Kev Tiv Thaiv Sludge Bulking Ntawm Nws Qhov Chaw: Ib Lub Tswv Yim Tseem Ceeb hauv Kev Kho Dej Ncua Txheej Txheem Tsim

Sludge bulking yog ib qho teeb meem uas tshwm sim ntau tshaj plaws thiab nyuaj hauv kev kho cov dej khib nyiab, ua kom pom kev ua haujlwm tsis zoo (SVI> 150 mL / g), tsis ua haujlwm ntawm cov sludge- dej sib cais hauv lub tank thib ob, thiab cov khib nyiab ntau dhau (SSluent) tuaj yeem ua rau cov kab mob loj heev. Cov kev daws teeb meem feem ntau tsom rau kev hloov kho xwm txheej ceev thaum lub sijhawm ua haujlwm (xws li ntxiv cov coagulants lossis kho cov pa oxygen (DO), tab sis cov kev ntsuas no tsuas yog kev daws teeb meem ib ntus thiab nce nqi kev khiav hauj lwm. Qhov tseeb, kev tiv thaiv sludge bulking yuav tsum tau ua nyob rau hauv cov txheej txheem tsim qauv- tshem tawm qhov ua rau cov kab mob filamentous ntau dhau los yog tsis yog {5} kingcousactiences. configuration xaiv, kev khiav hauj lwm parameter matching, thiab functional unit kev koom ua ke yog lub hauv paus txoj kev ua kom tiav ntev - lub sij hawm ruaj khov system ua hauj lwm tsab xov xwm no, raws li cov tsim mechanism ntawm sludge bulking, npaj ib tug kev tsim lub tswv yim uas npog "reactor xaiv- parameter optimization- pab pawg neeg tsim tag nrho.

Sludge bulking is primarily classified into two categories: filamentous bulking (accounting for >90%) thiab tsis yog -filamentous bulking. Lawv qhov tshwm sim yog ncaj qha ntsig txog qhov tsis xws luag hauv cov txheej txheem tsim. Kev nthuav qhia cov laj thawj thiab kev tsim kev sib raug zoo ntawm ob hom no yog qhov tsim nyog rau kev tsim kom raug.

1. Filamentous Bulking: "Ecological Imbalance" tshwm sim los ntawm kev tsim kho

Cov kab mob filamentous yog cov nroj tsuag ib txwm muaj nyob rau hauv activated sludge; lawv cov kev loj hlob nruab nrab tuaj yeem txhim kho kev ruaj ntseg ntawm cov qauv floc. Txawm li cas los xij, thaum cov txheej txheem tsim ua rau "kev sib tw kom zoo dua ntawm cov kab mob filamentous," bulking yuav tshwm sim. Cov qauv tsim tseem ceeb- cuam tshuam txog cov txiaj ntsig muaj xws li: Ua ntej, qhov tsis sib xws ntawm cov pa oxygen (DO) faib, xws li kev teeb tsa reactor ua rau cov kab mob anoxic hauv zos (DO < 0.5 mg / L), tso cai rau cov kab mob filamentous kom tau txais cov pa oxygen thiab cov as-ham vim lawv thaj chaw loj. Thib ob, qhov tsis tsim nyog substrate concentration gradient; Nyob rau hauv tag nrho cov reactors sib xyaw, qhov qis thiab tsis sib xws substrate concentration tso cai rau cov kab mob filamentous los ua tus thawj vim lawv cov khoom noj muaj txiaj ntsig zoo. Thib peb, ntev sludge retention time (SRT) tsim, ua rau muaj cov kab mob filamentous loj hauv cov laus sludge. Plaub, kev noj zaub mov tsis txaus; Tus tsim tsis xav txog qhov hloov pauv ntawm qhov cuam tshuam C / N piv thiab C / P piv, ua rau cov kab mob filamentous ntau dhau thaum nitrogen thiab phosphorus tsis txaus.

