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Yana nuna carousel na nunin faifai uku lokaci guda. Yi amfani da maɓallan da suka gabata da na gaba don matsawa ta cikin nunin faifai guda uku a lokaci ɗaya, ko amfani da maɓallan maɓalli a ƙarshen don matsawa ta cikin nunin faifai uku a lokaci ɗaya.
A cikin mahalli na ruwa, ana samun saurin lalata carbon da bakin karafa sau da yawa. An gudanar da binciken nutsewar tankin ruwa na tsawon watanni 22 a nan ta hanyar amfani da maki tara na karfe. An sami saurin lalata a cikin carbon da chromium karfe da simintin ƙarfe, yayin da a cikin bakin karfe ba a ga ɓarna da ta bayyana ba ko da bayan watanni 22. Wani bincike na al'ummar microbial ya nuna cewa a lokacin lalata gabaɗaya, Fe (II) - kwayoyin oxidizing sun wadatar da su a farkon matakin lalata, Fe (III) - rage ƙwayoyin cuta, a mataki na ci gaba da lalata, da sulfate-rage kwayoyin cuta, a mataki na lalata. mataki a mataki na karshe na lalata samfurin. Akasin haka, ƙwayoyin Beggiatocaea sun fi yawa a cikin ƙarfe tare da 9% Cr da aka lalatar da su. Waɗannan abubuwan haɗin gwiwar al'ummomin ƙananan ƙwayoyin cuta kuma sun bambanta da waɗanda ke cikin samfuran ruwa da na ƙasa. Don haka, yayin da lalata ke ci gaba, al'ummar ƙananan ƙwayoyin cuta suna fuskantar sauye-sauye masu ban mamaki, kuma makamashin da ke dogara da baƙin ƙarfe yana haifar da yanayi wanda zai iya wadatar da sauran ƙananan ƙwayoyin cuta.
Karfe na iya lalacewa da lalacewa saboda nau'ikan yanayi na zahiri da na sinadarai kamar pH, zafin jiki da tattarawar ion. Yanayin acidic, yanayin zafi mai girma da kuma adadin chloride musamman yana shafar lalatawar ƙarfe1,2,3. Ƙananan ƙwayoyin cuta a cikin mahalli na halitta da ginannun sau da yawa suna yin tasiri ga lalacewa da lalata karafa, halayen da aka bayyana a cikin lalatawar ƙananan ƙwayoyin cuta (MIC) 4,5,6,7,8. Ana samun MIC sau da yawa a cikin yanayi kamar bututu na cikin gida da tankunan ajiya, a cikin raƙuman ƙarfe, da cikin ƙasa, inda ya bayyana ba zato ba tsammani kuma yana haɓaka cikin sauri. Sabili da haka, saka idanu da gano farkon MICs yana da matukar wahala, don haka ana gudanar da bincike na MIC bayan lalata. An ba da rahoton nazarin shari'o'in MIC da yawa a cikin abin da ake samu akai-akai na ƙwayoyin cuta masu rage sulfate (SRB) a cikin samfuran lalata9,10,11,12,13. Duk da haka, har yanzu ba a sani ba ko SRBs suna ba da gudummawa ga farawa na lalata, tun da gano su ya dogara ne akan binciken bayan lalata.
Kwanan nan, ban da aidin-oxidizing bakteriya21, an ba da rahoton ƙwayoyin cuta iri-iri masu lalata baƙin ƙarfe, irin su SRB14 mai lalata ƙarfe, methanogens15,16,17, ƙwayoyin cuta masu rage nitrate18, baƙin ƙarfe-oxidizing bacteria19 da acetogens20. Karkashin yanayin dakin gwaje-gwaje anaerobic ko microaerobic, yawancinsu suna lalata ƙarfe-valent baƙin ƙarfe da ƙarfe carbon. Bugu da ƙari, hanyoyin lalata su suna ba da shawarar cewa methanogens masu lalata baƙin ƙarfe da SRBs suna haɓaka lalata ta hanyar girbi electrons daga ƙarfe mara kyau ta amfani da hydrogenases na extracellular da multiheme cytochromes, bi da bi22,23. MICs sun kasu zuwa nau'i biyu: (i) sunadarai MIC (CMIC), wanda shine lalata kai tsaye ta hanyar nau'in microbially, da (ii) MIC na lantarki (EMIC), wanda shine lalata kai tsaye ta hanyar lalata lantarki na karfe24. EIC wanda aka sauƙaƙe ta hanyar canja wurin lantarki na waje (EET) yana da matuƙar sha'awa saboda ƙananan ƙwayoyin cuta tare da kaddarorin EET suna haifar da lalata da sauri fiye da ƙananan ƙwayoyin cuta marasa EET. Yayin da ƙimar ƙimar ƙimar CMIC a ƙarƙashin yanayin anaerobic shine samar da H2 ta hanyar rage proton (H+), EIC yana ci gaba ta hanyar EET metabolism, wanda ke zaman kansa na samarwa na H2. Hanyar EET a cikin ƙwayoyin cuta daban-daban yana da alaƙa da aikin man fetur na ƙananan ƙwayoyin cuta da electrobiosynthesis25,26,27,28,29. Saboda yanayin al'ada na waɗannan ƙananan ƙwayoyin cuta sun bambanta da waɗanda ke cikin yanayin yanayi, ba a bayyana ko waɗannan matakan lalata ƙwayoyin ƙwayoyin cuta ba suna nuna lalata a aikace. Sabili da haka, yana da wahala a lura da tsarin MIC da waɗannan ƙananan ƙwayoyin cuta suka jawo a cikin yanayin yanayi.
Haɓaka fasahar sarrafa DNA ta sauƙaƙe nazarin cikakkun bayanai na al'ummomin ƙananan ƙwayoyin cuta a cikin yanayi na halitta da na wucin gadi, alal misali, ƙayyadaddun ƙayyadaddun ƙayyadaddun ƙayyadaddun ƙayyadaddun kwayoyin halitta bisa tsarin 16S rRNA ta hanyar amfani da sababbin tsararrun tsararraki an yi amfani da su a fagen ilimin halittu na microbial30,31. ,32. An buga karatun MIC da yawa waɗanda ke da cikakkun al'ummomin ƙananan ƙwayoyin cuta a cikin ƙasa da muhallin ruwa13,33,34,35,36. Baya ga SRB, haɓakawa a cikin Fe (II) -oxidizing (FeOB) da ƙwayoyin cuta masu nitrifying a samfuran lalata, misali FeOB, kamar Gallionella spp. da Dechloromonas spp., da kuma kwayoyin nitrifying, irin su Nitrospira, an kuma bayar da rahoton. spp., A cikin Carbon da ƙarfe masu ɗaukar ƙarfe a cikin ƙasa media33. Hakazalika, a cikin yanayin ruwa, an sami saurin yin mulkin mallaka na baƙin ƙarfe-oxidizing kwayoyin da ke cikin azuzuwan Zetaproteobacteria da Betaproteobacteria na makonni da yawa akan carbon karfe 36. Waɗannan bayanan suna nuna gudummawar waɗannan ƙananan ƙwayoyin cuta zuwa lalata. Duk da haka, a yawancin nazarin, tsawon lokaci da ƙungiyoyin gwaji suna da iyaka, kuma an san kadan game da yanayin al'ummomin ƙananan ƙwayoyin cuta a lokacin lalata.
