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Nyob rau hauv cov dej tshiab ib puag ncig, ceev corrosion ntawm carbon thiab stainless hlau yog feem ntau pom. Txoj kev kawm 22-hli lub tank dej tshiab dhia dej tau ua ntawm no siv cuaj qib ntawm cov hlau. Accelerated corrosion tau pom nyob rau hauv carbon thiab chromium steels thiab cam khwb cia hlau, thaum nyob rau hauv stainless hlau tsis pom corrosion tau pom txawm tias tom qab 22 lub hlis. Kev soj ntsuam ntawm cov zej zog microbial tau pom tias thaum lub sij hawm kev txhim kho corrosion, Fe(II)-oxidizing kab mob tau enriched nyob rau hauv thaum ntxov theem ntawm corrosion, Fe (III)-txo cov kab mob, nyob rau theem ntawm corrosion, thiab sulfate-txo cov kab mob, nyob rau hauv lub corrosion theem. theem nyob rau theem kawg ntawm cov khoom corrosion. Ntawm qhov tsis sib xws, cov kab mob Beggiatocaea tshwj xeeb tshaj yog nyob rau hauv cov hlau nrog 9% Cr raug rau hauv cheeb tsam corrosion. Cov kev sib xyaw ntawm cov zej zog microbial no kuj txawv ntawm cov qauv hauv dej thiab hauv qab cov sediment. Yog li, raws li kev txhim kho kev txhim kho, cov zej zog microbial tau hloov pauv ntau, thiab cov hlau-dependent microbial zog metabolism tsim ib puag ncig uas tuaj yeem txhawb nqa lwm cov kab mob.
Cov hlau tuaj yeem deteriorate thiab corrode vim ntau lub cev thiab tshuaj ib puag ncig xws li pH, kub thiab ion concentration. Acid tej yam kev mob, kub siab thiab chloride concentrations tshwj xeeb tshaj yog cuam tshuam rau corrosion ntawm hlau 1,2,3. Cov kab mob nyob hauv ib puag ncig ntuj thiab tsim ua feem ntau cuam tshuam rau kev hnav thiab corrosion ntawm cov hlau, tus cwj pwm qhia hauv microbial corrosion (MIC) 4,5,6,7,8. MIC feem ntau pom muaj nyob rau hauv ib puag ncig xws li cov kav dej hauv tsev thiab cov tso tsheb hlau luam, hauv cov hlau crevices, thiab hauv av, qhov chaw uas nws tshwm sim sai sai. Yog li ntawd, kev saib xyuas thiab kev tshawb pom ntxov ntawm MICs yog qhov nyuaj heev, yog li MIC tsom xam feem ntau yog ua tom qab corrosion. Ntau qhov kev tshawb fawb MIC tau tshaj tawm nyob rau hauv uas cov kab mob sulfate-txo cov kab mob (SRB) tau nquag pom hauv cov khoom siv corrosion9,10,11,12,13. Txawm li cas los xij, nws tseem tsis tau paub meej tias SRBs puas cuam tshuam rau qhov pib ntawm corrosion, vim tias lawv qhov kev kuaj pom yog raws li kev txheeb xyuas tom qab corrosion.
Tsis ntev los no, ntxiv rau iodine-oxidizing kab mob21, ntau yam hlau-degrading microorganisms tau tshaj tawm, xws li hlau-degrading SRB14, methanogens15,16,17, nitrate-txo cov kab mob18, hlau-oxidizing kab mob19 thiab acetogens20. Nyob rau hauv anaerobic lossis microaerobic kuaj mob, feem ntau ntawm lawv corrode xoom-valent hlau thiab carbon hlau. Tsis tas li ntawd, lawv cov txheej txheem kev txhim kho corrosion qhia tias hlau-corrosive methanogens thiab SRBs txhawb kev xeb los ntawm kev sau cov electrons los ntawm cov hlau tsis muaj txiaj ntsig siv extracellular hydrogenases thiab multiheme cytochromes, raws li 22,23. MICs muab faib ua ob hom: (i) tshuaj MIC (CMIC), uas yog indirect corrosion los ntawm microbially tsim hom, thiab (ii) hluav taws xob MIC (EMIC), uas yog ncaj qha corrosion los ntawm electron depletion ntawm cov hlau24. EMIC txhawb nqa los ntawm extracellular electron hloov chaw (EET) yog qhov txaus siab heev vim tias cov kab mob uas muaj EET cov khoom ua rau muaj kev xeb sai dua li cov kab mob uas tsis yog EET. Thaum lub sij hawm tus nqi-txwv cov lus teb ntawm CMIC nyob rau hauv anaerobic tej yam kev mob yog H2 ntau lawm ntawm proton txo (H +), EMIC nce los ntawm EET metabolism, uas yog ywj siab ntawm H2 ntau lawm. Lub mechanism ntawm EET nyob rau hauv ntau yam kab mob muaj feem xyuam rau kev ua tau zoo ntawm microbial cellular roj thiab electrobiosynthesis25,26,27,28,29. Vim hais tias kab lis kev cai tej yam kev mob rau cov kab mob corrosive txawv ntawm cov nyob rau hauv ib puag ncig ntuj, nws tsis paub meej tias cov kev soj ntsuam microbial corrosion muaj kev cuam tshuam corrosion hauv kev xyaum. Yog li ntawd, nws yog ib qho nyuaj rau soj ntsuam MIC mechanism induced los ntawm cov corrosive microorganisms nyob rau hauv ib puag ncig ntuj.
Txoj kev loj hlob ntawm DNA sequencing thev naus laus zis tau ua kom yooj yim rau kev kawm txog cov ntsiab lus ntawm cov zej zog microbial nyob rau hauv ib puag ncig ntuj thiab khoom tsim, piv txwv li, microbial profiling raws li 16S rRNA gene sequence siv cov tiam tshiab sequencers tau siv nyob rau hauv thaj tsam ntawm microbial ecology30,31. ,32 ib. Ntau cov kev tshawb fawb MIC tau luam tawm uas muaj cov ncauj lus kom ntxaws microbial cov zej zog hauv av thiab marine ib puag ncig13,33,34,35,36. Ntxiv rau SRB, ntxiv rau Fe(II)-oxidizing (FeOB) thiab nitrifying kab mob hauv cov qauv corrosion, xws li FeOB, xws li Gallionella spp. thiab Dechloromonas spp., thiab cov kab mob nitrifying, xws li Nitrospira, kuj tau tshaj tawm. spp., Carbon thiab tooj liab bearing steels hauv av media33. Ib yam li ntawd, nyob rau hauv ib puag ncig marine, ceev colonization ntawm hlau-oxidizing cov kab mob teej tug mus rau cov chav kawm Zetaproteobacteria thiab Betaproteobacteria tau raug soj ntsuam rau ob peb lub lis piam ntawm carbon steel 36. Cov ntaub ntawv no qhia txog kev koom tes ntawm cov kab mob no rau corrosion. Txawm li cas los xij, nyob rau hauv ntau txoj kev tshawb fawb, lub sij hawm thiab kev sim pab pawg muaj tsawg, thiab me ntsis tsis paub txog cov dynamics ntawm microbial zej zog thaum corrosion.
Ntawm no, peb tshawb xyuas MICs ntawm carbon steel, chromium steel, stainless hlau, thiab cam khwb cia hlau siv immersion kev tshawb fawb nyob rau hauv ib qho chaw aerobic dej qab zib nrog keeb kwm ntawm MIC txheej xwm. Cov qauv raug coj los ntawm 1, 3, 6, 14 thiab 22 lub hlis thiab qhov kev txhim kho corrosion ntawm txhua qhov hlau thiab microbial tivthaiv tau kawm. Peb cov txiaj ntsig muab kev nkag siab rau lub sijhawm ntev ntawm cov zej zog microbial thaum lub sij hawm corrosion.