2. Tsis yog -filamentous bulking: Metabolic teeb meem tshwm sim los ntawm kev tsim load imbalance

Non-filamentous bulking is mostly caused by excessive microbial proliferation producing viscous polysaccharides, leading to increased water content in sludge flocs. The design-related causes are concentrated in "load control defects": First, the organic load (F/M) is designed too high (>0.5 kg BOD₅/(kg MLSS·d)), and the reactor cannot quickly adapt when the concentration of easily degradable organic matter in the influent suddenly increases; second, the hydraulic load design is unreasonable, with excessively high surface load in the secondary settling tank (>1.5 m³ / (m²·h)), ua rau muaj kev cuam tshuam ntawm sludge txheej thiab floc tawg; Thib peb, chav pretreatment ploj lawm, ua rau muaj kev cuam tshuam ntau dhau ntawm cov teeb meem tshem tawm cov teeb meem (SS), uas adsorbs ntau cov organic teeb meem rau hauv reactor, exacerbating load fluctuations.

Tus txheej txheem tsim yuav tsum tsom mus rau "kev txwv tsis pub muaj kev sib tw ntawm cov kab mob filamentous, stabilizing lub microbial metabolic ib puag ncig, thiab txhim kho cov sludge- dej sib cais," thiab yuav tsum tau ua kom zoo dua los ntawm peb qhov loj: reactor configuration, tsis tseem ceeb, thiab functional units. 1. Reactor Configument a Microviguration: Constructing

Lub reactor configuration ncaj qha txiav txim qhov spatial faib ntawm DO thiab substrate concentrations, uas yog ib qho tseem ceeb rau kev tswj filamentous kab mob bulking. Kev teeb tsa ib puag ncig gradient yuav tsum tau ua qhov tseem ceeb hauv kev tsim kom tsis txhob muaj qhov tsis xws luag ntawm lub reactor sib xyaw ua ke.

(1) Ua Ntej Plug-flow thiab Composite Configurations

Plug-flow reactors (xws li cov tsoos aeration tso tsheb hlau luam thiab oxidation ditches) tsim ib tug natural substrate concentration gradient (siab nyob rau hauv pem hauv ntej, qis nyob rau sab nraum qab) thiab DO gradient (tsawg nyob rau hauv pem hauv ntej, siab nyob rau tom qab) raws cov dej ntws. Qhov gradient ib puag ncig no pab txhawb kev loj hlob sai ntawm floc- tsim cov kab mob (cov kab mob tseem ceeb uas tsim flocs) nyob rau hauv cov cheeb tsam uas muaj cov substrate txaus, inhibiting kev loj hlob ntau ntawm cov kab mob filamentous. Thaum lub sij hawm tsim, lub reactor ntev - rau - dav piv yuav tsum tau tswj kom ntau dua los yog sib npaug rau 5: 1, thiab lub tank qhov tob mus rau 3 ~ 5m kom ntseeg tau cov dej ntws zoo thiab tsis txhob luv -circuiting. Rau loj -tej dej khib nyiab kho cov nroj tsuag, "plug flow + segmented aeration" configuration tuaj yeem saws, faib cov reactor rau hauv 3-4 channels, txhua tus muaj ib qho kev ywj pheej aeration. Los ntawm kev kho tus nqi aeration ntawm txhua channel, cov pa oxygen yaj (DO) nyob rau hauv pem hauv ntej kawg yog tswj ntawm 0.5-1 mg / L (anoxic zone), thiab tom qab kawg ntawm 2-3 mg / L (aerobic zone), yog li ntsuas qhov xav tau tshem tawm nitrogen nrog kev tawm tsam ntawm cov kab mob filamentous.

Kev sib xyaw ua ke (xws li A²O, UCT, thiab MSBR) ua tiav kev siv cov khoom noj muaj txiaj ntsig los ntawm kev ua haujlwm zoning ntawm anaerobic, anoxic, thiab aerobic zones, txo qhov kev sib tw kom zoo dua ntawm cov kab mob filamentous. Thaum lub sij hawm tsim, kev sib cais hydraulic ntawm txhua ntu yuav tsum tau ntxiv dag zog, xws li los ntawm kev txhim kho cov phab ntsa ntawm cov anoxic thiab aerobic aerobic aav thiab tswj cov cawv sib xyaw ua ke (sab hauv qhov sib piv 200% -300%). Qhov no tiv thaiv nitrate los ntawm ntws rov qab mus rau thaj tsam anaerobic, inhibiting polyphosphate-accumulating kab mob, thaum siv denitrification nyob rau hauv anoxic cheeb tsam kom haus ib co yooj yim degradable carbon qhov chaw, txo cov as-ham kev sib tw siab ntawm filamentous kab mob nyob rau hauv aerobic cheeb tsam.

