiab (8.59±0.64) mg·L⁻¹, ntsig txog. Qhov siab tshaj plaws effluent NH₃-N tsuas yog 1.33 mg·L⁻¹, thiab qhov siab tshaj TN tsuas yog 9.7 mg·L⁻¹. Rau kev tshem tawm nitrogen, txij li cov activated sludge tseem ua lub luag haujlwm tseem ceeb tom qab kev tsim kho, raws li qhov tseem ceeb txuas ntxiv ntawm anoxic retention time, lub caij ntuj no denitrification volumetric load ntawm lub kaw lus ua ntej thiab tom qab kev tsim kho tsis hloov ntau. Rau nitrification, tom qab kev tsim kho dua tshiab, cov txiaj ntsig nitrification tau txhim kho los ntawm kev ntxiv cov cab kuj raug tshem tawm los ua ib qho hybrid MBBR system los txhawb NH₃-N tshem tawm. Raws li qhov txo qis ntawm aerobic tuav lub sij hawm, qhov tseeb lub caij ntuj no nitrification load tau nce los ntawm 0.081 txog 0.182 kg·(m³·d)⁻¹ tom qab kev tsim kho, nce 124.69% piv rau ua ntej kev tsim kho. Kev siv cov txheej txheem MBBR hauv qhov project no tau ua tiav qhov kev txhim kho tseem ceeb hauv kev ua haujlwm nitrification.

2.2 Kev soj ntsuam ntawm System Nitrogen tshem tawm kev ua tau zoo, muaj peev xwm, thiab lub luag haujlwm ntawm cov neeg nqa khoom raug tshem tawm

Txhawm rau txiav txim siab ntxiv cov txiaj ntsig ntawm kev tshem tawm nitrogen ntawm txhua qhov chaw ua haujlwm hauv thaj chaw lom neeg tom qab kev tsim kho, cov dej zoo raws li lub tank lom tau raug taug qab, thiab txoj kev tshem tawm nitrogen ntawm txhua qhov chaw ua haujlwm tom qab kev tsim kho tau tshuaj xyuas los ntawm qhov nruab nrab dej tsis zoo ntawm txhua qhov haujlwm. Raws li qhia hauvDaim duab 4, thaum lub sij hawm ntsuas, qhov nruab nrab qhov muaj peev xwm ntawm TN, NH₃-N, thiab COD concentrations ntawm lub tank lom yog 43.59, 38.50, thiab 278.00 mg·L⁻¹, raws li, thiab cov effluent TN, NH₃{{4.5}, N, thiab 24.46 mg·L⁻¹ Rau kev tshem tawm TN, lub kaw lus TN tshem tawm tus nqi xam los ntawm cov khoom siv hluav taws xob thiab cov dej ntws tawm TN yog 78.95 ± 6.01%, thiab kev tshem tawm feem ntau tshwm sim hauv thaj tsam ua ntej- anoxic, nrog cov nitrogen tshem tawm ntawm 27.51 mg·L⁻¹. Lub denitrification load thiab kev pab cuam yog 0.149 kg·(m³·d)⁻¹ thiab 79.16% ± 2.24%, feem. Ua ke nrog kev hloov pauv hauv COD concentration, COD / TN tau siv rau denitrification hauv thaj tsam ua ntej - anoxic yog 5.22 ± 0.21. Cov ncej-anoxic cheeb tsam siv sab nraud sodium acetate rau denitrification, nrog cov nitrogen tshem tawm thiab thauj khoom ntawm 4.35 mg·L⁻¹ thiab 0.024 kg·(m³·d)⁻¹, feem. Kev suav COD / TN siv rau denitrification yog 4.66 ± 0.57. Sodium acetate, raws li ib tug me me molecular organic acid ntsev, yog yooj yim siv los ntawm cov kab mob thiab muaj ntau dua denitrification efficiency tshaj cov complex organic carbon qhov chaw nyob rau hauv cov dej nyoos. Tom qab kev tsim kho dua tshiab, tus muaj zog muaj biodegradability zoo, thiab cov kev cai denitrification tuaj yeem ua tau raws li qhov ua ntej -anoxic cheeb tsam, yog li txo qhov siab ntawm post- anoxic denitrification thiab tus nqi ntawm cov pa roj carbon sab nraud. Rau NH₃-N tshem tawm, qhov DO hauv thaj tsam MBBR thaum lub sijhawm ua haujlwm tiag tiag yog 2–4 mg·L⁻¹, thiab lub kaw lus NH₃-N tshem tawm tus nqi suav los ntawm cov khoom siv hluav taws xob thiab cov dej ntws tawm NH₃-N concentrations yog 98.67%.

