Fouling Characterization thiab Aeration Performance Recovery of Fine-pore Diffuser hauv cov nroj tsuag kho dej khib nyiab
Raws li cov kauj ruam tseem ceeb hauv cov txheej txheem activated sludge ntawm cov chaw kho dej khib nyiab hauv nroog (WWTPs), aeration rau cov pa oxygen tsis yog tsuas yog muab cov pa oxygen txaus los txhawb nqa cov haujlwm tseem ceeb ntawm cov kab mob, tab sis kuj tseem ua rau cov sludge raug tshem tawm, pab txhawb cov adsorption thiab tshem tawm cov pa phem. Aeration kuj yog lub zog tshaj plaws -siv chav nyob hauv WWTPs, suav txog 45% txog 75% ntawm cov nroj tsuag siv zog tag nrho. Yog li ntawd, kev ua haujlwm ntawm lub tshuab aeration ncaj qha cuam tshuam rau kev kho mob thiab cov nqi ua haujlwm ntawm WWTP. Cov khoom siv aeration yog ib qho tseem ceeb ntawm lub tshuab aeration, nrog cov npuas aerators yog cov feem ntau siv nyob rau hauv lub nroog WWTPs vim lawv cov pa oxygen hloov efficiency (OTE). Txawm li cas los xij, thaum lub sijhawm ua haujlwm ntev -, cov pa phem inevitably accumulates nyob rau saum npoo thiab nyob rau hauv lub pores ntawm lub aerators. Txhawm rau kom muaj cov dej ntws zoo, yuav tsum muaj cua ntxiv los ntawm cov tshuab blowers, ua rau muaj zog siv zog ntxiv. Tsis tas li ntawd, cov pa phem exacerbates pore clogging thiab hloov cov khoom siv aerator. Lub siab poob (dynamic ntub dej siab, DWP) ntawm cov khoom siv aerator nce ntxiv rau kev ua haujlwm ntev, ua rau lub tshuab hluav taws xob lub qhov hluav taws xob cua siab thiab ua rau muaj zog ntxiv.
Cov pa phem accumulating rau ntawm qhov chaw thiab hauv lub qhov hws ntawm zoo npuas aerators muaj xws li lom, organic, thiab inorganic fouling. Organic fouling tshwm sim los ntawm adsorption thiab nag lossis daus ntawm cov organic teeb meem thiab deposition ntawm microbial secretions. Inorganic fouling feem ntau muaj cov tshuaj precipitates tsim los ntawm polyvalent cations, xws li hlau oxides. Raws li seb lawv puas tuaj yeem raug tshem tawm los ntawm kev ntxuav lub cev, cov pa phem tuaj yeem raug categorized li lub cev rov qab los yog lub cev irreversible fouling. Lub cev thim rov qab fouling tuaj yeem raug tshem tawm los ntawm txoj kev yooj yim lub cev zoo li kev txhuam txhuam, vim tias cov pa phem no tau xoob txuas mus rau qhov chaw aerator. Lub cev irreversible fouling tsis tuaj yeem tshem tawm los ntawm kev ntxuav lub cev thiab yuav tsum tau ua kom huv huv ntau dua. Nyob rau hauv lub cev irreversible fouling, cov pa phem uas yuav raug tshem tawm los ntawm tshuaj ntxuav yog hu ua chemically reversible fouling, thaum cov uas tsis tuaj yeem tshem tawm txawm tias los ntawm tshuaj ntxuav yog suav tias yog irrecoverable fouling.