Anan, muna bincika MICs na carbon karfe, chromium karfe, bakin karfe, da simintin ƙarfe ta amfani da nazarin nutsewa a cikin yanayin ruwan ruwa mai iska tare da tarihin abubuwan MIC. An ɗauki samfurori a cikin watanni 1, 3, 6, 14 da 22 kuma an yi nazarin ƙimar lalata kowane ƙarfe da ƙananan ƙwayoyin cuta. Sakamakonmu yana ba da haske game da dogon lokaci mai ƙarfi na al'ummomin ƙananan ƙwayoyin cuta yayin lalata.
Kamar yadda aka nuna a Table 1, an yi amfani da ƙarfe tara a cikin wannan binciken. Samfurori goma na kowane abu an nutsar da su a cikin wani tafkin ruwa mai dadi. Tsarin ingancin ruwa shine kamar haka: 30 ppm Cl-, 20 mS m-1, 20 ppm Ca2+, 20 ppm SiO2, turbidity 1 ppm da pH 7.4. Narkar da iskar oxygen (DO) a kasan tsanin samfurin ya kai kusan 8.2 ppm kuma zafin ruwa ya tashi daga 9 zuwa 23°C na yanayi.
Kamar yadda aka nuna a cikin Hoto 1, bayan wata 1 na nutsewa a cikin ASTM A283, ASTM A109 Yanayin # 4/5, ASTM A179, da ASTM A395 simintin ƙarfe, an lura da samfuran lalata launin ruwan kasa akan saman carbon karfe a cikin nau'in lalata gama gari. Rashin nauyi na waɗannan samfurori ya karu tare da lokaci (Ƙari na 1) kuma yawan lalata ya kasance 0.13-0.16 mm a kowace shekara (Fig. 2). Hakazalika, an lura da lalata gabaɗaya a cikin ƙarfe masu ƙarancin abun ciki na Cr (1% da 2.25%) tare da ƙimar lalata kusan 0.13 mm/yr (Hoto na 1 da 2). Sabanin haka, karfe tare da 9% Cr yana nuna lalatawar gida wanda ke faruwa a cikin gibin da gaskets suka yi. Matsakaicin lalata na wannan samfurin shine kusan 0.02 mm / shekara, wanda yayi ƙasa da ƙasa da na ƙarfe tare da lalata gabaɗaya. Sabanin haka, nau'in bakin karfe nau'in-304 da -316 ba su nuna lalatawar gani ba, tare da ƙididdige ƙimar lalata <0.001 mm y-1. Sabanin haka, nau'in bakin karfe nau'in-304 da -316 ba su nuna lalatawar gani ba, tare da ƙididdige ƙimar haɓakawa na <0.001 mm y-1. Напротив, нержавею стали типов 304 и 316 составляет <0,001 мм/год. Sabanin haka, Nau'in 304 da 316 bakin karfe ba su nuna lalatawar gani ba, tare da ƙididdige ƙimar lalata <0.001 mm/yr.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 m/gudu. Sabanin haka, nau'in 304 da -316 bakin karfe ba su nuna lalatawar gani ba tare da ƙirar ƙira na <0.001 mm/yr.
An nuna hotunan macroscopic na kowane samfurin (tsawo 50 mm × nisa 20 mm) kafin da bayan yankewa. 1 mita, wata 1; 3 mita, watanni 3; mita 6, watanni 6; mita 14, watanni 14; mita 22, watanni 22; S, ASTM A283; SP, ASTM A109, yanayin 4/5; FC, ASTM A395; B, ASTM A179; 1C, karfe 1% Cr; 3C karfe, 2.25% Cr karfe; karfe 9C, karfe 9% Cr; S6, 316 bakin karfe; S8, nau'in 304 bakin karfe.
An ƙididdige ƙimar lalata ta amfani da asarar nauyi da lokacin nutsewa. S, ASTM A283, SP, ASTM A109, taurare 4/5, FC, ASTM A395, B, ASTM A179, 1C, karfe 1% Cr, 3 C, karfe 2.25% Cr, 9 C, karfe 9% Cr, S6, nau'in 316 bakin karfe; S8, nau'in 304 bakin karfe.
A kan fig. 1 kuma yana nuna cewa samfuran lalata na carbon karfe, ƙarancin Cr karfe da simintin ƙarfe suna haɓaka gaba bayan nutsewa na tsawon watanni 3. Adadin lalata gabaɗaya a hankali ya ragu zuwa 0.07 ~ 0.08 mm/shekara bayan watanni 22 (Hoto 2). Bugu da kari, yawan lalata na 2.25% Cr karfe ya dan ragu kadan fiye da sauran gurbatattun samfurori, yana nuna cewa Cr na iya hana lalata. Baya ga lalata gabaɗaya, bisa ga ASTM A179, an lura da lalatawar gida bayan watanni 22 tare da zurfin lalata kusan 700 µm (Fig. 3). Matsakaicin lalata na gida, ƙididdiga ta amfani da zurfin lalata da lokacin nutsewa, shine 0.38 mm / yr, wanda shine kusan sau 5 cikin sauri fiye da lalata gabaɗaya. Ana iya yin la'akari da ƙimar lalata na ASTM A395 kamar yadda samfuran lalata ba su cire ma'auni gaba ɗaya ba bayan watanni 14 ko 22 na nutsewar ruwa. Duk da haka, bambancin ya kamata ya zama kadan. Bugu da ƙari, an lura da ƙananan ramuka da yawa a cikin ƙananan ƙananan ƙarfe na chromium.
Cikakken hoto (sandunan sikelin: 10 mm) da lalata gida (sanar da sikelin: 500 µm) na ASTM A179 da 9% Cr karfe a matsakaicin zurfin ta amfani da na'urar duban laser na 3D. Da'irar ja a cikin cikakken hoton suna nuna lalata da aka auna. Cikakken ra'ayi na 9% Cr karfe daga gefen baya yana nunawa a cikin Hoto 1.
Kamar yadda aka nuna a cikin fig. 2, don karfe tare da 9% Cr, ba a lura da lalata ba a cikin watanni 3-14, kuma ƙimar lalata ta kusan sifili. Koyaya, an lura da lalatawar gida bayan watanni 22 (Hoto 3) tare da ƙididdige ƙimar lalata na 0.04 mm/yr ta amfani da asarar nauyi. Matsakaicin zurfin lalatawar gida shine 1260 µm kuma ƙimar lalatawar gida da aka kiyasta ta amfani da zurfin lalata da lokacin nutsewa (watanni 22) shine 0.68 mm/yr. Domin ba a san ainihin wurin da lalata ke farawa ba, ƙimar lalata na iya zama mafi girma.
Sabanin haka, ba a ga wani lalata da aka gani akan bakin karfe ba ko da bayan watanni 22 na nutsewa. Ko da yake an lura da wasu ɓangarorin launin ruwan kasa a saman kafin a rage su (Fig. 1), an raunana su kuma ba samfurori na lalata ba. Tun da karfen ya sake bayyana saman bakin karfe bayan an cire sikelin, ƙimar lalata kusan sifili ne.