Raws li qhia hauv Table 1, cuaj hlau tau siv rau hauv txoj kev tshawb no. Kaum tus qauv ntawm txhua yam khoom raug muab tso rau hauv ib lub pas dej tshiab. Cov txheej txheem dej zoo yog raws li nram no: 30 ppm Cl-, 20 mS m-1, 20 ppm Ca2+, 20 ppm SiO2, turbidity 1 ppm thiab pH 7.4. Cov pa oxygen yaj (DO) concentration nyob rau hauv qab ntawm tus qauv ntaiv yog kwv yees li 8.2 ppm thiab cov dej kub ntawm 9 txog 23 ° C raws caij nyoog.
Raws li pom nyob rau hauv daim duab 1, tom qab 1 lub hlis ntawm immersion nyob rau hauv ASTM A283, ASTM A109 Kev mob #4/5, ASTM A179, thiab ASTM A395 cam khwb cia hlau puag ncig, xim av corrosion khoom raug soj ntsuam ntawm cov pa roj carbon steel nto nyob rau hauv daim ntawv ntawm generalized corrosion. Kev poob phaus ntawm cov qauv no tau nce nrog lub sijhawm (Cov Lus Qhia Ntxiv 1) thiab tus nqi corrosion yog 0.13–0.16 hli hauv ib xyoos (Daim duab 2). Ib yam li ntawd, kev xeb dav dav tau pom nyob rau hauv cov hlau tsis muaj Cr cov ntsiab lus (1% thiab 2.25%) nrog tus nqi corrosion ntawm li 0.13 hli / xyoo (Daim duab 1 thiab 2). Hauv qhov sib piv, cov hlau nrog 9% Cr nthuav tawm hauv zos corrosion uas tshwm sim hauv qhov khoob uas tsim los ntawm gaskets. Tus nqi corrosion ntawm cov qauv no yog kwv yees li 0.02 hli / xyoo, uas yog qis dua li ntawm cov hlau nrog kev xeb. Nyob rau hauv sib piv, stainless steels hom-304 thiab -316 zaub tsis pom corrosion, nrog kwv yees corrosion tus nqi ntawm <0.001 hli y-1. Nyob rau hauv sib piv, stainless steels hom-304 thiab -316 zaub tsis pom corrosion, nrog kwv yees acceleration tus nqi ntawm <0.001 hli y-1. Напротив, нержавеющие стали типов 304 и 316 не проявляют видимой коррозии, при этом росчетная ской составляет <0,001 мм/год. Hauv qhov sib piv, Hom 304 thiab 316 stainless hlau tsis pom kev xeb, nrog kev kwv yees corrosion ntawm <0.001 hli / xyoo.相比之下, 304 和-316 型不锈钢没有显示出可见的腐蚀，估计腐蚀速率 <0.001 mm y−1.相比之下, 304 和-316 型不锈钢没有显示出可见的腐蚀，估计腐蚀速率 <0.001 mm y−1. Напротив, нержавеющие стали типа 304 и -316 не показали видимой коррозии с расчетной скоросмью, 0 коростью, 0 коростью, Nyob rau hauv sib piv, hom 304 thiab -316 stainless hlau tsis pom corrosion nrog tus tsim corrosion tus nqi ntawm <0.001 mm/yr.
Qhia yog cov duab macroscopic ntawm txhua tus qauv (qhov siab 50 mm × dav 20 mm) ua ntej thiab tom qab descaling. 1 meter, 1 hli; 3m, 3 hli; 6m,6 hli; 14 m, 14 hli; 22 m, 22 hli; S, ASTM A283; SP, ASTM A109, mob 4/5; FC, ASTM A395; B, ASTM A179; 1C, steel 1% Cr; 3C steel, 2.25% Cr steel; hlau 9C, steel 9% Cr; S6, 316 stainless hlau; S8, hom 304 stainless hlau.
Tus nqi corrosion yog xam los ntawm kev poob phaus thiab immersion lub sij hawm. S, ASTM A283, SP, ASTM A109, hardened 4/5, FC, ASTM A395, B, ASTM A179, 1C, steel 1% Cr, 3 C, steel 2.25% Cr, 9 C, steel 9% Cr, S6, hom 316 stainless hlau; S8, hom 304 stainless hlau.
Ntawm daim duab. 1 kuj qhia tau hais tias corrosion khoom ntawm carbon steel, qis Cr steel thiab cam khwb cia hlau tsim ntxiv tom qab immersion rau 3 lub hlis. Tag nrho corrosion tus nqi maj mam txo mus rau 0.07 ~ 0.08 hli / xyoo tom qab 22 lub hlis (Daim duab 2). Tsis tas li ntawd, tus nqi corrosion ntawm 2.25% Cr steel yog me ntsis qis dua lwm cov qauv corroded, qhia tias Cr tuaj yeem tiv thaiv corrosion. Ntxiv nrog rau kev xeb dav dav, raws li ASTM A179, kev txhim kho corrosion hauv cheeb tsam tau pom tom qab 22 lub hlis nrog corrosion qhov tob txog 700 µm (Fig. 3). Tus nqi corrosion hauv zos, suav nrog qhov tob ntawm corrosion thiab immersion lub sij hawm, yog 0.38 hli / xyoo, uas yog kwv yees li 5 npaug sai dua li kev xeb. Tus nqi corrosion ntawm ASTM A395 alloy tuaj yeem kwv yees tsis zoo vim tias cov khoom siv corrosion tsis ua kom tiav cov nplai tom qab 14 lossis 22 lub hlis ntawm kev tso dej. Txawm li cas los xij, qhov sib txawv yuav tsum tsawg. Tsis tas li ntawd, ntau qhov me me tau pom nyob rau hauv cov corroded tsawg chromium hlau.
Daim duab tag nrho ( nplai bar: 10 hli) thiab thaj chaw corrosion ( nplai bar: 500 µm) ntawm ASTM A179 thiab 9% Cr steel ntawm qhov siab tshaj plaws uas siv lub 3D saib laser microscope. Cov voj voog liab nyob rau hauv daim duab tag nrho qhia txog qhov ntsuas qhov chaw hauv cheeb tsam corrosion. Kev pom tag nrho ntawm 9% Cr steel los ntawm sab nraub qaum yog qhia hauv daim duab 1.
Raws li qhia hauv daim duab. 2, rau cov hlau nrog 9% Cr, tsis muaj corrosion tau pom nyob rau hauv 3-14 lub hlis, thiab tus nqi corrosion yog xyaum xoom. Txawm li cas los xij, hauv cheeb tsam corrosion tau pom tom qab 22 lub hlis (Daim duab 3) nrog tus nqi corrosion ntawm 0.04 mm / xyoo suav nrog kev poob phaus. Qhov siab tshaj plaws hauv cheeb tsam corrosion qhov tob yog 1260 µm thiab tus nqi hauv cheeb tsam corrosion kwv yees siv lub sijhawm corrosion qhov tob thiab immersion lub sij hawm (22 lub hlis) yog 0.68 hli / xyoo. Vim tias qhov tseeb ntawm qhov pib corrosion tsis paub, tus nqi corrosion kuj yuav siab dua.
Nyob rau hauv sib piv, tsis pom corrosion tau pom ntawm stainless hlau txawm tias tom qab 22 lub hlis ntawm immersion. Txawm hais tias ob peb xim xim av tau pom nyob rau saum npoo ua ntej descaling (Daim duab 1), lawv tau tsis muaj zog txuas thiab tsis yog cov khoom siv corrosion. Txij li thaum cov hlau rov tshwm sim ntawm cov hlau tsis xeb tom qab qhov ntsuas tau raug tshem tawm, tus nqi corrosion yog xyaum xoom.
Amplicon sequencing tau ua kom nkag siab txog qhov sib txawv thiab qhov muaj zog ntawm cov zej zog microbial nyob rau lub sijhawm hauv cov khoom siv corrosion thiab biofilms ntawm cov hlau, hauv dej thiab sediments. Tag nrho ntawm 4,160,012 nyeem tau txais, nrog rau ntau yam ntawm 31,328 txog 124,183 nyeem.