Tam sim no, cov tshuab ua npuas zoo siv hauv tsev muaj xws li cov khoom siv roj hmab ib txwm muaj xws li ethylene propylene diene monomer (EPDM) thiab cov ntaub ntawv tshiab xws li siab - ntom polyethylene (HDPE). Cov roj faib txheej ntawm HDPE aerators yog tsim los ntawm txheej txheej hauv huab cua xa cov yeeb nkab nrog molten polymer, nrog pore diameters kwv yees li (4.0 ± 0.5) hli. HDPE muaj cov tshuaj zoo, txhua yam, thiab kev cuam tshuam cov khoom thiab lub neej ua haujlwm ntev. Txawm li cas los xij, nws qhov pore qhov ntau thiab tsawg yog qhov tsis sib xws thiab tsis sib xws, ua rau lawv ua rau muaj kuab paug paug. EPDM cov khoom yog hloov tau yooj yim, nrog rau qhov pores tsim los ntawm cov neeg kho tshuab txiav. EPDM aerators muaj cov pores ntau dua hauv ib cheeb tsam, ua npuas me me (tsawg kawg yog 0.5 hli). Lub hydrophilic xwm ntawm cov roj hmab daim nyias nyias kuj nyiam tsim npuas. Txawm li cas los xij, cov kab mob zoo li txuas thiab loj hlob ntawm EPDM nto, siv cov yas yas ua cov substrate. Raws li qhov tshwm sim, kev siv cov plasticizers ua rau cov khoom siv aerator harden, thaum kawg ua rau qaug zog puas tsuaj thiab ua rau lub neej ua haujlwm luv. Yog li ntawd, nws yog ib qho tsim nyog los soj ntsuam cov qauv ntawm cov pa paug ntawm cov khoom siv ob qho no thiab qhov kev hloov pauv ntawm cov pa oxygen hloov pauv tau zoo thiab poob siab.
Txoj kev tshawb no coj cov npuas aerators zoo hloov tom qab xyoo ntawm kev ua haujlwm los ntawm ob lub nroog WWTPs nrog cov txheej txheem zoo sib xws raws li kev tshawb fawb. Cov pa phem ntawm cov aerators tau muab rho tawm thiab cov txheej txheem los ntawm txheej los txheeb xyuas lawv cov khoom tseem ceeb. Raws li qhov no, kev ua tau zoo ntawm kev ntxuav hauv kev rov ua kom cov pa oxygen hloov pauv ntawm lub tshuab aerators tau soj ntsuam, txhawm rau muab cov ntaub ntawv tseem ceeb thiab cov ntaub ntawv siv rau lub sijhawm ntev - lub sijhawm ua haujlwm tau zoo thiab ruaj khov ntawm cov tshuab ua npuas zoo.
1 Cov ntaub ntawv thiab cov txheej txheem
1.1 Kev Taw Qhia Txog Cov Khoom Siv Hluav Taws Xob Hluav Taws Xob
Ob lub WWTPs nyob hauv Shanghai thiab siv cov txheej txheem Anaerobic-Anoxic-Oxic (AAO) ua cov txheej txheem tseem ceeb. WWTP A ntiav cov vortex grit chamber + cov pa AAO + siab -efficiency fiber filter + UV tshuaj tua kab mob. WWTP B siv lub aerated grit chamber + pa AAO + siab -efficiency sedimentation tank + UV tshuaj tua kab mob txheej txheem. Ob qho nroj tsuag ruaj khov ua tau raws li Qib A tus qauv ntawm "Kev Tso Tawm Ntawm Cov Khoom Ua Rau Cov Khoom Siv Hauv Nroog" (GB 18918-2002). Cov qauv tsim tshwj xeeb thiab kev ua haujlwm tsis ua haujlwm tau qhia hauvTable 1.
1.2 Extraction thiab Characterization ntawm Aerator Pollutants
Cov tshuab ua npuas zoo siv hauv kev sim yog tubular HDPE aerator (Ecopolemer, Ukraine) sau los ntawm Plant A thiab tubular EPDM aerator (EDI-FlexAir, USA) sau los ntawm Plant B. Cov duab ntawm ob qho tib si muaj nyob rau hauvDaim duab 1. Lub raj HDPE qub tau ua haujlwm rau 10 xyoo, nrog qhov ntev D × L =120 mm × 1000 mm thiab pore txoj kab uas hla ntawm (4 ± 0.50) mm, muaj peev xwm ua tau zoo npuas ntawm 2 ~ 5 hli. Lub raj EPDM qub tau ua haujlwm tau 3 xyoos, nrog qhov ntev D × L=91 hli × 1003 hli, ua npuas zoo ntawm 1.0 ~ 1.2 hli, nrog qhov tsawg kawg nkaus npuas txoj kab uas hla ntawm 0.5 hli.