An yi jerin abubuwan Amplicon don fahimtar bambance-bambance da haɓakar al'ummomin ƙananan ƙwayoyin cuta na tsawon lokaci a cikin samfuran lalata da biofilms a saman saman ƙarfe, a cikin ruwa da magudanar ruwa. An karɓi jimlar karatun 4,160,012, tare da kewayon 31,328 zuwa 124,183 karantawa.
Fihirisar Shannon na samfuran ruwa da aka ɗauka daga ruwan sha da tafkunan sun kasance daga 5.47 zuwa 7.45 (Fig. 4a). Tunda ana amfani da ruwan kogin da aka kwato azaman ruwan masana'antu, al'ummomin ƙananan ƙwayoyin cuta na iya canzawa a lokatai. Sabanin haka, ma'aunin Shannon na samfuran ruwa na ƙasa ya kasance kusan 9, wanda ya fi girma fiye da na samfuran ruwa. Hakazalika, samfuran ruwa suna da ƙananan ƙididdiga na Chao1 kuma sun lura da raka'a taxonomic na aiki (OTUs) fiye da samfuran laka (Fig. 4b, c). Wadannan bambance-bambancen suna da mahimmancin ƙididdiga (Tukey-Kramer gwajin; p-darajar <0.01, Fig. 4d), yana nuna cewa al'ummomin microbial a cikin samfurori na lalata sun fi rikitarwa fiye da wadanda ke cikin samfurori na ruwa. Wadannan bambance-bambancen suna da mahimmanci (Tukey-Kramer gwajin; p-values ​​<0.01, Fig. 4d), yana nuna cewa al'ummomin microbial a cikin samfurori na lalata sun fi rikitarwa fiye da wadanda ke cikin samfurori na ruwa. Эти различя статистически значимы (kryteriy Тьюky-Крамера; znaчения p <0,01, rис. 4d) сообщества в образцах донных отложений более сложны, чем в образцах воды. Waɗannan bambance-bambancen suna da mahimmancin ƙididdiga (Tukey-Kramer gwajin; p ƙimar <0.01, Fig. 4d), yana nuna cewa al'ummomin ƙananan ƙwayoyin cuta a cikin samfuran laka sun fi rikitarwa fiye da samfuran ruwa.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中 的 群落更….. Эти различия были статистически znachymymy (kryteriy Тьюky-Крамера; p-значение <0,01, рис. 4d), da sauransu. что микробные сообщества в образцах донных отложений Wadannan bambance-bambancen sun kasance masu mahimmanci (gwajin Tukey-Kramer; p-darajar <0.01, Fig. 4d), yana nuna cewa al'ummomin microbial a cikin samfurori na ruwa sun fi rikitarwa fiye da samfurori na ruwa.Tunda ruwan da ke cikin kwandon da ke kwarara yana ci gaba da sabuntawa kuma magudanar ruwa suna daidaitawa zuwa kasan kwandon ba tare da tada hankali ba, wannan bambance-bambancen bambance-bambancen microbial ya kamata ya nuna yanayin yanayin cikin kwandon.
a Shannon index, b Observed operational taxonomic unit (OTU), da c Chao1 uptake index (n=6) da basin (n=5) Ruwa, laka (n=3), ASTM A283 (S: n=5), ASTM A109 Temper #4/5 (SP: n=5), ASTM A179), (BFC: n=5), (BFC: n=5) C: n = 5), 2.25% (3 C: n = 5) da 9% (9 C: n = 5) Cr-karfe, da kuma nau'in 316 (S6: n = 5) da -304 (S8: n = 5) an nuna bakin karfe a matsayin akwatin-dimbin nau'i da whisker Charts. d p-darajar don fihirisar Shannon da Chao1 da aka samu ta amfani da gwajin kwatancen ANOVA da Tukey-Kramer. Abubuwan jajayen suna wakiltar nau'i-nau'i tare da p-darajar <0.05. Bayanan jajayen suna wakiltar nau'i-nau'i tare da p-darajar <0.05. Красные фоны представляют пары со значениями p <0,05. Jajayen bango suna wakiltar nau'i-nau'i tare da p-darajar <0.05.红色背景代表p 值< 0.05 的对。红色背景代表p 值< 0.05 的对。 Красные фоны представляют пары с p-значениями <0,05. Jajayen baya suna wakiltar nau'i-nau'i tare da p-darajar <0.05.Layin da ke tsakiyar akwatin, sama da kasa na akwatin, da wuka suna wakiltar tsaka-tsaki, 25th da 75th percentiles, da mafi ƙanƙanta da ƙimar ƙima, bi da bi.
Fihirisar Shannon na carbon karfe, ƙananan ƙarfe na chromium, da simintin ƙarfe sun yi kama da na samfuran ruwa (Fig. 4a). Sabanin haka, alamun Shannon na samfurori na bakin karfe suna da mahimmanci fiye da na kayan da aka lalata (p-values ​​<0.05, Fig. 4d) kuma kama da na sediments. Sabanin haka, alamun Shannon na samfurori na bakin karfe sun fi girma fiye da na kayan da aka lalata (p-values ​​<0.05, Fig. 4d) kuma kama da na sediments. Напротив, индексы Шеннона образцов из нержавеющей стали значительно выше, чем у корродированный 5 (p) рис. Sabanin haka, fihirisar Shannon na samfuran bakin karfe suna da girma fiye da na ɓawon ƙarfe (p-darajar <0.05, siffa 4d) kuma suna kama da fihirisar ajiya.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, 图4d），与沉积物相似。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，囉物与（4d Напротив, индекс Шеннона образцов из нержавеющей стали был значительно выше <0,05, рис. 4d), как у отложений. Sabanin haka, alamar Shannon na samfuran bakin karfe ya fi girma fiye da na gurɓataccen ƙarfe (p darajar <0.05, Fig. 4d), kamar yadda aka ajiye.Sabanin haka, alamar Shannon don karafa tare da 9% Cr ya kasance daga 6.95 zuwa 9.65. Wadannan dabi'u sun fi girma a cikin samfurori marasa lalacewa a cikin watanni 1 da 3 fiye da a cikin ɓatattun samfurori a watanni 6, 14 da 22 (Fig. 4a). Bugu da ƙari kuma, ma'aunin Chao1 da kuma lura da OTU na 9% Cr karfe sun fi girma fiye da na samfurori da aka lalata da ruwa da kuma ƙananan ƙananan samfurori (Fig. 4b, c), kuma bambance-bambancen suna da mahimmanci (p-values ​​<0.01, Fig. 4d). Bugu da ƙari kuma, ma'aunin Chao1 da kuma lura da OTU na 9% Cr karfe sun fi girma fiye da na samfurori da aka lalata da ruwa da kuma ƙananan ƙananan samfurori (Fig. 4b, c), kuma bambance-bambancen suna da mahimmanci (p-values ​​<0.01, Fig. 4d).Bugu da ƙari, Chao1 da kuma lura da OTU na karafa tare da 9% Cr sun fi girma fiye da na samfurori masu lalata da ruwa da kuma ƙananan samfurori marasa lalacewa (Fig. 4b, c), kuma bambance-bambancen suna da mahimmanci.(p-значения <0,01, рис. 4d). (p-darajar <0.01, Hoto 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），差异具蜉差异具蜉繭有绦0.01, da 4d.此外 ， 9% CR 钢 Chao1 指数 和 观察 的 Rtu 高于（图 图 4b ، c） 差异 统计学 意义 （p 值 <0.01 图 Кроме того, индекс Chao1 и наблюдаемые OTU стали с содержанием 9 % Cr были выше ниже, чем у некорродированных и осадочных образцов (рис. 4b,c), разница была статистически значимой (p. 4 г). Bugu da ƙari, ma'anar Chao1 da kuma lura da OTU na 9% Cr karfe sun kasance mafi girma fiye da na samfurori da aka lalata da ruwa da kuma ƙananan samfurori na samfurori marasa lalacewa (Fig. 4b, c), kuma bambancin ya kasance mai mahimmanci (p-darajar <0.01, Fig. 4d).Waɗannan sakamakon suna nuna cewa bambance-bambancen ƙananan ƙwayoyin cuta a cikin samfuran lalata sun yi ƙasa da na biofilms akan karafa marasa lalacewa.