Qhov ntsuas Shannon ntawm cov qauv dej coj los ntawm cov dej nkag thiab cov pas dej muaj li ntawm 5.47 txog 7.45 (Fig. 4a). Txij li cov dej ntws rov qab tau siv los ua cov dej lag luam, cov zej zog microbial tuaj yeem hloov raws caij nyoog. Hauv qhov sib piv, Shannon Performance index ntawm cov sediment hauv qab yog kwv yees li 9, uas yog siab dua li cov qauv dej. Ib yam li ntawd, cov qauv dej tau qis dua suav Chao1 qhov ntsuas thiab pom cov haujlwm ua haujlwm taxonomic units (OTUs) dua li cov qauv sediment (Fig. 4b, c). Cov kev sib txawv no tseem ceeb heev (Tukey-Kramer test; p-values ​​< 0.01, Fig. 4d), qhia tias cov zej zog microbial hauv cov qauv sediment yog qhov nyuaj dua li cov qauv hauv cov dej. Cov kev sib txawv no tseem ceeb heev (Tukey-Kramer test; p-values ​​​​< 0.01, Fig. 4d), qhia tias cov zej zog microbial nyob rau hauv cov qauv sediment yog complex dua cov hauv cov qauv dej. Эти различия статистически значимы (критерий Тьюки-Крамера; значения p <0,01, рис. 4d), чоно указыват, сообщества в образцах донных отложений более сложны, чем в образцах воды. Cov kev sib txawv no tseem ceeb heev (Tukey-Kramer test; p qhov tseem ceeb <0.01, Fig. 4d), qhia tias cov zej zog microbial hauv cov qauv sediment yog complex dua hauv cov qauv dej.这些差异具有统计学意义 (Tukey-Kramer 检验；p 值< 0.01，图4d），表明沉积物样本中的微生物群落比水样中的微生物群落更复杂。这些 差异 具有统计学 （tukey-kramer 检验 ； p 值 <0.01 ， 图 4d） 表明沉积物扷本 中用群落更…….. Эти различия были статистически значимыми (критерий Тьюки-Крамера; p-значение <0,01, рис. 4d), чвоя поя предположить, что микробные сообщества в образцах донных отложений были более сложными, чем в обрарать Cov kev sib txawv no yog qhov tseem ceeb (Tukey-Kramer test; p-value <0.01, Fig. 4d), qhia tias cov zej zog microbial hauv cov qauv sediment yog qhov nyuaj dua li cov qauv dej.Txij li thaum cov dej hauv lub pas dej ntws tas li rov ua dua tshiab thiab cov sediments nyob rau hauv qab ntawm lub phiab yam tsis muaj kev cuam tshuam, qhov sib txawv ntawm microbial ntau haiv neeg yuav tsum muaj kev cuam tshuam cov ecosystem hauv lub phiab.
a Shannon Performance index, b Observed operational taxonomic unit (OTU), thiab c Chao1 uptake Performance index (n=6) thiab phiab (n=5) Dej, sediment (n=3), ASTM A283 (S: n=5), ASTM A109 Temper #4/5 (SP: n=5), ASTM A175, A179 (B: ASTM A179), 1% (1 C: n = 5), 2.25% (3 C: n = 5) thiab 9% (9 C: n = 5) Cr-steels, as well as type 316 (S6: n = 5) and -304 (S8: n = 5) stainless steels are shown as box-shaped and whisker charts. d p-values ​​rau Shannon thiab Chao1 indices tau siv ANOVA thiab Tukey-Kramer ntau qhov kev sib piv. Cov keeb kwm liab liab sawv cev ua khub nrog p-tus nqi <0.05. Cov keeb kwm liab liab sawv cev ua khub nrog p-tus nqi <0.05. Красные фоны представляют пары со значениями p <0,05. Cov keeb kwm liab sawv cev ua khub nrog p-tus nqi <0.05.红色背景代表p 值 <0.05 对.红色背景代表p 值 <0.05 对. Красные фоны представляют пары с p-значениями <0,05. Cov keeb kwm liab sawv cev ua khub nrog p-tus nqi <0.05.Cov kab hauv nruab nrab ntawm lub thawv, sab saum toj thiab hauv qab ntawm lub thawv, thiab cov whiskers sawv cev rau qhov nruab nrab, 25 thiab 75 feem pua, thiab qhov tsawg kawg nkaus thiab qhov siab tshaj plaws, feem.
Shannon indices rau carbon steel, tsawg chromium hlau, thiab cam khwb cia hlau zoo ib yam li cov qauv dej (Fig. 4a). Nyob rau hauv sib piv, cov Shannon indices ntawm stainless-steel qauv yog ho siab tshaj cov corroded steels (p-values ​​<0.05, Fig. 4d) thiab zoo ib yam li cov sediments. Nyob rau hauv sib piv, cov Shannon indices ntawm stainless-steel qauv yog ho siab tshaj cov corroded steels (p-values ​​​​ <0.05, Fig. 4d) thiab zoo ib yam li cov sediments. Напротив, индексы Шеннона образцов из нержавеющей стали значительно выше, чем у корродированнный 5 корродированнный с рис. 4d), thiab аналогичны индексам отложений. Nyob rau hauv sib piv, cov Shannon indices ntawm stainless hlau specimens yog ho siab tshaj cov corroded steels (p-tus nqi <0.05, Fig. 4d) thiab zoo ib yam li deposit indices.相比之下，不锈钢样品的香农指数明显高于腐蚀钢的香农指数（p 值 < 0.05 牉囸 4d 漲),相比之下，不锈钢样品的香农指数明显高于腐蚀钢的香农指数（p 值< 0.05，囸4d） Напротив, индекс Шеннона образцов из нержавеющей стали был значительно выше, чем у корродированно <0,05, рис. 4d), как и у отложений. Nyob rau hauv sib piv, lub Shannon Performance index ntawm stainless hlau specimens yog ho siab tshaj ntawm cov corroded steel (p tus nqi <0.05, Fig. 4d), raws li yog cov deposit.Hauv qhov sib piv, Shannon Performance index rau steels nrog 9% Cr ranged ntawm 6.95 txog 9.65. Cov txiaj ntsig no tau ntau dua hauv cov qauv uas tsis muaj corroded ntawm 1 thiab 3 lub hlis tshaj li cov qauv corroded ntawm 6, 14 thiab 22 lub hlis (Fig. 4a). Tsis tas li ntawd, qhov ntsuas Chao1 thiab pom OTUs ntawm 9% Cr steels yog siab dua li cov qauv corroded thiab dej thiab qis dua cov qauv tsis corroded thiab sediment (Fig. 4b, c), thiab qhov sib txawv yog qhov tseem ceeb (p-values ​​<0.01, Fig. 4d). Tsis tas li ntawd, qhov ntsuas Chao1 thiab pom OTUs ntawm 9% Cr steels yog siab dua li cov qauv corroded thiab dej thiab qis dua cov qauv uas tsis yog corroded thiab sediment (Fig. 4b, c), thiab qhov sib txawv yog qhov tseem ceeb (p-values ​​<0.01, Fig. 4.Tsis tas li ntawd, Chao1 thiab pom OTU ntawm steels nrog 9% Cr yog siab dua li cov qauv corroded thiab aqueous thiab qis dua cov qauv uas tsis yog corroded thiab sedimentary (Fig. 4b, c), thiab qhov sib txawv yog qhov tseem ceeb.(p-значения <0,01, рис. 4d). (p-tus nqi <0.01, Fig. 4d).此外，9% Cr 钢的Chao1 指数和观察到的OTU高于腐蚀样品和水样，低于未腐蚀样品和沉积物样品（图4b，c），差异具有统讏幼0.01, 4d).此外 ， 9% CR 钢 Chao1 指数和 观察的的 rtu 高于 腐蚀 样品水样 ， 低于 腐蚀 牌岁图 4b ， c) 差异 统计学意义 (p 值 <0.01 图 图 图 图 图 图 ， ， ， ， ， ， 4 ， ， ， Кроме того, индекс Chao1 и наблюдаемые OTU стали с содержанием 9 % Cr были выше, чем у корродированных и ж водере, чем у некорродированных и осадочных образцов (рис. 4b,c), а разница была статистически значимой (p-0. , 4 нгей). Tsis tas li ntawd, Chao1 Performance index thiab pom OTU ntawm 9% Cr steel yog siab dua li cov qauv corroded thiab aqueous thiab qis dua li cov qauv uas tsis muaj corroded thiab sedimentary (Fig. 4b, c), thiab qhov sib txawv yog qhov tseem ceeb (p-value <0.01, Fig. 4d).Cov txiaj ntsig no qhia tau tias qhov sib txawv ntawm microbial hauv cov khoom siv corrosion yog qis dua hauv biofilms ntawm cov hlau tsis muaj hlau.