Cov laus HDPE thiab EPDM cov raj tau muab los ntawm cov tso tsheb hlau luam aerobic, muab tso rau hauv cov yeeb yaj kiab cling, thiab yaug nrog dej deionized. Kev txhuam txhuam tau ua tiav siv cov nplaim hluav taws- kom tsis muaj menyuam kom tshem tawm cov pa phem uas txuas rau lub tshuab aerator.
Txhawm rau kawm ntxiv txog qhov cuam tshuam ntawm fouling ntawm kev hloov pauv cov pa oxygen, tshuaj ntxuav tau ua rau ntawm HDPE raj. Tom qab kev txhuam cov tshuab, HDPE raj tau tsau rau hauv 5% HCl thiab 5% NaClO cov kev daws teeb meem rau 24 teev. Cov raj qub, cov raj txhuam txhuam, thiab cov raj tshuaj ntxuav tau qhuav hauv qhov cub 60℃(qauv XMTS-6000) rau 60 teev. Tom qab ntawd lawv qhov chaw raug tshuaj xyuas los ntawm kev siv tshuaj ntsuam xyuas electron microscopy (SEM, qauv JSM-7800F, Nyiv), lub zog-dispersive X-ray spectroscopy (EDX, Oxford Instruments, UK), thiab confocal laser scanning microscopy (CLSM, qauv TCS SP8, Lub teb chaws Yelemees). Cov tshuaj ntxuav HCl tau lim los ntawm 0.45 μm daim nyias nyias, thiab kev soj ntsuam ntau ntawm polyvalent cations (xws li Ca, Mg, Al, Fe ions, thiab lwm yam) tau ua los ntawm kev siv inductively txuas nrog plasma optical emission spectrometry (ICP, qauv ICPS-7510, Nyiv). Raws li HCl thiab NaClO tuaj yeem ua rau denaturation thiab aging ntawm EPDM membrane, tshuaj ntxuav tsis tau ua rau ntawm EPDM raj. EPDM raj raug txiav rau hauv 5 cm × 5 cm daim nyias nyias thiab soaked nyob rau hauv HCl rau kom muaj nuj nqis tsom xam ntawm polyvalent cations nyob rau hauv cov tshuaj.
1.3 Kev Ntsuas Cov Cuab Yeej thiab Txoj Kev rau Aerator Oxygen Hloov Kev Ua Haujlwm
Kev ua haujlwm ntawm cov pa oxygen hloov pauv ntawm lub tshuab ua npuas zoo tau raug sim raws li "Kev Txiav Txim ntawm Dej Oxygen Hloov Kev Ua Haujlwm ntawm Fine Bubble Aerators" (CJ / T 475-2015). Qhov kev sim teeb tsa tau pom hauvDaim duab 2.
Cov cuab yeej yog stainless-steel qauv ntsuas 1.2 m × 0.3 m × 1.4 m, nrog organic iav saib qhov rais ntawm ob sab. Lub aerator tau kho nyob rau hauv nruab nrab hauv qab siv ib tug hlau txhawb, nrog ib tug submergence qhov tob ntawm 1.0 m. Ib tug multi- parameter water quality analyzer (Hach HQ30D, USA) tau siv los saib xyuas cov pa oxygen (DO) concentration hauv lub sijhawm tiag -. Sodium sulfite anhydrous tau siv los ua tus neeg sawv cev deoxygenation, thiab cobalt chloride ua cov catalyst. Lub ntsuas ntsuas ntsuas tau sawv cev rau lub aerator lub zog ntub dej (DWP, kPa). Kev ntsuas ntsuas tau raug kho rau qhov kub thiab txias, salinity, thiab DO. Cov qauv kev hloov pauv cov pa oxygen (SOTE, %) tau siv los ua qhov ntsuas ntsuas.