A kan fig. 5a yana nuna ƙwararren Ƙwararren Ƙwararren Ƙwararren Ƙwararren Ƙwararren Ƙwararren Ƙwararren Ƙwararren Ƙwararren Ƙwararren Ƙwararren Ƙwararren Ƙwararren Ƙwararren Ƙwararren Ƙwararren Ƙwararren Ƙwararren Ƙwararren Ƙwararren Ƙwararren Ƙwararren Ƙwararren Ƙwararren Ƙwararren Ƙwararren Ƙwararren Ƙwararren Ƙwararren Ƙwararren Ƙwararren Ƙwararren Ƙwararren Ƙwararren Ƙwararren Ƙwararren Ƙwararren Ƙwararren Ƙwararren Ƙwararren Ƙwararren Ƙwararren Ƙwararren Ƙwararren Ƙwararren Ƙaddamarwa (PCoA) ya dogara da ta UniFrac mara nauyi ga duk samfurori, tare da manyan gungu uku da aka lura. Ƙungiyoyin ƙananan ƙwayoyin cuta a cikin samfuran ruwa sun bambanta sosai da sauran al'ummomi. Al'ummomin ƙananan ƙwayoyin cuta a cikin sediments kuma sun haɗa da al'ummomin bakin karfe, yayin da suke yaduwa a cikin samfuran lalata. Sabanin haka, taswirar karfe mai 9% Cr an raba shi zuwa gungu marasa lalacewa da lalata. Sakamakon haka, al'ummomin ƙananan ƙwayoyin cuta a saman saman ƙarfe da samfuran lalata sun bambanta sosai da waɗanda ke cikin ruwa.
Babban ƙididdigar haɗin kai (PCoA) dangane da nisan UniFrac mara nauyi a cikin duk samfuran (a), ruwa (b), da ƙarfe (c). Da'irori suna haskaka kowane gungu. Ana wakilta hanyoyin ta hanyar layukan da ke haɗa lokutan samfur a jere. 1 mita, wata 1; 3 mita, watanni 3; 6 mita, watanni 6; mita 14, watanni 14; mita 22, watanni 22; S, ASTM A283; SP, ASTM A109, yanayin 4/5; FC, ASTM A395; B, ASTM A179; 1C, karfe 1% Cr; 3C karfe, 2.25% Cr karfe; karfe 9C, karfe 9% Cr; S6, 316 bakin karfe; S8, nau'in 304 bakin karfe.
Lokacin da aka tsara shi cikin tsari na lokaci-lokaci, maƙallan PCoA na samfuran ruwa sun kasance a cikin tsarin madauwari (Fig. 5b). Wannan sauye-sauyen zagayowar na iya nuna sauye-sauyen yanayi.
Bugu da ƙari, kawai gungu biyu (lalata da maras lalacewa) an lura da su a kan matakan PCoA na samfurori na karfe, inda (ban da 9% chromium karfe) an kuma lura da motsi na ƙananan ƙwayoyin cuta daga watanni 1 zuwa 22 (Fig. 5c). Bugu da ƙari, tun da sauye-sauye a cikin samfurori masu lalacewa sun fi girma fiye da samfurori marasa lalacewa, akwai dangantaka tsakanin canje-canje a cikin al'ummomin microbial da ci gaban lalata. A cikin samfuran karfe tare da 9% Cr, an bayyana nau'ikan nau'ikan ƙananan ƙwayoyin cuta guda biyu: maki a cikin watanni 1 da 6, waɗanda ke kusa da bakin karfe, da sauransu (watanni 3, 14, da 22), waɗanda ke kusa da gurɓataccen ƙarfe. Watanni 1 da takardun shaida da aka yi amfani da su don hakar DNA a watanni 6 ba a lalata su ba, yayin da takardun shaida a 3, 14 da 22 watanni sun lalace (Ƙarin Hoto 1). Sabili da haka, al'ummomin ƙananan ƙwayoyin cuta a cikin samfurori masu lalata sun bambanta da waɗanda ke cikin ruwa, laka, da samfurori marasa lalacewa kuma sun canza yayin da lalata ta ci gaba.
Babban nau'ikan al'ummomin microbial da aka lura a cikin samfuran ruwa sune Proteobacteria (30.1-73.5%), Bacteroidates (6.3-48.6%), Planctomycetota (0.4-19.6%) da Actinobacteria (0-17.7%), yawan danginsu ya bambanta daga samfurin zuwa samfurin (Fig. 6), misali mafi girma fiye da ruwa. m ruwa. Wannan bambance-bambance na iya yin tasiri ta wurin zama lokacin da ruwa a cikin tanki mai ambaliya. An kuma lura da waɗannan nau'ikan a cikin samfuran ruwa na ƙasa, amma yawancin danginsu ya bambanta sosai da na samfuran ruwa. Bugu da ƙari, abun ciki na dangi na Acidobacteriota (8.7-13.0%), Chloroflexi (8.1-10.2%), Nitrospirota (4.2-4.4%) da Desulfobacterota (1.5-4.4%) %) ya fi girma fiye da samfurori na ruwa. Tunda kusan dukkanin nau'in Desulfobacterota sune SRB37, yanayin da ke cikin laka dole ne ya zama anaerobic. Kodayake Desulfobacterota na iya yin tasiri ga lalata, haɗarin ya kamata ya zama ƙasa sosai saboda yawan dangin su a cikin ruwan tafkin shine <0.04%. Kodayake Desulfobacterota na iya yin tasiri ga lalata, haɗarin ya kamata ya zama ƙasa sosai saboda yawan dangin su a cikin ruwan tafkin shine <0.04%. Хотя Desulfobacterota, возможно, влияют на коррозию содержание в воде бассейна составляет <0.04%. Kodayake Desulfobacterota na iya yin tasiri akan lalata, haɗarin ya kamata ya zama ƙasa sosai saboda yawan dangin su a cikin ruwan tafkin shine <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对<丰应。 <0.04% Хотя тип Desulfobacillus может влиять на бассейна составляет <0.04%. Kodayake nau'in Desulfobacillus na iya yin tasiri ga lalata, haɗarin ya kamata ya yi ƙasa sosai saboda yawan danginsu a cikin ruwan tafkin shine <0.04%.