Ntawm daim duab. 5a qhia txog Kev Tshawb Fawb Tus Thawj Saib Xyuas Kev Ua Haujlwm (PCoA) raws li UniFrac tsis muaj qhov hnyav rau txhua qhov qauv, nrog peb pawg loj tau pom. Cov zej zog microbial hauv cov qauv dej tau txawv txawv ntawm lwm cov zej zog. Cov zej zog microbial hauv cov sediments kuj suav nrog cov zej zog stainless hlau, thaum lawv tau nthuav dav hauv cov qauv corrosion. Hauv qhov sib piv, daim duab qhia ntawm cov hlau nrog 9% Cr muab faib ua cov pawg tsis muaj corroded thiab corroded. Yog li ntawd, cov zej zog microbial ntawm cov hlau thiab cov khoom siv corrosion yog qhov sib txawv ntawm cov dej hauv dej.
Tus Thawj Saib Xyuas Kev Ua Haujlwm (PCoA) cov phiaj xwm raws li qhov tsis hnyav UniFrac nyob rau hauv tag nrho cov qauv (a), dej (b), thiab hlau (c). Cov voj voog qhia txhua pawg. Cov trajectories yog sawv cev los ntawm cov kab txuas rau lub sij hawm sampling nyob rau hauv series. 1 meter, 1 hli; 3m, 3 hli; 6m,6 hli; 14 m, 14 hli; 22 m, 22 hli; S, ASTM A283; SP, ASTM A109, mob 4/5; FC, ASTM A395; B, ASTM A179; 1C, steel 1% Cr; 3C steel, 2.25% Cr steel; hlau 9C, steel 9% Cr; S6, 316 stainless hlau; S8, hom 304 stainless hlau.
Thaum teem sijhawm raws sijhawm, PCoA cov phiaj xwm ntawm cov qauv dej tau nyob rau hauv ib puag ncig (Fig. 5b). Qhov kev hloov pauv no tuaj yeem cuam tshuam txog kev hloov pauv raws caij nyoog.
Tsis tas li ntawd, tsuas yog ob pawg (corroded thiab tsis-corroded) tau pom nyob rau ntawm PCoA cov phiaj xwm ntawm cov qauv hlau, qhov twg (tshwj tsis yog ntawm 9% chromium steel) kev hloov ntawm lub zej zog microbial los ntawm 1 txog 22 lub hlis kuj tau pom (Fig. 5c). Tsis tas li ntawd, txij li qhov kev hloov pauv hauv cov qauv corroded ntau dua li cov qauv uas tsis yog corroded, muaj kev sib raug zoo ntawm kev hloov hauv cov zej zog microbial thiab kev txhim kho corrosion. Hauv cov qauv hlau nrog 9% Cr, ob hom microbial cov zej zog tau tshwm sim: cov ntsiab lus ntawm 1 thiab 6 lub hlis, nyob ze ntawm cov hlau tsis muaj steel, thiab lwm yam (3, 14, thiab 22 lub hlis), nyob ntawm cov ntsiab lus ze rau corroded steel. 1 lub hlis thiab daim coupons siv rau DNA rho tawm ntawm 6 lub hlis tsis corroded, thaum daim coupons ntawm 3, 14 thiab 22 lub hlis twb corroded (Ntxiv daim duab 1). Yog li ntawd, cov zej zog microbial nyob rau hauv cov qauv corroded txawv ntawm cov nyob rau hauv dej, sediment, thiab tsis-corroded kuaj thiab hloov raws li corrosion mus.
Lub hom phiaj tseem ceeb ntawm cov zej zog microbial pom hauv cov qauv dej yog Proteobacteria (30.1–73.5%), Bacteroidetes (6.3–48.6%), Planctomycetota (0.4–19.6%) thiab Actinobacteria (0 – 17.7%), lawv cov txheeb ze sib txawv ntawm cov qauv mus rau cov qauv dej (Daim duab 6, piv txwv li B. tau siab dua hauv cov dej paub daws teeb. Qhov sib txawv no tuaj yeem cuam tshuam los ntawm lub sijhawm nyob ntawm cov dej hauv lub tank dhau. Cov hom no kuj tau pom nyob rau hauv cov qauv sediment hauv qab, tab sis lawv cov txheeb ze abundance txawv heev ntawm cov qauv dej. Tsis tas li ntawd, cov ntsiab lus txheeb ze ntawm Acidobacteriota (8.7–13.0%), Chloroflexi (8.1–10.2%), Nitrospirota (4.2–4.4%) thiab Desulfobacterota (1.5–4.4%) %) yog siab dua hauv cov qauv dej. Txij li yuav luag txhua hom Desulfobacterota yog SRB37, ib puag ncig hauv cov av yuav tsum yog anaerobic. Txawm hais tias Desulfobacterota tuaj yeem cuam tshuam rau corrosion, qhov kev pheej hmoo yuav tsum tsis tshua muaj vim tias lawv cov txheeb ze muaj nyob hauv cov dej hauv pas dej yog <0.04%. Txawm hais tias Desulfobacterota tuaj yeem cuam tshuam rau corrosion, qhov kev pheej hmoo yuav tsum tsis tshua muaj vim tias lawv cov txheeb ze muaj nyob hauv cov dej hauv pas dej yog <0.04%. Хотя Desulfobacterota, возможно, влияют на коррозию, риск должен быть чрезвычайно низким, поскольку их относит воде бассейна составляет <0,04%. Txawm hais tias Desulfobacterota tej zaum yuav muaj kev cuam tshuam rau corrosion, qhov kev pheej hmoo yuav tsum tsis tshua muaj tsawg vim tias lawv cov txheeb ze muaj nyob hauv pas dej da dej yog <0.04%.尽管脱硫杆菌门可能影响腐蚀，但风险应该极低，因为它们在池水中的相妹 <0.4% <0.04%. Хотя тип Desulfobacillus может влиять на коррозию, риск должен быть крайне низким, поскольку их относит всьно bассейна составляет <0,04%. Txawm hais tias hom Desulfobacillus tuaj yeem cuam tshuam rau corrosion, qhov kev pheej hmoo yuav tsum tsis tshua muaj tsawg vim tias lawv cov txheeb ze muaj nyob hauv pas dej da dej yog <0.04%.
RW thiab Huab cua sawv cev rau cov qauv dej los ntawm cov dej nkag thiab hauv lub phiab, feem. Sediment-C, -E, -W yog cov qauv sediment coj los ntawm qhov nruab nrab ntawm lub hauv qab ntawm lub phiab, nrog rau sab hnub tuaj thiab sab hnub poob. 1 meter, 1 hli; 3m, 3 hli; 6m,6 hli; 14 m, 14 hli; 22 m, 22 hli; S, ASTM A283; SP, ASTM A109, mob 4/5; FC, ASTM A395; B, ASTM A179; 1C, steel 1% Cr; 3C steel, 2.25% Cr steel; hlau 9C, steel 9% Cr; S6, 316 stainless hlau; S8, hom 304 stainless hlau.
Nyob rau theem genus, ib qho kev faib ua feem ntau dua (6-19%) ntawm cov kab mob tsis muaj npe nyob hauv tsev neeg Trichomonadaceae, nrog rau Neosphingosine, Pseudomonas, thiab Flavobacterium, tau pom nyob rau txhua lub caij. Raws li cov khoom me me, lawv qhov sib txawv sib txawv (Fig. 1). . 7 a b). Hauv cov tributaries, qhov txheeb ze ntawm Flavobacterium, Pseudovibrio, thiab Rhodoferrobacter yog siab dua nyob rau lub caij ntuj no. Ib yam li ntawd, cov ntsiab lus siab dua ntawm Pseudovibrio thiab Flavobacterium tau pom nyob rau hauv lub caij ntuj no dej ntawm lub phiab. Yog li, cov zej zog microbial hauv cov qauv dej sib txawv nyob ntawm lub caij nyoog, tab sis tsis tau hloov pauv loj heev thaum lub sijhawm kawm.