Hauv kev ua haujlwm tiag tiag ntawm cov chaw kho dej khib nyiab, kev cuam tshuam tsis zoo feem ntau tshwm sim vim muaj tej yam ntuj tso xws li dej nag thiab snowmelt, cov khoom lag luam xws li kev lag luam ntau ntxiv lossis kev lag luam tsis zoo ib ntus, thiab kev sib raug zoo xws li hnub so thiab cov xwm txheej tshwj xeeb. Kev txhim kho qhov cuam tshuam tsis zoo ntawm kev kho mob lom neeg tau dhau los ua tus yuam sij rau kev nyab xeeb thiab ruaj khov ntawm cov nroj tsuag. Txhawm rau txheeb xyuas qhov siab tshaj plaws ntawm kev ua haujlwm siab ntawm lub kaw lus, ib qho kev sim kuaj nitrification nyob rau hauv siab substrate thiab siab DO tau ua. Nyob rau tib lub sijhawm, txhawm rau txheeb xyuas lub luag haujlwm tiag tiag ntawm cov neeg nqa khoom raug tshem tawm hauv hybrid MBBR system, peb pawg kev sim (hybrid, ntshiab-biofilm, thiab ntshiab-sludge) tau teeb tsa ob zaug. Cov kev hloov pauv hauv NH₃-N hauv txhua qhov system thaum lub sijhawm xeem tau pom hauvDaim duab 5. Nrog lub zog NH₃-N ntawm 25 mg·L⁻¹, cov hybrid thiab ntshiab-biofilm systems txo NH₃-N mus rau qis dua 1.5 mg·L⁻¹ hauv 2.5 thiab 3.0 h, raws li, thaum lub ntshiab{- sludge nyob rau hauv sludge lub sijhawm xeem. Qhov ntsuas txhais tau tias nitrification volumetric loads ntawm cov ntshiab-sludge, ntshiab-biofilm, thiab hybrid systems yog 0.072, 0.215, thiab 0.286 kg·(m³·d)⁻¹, feem. Raws li kev sib npaug (1), nyob rau hauv lub xub ntiag ntawm activated sludge, lub volumetric load ntawm tshem tawm cov cab kuj nyob rau hauv lub MBBR system yog 0.214 kg·(m³·d)⁻¹, uas yog tsis heev txawv ntawm cov ntsuas load ntawm cov ntshiab{19}}biofilm pawg. Piv nrog rau lwm cov nroj tsuag uas siv cov txheej txheem MBBR hybrid, nrog cov cab kuj zoo sib xws, qhov siab tshaj plaws nitrification load ntawm cov cab kuj raug tshem tawm hauv qhov project no kuj tseem nyob rau theem siab, uas tej zaum yuav cuam tshuam rau kev txhim kho ntxiv ntawm kev hloov pauv loj ntawm cov nqa nqa nqa thiab nce kev ua haujlwm ntawm cov kab mob ua haujlwm nyob rau hauv lub siab muaj zog load. Tsis tas li ntawd, nrog kev sib xyaw ua ke ntawm cov activated sludge, qhov siab tshaj plaws nitrification volumetric load nyob rau hauv siab substrate thiab siab DO tej yam kev mob mus txog 0.286 kg·(m³·d)⁻¹, lub rooj sib tham thiab tshaj qhov tsim load (0.275 kg·(m³·d)⁻¹), ntsib tsim kev cia siab.

To quantitatively analyze the maximum tolerance load of the biological system in this project, based on the volumetric load of the hybrid system measured in the laboratory test, combined with the influent water quality data along the flow path, the system could withstand a maximum treatment capacity of 1.23×10⁵ m³·d⁻¹ (calculated assuming a positive linear relationship between system nitrification load and hydraulic retention time) while ensuring stable effluent NH₃-N ua raws. Qhov no yog qhov nce ntawm 30.57% piv rau lub peev xwm kho lub caij ntuj no ntawm qhov project no, nrog rau lub sij hawm hydraulic retention ntxiv txo mus rau 3.43 h. Ib yam li ntawd, raws li lub peev xwm kho tau tiag tiag tom qab kev tsim kho dua tshiab, qhov ua tau zoo ntawm NH₃-N concentration ntawm cov roj ntsha tank siab li 55 mg·L⁻¹, nce 56.96% piv rau qhov nruab nrab lub caij ntuj no muaj txiaj ntsig NH₃-N ntawm qhov project no.