Blower zog noj muaj feem xyuam rau ob qho tib si huab cua txaus txaus thiab qhov hluav taws xob cua siab, uas yog cuam tshuam los ntawm lub aerator's SOTE thiab DWP, feem. Yog li ntawd, ib qho aeration zog noj Performance index J (kPa·h / g), sawv cev rau kev sib xyaw ua ke ntawm SOTE thiab DWP, tau siv los ntsuas kev ua haujlwm ntawm aerator. Nws yog txhais raws li lub siab poob lub aerator yuav tsum kov yeej ib chav tsev loj ntawm oxygen xa mus. J yog xam los ntawm txoj kab nqes ntawm txoj kab rov tav haum ntawm DWP / SOTE thiab huab cua txaus tus nqi (AFR), raws li qhia hauv kab zauv hauv qab no:
Qhov twg:
AFRyog huab cua ntws tus nqi, m³ / h;
ρhuab cuayog huab cua ceev, npaum li 1.29 × 10³ g / m³ ntawm 20 degree;
yO2yog cov pa oxygen hauv huab cua, noj li 0.23 g O₂ / g cua.
2 Kev Tshawb Fawb thiab Kev Tshawb Fawb
2.1 Oxygen Transfer Performance of New, Old, and Cleaned Aerators
Daim duab 3qhia SOTE thiab DWP ntawm cov aerators ntawm cov pa sib txawv.
Los ntawm cov duab 3(a) thiab (b), SOTE qhov tseem ceeb rau HDPE tshiab thiab EPDM tubes tshiab yog (7.36 ± 0.53)% thiab (9.68 ± 1.84)%, feem. Lub raj EPDM tsim cov npuas me me nrog thaj tsam loj dua, ua rau cov pa roj ntau dua -kua qhov chaw nyob thiab lub sijhawm nyob, yog li ua rau SOTE siab dua. Lub SOTE ntawm ob lub tshuab aerators tau txo qis nrog kev nce AFR vim tias AFR ntau dua nce cov npuas thiab pib tshaj tawm, ua rau muaj kev sib tsoo ntau dua thiab tsim cov npuas loj, uas cuam tshuam cov pa oxygen hloov ntawm cov pa mus rau theem ua kua. Lub SOTE ntawm EPDM raj tau qhia pom qhov txo qis dua nrog kev nce AFR piv rau HDPE raj. Qhov no yog vim qhov pores ntawm HDPE aerator yog nruj thiab tsis hloov nrog AFR, thaum lub pores ntawm EPDM aerator yog hloov tau thiab qhib dav nrog nce AFR, tsim npuas loj thiab ntxiv txo SOTE.
Tom qab ua haujlwm ntev - lub sijhawm ua haujlwm, SOTE ntawm HDPE raj poob rau (5.39 ± 0.62)%, qhov txo qis ntawm 26.7%, feem ntau yog vim muaj kuab paug paug clogging lub qhov hws thiab txo cov pores zoo rau kev tsim npuas. Kev txhuam txhuam tau nce SOTE ntawm HDPE raj mus rau (5.59 ± 0.66)%, tab sis qhov kev rov qab los tsis tseem ceeb, tej zaum vim tias cov pa phem ntawm HDPE raj tsis tsuas yog txuas rau saum npoo, tab sis kuj tso rau hauv lub qhov hws, ua rau lawv nyuaj rau tshem tawm los ntawm kev txhuam txhuam. Jiang et al. pom tias NaClO tuaj yeem tshem tawm cov pa phem los ntawm HDPE raj thiab kho lawv cov kev ua haujlwm aeration. Tom qab NaClO ntxuav, SOTE ntawm HDPE raj rov qab mus rau (6.14 ± 0.63)%, uas yog 83.4% ntawm cov raj tshiab theem, tseem tsis tuaj yeem rov qab zoo tag nrho. Qhov no yog vim hais tias, dhau sijhawm ua haujlwm ntev, cov pa phem ua rau nruj nreem, hloov cov qauv pore, cuam tshuam airflow, nce npuas coalescence, txo cov npuas tshwj xeeb ntawm thaj chaw thiab lub sijhawm nyob, thiab yog li cuam tshuam cov pa xa mus. Tib lub sijhawm, fouling ua rau huab cua tsis sib xws, ua rau kev ua haujlwm tag nrho.