Cov dej haus, b Cov dej hauv pas dej, c ASTM A283, d ASTM A109 kub #4/5, e ASTM A179, f ASTM A395, g 1% Cr, h 2.25% Cr, thiab i 9% Cr steel, j Hom-316 thiab stainless hlau K-30.
Proteobacteria yog cov ntsiab lus tseem ceeb hauv txhua qhov qauv, tab sis lawv cov txheeb ze muaj nyob rau hauv cov qauv corroded poob qis raws li kev txhim kho corrosion (Fig. 6). Hauv cov qauv ASTM A179, ASTM A109 Temp No. 4/5, ASTM A179, ASTM A395 thiab 1% thiab 2.25% Cr, qhov txheeb ze ntawm cov kab mob proteobacteria txo qis los ntawm 89.1%, 85.9%, 89.6%, 79.5%, 84. , 83.8% yog 43.3%, 52.2%, 50.0%, 41.9%, 33.8% thiab 31.3% feem. Hauv qhov sib piv, cov txheeb ze ntawm Desulfobacterota maj mam nce los ntawm <0.1% mus rau 12.5-45.9% nrog rau kev txhim kho corrosion. Hauv qhov sib piv, cov txheeb ze ntawm Desulfobacterota maj mam nce los ntawm <0.1% mus rau 12.5-45.9% nrog rau kev txhim kho corrosion. Напротив, относительное содержание Desulfobacterota постепенно увеличивается с <0,1% до 12,5–45,9% по зкиря ра Hauv qhov sib piv, qhov txheeb ze ntawm Desulfobacterota maj mam nce ntawm <0.1% mus rau 12.5-45.9% raws li kev txhim kho corrosion.相反，随着腐蚀的进展，脱硫杆菌的相对丰度从 <0.1% 逐渐增加到12.5-45.9%.Cov ntaub ntawv pov thawj, cov ntaub ntawv pov thawj <0.1% Напротив, относительная численность Desulfobacillus постепенно увеличивалась с <0,1% до 12,5–45,9% по мритер. Hauv qhov sib piv, qhov txheeb ze ntawm Desulfobacillus maj mam nce los ntawm <0.1% mus rau 12.5-45.9% raws li kev txhim kho corrosion.Yog li, raws li kev txhim kho corrosion, Proteobactereira tau hloov los ntawm Desulfobacterota.
Nyob rau hauv sib piv, biofilms ntawm uncorroded stainless hlau muaj tib proportions ntawm txawv kab mob. Proteobacteria (29.4–34.1%), Planctomycetota (11.7–18.8%), Nitrospirota (2.9–20.9%), Acidobacteriota (8.6–18.8%), Bacteroidota (3.1–9.2%) thiab Chloroflexi (2.1–8.8%) Nws tau pom tias qhov kev faib ua feem ntawm Nitrospirota hauv cov qauv stainless hlau maj mam nce (Fig. 6). Cov piv txwv no zoo ib yam li cov hauv cov qauv sediment, uas sib haum rau PCoA zaj lus qhia hauv daim duab 5a.
Hauv cov qauv hlau uas muaj 9% Cr, ob hom microbial cov zej zog tau pom: 1-hli thiab 6-hli cov zej zog microbial zoo ib yam li cov hauv qab cov qauv sediment, thaum qhov feem pua ​​​​ntawm cov kab mob proteobacteria hauv cov qauv corrosion 3, 14, thiab 22 tau nce ntau. Lub hlis Ntxiv rau, ob lub zej zog microbial no nyob rau hauv 9% Cr steel cov qauv sib txuas rau kev sib cais pawg hauv PCoA zaj duab xis qhia hauv daim duab 5c.
Nyob rau theem genus,> 2000 OTUs uas muaj cov kab mob uas tsis tau tso cai thiab archaea tau pom. Nyob rau theem genus,> 2000 OTUs uas muaj cov kab mob uas tsis tau tso cai thiab archaea tau pom.Nyob rau theem genus, ntau dua 2000 OTUs tau pom muaj cov kab mob uas tsis paub tseeb thiab archaea.Nyob rau theem genus, ntau dua 2000 OTUs tau pom muaj cov kab mob uas tsis tau teev tseg thiab archaea. Ntawm lawv, peb tsom mus rau 10 OTUs nrog cov pej xeem siab hauv txhua tus qauv. Qhov no suav nrog 58.7-70.9%, 48.7-63.3%, 50.2-70.7%, 50.8-71.5%, 47.2-62.7%, 38.4 -64.7%, 12.8-49.7%, 17.5-46.8% thiab 21.9% A AST , ASTM A109 Temp No. 4/5, ASTM A179, ASTM A395, 1%, 2.25% thiab 9% Cr steels thiab Hom 316 thiab -304 stainless hlau.
Cov ntsiab lus siab ntawm dechlorinated monoliths nrog Fe (II) oxidizing zog tau pom nyob rau hauv cov qauv corrosion xws li ASTM A179, ASTM A109 Temp No. 4/5, ASTM A179, ASTM A395 thiab steels nrog 1% thiab 2.25% Cr. thaum ntxov ntawm corrosion (1 hli thiab 3 lub hlis, daim duab 7c-h). Qhov kev faib ua feem ntawm Dechloromonas tau txo qis thaum lub sijhawm, uas cuam tshuam rau kev txo qis hauv Proteobacteria (Fig. 6). Tsis tas li ntawd, qhov kev faib ua feem ntawm Dechloromonas hauv biofilms ntawm cov qauv uas tsis yog corroded yog <1%. Tsis tas li ntawd, qhov kev faib ua feem ntawm Dechloromonas hauv biofilms ntawm cov qauv uas tsis yog corroded yog <1%. Кроме того, доля Dechloromonas в биопленках на некорродированных образцах составляет <1%. Tsis tas li ntawd, qhov kev faib ua feem ntawm Dechloromonas nyob rau hauv biofilms ntawm uncorroded specimens yog <1%.此外，未腐蚀样品的生物膜中脱氯单胞菌的比例 <1%.此外，未腐蚀样品的生物膜中脱氯单胞菌的比例 <1% Кроме того, доля Dechloromonas в биопленке некорродированных образцов была <1%. Tsis tas li ntawd, qhov kev faib ua feem ntawm Dechloromonas nyob rau hauv biofilm ntawm uncorroded specimens yog <1%.Yog li ntawd, ntawm cov khoom siv corrosion, Dechloromonas yog qhov muaj txiaj ntsig zoo thaum ntxov ntawm corrosion.
Hauv qhov sib piv, ASTM A179, ASTM A109 tempered #4/5, ASTM A179, ASTM A395 thiab steels nrog 1% thiab 2.25% Cr, qhov feem ntawm SRB Desulfovibrio hom thaum kawg tau nce tom qab 14 thiab 22 lub hlis (Daim duab 7c–h). Desulfofibrion yog tsawg heev los yog tsis pom nyob rau hauv thaum ntxov theem ntawm corrosion, nyob rau hauv cov qauv dej (Fig. 7a, b) thiab nyob rau hauv uas tsis yog-corroded biofilms (Fig. 7j, j). Qhov no qhia tau hais tias Desulfovibrio nyiam ib puag ncig ntawm cov khoom tsim corrosion, txawm hais tias lawv tsis cuam tshuam rau corrosion thaum ntxov ntawm corrosion.
Fe(III)-txo cov kab mob (RRB), xws li Geobacter thiab Geotrix, tau pom nyob rau hauv cov khoom siv corrosion nyob rau hauv nruab nrab theem ntawm corrosion (6 thiab 14 lub hlis), tab sis qhov feem ntawm lig (22 lub hlis) theem ntawm corrosion yog siab dua nyob rau hauv lawv. kuj tsawg (Fig. 7c, eh). Cov genus Sideroxydans nrog Fe (II) oxidation zog tau pom muaj tus cwj pwm zoo sib xws (Fig. 7f), yog li qhov kev faib ua feem ntawm FeOB, IRB, thiab SRB tsuas yog siab dua hauv cov qauv corroded. Qhov no qhia tau hais tias kev hloov pauv hauv cov zej zog microbial no cuam tshuam nrog kev txhim kho corrosion.