RW da Air suna wakiltar samfuran ruwa daga sha da kwandon ruwa, bi da bi. Sediment-C, -E, -W samfurori ne da aka ɗauka daga tsakiyar kasan kwandon, da kuma daga gabas da yamma. 1 mita, wata 1; 3 mita, watanni 3; mita 6, watanni 6; mita 14, watanni 14; mita 22, watanni 22; S, ASTM A283; SP, ASTM A109, yanayin 4/5; FC, ASTM A395; B, ASTM A179; 1C, karfe 1% Cr; 3C karfe, 2.25% Cr karfe; karfe 9C, karfe 9% Cr; S6, 316 bakin karfe; S8, nau'in 304 bakin karfe.
A matakin jinsin, an lura da ɗan ƙaramin adadin (6-19%) na ƙwayoyin cuta waɗanda ba a tantance su ba na dangin Trichomonadaceae, da Neosphingosine, Pseudomonas, da Flavobacterium, a duk yanayi. A matsayin ƙananan manyan abubuwan haɗin gwiwa, hannun jarin su ya bambanta (Fig. 1). . 7 a da b). A cikin tributaries, dangi yawan Flavobacterium, Pseudovibrio, da Rhodoferrobacter ya fi girma kawai a cikin hunturu. Hakazalika, an sami babban abun ciki na Pseudovibrio da Flavobacterium a cikin ruwan sanyi na kwandon. Don haka, al'ummomin ƙananan ƙwayoyin cuta a cikin samfuran ruwa sun bambanta dangane da yanayi, amma ba su sami sauye-sauye masu yawa a lokacin nazarin ba.
Ruwan sha, b ruwan wanka, c ASTM A283, d ASTM A109 zazzabi #4/5, e ASTM A179, f ASTM A395, g 1% Cr, h 2.25% Cr, da i 9% Cr karfe, j Type-316 da bakin karfe K-304.
Proteobacteria sune manyan abubuwan da ke cikin dukkanin samfurori, amma yawancin dangin su a cikin samfurori masu lalata sun ragu yayin da lalacewa ta ci gaba (Fig. 6). A cikin samfurori ASTM A179, ASTM A109 Temp No. 4/5, ASTM A179, ASTM A395 da 1% da 2.25% Cr, dangi yawan proteobacteria ya ragu daga 89.1%, 85.9%, 89.6%, 79.5%, 84.8%. , 83.8% sune 43.3%, 52.2%, 50.0%, 41.9%, 33.8% da 31.3% bi da bi. Sabanin haka, ƙarancin dangi na Desulfobacterota a hankali yana ƙaruwa daga <0.1% zuwa 12.5-45.9% tare da ci gaban lalata. Sabanin haka, ƙarancin dangi na Desulfobacterota a hankali yana ƙaruwa daga <0.1% zuwa 12.5-45.9% tare da ci gaban lalata. Напротив, относительное содержание Desulfobacterota постепенно увеличивается с <0,1% до 12,5-45,9% по меррази . Sabanin haka, yawancin dangi na Desulfobacterota a hankali yana ƙaruwa daga <0.1% zuwa 12.5-45.9% yayin da lalata ke ci gaba.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%.相反，随着腐蚀的进展，脱硫杆菌的相对丰度从<0.1% Напротив, относительная численность Desulfobacillus постепенно увеличивалась с <0,1% до 12,5-45,9% по мивив по мивививири разив. Sabanin haka, yawan dangi na Desulfobacillus a hankali ya karu daga <0.1% zuwa 12.5-45.9% yayin da lalata ta ci gaba.Don haka, yayin da lalata ta ci gaba, Desulfobacterota ya maye gurbin Proteobactereira.
Sabanin haka, biofilms akan bakin karfe mara lahani yana ƙunshe da adadin ƙwayoyin cuta iri ɗaya. Proteobacteria (29.4-34.1%), Planctomycetota (11.7-18.8%), Nitrospirota (2.9-20.9%), Acidobacteriota (8.6-18.8%), Bacteridota (3.1-9.2%) da Chloroflexi (2.1-8.8%) An gano cewa rabon Nitrospirota a cikin samfuran bakin karfe ya karu a hankali (Fig. 6). Waɗannan ma'auni sun yi kama da waɗanda ke cikin samfurori na sediment, wanda ya dace da makircin PCoA da aka nuna a cikin siffa 5a.
A cikin samfuran karfe da ke dauke da 9% Cr, an lura da nau'ikan nau'ikan ƙwayoyin cuta guda biyu: 1-watanni da watanni 6 al'ummomin ƙananan ƙwayoyin cuta sun kasance daidai da waɗanda ke cikin samfuran laka na ƙasa, yayin da adadin proteobacteria a cikin samfuran lalata 3, 14, da 22 ya karu sosai. watanni Bugu da ƙari, waɗannan ƙananan ƙananan al'ummomi guda biyu a cikin samfuran karfe na 9% Cr sun dace da tsaga gungu a cikin shirin PCoA da aka nuna a cikin siffa 5c.
A matakin jinsin,> 2000 OTUs dauke da kwayoyin da ba a raba su ba da archaea an lura. A matakin jinsin,> 2000 OTUs dauke da kwayoyin da ba a raba su ba da archaea an lura.A matakin jinsi, an lura da OTU sama da 2000 dauke da kwayoyin cuta da archaea da ba a tantance su ba.A matakin jinsi, an lura da fiye da 2000 OTU dauke da kwayoyin cuta da archaea da ba a bayyana ba. Daga cikin su, mun mayar da hankali kan 10 OTU tare da yawan jama'a a kowane samfurin. Wannan yana rufe 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%, 17.5-49.8% in AS A179. , ASTM A109 Temp No. 4/5, ASTM A179, ASTM A395, 1%, 2.25% da 9% Cr karfe da Nau'in 316 da -304 bakin karfe.
An lura da babban abun ciki na dechlorinated monoliths tare da Fe(II) kaddarorin oxidizing a samfuran lalata kamar ASTM A179, ASTM A109 Temp No. 4/5, ASTM A179, ASTM A395 da karafa tare da 1% da 2.25% Cr. farkon matakin lalata (watanni 1 da watanni 3, Fig. 7c-h). Matsakaicin Dechloromonas ya ragu a tsawon lokaci, wanda ya dace da raguwar Proteobacteria (Fig. 6). Bugu da ƙari kuma, ƙimar Dechloromonas a cikin biofilms akan samfuran da ba a lalata su ne <1%. Bugu da ƙari kuma, ƙimar Dechloromonas a cikin biofilms akan samfuran da ba a lalata su ne <1%. Кроме того, доля Dechloromonas в биопленках на некорродированных образцах составляет <1%. Bugu da ƙari, adadin Dechloromonas a cikin biofilms akan samfurori marasa lahani shine <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%. Bugu da ƙari, adadin Dechloromonas a cikin biofilm na samfurori marasa lahani shine <1%.Sabili da haka, a cikin samfuran lalata, Dechloromonas yana haɓakawa sosai a farkon matakin lalata.
Sabanin haka, a cikin ASTM A179, ASTM A109 mai fushi # 4/5, ASTM A179, ASTM A395 da karfe tare da 1% da 2.25% Cr, rabon nau'in SRB Desulfovibrio a ƙarshe ya karu bayan watanni 14 da 22 (Fig. 7c-h) . Desulfofibrion yana da ƙananan ƙananan ko ba a gano shi ba a farkon matakan lalata, a cikin samfurori na ruwa (Fig. 7a, b) da kuma a cikin biofilms marasa lalacewa (Fig. 7j, j). Wannan yana ba da shawarar sosai cewa Desulfovibrio ya fi son yanayin da aka samar da samfuran lalata, kodayake ba sa shafar lalata a farkon matakan lalata.