(2) Rational Design of the Aeration System: Xyuas kom DO Uniformity thiab Controllability

Tsim kev tsis haum nyob rau hauv lub aeration system yog lub ntsiab ua rau lub zos DO insufficiency. DO tswj qhov tseeb yuav tsum tau txhim kho los ntawm peb yam: aeration method, khoom xaiv, thiab optimized tso. Rau cov ntsaws ntsaws reactors, microporous aeration (xws li membrane aerators) yog qhov zoo dua, vim nws cov pa siv hluav taws xob tuaj yeem ncav cuag 25% ~ 35%, siab tshaj qhov aeration saum npoo (8% ~ 15%). Aerator qhov chaw yuav tsum tau muab sib npaug sib npaug ntawm txoj kab hauv kev ntev, nrog qhov ceev ntawm qhov kawg ntawm qhov kawg txo los ntawm 10% ~ 20% thiab nce ntxiv tom qab kawg kom ntseeg tau tias ruaj khov DO gradient. Ib txhij, online DO saib xyuas cov ntsiab lus thiab aeration regulating li qub yuav tsum tau muab ntsia rau hauv txhua txoj kev hauv tsev kom ua tiav kev tswj hwm ntawm qhov ntim aeration.

Rau cov reactors sib xyaw ua ke (xws li SBRs), yog tias lawv yuav tsum tau siv vim qhov chaw txwv, yuav tsum siv "kev sib tshuam aeration + stirring" hom. Qhov no suav nrog kev hloov pauv ntawm "anaerobic stirring (1 ~ 2h) - aerobic aeration (2 ~ 3h)" los simulate ib puag ncig ntsaws ntsaws thiab inhibit cov kab mob filamentous. Lub aeration siv yuav tsum raug xam raws li lub sij hawm tsim qauv kom paub tseeb tias DO sai nce mus rau saum toj 2 mg / L thaum lub sij hawm aerobic theem thiab ORP yog tswj ntawm -100 mus rau -50 mV thaum lub sij hawm anoxic theem.

2. Qhov tseem ceeb Parameters: Sib piv cov kev ua haujlwm ciam teb ntawm "Floc Advantage"

Kev tsim ntawm cov ntsiab lus tseem ceeb xws li sludge hnub nyoog (SRT), organic loading (F / M), thiab cov khoom noj khoom haus yuav tsum tau tswj nruj me ntsis hauv cov kab mob loj hlob ntawm cov kab mob floc kom inhibit sludge bulking los ntawm qhov kev xav ntawm metabolic.

(1) Sludge Age (SRT): Precisely Matching Microbial Generation Cycle

Qhov ntev ntev SRT yog ib qho tseem ceeb ua rau cov kab mob filamentous bulking - lub voj voog ntawm cov kab mob filamentous feem ntau ntev dua li cov kab mob floc, thiab SRT ntev dhau los ua rau cov kab mob filamentous zuj zus zuj zus. Tus qauv tsim yuav tsum txiav txim siab qhov tsim nyog SRT (Tus Kheej- Tshem Tawm Lub Sijhawm) raws li cov hom phiaj kev kho mob (nitrification / phosphorus tshem tawm) thiab cov dej zoo: Rau kev tshem tawm cov khoom organic nkaus xwb, SRT yuav tsum tau tswj ntawm 3-5 hnub; rau kev tshem tawm nitrogen ib txhij, SRT yuav tsum tau txuas ntxiv mus rau 10-15 hnub (kom tau raws li qhov xav tau ntawm cov kab mob nitrifying); rau kev tshem tawm cov nitrogen thiab phosphorus ib txhij, SRT yuav tsum tau tswj hwm ntawm 8-12 hnub kom sib npaug ntawm kev loj hlob ntawm cov kab mob polyphosphate-accumulating thiab nitrifying kab mob.