Hauv cov hlau nrog 9% Cr corroded tom qab 3, 14 thiab 22 lub hlis, qhov feem ntau ntawm cov tswv cuab ntawm Beggiatoacea tsev neeg (8.5-19.6%) tau pom, uas tuaj yeem pom cov tshuaj sulfur oxidizing, thiab sideroxidans tau pom (8.4- 13.7%) (Fig. 1). ). 7i) Tsis tas li ntawd, Thiomonas, sulfur oxidizing kab mob (SOB), tau pom ntau dua (3.4% thiab 8.8%) ntawm 3 thiab 14 lub hlis. Hauv qhov sib piv, nitrate-txo cov kab mob Nitrospira (12.9%) tau pom nyob rau hauv 6-hlis-laus cov qauv uas tsis muaj corroded. Ib qho ntxiv ntawm Nitrospira kuj tau pom nyob rau hauv biofilms ntawm stainless hlau tom qab dipping (Fig. 7j,k). Yog li, cov zej zog microbial ntawm 1- thiab 6-hli-laus uncorroded 9% Cr steels zoo ib yam li cov hauv stainless hlau biofilms. Tsis tas li ntawd, cov zej zog microbial ntawm 9% Cr steel corroded ntawm 3, 14 thiab 22 lub hlis txawv ntawm cov khoom siv corrosion ntawm carbon thiab tsawg chromium steels thiab cam khwb cia hlau.
Kev txhim kho corrosion feem ntau qeeb hauv cov dej tshiab dua hauv dej hiav txwv vim tias qhov concentration ntawm chloride ions cuam tshuam rau corrosion ntawm cov hlau. Txawm li cas los xij, qee cov hlau tsis muaj steel yuav corrode nyob rau hauv cov dej tshiab ib puag ncig38,39. Tsis tas li ntawd, MIC tau pib xav tias yog cov khoom siv corroded yav dhau los tau pom nyob rau hauv lub pas dej tshiab uas siv hauv txoj kev tshawb no. Nyob rau hauv kev tshawb fawb mus ntev immersion, ntau hom kev xeb, peb hom microbial cov zej zog, thiab kev hloov hauv cov zej zog microbial hauv cov khoom siv corrosion tau pom.
Cov dej qab zib nruab nrab siv hauv txoj kev tshawb no yog lub tank kaw rau cov dej siv los ntawm tus dej uas muaj cov tshuaj lom neeg ruaj khov thiab muaj kev hloov pauv raws caij nyoog hauv dej kub ntawm 9 txog 23 ° C. Yog li, kev hloov pauv raws caij nyoog hauv cov zej zog microbial hauv cov qauv dej yuav cuam tshuam nrog kev hloov pauv ntawm qhov kub thiab txias. Tsis tas li ntawd, lub zej zog microbial nyob rau hauv lub pas dej ua ke txawv me ntsis ntawm cov dej input (Fig. 5b). Cov dej hauv lub pas dej tau hloov tas li vim muaj dej ntau dhau. Yog li ntawd, DO tseem nyob ntawm ~ 8.2 ppm txawm nyob rau nruab nrab qhov tob ntawm lub phiab nto thiab hauv qab. Ntawm qhov tsis sib xws, ib puag ncig ntawm cov pob zeb yuav tsum yog anaerobic, vim nws nyob hauv qab ntawm lub reservoir, thiab cov kab mob microbial nyob rau hauv nws (xws li CRP) yuav tsum txawv ntawm microbial flora hauv dej (Fig. 6). Txij li thaum daim coupons nyob rau hauv lub pas dej ua ke nyob deb ntawm cov sediments, lawv tsuas yog raug rau cov dej tshiab thaum lub sij hawm immersion kawm nyob rau hauv aerobic tej yam kev mob.
General corrosion tshwm sim nyob rau hauv carbon steel, tsawg chromium hlau, thiab cam khwb cia hlau nyob rau hauv cov dej tshiab (Daim duab 1) vim hais tias cov ntaub ntawv no tsis corrosion resistant. Txawm li cas los xij, tus nqi corrosion (0.13 mm yr-1) nyob rau hauv cov dej tsis qab ntsev yog siab dua hauv cov kev tshawb fawb yav dhau los40 (0.04 mm yr-1) thiab tau muab piv rau tus nqi corrosion (0.02–0.76 mm yr-1) nyob rau hauv muaj cov kab mob 1) Zoo ib yam li cov dej qab zib 40,41,42. Qhov kev nrawm nrawm nrawm no yog tus yam ntxwv ntawm MIC.
Tsis tas li ntawd, tom qab 22 lub hlis ntawm immersion, localized corrosion tau pom nyob rau hauv ob peb hlau nyob rau hauv cov khoom corrosion (Fig. 3). Tshwj xeeb, qhov kev txhim kho corrosion hauv cheeb tsam pom hauv ASTM A179 yog li tsib zaug sai dua li kev xeb. Daim ntawv txawv txawv no ntawm corrosion thiab ceev corrosion tus nqi kuj tau pom nyob rau hauv corrosion tshwm sim ntawm tib yam khoom. Yog li, qhov immersion ua nyob rau hauv txoj kev tshawb no qhia txog corrosion hauv kev xyaum.
Ntawm cov hlau kawm, 9% Cr steel tau nthuav tawm qhov corrosion hnyav tshaj plaws, nrog rau qhov tob corrosion ntawm> 1.2 hli, uas yuav yog MIC vim yog qhov nrawm nrawm thiab qhov txawv txav ntawm corrosion. Ntawm cov hlau kawm, 9% Cr steel tau nthuav tawm qhov corrosion hnyav tshaj plaws, nrog rau qhov tob corrosion ntawm> 1.2 hli, uas yuav yog MIC vim yog qhov nrawm nrawm thiab qhov txawv txav ntawm corrosion. Среди исследованных металлов сталь с 9% Cr показала наиболее сильную корозию с глубиной кор розиия , 1 , 2 , является МИК из-за ускоренной коррозии и аномальной формы коррозии. Ntawm cov hlau soj ntsuam, hlau nrog 9% Cr pom qhov corrosion hnyav tshaj plaws nrog corrosion qhov tob> 1.2 hli, uas yog tej zaum MIC vim yog ceev corrosion thiab ib qho txawv txav ntawm corrosion.在所研究的金属中，9% Cr 钢的腐蚀最为严重，腐蚀深度>1.2 mm, 由于加速腐蚀和异常腐蚀形式，很可能是MIC.在所研究的金属中，9% Cr Среди исследованных металлов наиболее сильно корродировала сталь с 9% Cr, с глубиной коррозии > 1,2 в мром, из-за ускоренных и аномальных форм коррозии. Ntawm cov hlau kawm, steel nrog 9% Cr corroded feem ntau hnyav, nrog rau corrosion qhov tob ntawm> 1.2 hli, feem ntau yuav MIC vim yog ceev thiab anomalous cov ntaub ntawv ntawm corrosion.Vim tias 9% Cr steel yog siv rau hauv cov ntawv thov kub, nws cov kev coj ua corrosion tau kawm yav dhau los 43,44 tab sis tsis muaj MIC tau tshaj tawm yav dhau los rau cov hlau no. Raws li ntau cov kab mob, tshwj tsis yog rau hyperthermophiles, tsis muaj zog nyob rau hauv qhov kub thiab txias (> 100 ° C), MIC hauv 9% Cr steel tej zaum yuav tsis quav ntsej rau hauv cov xwm txheej zoo li no. Raws li ntau cov kab mob, tshwj tsis yog rau hyperthermophiles, tsis ua haujlwm nyob rau hauv qhov chaw kub siab (> 100 ° C), MIC hauv 9% Cr steel tej zaum yuav tsis quav ntsej rau hauv cov xwm txheej zoo li no. Поскольку многие микроорганизмы, за исключением гипертермофилов, неактивны в высокотемпературной), 1 Мед Ирной свературной стали с 9% Cr в таких случаях можно не учитывать. Txij li thaum muaj ntau yam kab mob, tshwj tsis yog hyperthermophiles, tsis ua haujlwm nyob rau hauv qhov chaw kub siab (> 100 ° C), MIC hauv cov hlau nrog 9% Cr tuaj yeem tsis quav ntsej rau hauv cov xwm txheej zoo li no.由于除超嗜热菌外，许多微生物在高温环境(> 100 °C) 中不活跃，因此在这种情况下忽Cov ntaub ntawv MIC. 9% Cr 颃 (> 100 ° C) Поскольку многие микроорганизмы, кроме гипертермофилов, не проявляют активности в высокотемпырат, С0дертемпырат, С0дерокотемпырат, МПК в стали с 9% Cr в данном случае можно не учитывать. Txij li thaum muaj ntau yam kab mob, tshwj tsis yog rau hyperthermophiles, tsis pom kev ua haujlwm hauv qhov chaw kub siab (> 100 ° C), MIC hauv cov hlau nrog 9% Cr tuaj yeem tsis quav ntsej rau qhov no.Txawm li cas los xij, thaum 9% Cr steel siv nyob rau hauv qhov chaw nruab nrab kub, ntau yam kev ntsuas yuav tsum tau coj los txo MIC.