Fe (III) - rage ƙwayoyin cuta (RRB), irin su Geobacter da Geothrix, an samo su a cikin samfuran lalata a tsakiyar matakan lalata (watanni 6 da 14), amma rabon ƙarshen (watanni 22) matakan lalata sun fi girma a cikinsu. ƙananan ƙananan (Fig. 7c, eh). Halin Sideroxydans tare da Fe (II) oxidation Properties ya nuna irin wannan hali (Fig. 7f), don haka rabon FeOB, IRB, da SRB ya kasance kawai mafi girma a cikin samfurori masu lalata. Wannan yana nuna ƙarfi sosai cewa canje-canje a cikin waɗannan ƙananan al'ummomin suna da alaƙa da ci gaban lalata.
A cikin karfe tare da 9% Cr da aka lalata bayan watanni 3, 14 da 22, an lura da yawancin mambobi na dangin Beggiatoacea (8.5-19.6%), wanda zai iya nuna kaddarorin sulfur oxidizing, kuma an lura da sideroxidans (8.4- 13.7%) (Fig. 1). ). 7i) Bugu da ƙari, Thiomonas, sulfur oxidizing bacterium (SOB), an samo shi a cikin adadi mafi girma (3.4% da 8.8%) a cikin watanni 3 da 14. Sabanin haka, an lura da ƙwayoyin cuta masu rage nitrate Nitrospira (12.9%) a cikin samfurori na watanni 6 marasa lalacewa. An kuma lura da karuwar adadin Nitrospira a cikin biofilms akan bakin karfe bayan dipping (Fig. 7j, k). Don haka, al'ummomin ƙananan ƙwayoyin cuta na 1- da 6-watanni marasa lalacewa 9% Cr karafa sun yi kama da waɗanda ke cikin ƙananan ƙarfe na biofilms. Bugu da kari, al'ummomin microbial na 9% Cr karfe da suka lalace a watanni 3, 14 da 22 sun bambanta da samfuran lalata na carbon da ƙananan karafa na chromium da simintin ƙarfe.
Ci gaban lalata yawanci yana raguwa a cikin ruwa mai daɗi fiye da na ruwan teku saboda yawan ions na chloride yana shafar lalatawar ƙarfe. Koyaya, wasu bakin karafa na iya lalacewa a cikin mahalli na ruwa38,39. Bugu da ƙari, an fara zargin MIC kamar yadda aka riga an lura da kayan da aka lalata a cikin tafkin ruwan da aka yi amfani da shi a cikin wannan binciken. A cikin nazarin nutsewa na dogon lokaci, an lura da nau'ikan lalata iri-iri, nau'ikan al'ummomin ƙananan ƙwayoyin cuta guda uku, da canji a cikin al'ummomin ƙananan ƙwayoyin cuta a cikin samfuran lalata.
Matsakaicin ruwan da aka yi amfani da shi a cikin wannan binciken wani tanki ne mai rufaffiyar ruwa na fasaha da aka ɗauka daga kogi tare da ingantaccen tsarin sinadarai da kuma canjin yanayi na yanayi a yanayin zafi daga 9 zuwa 23 ° C. Don haka, canjin yanayi na yanayi a cikin al'ummomin ƙananan ƙwayoyin cuta a cikin samfuran ruwa na iya haɗawa da canje-canjen yanayin zafi. Bugu da ƙari, al'ummar ƙananan ƙwayoyin cuta a cikin ruwan tafki sun ɗan bambanta da na a cikin ruwan shigarwa (Fig. 5b). Kullum ana maye gurbin ruwan da ke cikin tafkin saboda ambaliya. Sakamakon haka, DO ya kasance a ~ 8.2 ppm har ma a zurfin tsaka-tsaki tsakanin saman kwandon ruwa da ƙasa. Sabanin haka, yanayin da ke cikin laka ya kamata ya zama anaerobic, tun da yake ya zauna kuma ya kasance a kasa na tafki, kuma flora microbial a cikinta (kamar CRP) ya kamata ya bambanta da ƙananan ƙwayoyin cuta a cikin ruwa (Fig. 6). Tun da takardun shaida a cikin tafkin sun kasance da nisa daga maɓuɓɓugar ruwa, kawai an fallasa su ga ruwa mai tsabta a lokacin nazarin nutsewa a ƙarƙashin yanayin yanayi.
Lalacewar gabaɗaya tana faruwa a cikin ƙarfen carbon, ƙarancin ƙarfe na chromium, da simintin ƙarfe a cikin wuraren ruwa mai daɗi (Hoto na 1) saboda waɗannan kayan ba su da juriya na lalata. Koyaya, ƙimar lalata (0.13 mm yr-1) a ƙarƙashin yanayin ruwan ruwa na abiotic ya fi na karatun baya40 (0.04 mm yr-1) kuma ya yi daidai da ƙimar lalata (0.02-0.76 mm yr-1) a gaban ƙananan ƙwayoyin cuta 1) Kama da yanayin ruwan ruwa40,41,42. Wannan saurin lalata ƙimar sifa ce ta MIC.
Bugu da kari, bayan watanni 22 na nutsewa, an lura da lalatawar gida a cikin karafa da yawa a ƙarƙashin samfuran lalata (Fig. 3). Musamman, ƙimar lalata da aka gani a cikin ASTM A179 ya kusan sau biyar sauri fiye da lalata gabaɗaya. Wannan sabon nau'i na lalata da saurin lalata kuma an lura dashi a cikin lalata da ke faruwa akan abu ɗaya. Don haka, nutsewar da aka yi a cikin wannan binciken yana nuna lalata a aikace.
Daga cikin karafa da aka yi nazari, 9% Cr karfe ya nuna mafi tsananin lalacewa, tare da zurfin lalata> 1.2 mm, wanda wataƙila MIC saboda haɓakar lalata da kuma nau'in lalata. Daga cikin karafa da aka yi nazari, 9% Cr karfe ya nuna mafi tsananin lalacewa, tare da zurfin lalata> 1.2 mm, wanda wataƙila MIC saboda haɓakar lalata da kuma nau'in lalata. Среди иследованных металлов стальс 9% Cr показала наиболее вероятно, является МИК из-за ускоренной коррозии и аномальной формы. Daga cikin karafa da aka bincika, karfe tare da 9% Cr ya nuna mafi girman lalata tare da zurfin lalata> 1.2 mm, wanda tabbas shine MIC saboda haɓakar lalata da kuma wani nau'in lalata.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 МИК из-за ускоренных и аномальных форм коррозии. Daga cikin karafa da aka yi nazari, karfe mai 9% Cr ya lalace sosai, tare da zurfin lalata> 1.2 mm, mai yuwuwa MIC saboda haɓaka da nau'ikan lalata.Saboda 9% Cr karfe ana amfani dashi a cikin aikace-aikacen zafin jiki, an yi nazarin halayen lalatarsa ​​a baya43,44 amma ba a taɓa bayar da rahoton MIC akan wannan ƙarfe ba. Kamar yadda yawancin ƙananan ƙwayoyin cuta, ban da hyperthermophiles, ba su aiki a cikin yanayin zafi mai zafi (> 100 ° C), MIC a cikin 9% Cr karfe za a iya watsi da su a irin waɗannan lokuta. Kamar yadda yawancin ƙananan ƙwayoyin cuta, ban da hyperthermophiles, ba su aiki a cikin yanayin zafi mai zafi (> 100 ° C), MIC a cikin 9% Cr karfe na iya zama watsi da irin waɗannan lokuta. Поскольky в стали с 9% Cr в таких случаях можно не учитывать. Tun da yawancin ƙananan ƙwayoyin cuta, ban da hyperthermophiles, ba su aiki a cikin yanayin zafi mai zafi (> 100 ° C), MIC a cikin karfe tare da 9% Cr za a iya watsi da su a irin waɗannan lokuta.由于除超嗜热菌外，许多微生物在高温环境(>100 °C)钢中的MIC. 9% Cr (> 100 ° C) Поскольky МПК стали с 9% Cr в данном случае можно не учитывать. Tun da yawancin ƙwayoyin cuta, sai dai hyperthermophiles, ba su nuna aiki a cikin yanayin zafi mai zafi (> 100 ° C), MIC a cikin karfe tare da 9% Cr za a iya watsi da shi a wannan yanayin.Koyaya, lokacin da aka yi amfani da ƙarfe 9% Cr a cikin yanayin zafi mai matsakaici, dole ne a ɗauki matakai daban-daban don rage MIC.