Lub SOTE ntawm lub qub EPDM raj poob rau (9.06 ± 1.75)%, txo qis ntawm 6.4%. Dhau li ntawm qhov pore clogging los ntawm cov pa paug paug, lom fouling siv plasticizers hauv cov khoom, hardening lub aerator thiab deforming lub pores. Cov pores deformed tsis tuaj yeem rov qab mus rau lawv qhov qub, ua npuas loj dua thiab txo SOTE. Kev txhuam txhuam tau nce SOTE ntawm EPDM raj mus rau (9.47 ± 1.87)%, yuav luag rov ua kom nws mus rau theem ntawm cov raj tshiab, qhia tias cov pa phem ntawm EPDM raj tau xoob txuas mus rau saum npoo thiab feem ntau yuav raug tshem tawm los ntawm kev txhuam txhuam.
Los ntawm cov duab 3(c) thiab (d), DWP ntawm lub raj EPDM tshiab yog (6.47 ± 0.66) kPa, ntau dua li ntawm HDPE raj tshiab [(1.47 ± 0.49) kPa]. Qhov no yog vim qhov pore txoj kab uas hla ntawm EPDM raj yog me dua li ntawm HDPE raj, uas ua rau muaj kev tiv thaiv ntau dua thaum npuas raug nyem los ntawm. Tom qab ua haujlwm ntev -, DWP ntawm lub qub HDPE raj tau nce mus rau (4.36 ± 0.56) kPa, 2.97 npaug ntawm lub raj tshiab. Qhov nce hauv DWP muaj feem xyuam rau ob qho tib si ntawm qhov pore clogging thiab cov khoom hloov pauv. Kev txhuam txhuam tau txo DWP ntawm HDPE raj rau 2.25 npaug ntawm lub raj tshiab. NaClO tu ntxiv txo nws mus rau (2.04 ± 0.45) kPa, 1.39 npaug ntawm cov raj tshiab. Qhov no ntxiv qhia tias feem ntau cov pa phem ntawm HDPE raj tau tso rau hauv lub qhov hws thiab tsis tuaj yeem tshem tawm tau zoo los ntawm kev txhuam txhuam, yuav tsum tau ntxuav NaClO kom rov ua haujlwm. Lub DWP ntawm lub qub EPDM raj tau nce mus rau (8.10 ± 0.94) kPa, 1.25 npaug ntawm cov raj tshiab, thiab txo mus rau 1.10 npaug tom qab siv tshuab txhuam.
Daim duab 4qhia txog kev hloov pauv ntawm DWP / SOTE (tus cim raws li DWP') nrog AFR rau cov aerators.
Ib txoj kab rov tav kab sib npaug tau siv los ua kom haum DWP 'piv rau AFR, thiab lub zog siv hluav taws xob J tau txais los ntawm txoj kab nqes. J qhov tseem ceeb rau HDPE tshiab thiab EPDM raj tshiab yog 0.064 thiab 0.204 kPa·h / g, raws li qhia tau hais tias ib chav tsev loj ntawm cov pa xa mus, EPDM raj yuav tsum kov yeej lub siab poob ntau dua. Thaum lub sijhawm hloov, J qhov tseem ceeb rau cov raj HDPE thiab EPDM tau nce mus rau 0.251 thiab 0.274 kPa·h / g, raws li. Aerator fouling ua rau muaj kev poob siab tuaj yeem cuam tshuam rau lub tshuab ua haujlwm nyab xeeb. Tom qab kev txhuam cov tshuab, J qhov tseem ceeb rau HDPE thiab EPDM raj tau txo qis rau 0.184 thiab 0.237 kPa·h / g, raws li. Kev hloov pauv hauv J tuaj yeem siv rau kev txheeb xyuas ntau ntawm cov pa phem aerator. Qhov sib txawv hauv J ntawm cov raj qub thiab cov raj siv tshuab ntxhua khaub ncaws yog tshwm sim los ntawm lub cev rov qab fouling. Qhov sib txawv ntawm cov tshuab ntxhua khaub ncaws thiab cov raj tshiab yog tshwm sim los ntawm lub cev tsis muaj zog fouling. Qhov sib txawv ntawm cov tshuab ntxhua khaub ncaws thiab cov tshuaj ntxuav lub raj yog tshwm sim los ntawm cov tshuaj chemically reversible fouling, thaum qhov sib txawv ntawm cov tshuaj ntxuav lub raj thiab lub raj tshiab yog tshwm sim los ntawm irrecoverable fouling. Daim duab 5 qhia txog kev hloov pauv ntawm kev siv lub zog J rau lub tshuab aerators.