Ntau lub zej zog microbial thiab lawv cov kev hloov pauv tau pom nyob rau hauv cov khoom siv tsis zoo thiab cov khoom siv corrosion nyob rau hauv biofilms piv rau cov dej, ntxiv rau kev ceev corrosion (Fig. 5-7), xav hais tias qhov corrosion no yog microphone. Ramirez et al.13 qhia txog kev hloov pauv 3-kauj ruam (FeOB => SRB/IRB => SOB) nyob rau hauv marine microbial ecosystem tshaj 6 mo, nyob rau hauv hydrogen sulfide uas tsim los ntawm theem nrab enriched SRB thaum kawg yuav pab txhawb rau enrichment ntawm SOB. Ramirez et al.13 qhia txog kev hloov pauv 3-kauj ruam (FeOB => SRB/IRB => SOB) nyob rau hauv marine microbial ecosystem tshaj 6 mo, thaum hydrogen sulfide tsim los ntawm theem nrab enriched SRB thaum kawg tuaj yeem pab txhawb SOB. Ramirez et al.13 сообщают о трехэтапном переходе (FeOB => SRB/IRB => SOB) в морской микробной экосистеме в течение в течение сероводород, образующийся при вторичном обогащении SRB, может, наконец, способствовать обогащению SOB. Ramirez et al.13 qhia txog kev hloov pauv peb-theem (FeOB => SRB/IRB => SOB) nyob rau hauv marine microbial ecosystem nyob rau lub sij hawm ntawm 6 lub hlis, qhov twg hydrogen sulfide generated los ntawm SRB theem ob enrichment thaum kawg pab rau SOB enrichment. Ramirez 等人13 报告了一个超过6 个月的海洋微生物生态系统中的三步转变(FeOB => SRB/IRB => SOB) 兯产生的硫化氢可能最终有助于SOB的富集.Ramirez 等人 13 报告了个超过超过 6 个月海洋微生物生态系统中的三召彘轘转变 转变 转变 转变 转变 转变 转变 转变 r srb / IRB) , 其中次富 盺硫化氢可能 最终 有助于 sob 的富集. Ramirez et al.13 сообщили о трехступенчатом переходе (FeOB => SRB/IRB => SOB) в морской микробной экосистеме в те чеме в те котором сероводород, образующийся в результате вторичного обогащения SRB, может в конечном итбогь споста SOB. Ramirez et al.13 qhia txog kev hloov peb-kauj ruam (FeOB => SRB/IRB => SOB) nyob rau hauv marine microbial ecosystem nyob rau lub sij hawm ntawm 6 lub hlis, nyob rau hauv uas hydrogen sulfide tsim los ntawm SRB theem ob enrichment nws thiaj li pab tau rau SOB enrichment.McBeth thiab Emerson36 tau tshaj tawm thawj qhov kev txhawb nqa hauv FeOB. Ib yam li ntawd, kev txhawb nqa ntawm FeOB thaum lub sij hawm ntxov corrosion yog pom nyob rau hauv txoj kev tshawb no, tab sis cov microbial hloov nrog kev loj hlob ntawm corrosion pom nyob rau hauv cov pa roj carbon thiab 1% thiab 2.25% Cr steels thiab cam khwb cia hlau tshaj 22 mo yog FeOB => IRB = > SRB (Fig. 7 thiab 8). Ib yam li ntawd, kev txhawb nqa ntawm FeOB thaum lub sij hawm ntxov corrosion yog pom nyob rau hauv txoj kev tshawb no, tab sis cov microbial hloov nrog kev loj hlob ntawm corrosion pom nyob rau hauv cov pa roj carbon thiab 1% thiab 2.25% Cr steels thiab cam khwb cia hlau tshaj 22 mo yog FeOB => IRB => SRB (Fig. 7 thiab 8). Точно так же в этом исследовании наблюдается обогащение FeOB на ранней стадии коррозии, но микробные я и зместа прогрессирования коррозии, наблюдаемые в углеродистых thiab 1% thiab 2,25% Cr сталях и чугуне в течение 22 врестя м собой FeOB => IRB = > SRB (рис. 7 и 8). Ib yam li ntawd, nyob rau hauv txoj kev tshawb no enrichment nyob rau hauv FeOB nyob rau hauv thaum ntxov theem ntawm corrosion yog pom, tab sis microbial hloov raws li corrosion nce, pom nyob rau hauv carbon thiab 1% thiab 2.25% Cr steels thiab cam khwb cia hlau tshaj 22 lub hlis, yog FeOB => IRB => SRB (Figures 7 thiab 8).同样，在本研究中观察到早期腐蚀阶段FeOB的富集，但在碳和1% 和2.25% Cr 钢以及2超过个月的铸铁中观察到的微生物随着腐蚀的进展而变化是 FeOB => IRB => SRB (图7 和8).同样，在本研究中观察早期 腐蚀阶段 feob的富集，但碳和和 1% 和 2.25% Cr.的铸铁中到的微生物腐蚀的进展 而变化 FEOB => IRB => SRB (图7和8). Аналогичным образом, в этом исследовании наблюдалось обогащение FeOB на ранних стадиях коррозии, но микро изменения, наблюдаемые в углеродистых и 1% и 2,25% Cr сталях и чугуне в течение 22 месяцев, были Bирири с. IR. Ib yam li ntawd, FeOB enrichment nyob rau hauv cov theem thaum ntxov ntawm corrosion tau pom nyob rau hauv txoj kev tshawb no, tab sis cov microbiological hloov tau pom nyob rau hauv carbon thiab 1% thiab 2.25% Cr steels thiab cam khwb cia hlau tshaj 22 lub hlis yog FeOB => IRB => SRB (Fig. 7 thiab 8).SRBs tuaj yeem yooj yim sau rau hauv cov dej hiav txwv ib puag ncig vim muaj cov sulfate ion ntau ntau, tab sis lawv cov kev nplua nuj nyob hauv cov dej tsis huv yog ncua los ntawm qhov tsis tshua muaj sulfate ion concentrations. SRB enrichment nyob rau hauv dej hiav txwv tau nquag tshaj tawm 10,12,45.
Ib qho Organic carbon thiab nitrogen ntawm Fe(II)-dependent zog metabolism hlau oxide (liab [Dechloromonas sp.] thiab ntsuab [Sideroxydans sp.] hlwb) thiab Fe(III) txo cov kab mob (grey hlwb [Geothrix sp. thiab Geobacter sp.]) nyob rau theem pib ntawm corrosion, ces anaerobic sulfate-txo cov kab mob microorganisms (SRP. kev txhim kho corrosion los ntawm kev noj cov organic chiv. b Kev hloov pauv hauv cov zej zog microbial ntawm cov hlau uas tiv taus corrosion. Violet, xiav, daj, thiab dawb hlwb sawv cev cov kab mob los ntawm cov tsev neeg Comamonadaceae, Nitrospira sp., Beggiatoacea, thiab lwm yam, raws li.