An lura da al'ummomin microbial daban-daban da canje-canjen su a cikin adibas na kayan da ba su da tushe da kuma samfuran lalata a cikin biofilms idan aka kwatanta da ruwa, ban da haɓakar lalata (Fig. 5-7), yana ba da shawarar da ƙarfi cewa wannan lalata shine makirufo. Ramirez et al.13 sun ba da rahoton canji na 3-mataki (FeOB => SRB/IRB => SOB) a cikin yanayin halittu na microbial na ruwa a kan 6 mo, inda hydrogen sulfide ya samar da SRB na biyu mai wadata na iya ƙarshe ya ba da gudummawa ga haɓakar SOB. Ramirez et al.13 sun ba da rahoton sauyin mataki na 3 (FeOB => SRB/IRB => SOB) a cikin yanayin halittu masu rairayi na ruwa sama da 6 mo, lokacin da hydrogen sulfide da aka samar ta hanyar SRB mai haɓakawa na biyu na iya ƙarshe ba da gudummawa ga haɓakar SOB. Ramirez & сероводород, образующийся при вторичном обогащении SRB, может, наконец, способствовать обогащению. Ramirez et al.13 sun ba da rahoton sauyi na matakai uku (FeOB => SRB/IRB => SOB) a cikin yanayin halittu masu rairayi na ruwa a cikin tsawon watanni 6, inda hydrogen sulfide da aka samar daga SRB na biyu na haɓakawa zai iya taimakawa a ƙarshe don inganta SOB. Ramirez 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)，其中二次富集SRB 产生的硫化氢可能最终有助于SOB 的富集。Ramirez 三 人 13 报告转变 转变 转变 转变 转变 转变 转变 转变 转变硫化氢 可能 最终 有助于 sob 的富集。 Ramirez et al.13 собщили сероводород, образующийся в результате вторичного обогащения SRB, может | Ramirez et al.13 ya ba da rahoton sauyi na matakai uku (FeOB => SRB/IRB => SOB) a cikin yanayin halittu masu rairayi na ruwa a cikin tsawon watanni 6, wanda hydrogen sulfide da aka samar daga SRB na biyu na haɓakawa zai iya taimakawa a ƙarshe don inganta SOB.McBeth da Emerson36 sun ba da rahoton haɓaka na farko a cikin FeOB. Hakazalika, ana lura da wadatar da FeOB a lokacin farkon lalata a cikin wannan binciken, amma canje-canjen microbial tare da ci gaba da lalata da aka lura a cikin carbon da 1% da 2.25% Cr karfe da kuma jefa baƙin ƙarfe a kan 22 mo shine FeOB => IRB => SRB (Figs. 7 da 8). Hakazalika, ana lura da wadatar da FeOB a lokacin farkon lalata a cikin wannan binciken, amma canje-canjen microbial tare da ci gaban lalata da aka lura a cikin carbon da 1% da 2.25% Cr karfe da kuma jefa baƙin ƙarfe a kan 22 mo shine FeOB => IRB => SRB (Figs. 7 da 8). Точно так же в этом иследовании наблюдаетя огащение FeOB. прогрессирования корррозии, наблюдаемые в углеродистых 1% da 2,25% Cr сталях и чугуне в течение 22 собой FeOB => IRB = > SRB (рис. 7 и 8). Hakazalika, a cikin wannan binciken haɓakawa a cikin FeOB a farkon matakin lalata ana lura da shi, amma canje-canje na microbial yayin da lalacewa ke ci gaba, ana lura da su a cikin carbon da 1% da 2.25% Cr karfe da kuma jefa baƙin ƙarfe a kan watanni 22, sune FeOB => IRB => SRB (Hoto na 7 da 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）。在 本 研究 中 观察 早期 腐蚀 阶段 feob 的 富集 ， 但 碳 和 1% 和 2.25% C.的 铸铁 中 到 的 微生物 腐蚀 的 进展 而 变化 FEOB => IRB => SRB（图7和8）。 Аналогиchnыm obrazom, в этоm иssledovanny наблюдалось обогащение FeOB изменения, наблюдаемые углеродистых и 1% и 2,25% Cr сталях и чугуне в течение 22 месяцев, были FEB7 => рис . Hakazalika, an lura da haɓakar FeOB a farkon matakan lalata a cikin wannan binciken, amma canje-canjen microbiological da aka lura a cikin carbon da 1% da 2.25% Cr karfe da simintin ƙarfe a kan watanni 22 sune FeOB => IRB => SRB (Fig. 7 da 8).SRBs na iya taruwa cikin sauƙi a cikin mahalli na ruwan teku saboda yawan adadin sulfate ion, amma haɓakar su a cikin mahalli na ruwa mai daɗi yana jinkiri ta ƙarancin ƙarancin ion sulfate. An sami rahoton wadatar SRB a cikin ruwan teku akai-akai 10,12,45.
wani Organic carbon da nitrogen via Fe (II) - dogara makamashi metabolism baƙin ƙarfe oxide (ja [Dechloromonas sp.] da kore [Sideroxydans sp.] Kwayoyin) da Fe (III) rage kwayoyin cuta (Geothrix sp. da Geobacter sp.)) a farkon mataki na lalata, sa'an nan anaerobic sulfate-rage kwayoyin cuta (SRP) da microorganisms mataki entrophro. ta hanyar cinye kwayoyin halitta da aka tara. b Canje-canje a cikin al'ummomin ƙananan ƙwayoyin cuta akan karafa masu jure lalata. Violet, blue, yellow, da fari Kwayoyin wakiltar kwayoyin cuta daga iyalan Comamonadaceae, Nitrospira sp., Beggiatoacea, da sauransu, bi da bi.