Hais txog lub luag haujlwm ntawm cov neeg nqa khoom raug tshem tawm hauv hybrid MBBR system ntawm txoj haujlwm no, raws li kev sib npaug (2), tus nqi nitrification ntawm cov khoom thauj biofilm raug tshem tawm hauv qhov project no yog 74.83%. Nws tuaj yeem pom tau tias nyob rau hauv qis- qhov kub thiab txias, cov cab kuj raug tshem tawm tau dhau los ua qhov tseem ceeb rau nitrification hauv hybrid MBBR system. Ua ke nrog cov ntaub ntawv cov ntaub ntawv, nws tau soj ntsuam tias nyob rau hauv lub caij ntuj no tsis tshua muaj kub, lub activated sludge system, txwv tsis pub los ntawm nws cov qauv xoob thiab siab tshwj xeeb thaj chaw, muaj zoo tshav kub dissipation kev ua tau zoo thiab tsis zoo thermal rwb thaiv tsev rau cov kab mob hauv cov kab mob, ua rau txo nitrification kev ua tau zoo. In contrast, the biofilm on the suspended carriers, benefiting from its dense structure and high EPS protection, provides good thermal insulation for the inner layer of the biofilm, thus ensuring good nitrification performance under low-temperature conditions. Tsis tas li ntawd, nyob rau hauv - cov txiaj ntsig ntsuas ntws ntawm qhov project no tau pom qhov tshwm sim tseem ceeb ntawm TN tshem tawm hauv thaj tsam MBBR. Ua ke nrog cov kev hloov pauv hauv NH₃-N concentration raws thaj chaw aerobic thiab qhov rov ua dua, qhov kev tshem tawm TN yog (3.42 ± 0.11) mg·L⁻¹, nrog rau kev koom tes ntawm 9.83% ± 0.67%, qhia tias muaj kev cuam tshuam SND hauv lub cev.

2.3 Kev txheeb xyuas ntawm SND Effects thiab Kev Tshawb Fawb Txog Kev cuam tshuam

Tam sim no, feem ntau cov chaw kho dej khib nyiab siv cov txheej txheem MBBR tuaj yeem soj ntsuam kev tshem tawm nitrogen hauv thaj chaw aerobic, feem ntau tshem tawm 3-8 mg·L⁻¹ ntawm TN. Qhov laj thawj rau qhov tshwm sim no feem ntau yog los ntawm SND cov nyhuv ntawm biofilm. Ntawd yog, raws li lub peev xwm nkag mus ntawm cov pa oxygen tsis muaj zog, cov txheej txheem anoxic / hypoxic tsim nyob rau hauv txheej txheej ntawm biofilm, muab cov xwm txheej rau kev txhawb nqa cov kab mob denitrifying, yog li tso lub hauv paus rau SND nitrogen tshem tawm.

Txhawm rau kom paub meej ntxiv txog qhov chaw ntawm aerobic SND, ib qho kev sim kuaj denitrification siv aerobic biofilm tau ua, raws li qhia hauvDaim duab 6. Thoob plaws lub sijhawm sim, qhov txo qis hauv NO₃-N yog qhov sib tw thiab zoo ib yam, nrog rau lub cev tshem tawm 3.72 mg·L⁻¹ ntawm nitrate nitrogen hauv 120 min. Qhov nruab nrab C / N noj los ntawm lub cev yog 3.43 ± 0.05. Raws li txoj cai, C / N xav tau rau denitrification yog 2.86. Xav txog kev noj los ntawm kev siv tshuaj lom neeg thiab DO hauv cov dej nyoos, qhov yuav tsum tau C / N feem ntau nce mus txog 4. Txawm li cas los xij, C / N xav tau rau kev tshem tawm nitrogen los ntawm cov neeg nqa khoom raug tshem tawm hauv qhov project no qis dua qhov uas tau noj los ntawm kev siv cov microbial denitrification. Nws tau kwv yees tias thaum cov neeg nqa khoom raug tshem tawm hauv thaj tsam MBBR siv SND nitrogen tshem tawm, lawv tsuas yog siv cov pa roj carbon monoxide uas tsim los ntawm kev laus thiab lysis ntawm biofilm raws li cov khoom siv hluav taws xob, yog li kev siv tus nqi ntawm cov organic teeb meem (sab nraud carbon qhov chaw) hauv cov dej nyoos feem ntau qis. Kev siv cov hnub nyoog biofilm ua cov pa roj carbon monoxide rau denitrification kuj qhia tau tias cov txheej txheem MBBR yuav muaj cov sludge qis dua. Siv tag nrho lub sij hawm xeem raws li qhov node, lub laij lej denitrification volumetric load ntawm aerobic biofilm yog (0.045 ± 0.003) kg·(m³·d)⁻¹. Cov biofilm ntawm cov cab kuj raug tshem tawm ntxiv hauv thaj chaw aerobic muaj cov nyhuv denitrification, muab pov thawj rau qhov tshwm sim ntawm ib txhij nitrification thiab denitrification hauv biofilm.