Hais txog kev hloov pauv hauv zej zog microbial thiab ua tau SRB enrichment, FeOB yog qhov tseem ceeb nyob rau theem pib ntawm corrosion, thiab Dechloromonas tuaj yeem tau txais lawv lub zog loj hlob los ntawm Fe(II) oxidation. Cov kab mob tuaj yeem muaj sia nyob hauv cov xov xwm uas muaj cov kab ke, tab sis lawv yuav tsis loj hlob exponentially. Txawm li cas los xij, lub pas dej plunge siv nyob rau hauv txoj kev tshawb no yog ib lub pas dej ntws, nrog rau kev nkag ntawm 20 m3 / h, uas txuas ntxiv cov khoom siv cov khoom uas muaj inorganic ions. Nyob rau theem pib ntawm corrosion, ferrous ions raug tso tawm los ntawm carbon steel thiab cam khwb cia hlau, thiab FeOBs (xws li Dechloromonas) siv lawv los ua lub zog. Cov pa roj carbon, phosphate thiab nitrogen xav tau rau kev loj hlob ntawm tes yuav tsum muaj nyob hauv cov txheej txheem dej hauv daim ntawv ntawm cov organic thiab inorganic. Yog li ntawd, nyob rau hauv cov dej tshiab no, FeOB yog thawj zaug enriched ntawm hlau nto xws li carbon steel thiab cam khwb cia hlau. Tom qab ntawd, IRBs tuaj yeem loj hlob thiab siv cov organic teeb meem thiab cov hlau oxides ua lub zog thiab cov khoom siv hluav taws xob, raws li. Hauv cov khoom lag luam zoo corrosion, anaerobic tej yam kev mob enriched nrog nitrogen yuav tsum tau tsim vim lub metabolism ntawm FeOB thiab IRB. Yog li, SRB tuaj yeem loj hlob sai thiab hloov FeOB thiab IRB (Fig. 8a).
Tsis ntev los no, Tang et al. Tshaj tawm corrosion ntawm stainless hlau los ntawm Geobacter ferroreducens nyob rau hauv dej tshiab ib puag ncig vim ncaj qha electron hloov ntawm hlau mus rau microbes46. Xav txog EMIC, kev koom tes ntawm cov kab mob nrog EET cov khoom yog qhov tseem ceeb. SRB, FeOB, thiab IRB yog hom microbial tseem ceeb hauv cov khoom siv corrosion hauv txoj kev tshawb no, uas yuav tsum muaj EET yam ntxwv. Yog li, cov kab mob electrochemically nquag tuaj yeem ua rau muaj kev xeb los ntawm EET, thiab cov khoom sib xyaw ntawm lawv cov zej zog hloov pauv raws li kev cuam tshuam ntawm ntau hom ionic raws li cov khoom siv corrosion raug tsim. Ntawm qhov tsis sib xws, cov zej zog microbial hauv cov hlau nrog 9% Cr txawv ntawm lwm cov hlau (Fig. 8b). Tom qab 14 lub hlis, ntxiv rau kev txhawb nqa nrog FeOB, xws li Sideroxydans, SOB47Beggiatoacea, thiab Thiomonas kuj tau ntxiv lawm (Fig. 7i). Qhov kev hloov no yog qhov txawv ntawm lwm cov khoom siv corrosive, xws li carbon steel, thiab tuaj yeem cuam tshuam los ntawm chromium-nplua nuj ions yaj thaum lub sij hawm corrosion. Tshwj xeeb tshaj yog, Thiomonas tsis tsuas yog sulfur oxidizing zog, tab sis kuj Fe (II) oxidizing zog, EET system, thiab hnyav hlau kam rau ua48,49. Lawv tuaj yeem ua kom muaj txiaj ntsig zoo vim yog oxidative kev ua haujlwm ntawm Fe (II) thiab / lossis kev noj cov hlau electrons ncaj qha. Nyob rau hauv ib txoj kev tshawb fawb dhau los, kuj muaj ntau ntau ntawm Beggiatoacea tau pom nyob rau hauv biofilms ntawm Cu siv lub tshuab biofilm tsis tu ncua, qhia tias cov kab mob no tuaj yeem tiv taus cov tshuaj lom neeg xws li Cu thiab Cr. Txawm li cas los xij, lub zog xav tau los ntawm Beggiatoacea kom loj hlob hauv ib puag ncig no tsis paub.
Txoj kev tshawb no qhia txog kev hloov pauv hauv cov zej zog microbial thaum lub sij hawm corrosion nyob rau hauv cov dej tshiab. Nyob rau tib qhov chaw, cov zej zog microbial sib txawv ntawm hom hlau. Tsis tas li ntawd, peb cov txiaj ntsig tau lees paub qhov tseem ceeb ntawm FeOB nyob rau theem pib ntawm corrosion, raws li cov hlau dependent microbial zog metabolism txhawb kev tsim cov khoom noj khoom haus nplua nuj ib puag ncig nyiam los ntawm lwm cov kab mob xws li SRB. Yuav kom txo tau MIC nyob rau hauv cov dej tshiab, FeOB thiab IRB enrichment yuav tsum raug txwv.
Nine hlau tau siv rau hauv txoj kev tshawb no thiab ua tiav rau hauv cov blocks ntawm 50 × 20 × 1-5 hli (thickness rau ASTM 395 steel thiab 1%, 2.25% thiab 9% Cr: 5 hli; thickness rau ASTM A283 thiab ASTM A179 : 3 hli). mm; ASTM A109 Temper 4/5 thiab Hom 304 thiab 316 Stainless Hlau, thickness: 1mm), nrog ob lub qhov 4 hli. Chromium steels tau polished nrog sandpaper thiab lwm yam hlau tau polished nrog 600 grit sandpaper ua ntej dipping. Tag nrho cov qauv raug sonicated nrog 99.5% ethanol, qhuav thiab hnyav. Kaum cov qauv ntawm txhua cov hlau tau siv rau kev ntsuas tus nqi corrosion thiab microbiome tsom xam. Txhua tus qauv raug kho nyob rau hauv tus ntaiv zam nrog PTFE rods thiab spacers (φ 5 × 30 mm, Supplementary Fig. 2).
Lub pas dej muaj qhov ntim ntawm 1100 cubic meters thiab qhov tob txog li 4 meters. Cov dej ntws tawm yog 20 m3 h-1, cov dej ntws tawm, thiab cov dej zoo tsis hloov pauv raws caij nyoog (Ntxiv daim duab 3). Cov qauv ntaiv yog txo qis mus rau 3 m steel hlau tshem tawm hauv nruab nrab ntawm lub tank. Ob txheej txheej ntaiv raug tshem tawm ntawm lub pas dej ntawm 1, 3, 6, 14 thiab 22 lub hlis. Cov qauv los ntawm ib tus ntaiv tau siv los ntsuas qhov hnyav poob thiab xam cov nqi corrosion, thaum cov qauv los ntawm lwm tus ntaiv tau siv rau kev tshuaj xyuas microbiome. Dissolved oxygen nyob rau hauv lub immersion tank yog ntsuas nyob ze ntawm lub nto thiab hauv qab, thiab nyob rau hauv nruab nrab, siv ib tug yaj oxygen sensor (InPro6860i, Mettler Toledo, Columbus, Ohio, USA).
Corrosion khoom thiab biofilms ntawm cov qauv raug tshem tawm los ntawm scraping nrog ib tug yas scraper los yog so nrog ib tug paj rwb swab, thiab ces ntxuav nyob rau hauv 99.5% ethanol siv ib tug ultrasonic da dej. Cov qauv no tau muab tso rau hauv Clark txoj kev daws teeb meem raws li ASTM G1-0351. Tag nrho cov qauv raug ntsuas tom qab ziab tiav. Xam tus nqi corrosion (mm/yr) rau txhua tus qauv siv cov qauv hauv qab no:
qhov twg K yog qhov tsis tu ncua (8.76 × 104), T yog lub sijhawm raug (h), A yog tag nrho thaj chaw (cm2), W yog qhov poob (g), D yog qhov ceev (g cm–3).
Tom qab ntsuas cov qauv, 3D cov duab ntawm ntau cov qauv tau txais los ntawm 3D ntsuas laser microscope (LEXT OLS4000, Olympus, Tokyo, Nyiv).