Txhawm rau kom ruaj khov SRT, lub kaw lus sludge paug yuav tsum tau suav nrog hauv kev tsim, ua haujlwm "nruam sludge tawm + kev saib xyuas online" hom. Lub sludge concentration meter yuav tsum tau muab tso rau hauv lub tank thib ob kom tau txais kev kho cov sludge tshaj tawm raws li MLSS concentration (tswj ntawm 2000-4000 mg / L). Rau cov tshuab loj, sludge thickening tank thiab rov qab sludge twj tso kua mis tuaj yeem ntsia tau. Los ntawm kev tswj tus nqi rov qab (50% -100%), cov sludge concentration nyob rau hauv lub reactor tuaj yeem khaws cia ruaj khov, zam kev hloov pauv SRT.

(2) Organic Loading Ratio (F/M): Zam "Load Shock" thiab "Low Load Starvation"

F / M tsim yuav tsum sib npaug "floc proliferation requirements" thiab "load stability," kom tsis txhob muaj ntau dhau los yog tsawg. Rau kev kho dej khib nyiab hauv nroog, F / M yuav tsum tau tswj kom zoo ntawm 0.2 thiab 0.4 kg BOD₅ / (kg MLSS·d), nyob rau hauv uas cov kab mob metabolism hauv flocs muaj zog, sai sai ua ntom flocs. Rau cov dej khib nyiab hauv kev lag luam (xws li cov dej khib nyiab ua zaub mov, uas muaj biodegradability zoo), F / M tuaj yeem nce mus rau 0.3 txog 0.5 kg BOD₅/(kg MLSS·d), tab sis yuav tsum tau ua ntej -kev kho lub tank sib npaug yuav tsum tsis txhob muaj qhov hloov pauv. Tus qauv tsim yuav tsum tswj cov load shocks los ntawm "pretreatment + load distribution": Ua ntej, lub tank homogenization yuav tsum tau teeb tsa nrog lub ntim zoo tsim rau 8-12 teev ntawm qhov siab tshaj plaws txhua hnub ntws los xyuas kom meej cov khoom muaj txiaj ntsig zoo thiab muaj nuj nqis; thib ob, ib qho "parallel reactor" configuration yuav tsum tau saws. Thaum lub zog muaj zog dheev nce, F / M piv ntawm ib lub tank tuaj yeem nce ib ntus los ntawm kev hloov cov reactors hauv kev ua haujlwm (piv txwv li, hloov ntawm 2 mus rau 1), zam tag nrho cov khoom tsis txaus ntseeg.

(3) Cov khoom noj muaj txiaj ntsig: Kev tswj xyuas meej ntawm C / N / P tshuav nyiaj li cas

Nitrogen thiab phosphorus deficiency tuaj yeem ua rau kev loj hlob ntawm cov kab mob filamentous ntau dhau. Tus qauv tsim yuav tsum xyuas kom meej tias qhov muaj txiaj ntsig C / N piv yog Ntau dua lossis sib npaug rau 3-5 thiab C / P piv yog Ntau dua lossis sib npaug rau 15-20. Rau cov dej khib nyiab tsawg (xws li cov dej khib nyiab hauv nroog, COD / TN<5), a carbon source addition system should be reserved, with the addition point set at the front end of the anaerobic section, using a metering pump for precise addition; for high carbon-to-nitrogen ratio industrial wastewater (e.g., chemical wastewater), a nitrogen and phosphorus addition device should be reserved, with the addition point set at the inlet of the aerobic section to avoid nutrient imbalance.

Tus qauv tsim tuaj yeem koom ua ke "kev saib xyuas dej hauv online + tsis siv neeg dosing" system los saib xyuas cov txiaj ntsig ntawm COD, TN, thiab TP hauv lub sijhawm tiag tiag, thiab cia li xam qhov ntau npaum li cas los ntawm cov khoom sib npaug kom ntseeg tau tias cov khoom noj muaj txiaj ntsig zoo. Piv txwv li, thaum lub zog C / N piv yog tsawg dua 3, sodium acetate (COD sib npaug 0.78) tau txais kev ntxiv los ntxiv cov pa roj carbon; Thaum qhov sib piv C / P tsawg dua 15, poov tshuaj dihydrogen phosphate ntxiv los ntxiv cov phosphorus.