SND, raws li cov txiaj ntsig zoo tom qab siv cov txheej txheem MBBR rau kev kho dua tshiab hauv txoj haujlwm no, ntxiv txhim kho lub kaw lus TN tshem tawm tus nqi thiab txo qhov kev cia siab ntawm cov khoom siv sab nraud rau denitrification rau qee yam. Txhawm rau nthuav dav ntxiv cov nyhuv aerobic SND, los ntawm qhov kev xav ntawm kev ua haujlwm zoo, kev cuam tshuam ntawm cov dej ntws zoo thiab cov dej tsis zoo thiab kev tswj tsis tau ntawm SND cov nyhuv ntawm MBBR cheeb tsam tau tshawb nrhiav ntxiv. Los ntawm kev taug qab ntev - lub sij hawm taug qab ntawm kev tswj tsis tau xws li influent nitrate nitrogen (NO₃-Ninf), effluent nitrate nitrogen (NO₃-Neff), influent organic teeb meem (CODinf), effluent organic teeb meem (CODeff), influent ammonia nitrogen ({5}NH ent), (NH₃-Neff), tag nrho cov nitrogen tshem tawm (ΔTN), thiab DO nyob rau hauv cheeb tsam MBBR thoob plaws lub caij ntuj no, cov ntsiab lus tseem ceeb tsom xam (PCA) tau siv los tshawb txog cov kev sib raug zoo ntawm cov kev txwv no. Cov txiaj ntsig tau qhia hauvDaim duab 7. Lub ΔTN hauv thaj chaw aerobic pom qhov cuam tshuam tsis zoo nrog DO, thaum kev sib raug zoo nrog CODinf, CODeff, thiab NO₃-Ninf tsis pom tseeb. DO siab dhau ua rau kev hloov pauv loj hauv biofilm, ua rau nws nyuaj rau tsim ib qho chaw anoxic sab hauv, uas tsis zoo rau cov txheej txheem denitrification thiab inhibits SND nyhuv. Tsis tas li ntawd, CODinf thiab NO₃-Ninf hauv thaj chaw MBBR tsis muaj kev cuam tshuam loj rau SND cov txiaj ntsig ntawm cov cab kuj raug tshem tawm. Ntawm qhov tod tes, qhov no rov xyuas dua tias cov txheej txheem SND ntawm biofilm feem ntau siv cov pa roj carbon monoxide es tsis yog cov khoom siv sab nraud. Ntawm qhov tod tes, nws tseem qhia tau tias NO₃-N tshem tawm los ntawm SND hauv thaj tsam MBBR tsis yog los ntawm NO₃-N, tab sis feem ntau yog los ntawm NO₃-N tsim los ntawm nitrification hauv lub tank aerobic. NO₃-Neff tsis zoo cuam tshuam nrog ΔTN hauv thaj chaw aerobic. Raws li qhov tshwm sim ntawm kev sib xyaw ua ke ntawm nitrification thiab SND hauv thaj chaw aerobic, ntawm ib sab, DO ntau dua ua rau muaj nitrification zoo dua thiab ntau dua NO₃-Neff; ntawm qhov tod tes, siab dua DO ua rau cov neeg pluag SND thiab ntau inhibited nitrogen tshem tawm, ntxiv ua rau ntau dua effluent NO₃-Neff.