Los ntawmDaim duab 5, rau HDPE raj, lub cev thim rov qab thiab lub cev irreversible fouling accounted rau 35.8% thiab 64.2% ntawm tag nrho fouling, feem. Nyob rau hauv lub cev irreversible fouling, tshuaj reversible thiab irrecoverable fouling accounted rau 42.8% thiab 21.4%, feem. Rau EPDM raj, lub cev thim rov qab thiab lub cev tsis tuaj yeem rov qab fouling suav txog 52.9% thiab 47.1%, feem. Irrecoverable fouling tsis tshwm sim thaum pib tab sis accumulates dhau lub sij hawm, thaum kawg txiav txim siab lub aerator lub neej kev pab cuam. Yog li ntawd, cov sij hawm tu kom tsim nyog yuav tsum tau tsim kom qeeb qhov kev hloov pauv los ntawm kev thim rov qab mus rau qhov tsis tuaj yeem fouling thiab txo qis qhov tsub zuj zuj ntawm irrecoverable fouling.
2.2 SEM Kev soj ntsuam tshiab, qub, thiab huv si aerators
Daim duab 6qhia SEM cov duab ntawm qhov chaw tshiab, qub, thiab tshuab ntxhua khaub ncaws aerators. Cov qauv ntxeem tau ntawm lub raj HDPE tshiab tau pom meej meej, thaum lub ntsej muag ntawm lub raj EPDM tshiab yog du nrog huv - txiav qhov pores. Tom qab ob peb xyoos ntawm kev ua haujlwm, qhov chaw morphology ntawm ob lub aerators hloov pauv loj heev. Cov pas nrig tsis sib xws-zoo li thiab cov pa phem ua paug npog tag nrho ntawm qhov chaw, nrog cov pa phem sib sau ua ke nyob ib puag ncig thiab sab hauv lub qhov hws, cuam tshuam kev hloov pauv oxygen thiab nce siab poob. Tom qab kev txhuam cov tshuab, feem ntau cov pa phem ntawm EPDM raj nto tau raug tshem tawm, tab sis cov pores tseem txhaws. Rau HDPE raj, cov pa phem txheej thickness txo, tab sis qhov pores tseem npog.
2.3 Inorganic Fouling Analysis of New, Old, and Cleaned Aerators
EDX tau siv los txheeb xyuas cov ntsiab lus tseem ceeb ntawm qhov chaw aerator, nrog cov txiaj ntsig tau pom hauvRooj 2. Cov pa roj carbon, oxygen, hlau, silicon, thiab calcium tau kuaj pom ntawm ob qho tib si HDPE thiab EPDM. HDPE raj kuj muaj magnesium, thaum lub EPDM raj muaj txhuas. Nws yog inferred tias inorganic kuab paug nyob rau hauv lub HDPE raj yog silicon dioxide, calcium carbonate, magnesium carbonate, thiab hlau phosphate, hos cov nyob rau hauv lub EPDM raj yog silicon dioxide thiab txhuas oxide. Cov inorganic precipitates tsim thaum cov concentrations ntawm inorganic ions los ntawm cov dej khib nyiab hauv nroog thiab cov activated sludge mus txog saturation ntawm lub aerator nto. Tom qab kev txhuam cov tshuab, cov khoom siv tsis zoo ntawm lub tshuab aerator tau pom qhov txawv me ntsis piv rau cov raj qub, qhia tias kev txhuam cov tshuab tsis tuaj yeem tshem tawm cov pa phem tsis zoo. Kim et al. pom tias tom qab ua haujlwm ntev - lub sijhawm ua haujlwm, cov kuab paug tsis muaj kuab paug tau npog los ntawm cov pa phem hauv cov organic, nruj nreem adhering rau saum npoo thiab sab hauv lub qhov hws, ua rau lawv nyuaj rau tshem tawm los ntawm kev txhuam txhuam.