Game da canje-canje a cikin ƙananan ƙwayoyin cuta da kuma yiwuwar haɓakar SRB, FeOB yana da mahimmanci a farkon matakin lalata, kuma Dechloromonas na iya samun ƙarfin haɓakarsu daga Fe (II) oxidation. Ƙananan ƙwayoyin cuta na iya rayuwa a cikin kafofin watsa labaru masu ɗauke da abubuwan ganowa, amma ba za su yi girma da yawa ba. Duk da haka, tafkin da aka yi amfani da shi a cikin wannan binciken wani kwano ne mai cike da ruwa, tare da kwararar 20 m3 / h, wanda ke ci gaba da samar da abubuwan da ke dauke da ion inorganic. A farkon matakan lalata, ana fitar da ions ferrous daga ƙarfe na carbon da simintin ƙarfe, kuma FeOBs (kamar Dechloromonas) suna amfani da su azaman tushen makamashi. Matsakaicin adadin carbon, phosphate da nitrogen da ake buƙata don haɓakar tantanin halitta dole ne su kasance a cikin ruwa mai sarrafawa a cikin nau'in sinadarai da ƙwayoyin cuta. Sabili da haka, a cikin wannan yanayin ruwa mai tsabta, FeOB an fara inganta shi a kan sassa na karfe kamar carbon karfe da simintin ƙarfe. Daga baya, IRBs na iya girma da amfani da kwayoyin halitta da baƙin ƙarfe oxides a matsayin tushen makamashi da masu karɓar wutar lantarki, bi da bi. A cikin samfuran lalata balagagge, yanayin anaerobic da aka wadatar da nitrogen yakamata a ƙirƙira saboda haɓakar FeOB da IRB. Saboda haka, SRB na iya girma da sauri kuma ya maye gurbin FeOB da IRB (Fig. 8a).
Kwanan nan, Tang et al. An ba da rahoton lalata bakin karfe ta Geobacter ferreducens a cikin mahallin ruwan ruwa saboda canja wurin lantarki kai tsaye daga ƙarfe zuwa microbes46. Yin la'akari da EMC, gudummawar ƙananan ƙwayoyin cuta tare da kaddarorin EET yana da mahimmanci. SRB, FeOB, da IRB sune manyan nau'ikan ƙwayoyin cuta a cikin samfuran lalata a cikin wannan binciken, waɗanda yakamata su sami halayen EET. Don haka, waɗannan ƙananan ƙwayoyin cuta masu aiki na lantarki na iya ba da gudummawa ga lalata ta hanyar EET, kuma abubuwan da ke cikin al'ummarsu suna canzawa ƙarƙashin rinjayar nau'ikan ionic iri-iri yayin da samfuran lalata suka samu. Akasin haka, al'ummar microbial a cikin karfe tare da 9% Cr sun bambanta da sauran karafa (Fig. 8b). Bayan watanni 14, ban da haɓakawa tare da FeOB, irin su Sideroxydans, SOB47Beggiatoacea, da Thiomonas kuma an wadata su (Fig. 7i). Wannan canjin ya sha bamban da na sauran abubuwa masu lalata, kamar carbon karfe, kuma ana iya yin tasiri ta hanyar ions masu wadatar chromium da aka narkar da su yayin lalata. Musamman, Thiomonas ba kawai sulfur oxidizing Properties, amma kuma Fe(II) oxidizing Properties, wani EET tsarin, da nauyi karfe haƙuri48,49. Ana iya wadatar su saboda aikin iskar oxygen na Fe(II) da/ko amfani da wutar lantarki kai tsaye. A cikin binciken da ya gabata, an lura da yawan adadin Beggiatoacea a cikin biofilms akan Cu ta amfani da tsarin kula da biofilm mai katsewa, yana nuna cewa waɗannan ƙwayoyin cuta na iya jure wa karafa masu guba kamar Cu da Cr. Koyaya, tushen makamashin da Beggiatoacea ke buƙata don girma a cikin wannan yanayin ba a san shi ba.
Wannan binciken ya ba da rahoton canje-canje a cikin al'ummomin ƙananan ƙwayoyin cuta yayin lalata a cikin wuraren ruwa mai tsabta. A cikin yanayi guda, al'ummomin ƙananan ƙwayoyin cuta sun bambanta da nau'in ƙarfe. Bugu da ƙari, sakamakon mu ya tabbatar da muhimmancin FeOB a farkon matakan lalata, kamar yadda baƙin ƙarfe dogara da ƙananan makamashi na makamashi yana inganta samuwar yanayi mai wadataccen abinci mai gina jiki wanda wasu ƙananan ƙwayoyin cuta kamar SRB suka fi so. Domin rage MIC a cikin mahalli na ruwa, FeOB da haɓakar IRB dole ne a iyakance.
An yi amfani da karafa tara a cikin wannan binciken kuma aka sarrafa su zuwa tubalan 50 × 20 × 1-5 mm (kauri don ASTM 395 karfe da 1%, 2.25% da 9% Cr: 5 mm; kauri don ASTM A283 da ASTM A179: 3 mm). mm; ASTM A109 Temper 4/5 da Nau'in 304 da 316 Bakin Karfe, kauri: 1mm), tare da ramukan 4mm guda biyu. An goge karafunan Chromium da takarda yashi kuma an goge wasu karafa da takarda yashi 600 kafin a tsoma su. Duk samfurori an sonicated tare da 99.5% ethanol, bushe da auna. An yi amfani da samfurori goma na kowane ƙarfe don ƙididdige ƙimar lalata da kuma nazarin microbiome. Kowane samfurin an gyara shi a cikin salon tsani tare da sandunan PTFE da masu sarari (φ 5 × 30 mm, Ƙarin Hoto 2).
Tafkin yana da girma na mita cubic 1100 da zurfin kimanin mita 4. Ruwan shigar da ruwa ya kasance 20 m3 h-1, an sake zubar da ruwa, kuma ingancin ruwan ba ya canzawa lokaci-lokaci (Ƙarin Hoto 3). Ana saukar da matakan samfurin akan waya mai ƙarfe 3 m da aka dakatar a tsakiyar tanki. An cire tsani guda biyu daga tafkin a watanni 1, 3, 6, 14 da 22. An yi amfani da samfurori daga tsani ɗaya don auna asarar nauyi da ƙididdige ƙimar lalata, yayin da aka yi amfani da samfurori daga wani tsani don nazarin microbiome. Narkar da iskar oxygen a cikin tankin nutsewa an auna kusa da ƙasa da ƙasa, da kuma a tsakiya, ta amfani da narkar da iskar oxygen (InPro6860i, Mettler Toledo, Columbus, Ohio, Amurka).
Abubuwan lalata da biofilms akan samfuran an cire su ta hanyar gogewa tare da gogewar filastik ko gogewa tare da swab na auduga, sannan a tsabtace su a cikin 99.5% ethanol ta amfani da wanka na ultrasonic. Daga nan aka nutsar da samfuran a cikin maganin Clark daidai da ASTM G1-0351. An auna dukkan samfurori bayan an gama bushewa. Yi ƙididdige ƙimar lalata (mm/yr) ga kowane samfurin ta amfani da dabara mai zuwa:
inda K shine akai-akai (8.76 × 104), T shine lokacin bayyanarwa (h), A shine jimlar sararin samaniya (cm2), W shine asarar taro (g), D shine yawa (g cm-3).
Bayan auna samfuran, an sami hotunan 3D na samfurori da yawa ta amfani da microscope mai auna laser na 3D (LEXT OLS4000, Olympus, Tokyo, Japan).