Txhawm rau ua tiav "kev ntsuas tau thiab tswj tau" SND thiab muab kev taw qhia rau kev tswj kev cog qoob loo, DO, uas tuaj yeem tswj tau manually, raug xaiv los ua qhov sib txawv ntawm tus kheej, thiab ΔTN tau siv los ua qhov sib txawv ntawm kev txheeb xyuas kab rov tav. Cov txiaj ntsig tau qhia hauvDaim duab 8(a). Thaum qhov tseeb DO nyob rau hauv thaj tsam MBBR ntawm cov nroj tsuag yog 2.06–3.67 mg·L⁻¹, muaj cov nyhuv SND, nrog rau kev tshem tawm nitrogen ntawm 2.36–4.10 mg·L⁻¹, thiab ΔTN thiab ua kom txaus siab ΔTN=6.0040 - 0.9579 DO (R²) . Tsis tas li ntawd, siv cov nkhaus haum, nws tau suav hais tias txoj kev xav, thaum DO raug tswj qis dua 6.27 mg·L⁻¹, thaj tsam MBBR tuaj yeem ua rau SND nitrogen tshem tawm. Qhov no yog raws li qhov xaus ntawm Wang Xuejiang li al. Hauv kev kawm txog cov txiaj ntsig ntawm DO ntawm SND cov nyhuv ntawm MBBR system, qhov uas lawv pom tias qhov kev tshem tawm TN tseem tuaj yeem tshaj 30% thaum DO yog siab li 6.0 mg·L⁻¹. Txawm li cas los xij, nws yuav tsum tau muab sau tseg tias tus nqi no yog tus nqi theoretical tau los ntawm kev haum, thiab cov txiaj ntsig siv tiag tiag xav tau kev kawm ntxiv hauv kev ua haujlwm tom ntej. Tsis tas li ntawd, nws yuav tsum raug txiav txim siab tias DO cov cai ib txhij cuam tshuam rau cov txiaj ntsig nitrification ntawm lub cev, yog li cuam tshuam rau NH₃-N tshem tawm kev ua haujlwm. Yog li, cov txiaj ntsig ntawm kev txheeb xyuas kab rov tav siv DO raws li qhov sib txawv ntawm tus kheej thiab ΔNH₃-N raws li qhov sib txawv ntawm qhov muaj nyob hauv daim duab 8(b). Raws li qhov txhais tau tias muaj txiaj ntsig NH₃-N ntawm thaj chaw MBBR thaum lub caij ntuj no (10.47 mg·L⁻¹) thiab tus qauv tsim tawm (1.50 mg·L⁻¹), nws suav tias ΔNH₃-N yuav tsum tswj tsis pub tsawg dua 8.97 mg·L. Ua ke nrog cov txiaj ntsig ntawm cov kab rov tav, DO yuav tsum tswj tau siab dua 2.47 mg·L⁻¹. Hauv cov ntsiab lus, thaum DO hauv qhov project no yog 2.06-3.67 mg·L⁻¹, muaj qhov cuam tshuam SND. Txawm li cas los xij, raws li lub hauv paus ntsiab lus ntawm kev ua tau zoo ntawm cov qauv ammonia nitrogen thaum txo kev siv lub zog aeration, DO tuaj yeem tswj tau nyob ib puag ncig 2.47 mg·L⁻¹, qhov twg SND nyhuv ntawm lub cev yog qhov zoo, tshem tawm 3.64 mg·L⁻¹ ntawm TN.

Txhawm rau txheeb xyuas qhov cuam tshuam ntawm kev ua haujlwm tsis zoo ntawm SND cov nyhuv ntawm biofilm thiab tau txais cov qauv dav dav, SND cuam tshuam ntawm rau 6 lub chaw kho dej khib nyiab siv cov txheej txheem MBBR nyob rau hauv cov haujlwm sib txawv tau muab piv. Cov txiaj ntsig tau qhia hauvRooj 2. Ua ntej, DO hauv thaj chaw aerobic ntawm txhua tsob nroj feem ntau tswj ntawm 2–3 mg·L⁻¹, thiab cov sludge concentration yog 3.0–4.0 g·L⁻¹. Raws li cov xwm txheej no, qhov cuam tshuam SND pom tseeb tuaj yeem ua tiav. Raws li cov txiaj ntsig zoo ntawm ΔTN thiab DO hauv qhov project no, thaum DO tau tswj qis dua 6.27 mg·L⁻¹, qhov cuam tshuam SND tuaj yeem tshwm sim. Txoj haujlwm no, nrog cov ntaub ntawv biofilm tuab dua nyob rau lub caij ntuj no, muaj lub siab ntev rau DO. Thib ob, tsob nroj B, nrog qhov qis tshaj sludge concentration, muaj qhov zoo tshaj plaws SND nyhuv. Nroj tsuag A, D, thiab E, nrog cov cab kuj ntau dua qhov sib piv, muaj qhov cuam tshuam SND ntau dua, txhua qhov qhia tau tias nyob rau hauv hybrid MBBR system, SND phenomenon feem ntau yog los ntawm biofilm.

Hauv cov ntsiab lus, ntxiv rau kev txhim kho SND cov txiaj ntsig los ntawm kev tswj DO, qhov project no kuj tseem tuaj yeem sim maj mam txo cov kab ke sludge txog li 3.0 g·L⁻¹, muab cov xwm txheej zoo dua rau biofilm thickness cultivation thiab anoxic txheej tsim los ntawm qis sludge concentration, yog li muab tej yam kev mob rau ntxiv SND kev ua tau zoo.

