Secondary settling tank yog ib qho tseem ceeb qauv nyob rau hauv activated sludge wastewater kho tshuab. Nws lub luag haujlwm tseem ceeb yog cais cov khib nyiab thiab cov kua dej ntawm cov cawv sib xyaw hauv cov tshuaj tiv thaiv tank, ua kom ruaj khov effluent zoo thiab system sludge concentration. Cov theem ntawm kev khiav hauj lwm thiab kev tswj ntawm lub thib ob settling tank ncaj qha cuam tshuam rau tag nrho cov kev kho mob efficiency thiab kev khiav hauj lwm nqi ntawm cov dej khib nyiab kho nroj tsuag. Kab lus no, raws li kev paub dhau los ntawm kev ua haujlwm thiab kev suav cov txheej txheem, qhia txog cov ntsiab lus tseem ceeb ntawm kev tswj hwm lub tank thib ob, cov qauv tshem tawm cov sludge, thiab cov kev tiv thaiv rau cov teeb meem kev ua haujlwm.
I. Kev suav thiab kev tswj cov dej ntws tawm
Hauv cov txheej txheem kho dej khib nyiab, qhov zaus thiab qhov ntau ntawm cov sludge tawm ncaj qha cuam tshuam rau kev ruaj ntseg ntawm lub kaw lus MLSS (Mixed Liquor Suspended Solids) thiab kev kho mob ntawm cov tshuaj tiv thaiv tank.
1. Sludge Discharge zaus
Tsis txhob muaj kev tso tawm txhua hnub. Kev tso tawm yuav tsum tau nqa tawm thaum lub sijhawm txawm tias ua tau, txhua 2-3 teev, txhawm rau txo qhov cuam tshuam ntawm cov dej tsis zoo thiab cov zej zog microbial.
2. Txoj kev suav rau kev tso tawm
Lub hom phiaj MLSS concentration yuav tsum tau khaws cia rau hauv lub reactor yog siv los ua lub hauv paus rau kev suav, txiav txim siab los ntawm SS concentration (suspended solids) thiab soluble organic teeb meem concentration (feem ntau yaj BOD) ntawm cov influent. Cov mis laij lej yog raws li nram no:
Qhov twg: a yog tag nrho SS load ntws mus rau hauv lub reactor nyob rau hauv ib hnub, kg / d; b yog BOD5 tshem tawm tus nqi (kg / d) × sludge hloov pauv tus nqi rau BOD tshem tawm − activated sludge ntim hauv cov cawv tov (kg) × endogenous respiration auto- oxidation tus nqi (d⁻¹). Tus nqi hloov pauv sludge rau BOD5 tshem tawm tuaj yeem raug coj los ua 0.7, thiab qhov pib ua pa endogenous -oxidation tus nqi tuaj yeem raug coj los ua 0.07.
Txoj kev no yog qhov tseeb, tab sis cumbersome hauv kev siv txhua hnub. Rau kev tswj kom yooj yim dua, kev suav yooj yim tuaj yeem siv tau raws li qhov sib npaug sib npaug ntawm SV (sludge ntim index) thiab MLSS, raws li qhia hauv qab no.
Qhov twg: Qg yog cov sludge tawm ntim raws li ib txwm muaj, suav los ntawm cov ntaub ntawv ua haujlwm, m³ / d; V yog qhov ntim ntawm cov tshuaj tiv thaiv tank, m³; Xr yog qhov concentration ntawm cov sludge rov qab (mg / L, uas tuaj yeem hloov tau los ntawm MLSS × 2 yog tias nws ntsuas tsis tau).
II. Cov teeb meem tshwm sim thiab kev tiv thaiv hauv kev ua haujlwm ntawm Secondary Settling Tanks
Thaum lub sijhawm ua haujlwm ntawm ob lub tso tsheb hlau luam, cov teeb meem xws li flocculent effluent thiab sludge ntab tuaj yeem tshwm sim, uas tsis tsuas yog cuam tshuam rau cov dej ntws zoo tab sis kuj cuam tshuam cov txheej txheem tom ntej. Cov laj thawj thiab kev tiv thaiv tau txheeb xyuas hauv qab no.
1. High Concentration ntawm Suspended Solids hauv Effluent
(1) Ua rau
1) Cov dej ntws ntau dhau, lub sijhawm tuav tsis txaus nyob rau hauv lub tank thib ob, thiab nce qhov chaw thauj khoom;
2) Kev daws teeb meem tsis zoo ntawm kev ua haujlwm sludge (siab SVI).
(2) Kev tiv thaiv
1) Tswj tus nqi ntws ntws thiab sib npaug ntawm qhov ntws hauv pem hauv ntej -kawg sib npaug ntawm lub tank;
2) Thaum lub sij hawm los nag, nres lub twj tso kua mis rov qab los txo cov dej ntws tawm thiab txo qis qhov chaw ntawm lub tank thib ob;
3) Hauv qhov project tsim, xaiv ib lub voj voog thib ob sedimentation tank hla ib lub xwmfab kom tsis txhob muaj teeb meem sludge tshuab thaum kawg ntawm cov saw scraper.
2. Sludge ntab
Sludge floating ua rau muaj kev nce ntxiv hauv cov khib nyiab hauv cov effluent, ua rau cov ntxhiab tsw phem. Qhov laj thawj yuav tsum tau txheeb xyuas sai thiab daws teeb meem. Feem ntau ua rau poob rau hauv peb pawg:
(1) Anaerobic decomposition ua pa roj (CO₂, CH₄)
Kev tshwm sim: Floating sludge yog dub thiab nyob sai sai tom qab txau.