3. Kev Pabcuam Kev Pabcuam: Ua kom muaj zog "Sludge-Kev cais dej" thiab "Risk Buffer"

Tsim qhov tsis xws luag nyob rau hauv lub thib ob sedimentation tank thiab tsis muaj ib tug thaum muaj xwm ceev system yuav exacerbate qhov teeb meem ntawm sludge bulking. Nws yog ib qho tsim nyog los txhim kho cov kab ke kev pheej hmoo los ntawm kev ua kom zoo dua cov sludge - chav dej sib cais thiab teeb tsa cov chaw muaj xwm txheej ceev.

(1) Secondary Sedimentation Tank: Optimizing Hydraulic Conditions thiab Sludge Discharge Efficiency

Qhov chaw thau khoom, dej qhov tob zoo, thiab sludge scraping txoj kev ntawm cov theem nrab sedimentation tank ncaj qha cuam tshuam cov sludge settling nyhuv. Qhov chaw thau khoom yuav tsum nruj me ntsis tswj nyob rau hauv 0.8 ~ 1.2 m³ / (m²·h) thaum lub sij hawm tsim theem (tsawg tshaj li cov qauv tsim tus nqi ntawm 1.5 m³ / (m²·h)), nrog rau qhov dej tob tob dua los yog sib npaug li 4m kom paub meej qhov chaw txaus rau cov sludge txheej. Lub radial ntws theem nrab sedimentation tank nrog lub hauv paus inlet thiab peripheral qhov hluav taws xob yog saws, thiab ib tug txaus straightener yog ntsia nyob rau hauv lub inlet cheeb tsam kom txo tau cov kev cuam tshuam ntawm cov dej los ntawm cov sludge txheej.

Cov sludge scraping system nyiam siv cov khoom siv hluav taws xob txuas ntxiv, nrog rau kev sib tsoo ceev ntawm 1 ~ 2 m / min kom tsis txhob muaj kev sib tsoo ntau dhau ua rau sludge floc tawg. Lub hauv qab aeration cuam tshuam cov cuab yeej tseem raug ntsia; Thaum cov sludge txheej thickness tshaj 1.5m, qis - siab aeration (DO tswj hauv qab 0.5 mg/L) yog qhib kom tiv thaiv anaerobic decomposition thiab sludge ntab. Tsis tas li ntawd, qhov thib ob sedimentation tank yuav tsum tau nruab nrog sludge interface meter installation interface los saib xyuas cov sludge interface qhov siab ntawm lub sijhawm; thaum lub interface tshaj 1/2 ntawm qhov zoo dej qhov tob, cov sludge paug tus nqi yog cia li nce.

(2) Pretreatment and Emergency System: Blocking the Source of Risk

Lub pretreatment system tsim yuav tsum tsom rau "tshem tawm cov tshuaj lom thiab cov khoom siv rov ua dua tshiab" los tiv thaiv lawv los ntawm inhibiting microbial kev ua ub no thiab ua rau bulking. Ua ntej, ib qho screen (1-3mm qhov sib nrug) thiab lub chamber grit (cyclone type) yuav tsum tau ntsia kom tshem tawm cov khib nyiab thiab xuab zeb. Thib ob, rau cov dej khib nyiab hauv kev lag luam, lub tank hydrolysis acidification tank (HRT=4-6}h) yuav tsum tau ntxiv los hloov cov organic teeb meem rau hauv VFAs, txhim kho biodegradability ntawm cov dej khib nyiab thiab txo cov load ntawm cov reactors tom ntej.

Kev tsim kho qhov xwm txheej ceev yuav tsum daws qhov kev pheej hmoo ntawm kev loj hlob sai sai los ntawm kev khaws qhov sib cuam tshuam rau "coagulant ntxiv + sludge hloov": lub coagulant dosing ntaus ntawv yuav tsum tau nruab rau ntawm qhov nkag ntawm lub tank thib ob, tso cai ntxiv ntawm PAC (50-100mg / L) lossis PAM (1- 5mg / L) kev ua tau zoo sai sai. Lub siab zoo sludge rov qab interface yuav tsum tau muab ntsia rau ntawm lub reactor inlet, tso cai rau cov kev taw qhia ntawm high-zoo activated sludge los ntawm ib puag ncig cov dej khib nyiab kho cov nroj tsuag (hloov 20% -30% ntawm lub kaw lus sludge ntim) kom sai li sai tau cov microbial zej zog qauv nyob rau hauv cov kev tshwm sim ntawm loj bulking. III. Tsim Validation: Ua kom muaj txiaj ntsig los ntawm kev simulation thiab Case Studies

Tom qab tus txheej txheem tsim tiav lawm, qhov ua tau zoo ntawm sludge bulking tswj yuav tsum tau lees paub los ntawm cov lej simulation thiab sib piv nrog cov ntaub ntawv kev tshawb fawb engineering kom tsis txhob tsim qhov teeb meem.