2.4 Kev Ntsuam Xyuas Nitrogen-Kev tshem tawm cov kab mob hauv zej zog

Nyob rau hauv cov nqe lus ntawm qhov sib txawv ntawm hom kev nplua nuj thiab ntau haiv neeg ntawm cov sludge thiab biofilm theem, raws li qhov sib txawv me me hauv cov txiaj ntsig ntawm ob lub amplicon sequencing khiav, ib pawg ntawm cov ntaub ntawv raug xaiv los tshuaj xyuas. Raws li qhia hauvDaim duab 9, Chao, Ace, thiab Simpson indices qhia txog kev nplua nuj thiab kev faib khoom sib xws ntawm cov zej zog microbial, thaum Shannon Performance index sawv cev rau ntau haiv neeg ntawm microbial zej zog. Siab dua Chao thiab Ace qhov ntsuas qhia ntau dua OTU kev nplua nuj, qhov qis Simpson qhia tau hais tias zoo dua hom kev faib khoom sib xws, thiab qhov siab dua Shannon qhia tau tias muaj ntau haiv neeg sib txawv. Cov txiaj ntsig tau pom tias ob hom kev nplua nuj thiab ntau haiv neeg muaj ntau dua nyob rau hauv biofilm ntau dua li hauv cov activated sludge, thiab cov tsiaj faib hauv biofilm kuj zoo ib yam li hauv cov activated sludge. Tag nrho cov naj npawb ntawm OTUs hauv biofilm thiab activated sludge yog 1,652 thiab 1,372, feem, nrog 770 sib koom OTUs, suav txog 46.6% thiab 56.1% ntawm tag nrho OTUs hauv biofilm thiab activated sludge, raws li. Lub biofilm muaj 882 OTU tshwj xeeb, suav txog ze li 40% ntawm tag nrho OTUs. Nws tuaj yeem pom tau tias biofilm enriched ib feem ntawm cov kab mob uas tsis muaj nyob rau hauv thawj activated sludge. Qhov sib ntxiv ntawm cov cab kuj tau nce qhov kev nplua nuj thiab ntau haiv neeg ntawm microbial zej zog nyob rau hauv lub cev, thiab cov complex microbial zej zog muaj pes tsawg leeg kuj nteg lub hauv paus rau qhov cuam tshuam ntawm MBBR system.

Txhawm rau nkag siab ntxiv txog qhov sib txawv ntawm cov hom tseem ceeb thiab cov kab mob ua haujlwm ntawm cov kab mob biofilm thiab cov activated sludge thiab muab kev txhawb nqa microscopic rau SND phenomenon hauv biofilm, microbial muaj pes tsawg leeg ntawm qib genus tau txheeb xyuas. Raws li qhia hauvDaim duab 10, cov hom tseem ceeb hauv cov kab mob lom ntawm qhov project no suav nrog norank_f_Caldilineaceae, norank_f_JG30-KF-CM45, Nitrospira, Pedomicrobium, thiab SWB02. Ntawm lawv, norank_f_Caldilineaceae thiab norank_f_JG30-KF-CM45 tuaj yeem ua kom muaj txiaj ntsig zoo hauv ob qho tib si biofilm thiab activated sludge, nrog cov txheeb ze nplua nuj nyob rau hauv biofilm thiab activated sludge ntawm 3.05, 5.69% thiab 7.086, hwm. norank_f_Caldilineaceae feem ntau yog cov kab mob filamentous, thiab qee cov genera muaj peev xwm denitrification. Lawv tau enriched nyob rau hauv biofilm vim hais tias cov biofilm yuav secrete ntau EPS rau lawv proliferation. Ntawm qhov tod tes, lawv tuaj yeem ua kom muaj txiaj ntsig zoo hauv cov sludge li PAOs, txhawb kev tshem tawm phosphorus. norank_f_JG30-KF-CM45 tuaj yeem koom nrog cov txheej txheem carbon thiab nitrogen transformation, txhim khu kev tshem tawm cov organic teeb meem thiab nitrogen.

Raws li cov ntaub ntawv qhia, nws tau pom tias cov txheej txheem MBBR tuaj yeem ua tiav cov txiaj ntsig zoo ntawm cov kab mob nitrifying xws li Nitrospirota, Nitrosomonas, thiab Nitrolancea ntawm qhov kub thiab txias. Lub ntsiab nitrifying genus hauv qhov project no yog Nitrospira, uas muaj peev xwm ua tiav nitrification. Nws cov txheeb ze nplua nuj nyob rau hauv biofilm thiab activated sludge yog 4.73% thiab 0.39%, feem. Raws li cov ntaub ntawv qhia, cov txheeb ze ntawm cov kab mob nitrifying nyob rau hauv lwm cov nroj tsuag siv activated sludge systems nyob rau hauv qis lub caij ntuj no kub yog feem ntau qis dua 1%. Tom qab hybrid MBBR reconstruction nyob rau hauv qhov project no, tus txheeb ze ntawm cov kab mob nitrifying nyob rau hauv lub activated sludge kuj tsis tshua muaj, muab pov thawj rau redistribution ntawm nitrifying kab mob nyob rau hauv lub MBBR system nyob rau hauv qis - kub, raws li tau hais ua ntej lawm. Cov txheeb ze nplua nuj ntawm Nitrospira nyob rau hauv biofilm ntawm qhov project no yog ntau tshaj 10 lub sij hawm uas nyob rau hauv lub activated sludge, thiab nws tau xam tias ntau tshaj 92% ntawm cov kab mob nitrifying nyob rau hauv lub system tau enriched nyob rau hauv lub biofilm. Qhov no yog qhov zoo ntawm cov txheej txheem MBBR nyob rau hauv qis- qhov kub thiab txias, ua kom lub zog ruaj khov.