Ua rau: Anaerobic decomposition ntawm sludge deposited nyob rau hauv tuag ces kaum ntawm lub thib ob sedimentation tank, tshwj xeeb tshaj yog muaj nyob rau hauv lub caij ntuj sov.
Kev ntsuas kev ntsuas: Txhim kho kev ua haujlwm ntawm cov scraper, tshem tawm cov kab tuag ntawm cov sludge, thiab manually ntxuav thaum tsim nyog.
(2) Nitrogen ntau lawm thaum denitrification (N₂)
Kev tshwm sim: Floating sludge yog xim av - daj, tab sis nyob tom qab txau.
Ua rau: Nitrification nyob rau hauv cov tshuaj tiv thaiv tank yog sai heev, ua rau ib tug loj npaum li cas ntawm nitrate nkag mus rau hauv anaerobic cheeb tsam nyob rau hauv qab ntawm lub thib ob settling tank, triggering denitrification thiab roj ntau lawm.
Countermeasures: 1) Nruab ib qho anaerobic seem ntawm qhov kawg ntawm cov tshuaj tiv thaiv tank; 2) Yog tias tsim nyog, kho cov txheej txheem kom tsis txhob muaj nitrification (xws li cov kev cai ib puag ncig ntawm cov effluent kom tsis txhob muaj ammonia nitrogen tshaj tus qauv); 3) Rau cov xwm txheej tshwj xeeb uas cuam tshuam nrog ze - ntug dej ntws tawm thiab qhov xav tau los muab ammonia nitrogen ua cov as-ham rau aquaculture, ammonia nitrogen tswj tau tsim nyog.
(3) Actinomycete proliferation thiab roj ntau lawm
Kev tshwm sim: Ib qho loj me me ntawm cov sludge ntab ntab rau saum npoo, nrog cov pa npuas txuas nrog cov sludge hauv filamentous lossis millet- zoo li cov duab, tsis kho tom qab txau.
Countermeasures: 1) Tshawb xyuas cov sludge nyob rau hauv lub tshuab ntsuas kom paub meej tias muaj cov actinomycetes; 2) Siv sij hawm ntsuas los tiv thaiv cov actinomycetes (xws li kho cov hnub nyoog sludge, tswj cov ntsiab lus ntawm cov roj thiab cov organic acids hauv lub zog).
III. Cov lus qhia ua haujlwm thiab kev tswj xyuas
1. Kev kuaj thiab saib xyuas tsis tu ncua
(1) Saib xyuas MLSS, SVI, thiab sludge rov qab concentration txhua hnub;
(2) Muab cov neeg ua haujlwm nrog nitrate thiab nitrite kuaj strips. Siv cov ntawv xeem kom tsis tu ncua xyuas nitrate nitrogen thiab nitrite nitrogen. Yog tias cov qib siab tshaj qhov ntsuas kab ntsuas qhov ntsuas, dilute tus qauv ua ntej kuaj.
2. Tiv thaiv Sludge Deposition
(1) Xyuas kom cov sludge scraper ua haujlwm ib txwm los tiv thaiv sedimentation nyob rau hauv cov ces kaum tuag ntawm cov sedimentation tank thib ob;
(2) Tsis tu ncua ntxuav cov sludge hauv qab ntawm lub tank sedimentation thib ob, tshwj xeeb tshaj yog thaum lub sij hawm siab -kub lub caij (kev tuav tes tu yuav tsum tau kuaj cov pa phem thiab cov pa phem, cov pa taws kub hnyiab thiab tawg, thiab cov pa oxygen hauv cov chaw kaw; tam sim no, muaj cov sludge tu neeg hlau nyob rau hauv kev ua lag luam uas tuaj yeem hloov cov neeg ua haujlwm thiab muaj kev nyab xeeb dua).
3. Kev Kho Sludge Discharge
(1) Raws li kev suav cov txiaj ntsig thiab kev ua haujlwm, tsis txhob muaj qhov hloov pauv ntau zaus thiab loj;
(2) Kho cov sludge tso tawm zaus thiab ib qho kev tso tawm sai sai thaum hnub los nag lossis thaum cov dej zoo hloov pauv.
4. Xav txog qhov yuav tsum tau muaj ntawm ib puag ncig effluent:
(1) Nkag siab txog cov yam ntxwv ntawm thaj chaw tso tawm (piv txwv li, aquaculture, toj roob hauv pes dej);
(2) Tsim ib txoj kev npaj ua haujlwm uas ua tau raws li cov qauv dej hauv zos thiab cov kev xav tau ntawm ecological.
Cov ntsiab lus: Lub tank thib ob yuav zoo li tsuas yog lub tank sedimentation, tab sis nws yog "kawg checkpoint" txuas cov tshuaj tiv thaiv tank thiab qhov hluav taws xob effluent. Nws yuav tsum tsis tsuas yog stabilize lub effluent zoo tab sis kuj muab ib tug ruaj khov khoom ntawm rov qab sludge rau cov tshuaj tiv thaiv tank. Kev ua haujlwm thiab kev tswj hwm yuav tsum ua raws li cov hauv paus ntsiab lus ntawm kev tshawb fawb txog kev suav + kev paub -raws li kev txiav txim + kev hloov pauv hloov pauv, ua ke nrog cov ntaub ntawv tiag - lub sijhawm saib xyuas thiab tso tawm ib puag ncig, tiv thaiv teeb meem ua ntej lawv tshwm sim. Tsuas yog nyob rau hauv txoj kev no tuaj yeem ua tau zoo, ruaj khov, thiab kev ua haujlwm zoo ib puag ncig ntawm kev kho dej khib nyiab tuaj yeem ua tiav.