Ua ntej, cov cuab yeej ua lej suav (xws li BioWin thiab GPS-X) yog siv. Cov qauv tsim (reactor configuration, SRT, F / M, DO, thiab lwm yam) thiab cov ntaub ntawv muaj txiaj ntsig zoo hauv dej yog cov tswv yim los simulate cov sludge bulking txaus ntshai (xws li SVI hloov thiab cov kab mob filamentous suav) nyob rau hauv kev ua haujlwm sib txawv. Piv txwv li, simulating SVI qhov sib txawv ntawm cov ntsaws ntsaws thiab tag nrho cov reactors sib xyaw thaum DO fluctuates rau 0.3 mg / L tso cai rau kev ua kom zoo ntawm aeration system tso; simulating qhov cuam tshuam ntawm cov pa roj carbon ntau npaum li cas ntawm SVI thaum lub zog C / N piv poob rau 2 txiav txim siab tus qauv tsim ntawm kev siv tshuaj.

Qhov thib ob, cov ntaub ntawv tshawb fawb engineering tau ua, xa mus rau kev tsim kev paub zoo ntawm cov nroj tsuag dej khib nyiab zoo sib xws. Piv txwv li, cov nroj tsuag A²O kho cov khoom noj khoom haus cov dej khib nyiab, los ntawm kev tsim "plug-flow aerobic tank + segmented aeration + meej sludge paug," tswj sludge turnover lub sij hawm (SRT) mus rau 10 hnub thiab kua ntom ntom (F / M) txog 0.3 kg BOD₅ / (kg). Tom qab peb xyoos ntawm kev ua haujlwm, tsis muaj filamentous bulking tshwm sim, thiab cov effluent suspended solids (SS) tseem tsis tu ncua qis dua 10 mg / L. Lub chaw kho dej khib nyiab hauv nroog, los ntawm kev ntxiv lub tank hydrolysis acidification thiab cov pa roj carbon ntxiv qhov system, daws qhov teeb meem bulking los ntawm cov pa roj carbon tsawg, txo cov sludge ntim index (SVI) los ntawm 200 mL / g rau 120 mL / g.

Lub hauv paus ntawm sludge bulking tiv thaiv thiab tswj yog nyob rau hauv "qhov chaw tsim," tsis ua haujlwm kho. Tus txheej txheem tsim yuav tsum tau ua txhaum los ntawm cov kev xav ib txwm muaj ntawm "kev sib ntsib cov qauv tso tawm nkaus xwb," tsom rau "microbial ecological tshuav nyiaj li cas." Qhov no suav nrog kev txhim kho reactor configuration los tsim microenvironment uas inhibits cov kab mob filamentous, ua kom muaj kev loj hlob ntawm cov kab mob flocculent los ntawm kev sib piv qhov tseeb, thiab ntxiv dag zog rau cov sludge - dej sib cais thiab kev pheej hmoo buffering los ntawm cov koom haum pab. Nyob rau hauv lub neej yav tom ntej, nrog rau kev txhim kho cov kev soj ntsuam ntse thiab cov lej simulation thev naus laus zis, cov txheej txheem tsim yuav raug hloov kho ntxiv mus rau "tus kheej thiab meej"- sib txuas cov yam ntxwv ntawm cov dej muaj txiaj ntsig zoo thiab cov xwm txheej hauv cheeb tsam, kev tiv thaiv thiab tswj cov tswv yim yuav tsim kom ua tiav ntev - lub sijhawm ruaj khov thiab muaj txiaj ntsig kev ua haujlwm ntawm cov dej khib nyiab rau kev kho dej.