Hais txog qhov tshwm sim SND hauv biofilm, cov neeg nqa khoom raug tshem tawm kuj tau pom tias muaj peev xwm ua kom muaj zog ntxiv rau qee cov kab mob denitrifying dua li cov activated sludge. Cov kev tshawb fawb tau pom tias ob qho tib si SWB02 thiab Pedomicrobium tuaj yeem koom nrog hauv cov txheej txheem denitrification, thiab SWB02 tuaj yeem tso tawm C6-HSL, uas muaj cov txiaj ntsig zoo inhibitory ntawm sludge bulking. Cov txheeb ze ntawm SWB02 thiab Pedomicrobium nyob rau hauv biofilm yog 3.68% thiab 3.78%, feem, ntau dua li lawv cov txheeb ze abundance nyob rau hauv activated sludge (0.21% thiab 0.22%). Tsis tas li ntawd, nws tau suav hais tias qhov kev faib ua feem ntawm SWB02 thiab Pedomicrobium nyob rau hauv tag nrho hybrid system yog ob qho tib si tshaj 94.5%. Txawm hais tias cov neeg nqa khoom raug tshem tawm tsuas yog ntxiv rau hauv thaj chaw aerobic, cov biofilm paub tab muaj qee qhov tuab. Vim muaj kev txwv ntawm kev hloov pauv huab cua thiab hloov pauv oxygen, ib puag ncig anoxic / hypoxic muaj nyob rau hauv txheej txheej ntawm biofilm, enriching denitrifying kab mob, yog li endowing biofilm nrog denitrification muaj peev xwm. Qhov no yog lub hauv paus microbiological rau lub simultaneous nitrification thiab denitrification peev xwm ntawm biofilm. Tsis tas li ntawd, nws tau pom tias Hyphomicrobium kuj tuaj yeem ua kom muaj txiaj ntsig zoo hauv qhov chaw qis qis. Cov genus no tuaj yeem siv cov tshuaj lom thiab refractory organic tebchaw rau denitrification. Nws cov txheeb ze kev nplua nuj nyob rau hauv biofilm yog 1.80%, kuj ntau dua li nws cov txheeb ze nplua nuj nyob rau hauv cov activated sludge (0.12%).

Muab piv cov kab mob tseem ceeb ntawm cov kab mob denitrifying (DNB) thiab lawv cov txheeb ze nplua nuj nyob hauv biofilm ntawm lwm cov nroj tsuag, cov txiaj ntsig tau pom hauvTable 3. Ua ntej, nyob rau hauv cov nqe lus ntawm muaj pes tsawg leeg ntawm denitrifying kab mob nyob rau hauv lub aerobic biofilm, hom denitrifying kab mob enriched nyob rau hauv lub aerobic biofilm ntawm txhua qhov project tsis zoo ib yam. Tsuas yog cov genera rov tshwm sim yog Terrimonas thiab Hyphomicrobium. Terrimonas kuj yog ib hom kab mob denitrifying nyob rau hauv activated sludge systems, thiab zoo ib yam li Hyphomicrobium, nws muaj peev xwm degrade anthracene tebchaw, thiab ib co yog cais raws li aerobic denitrifying kab mob. Ob tug kab mob no tau tshwm sim hauv Nroj Tsuag F, H, thiab qhov project no. Nroj H thiab txoj haujlwm no feem ntau cuam tshuam los ntawm cov dej khib nyiab hauv kev lag luam thaum lub sijhawm ua haujlwm tiag tiag, thiab cov dej tshwj xeeb ntawm cov dej hauv kev lag luam yuav yog ib qho laj thawj rau kev txhawb nqa ntawm ob pawg kab mob no. Yog li, nws tuaj yeem suav tau tias qhov tshwj xeeb denitrifying genera hauv aerobic biofilm tsis yog qhov tsim nyog rau SND, thiab qhov sib txawv ntawm cov dej zoo ntawm cov haujlwm sib txawv yuav yog qhov laj thawj tseem ceeb rau qhov sib txawv ntawm cov kab mob denitrifying. Thib ob, hais txog cov txheeb ze ntawm cov kab mob denitrifying nyob rau hauv aerobic biofilm, tshwj tsis yog cov nroj tsuag F, H, thiab qhov project no, lwm cov haujlwm tau ua tiav cov txheeb ze ntawm cov kab mob denitrifying nyob rau hauv aerobic biofilm txog li 8%, nrog rau SND nitrogen tshem tawm ntau tshaj 2 mg·L⁻¹. Raws li qhov cuam tshuam ntawm cov dej hauv kev lag luam, txawm hais tias tus txheeb ze ntawm cov kab mob denitrifying ntau nyob rau hauv aerobic biofilm ntawm tsob nroj H thiab qhov project no kuj siab heev, cov denitrification efficiency tsis yog tshwj xeeb tshaj yog zoo. Nws tuaj yeem pom tau tias cov dej muaj txiaj ntsig zoo muaj qhov tseem ceeb hauv kev xaiv cov kab mob denitrifying hauv aerobic biofilm, thiab qhov cuam tshuam ntawm cov dej ua haujlwm inhibits denitrification efficiency ntawm aerobic biofilm.