Tom qab HCl ntxuav, hlau ions ntawm lub aerator nto raug tshem tawm tag nrho. HCl corroded ib feem ntawm cov organic txheej npog qhov chaw, nkag mus rau nws, thiab reacted nrog hlau ions, tshem tawm inorganic precipitates los ntawm neutralization thiab decomposition. HCl ntxuav cov tshuaj siv rau soaking lub aerators tau soj ntsuam los ntawm ICP los xam cov ntsiab lus ntawm inorganic pollutants. Cov ntsiab lus Ca, Mg, thiab Fe rau HDPE raj yog 18.00, 1.62, thiab 13.90 mg / cm², raws li, thaum rau EPDM raj, Ca, Al, thiab Fe cov ntsiab lus yog 9.55, 1.61, thiab 3.38 mg / cm², raws li.
2.4 Organic Fouling Analysis of New, Old, and Cleaned Aerators
Txhawm rau txhawm rau txheeb xyuas qhov kev faib tawm ntawm cov kuab paug organic, Duab J software tau siv los suav cov biovolume thiab substrate kev pab them nqi ntawm tag nrho cov hlwb, polysaccharides, thiab cov proteins los ntawm CLSM micrographs, nrog rau qhov nruab nrab ntawm cov txiaj ntsig kawg (Daim duab 7).
Los ntawm daim duab 7(a), cov proteins thiab tag nrho cov hlwb yog cov khoom tseem ceeb ntawm cov kuab paug organic ntawm cov hlab HDPE thiab EPDM, feem, nrog rau qhov siab tshaj plaws tag nrho mus txog 7.66 × 10⁵ thiab 7.02 × 10⁵ μm³. Tag nrho cov xov tooj ntawm tes ntawm EPDM raj yog 2.5 npaug ntawm HDPE raj, raws li kev tshawb pom los ntawm Garrido-Baserba li al., uas tau tshaj tawm ntau dua tag nrho DNA concentration ntawm cov qub EPDM aerators piv rau lwm cov ntaub ntawv. Wanger et al. pom tias thaum cov kab mob txuas mus rau EPDM hlab, yog tias ib puag ncig ib puag ncig tsis muaj cov organic substrate txaus, lawv tig mus siv EPDM membrane plasticizers. Cov kab mob tuaj yeem siv cov yas yas los ua cov pa roj carbon monoxide, ua kom muaj kev loj hlob sai thiab kev tsim tawm, yog li ua kom muaj roj ntsha fouling ntawm EPDM nto. Cov ntsiab lus ntawm polysaccharide thiab cov protein nyob rau hauv EPDM raj tau qis dua li cov hauv HDPE raj, tej zaum vim yog lub hnub nyoog sludge ntau dua hauv tsob nroj B piv rau tsob nroj A, ua rau qis dua cov khoom siv polymeric (EPS) concentration. Raws li cov khoom tseem ceeb ntawm EPS, cov proteins thiab polysaccharides secreted los ntawm cov kab mob tau dhau los ua qhov tseem ceeb ntawm cov organic pollutants ntawm HDPE raj nto ntawm tsob ntoo A.
Tom qab kev txhuam cov tshuab, qhov ntau ntawm tag nrho cov hlwb, polysaccharides, thiab cov proteins ntawm HDPE raj tau txo los ntawm 1.49 × 10⁵, 0.13 × 10⁵, thiab 1.33 × 10⁵ μm³, raws li. Ntawm EPDM raj, qhov sib thooj txo qis yog 2.20 × 10⁵, 1.88 × 10⁵, thiab 2.38 × 10⁵ μm³, feem. Qhov no qhia tau tias kev txhuam cov tshuab tuaj yeem txo cov organic fouling rau qee qhov.
Txawm li cas los xij, rau HDPE raj, thaj tsam substrate npog ntawm polysaccharides thiab cov proteins tau nce ntxiv tom qab kev txhuam cov tshuab-los ntawm 2.75% thiab 6.28% mus rau 4.67% thiab 7.09%, ntsig txog [Daim duab 7(b)]. Qhov no tshwm sim vim hais tias cov extracellular polymeric tshuaj (EPS) muaj viscosity siab. Yog li ntawd, kev txhuam cov tshuab muaj qhov cuam tshuam ntawm kev sib kis ntawm cov proteins, polysaccharides, thiab cov khoom tsis muaj kuab lom ntau dua thoob plaws HDPE tube qhov chaw, ua rau thaj tsam ntau dua. Qhov no yuav piav qhia tias yog vim li cas cov tshuab ntxhua khaub ncaws ua tsis tau zoo los kho qhov ua kom zoo dua ntawm HDPE raj.