Hauv cov ntsiab lus, cov txheej txheem MBBR tuaj yeem ua rau muaj kev nplua nuj thiab ntau haiv neeg ntawm cov zej zog microbial hauv lub cev. Lub peev xwm ntxiv ntawm biofilm rau nitrifying genus Nitrospira yog ntau tshaj 10 npaug ntawm cov activated sludge, zoo heev txhim kho cov nyhuv nitrification ntawm lub cev. Denitrifying genera xws li SWB02, Pedomicrobium, thiab Hyphomicrobium zoo dua ntxiv rau hauv aerobic biofilm, muab lub hauv paus microscopic rau SND kev ua tau zoo thiab txhim kho TN tshem tawm. Txawm li cas los xij, vim muaj kev cuam tshuam ntawm kev lag luam dej, SND denitrification efficiency tsis tseem ceeb.

3 Cov lus xaus

① Ib lub chaw kho dej khib nyiab nyob rau sab hnub poob Tuam Tshoj tau hloov kho nws qhov qub CASS tank rau Bardenpho-MBBR lom tank thiab sedimentation tank kom ua tiav qib A mus rau quasi-Class IV qauv. Tom qab kev tsim kho dua tshiab, nyob rau hauv lub caij ntuj no dej kub ntawm 9.3-13.1℃thiab nrog cov txiaj ntsig zoo NH₃-N thiab TN loads nce li ntawm 20% piv rau ua ntej kev tsim kho, cov ntsuas dej tau ruaj khov ua tau raws li quasi-Class IV cov qauv dej. Qhov siab tshaj plaws nitrification load ntawm MBBR system mus txog 0.286 kg·(m³·d)⁻¹, ua tau raws li kev xav tau tsim. Cov txiaj ntsig nitrification ntawm cov neeg nqa khoom raug tshem tawm yog 74.83%, tuav txoj haujlwm tseem ceeb. Lub kaw lus tseem muaj peev xwm ua kom cov dej zoo ntxiv los ntawm 56.96% thiab ntws los ntawm 30.57%.

② Hauv thaj tsam MBBR, cov neeg nqa khoom raug tshem tawm siv cov pa roj carbon monoxide los ua kom muaj txiaj ntsig SND, ua tiav cov txiaj ntsig kev tshem tawm nitrogen ntawm 9.83% ± 0.67%. Txhawm rau nthuav tawm cov nyhuv SND, DO yuav tsum tau tswj kom ntau li ntau tau ntawm 2.47 mg·L⁻¹ hauv kev ua haujlwm tiag tiag, qhov twg SND tuaj yeem tshem tawm 3.64 mg·L⁻¹ ntawm TN. Tom qab ntawd, kev sim tuaj yeem ua kom txo qis cov sludge concentration mus txog 3.0 g·L⁻¹ los muab cov xwm txheej rau kev nthuav dav ntxiv ntawm SND nyhuv ntawm biofilm.

③ Cov txheej txheem MBBR ua rau muaj kev nplua nuj thiab ntau haiv neeg ntawm cov kab mob microbial hauv lub cev. Lub peev xwm ntxiv ntawm biofilm rau nitrifying genus Nitrospira yog ntau tshaj 10 npaug ntawm cov activated sludge, muab lub hauv paus microbiological rau txhim kho nitrification hauv qhov project no. Lub denitrifying genera enriched nyob rau hauv aerobic biofilm, xws li SWB02, Pedomicrobium, thiab Hyphomicrobium, nteg lub microscopic foundation rau qhov tshwm sim ntawm SND phenomenon nyob rau hauv lub biofilm.