Tom qab NaClO tu, tag nrho cov hlwb, polysaccharides, thiab cov proteins ntawm HDPE raj poob los ntawm 2.34 × 10⁵, 3.42 × 10⁵, thiab 4.53 × 10⁵ μm³, raws li, qhia tau zoo dua kev tshem tawm ntau dua li cov tshuab txhuam. NaClO oxidizes cov pab pawg ua haujlwm ntawm cov pa phem rau hauv ketones, aldehydes, thiab carboxylic acids, ua rau cov hydrophilicity ntawm cov niam txiv sib txuas thiab txo cov pa phem adhesion rau lub aerator. Tsis tas li ntawd, sludge flocs thiab colloids tuaj yeem decomposed los ntawm oxidants rau hauv cov khoom zoo thiab yaj cov organic.
3 Cov lus xaus
①SOTE qhov tseem ceeb rau HDPE tshiab thiab EPDM raj tshiab yog (7.36 ± 0.53)% thiab (9.68 ± 1.84)%, feem. Lub SOTE ntawm EPDM raj tau qhia pom qhov txo qis dua nrog kev nce AFR piv rau HDPE raj. Qhov no yog vim qhov pores ntawm HDPE aerator yog nruj thiab tsis hloov nrog AFR, thaum lub pores ntawm EPDM aerator yog hloov tau thiab qhib dav nrog nce AFR, tsim npuas loj thiab ntxiv txo SOTE.
②Vim muaj kuab paug paug rau ntawm qhov chaw thiab hauv qhov pores, cov pa oxygen hloov pauv ntawm HDPE raj tau txo qis los ntawm 26.7%, thiab nws lub siab poob nce mus rau 2.97 npaug ntawm lub raj tshiab. Raws li feem ntau cov pa phem ntawm HDPE raj tau tso rau hauv lub qhov hws, kev txhuam txhuam tsis zoo. Tom qab ntxuav cov tshuaj, SOTE ntawm HDPE raj rov qab mus rau 83.4% ntawm cov raj tshiab theem, thiab DWP poob rau 1.39 npaug ntawm lub raj tshiab, qhia txog kev txhim kho tseem ceeb. Txawm li cas los xij, vim muaj kuab paug pov tseg, nws tsis tuaj yeem rov qab los rau nws lub xeev qub. Rau HDPE raj, lub cev thim rov qab, chemically reversible, thiab irrecoverable fouling accounted rau 35.8%, 42.8%, thiab 21.4%, feem.
③Tom qab lub sijhawm ua haujlwm ntev -, cov pa oxygen hloov pauv ntawm EPDM raj tau txo qis los ntawm 6.4%, thiab nws qhov siab poob tau nce mus rau 1.25 npaug ntawm lub raj tshiab. Tom qab kev txhuam cov tshuab, qhov kev ua haujlwm aeration ntawm EPDM raj tau yuav luag rov qab los rau qib ntawm cov raj tshiab, qhia tias cov pa phem ntawm EPDM raj tau xoob txuas mus rau saum npoo thiab tuaj yeem tshem tawm ntau los ntawm kev txhuam txhuam. Rau EPDM raj, lub cev thim rov qab thiab lub cev tsis tuaj yeem rov qab fouling suav txog 52.9% thiab 47.1%, feem.
④Cov proteins yog cov ntsiab lus tseem ceeb ntawm cov pa phem hauv lub raj HDPE, thaum tag nrho cov hlwb yog cov khoom tseem ceeb ntawm EPDM raj. Qhov no yog vim hais tias cov kab mob siv cov plasticizers hauv EPDM cov khoom siv los ua cov pa roj carbon monoxide, ua kom lawv txoj kev loj hlob thiab kev loj hlob, yog li ua kom muaj roj ntsha fouling ntawm EPDM cov khoom siv aerators.