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Microbial corrosion (MIC) bụ nnukwu nsogbu n'ọtụtụ ụlọ ọrụ n'ihi na ọ nwere ike ibute nnukwu mfu akụ na ụba.A na-eji Super duplex igwe anaghị agba nchara 2707 (2707 HDSS) na gburugburu mmiri n'ihi nguzogide kemịkalụ ya dị mma.Agbanyeghị, egosipụtabeghị nguzogide ya na MIC.Ọmụmụ ihe a nyochara omume MIC 2707 HDSS kpatara site na nje aerobic mmiri mmiri Pseudomonas aeruginosa.Nyocha electrochemical gosiri na n'ihu Pseudomonas aeruginosa biofilm na 2216E ọkara, ikike nke corrosion gbanwere nke ọma, na njupụta corrosion ugbu a mụbara.Nsonaazụ nke nyocha X-ray photoelectron spectroscopy (XPS) gosiri mbelata nke ọdịnaya Cr n'elu nlele n'okpuru biofilm.Nyocha nke onyonyo olulu gosiri na Pseudomonas aeruginosa biofilms mepụtara omimi olulu kachasị nke 0.69 µm mgbe ụbọchị 14 nke ọdịbendị gasịrị.Ọ bụ ezie na nke a dị ntakịrị, ọ na-egosi na 2707 HDSS adịghị egbochi kpamkpam mmetụta nke P. aeruginosa biofilms na MIC.
Duplex igwe anaghị agba nchara (DSS) ọtụtụ ebe a na-eji dị iche iche ọrụ n'ihi na zuru okè Nchikota nke magburu onwe n'ibu Njirimara na corrosion resistance1,2.Otú ọ dị, oghere mpaghara nwere ike ime, nke nwere ike imetụta iguzosi ike n'ezi ihe nke ígwè 3, 4 a.A naghị echebe DSS pụọ na corrosion microbial corrosion (MIC) 5,6.Ọ bụ ezie na ụdị ngwa DSS dị obosara nke ukwuu, a ka nwere gburugburu ebe nguzogide corrosion nke DSS adịghị ezuru iji ogologo oge.Nke a pụtara na a na-achọ ihe ndị dị oke ọnụ nke nwere nguzogide corrosion dị elu.Jeon et al.7 chọpụtara na ọbụna super duplex igwe anaghị agba nchara (SDSS) nwere ụfọdụ adịghị ike na okwu nke corrosion iguzogide.Ya mere, ọ dị mkpa maka super duplex igwe anaghị agba nchara (HDSS) nwere nguzogide corrosion dị elu na ngwa ụfọdụ.Nke a butere mmepe nke HDSS alloyed nke ukwuu.
A na-ekpebi nguzogide corrosion nke DSS site na oke nke α-phase na γ-phase na mpaghara agwụla na Cr, Mo na W n'akụkụ akụkụ nke abụọ8,9,10.HDSS nwere nnukwu ọdịnaya nke Cr, Mo na N11, nke na-enye ya ezigbo nguzogide corrosion na uru dị elu (45-50) nha nha nguzogide pitting (PREN), nke akọwapụtara wt.% Cr + 3.3 (wt.% Mo). + 0, 5 wt % W) + 16 wt %.N12.Nguzogide corrosion ya kacha mma dabere na ngwakọta ziri ezi nwere ihe dịka 50% ferritic (α) na 50% austenitic (γ).HDSS emelitela akụrụngwa akụrụngwa yana nguzogide chlorine dị elu ma e jiri ya tụnyere DSS13.Njirimara nke chemical corrosion.Nguzogide corrosion emelitere na-agbatị iji HDSS na gburugburu chloride na-eme ihe ike dị ka gburugburu mmiri.
MIC bụ nnukwu nsogbu n'ọtụtụ ụlọ ọrụ, gụnyere mmanụ na gas na mmiri 14.MIC na-aza 20% nke mmebi nrụrụ niile15.MIC bụ corrosion bioelectrochemical nke enwere ike ịhụ n'ọtụtụ gburugburu16.Nhazi nke biofilms na elu igwe na-agbanwe ọnọdụ electrochemical ma si otú a na-emetụta usoro mmebi ahụ.A na-anabatakarị na ọ bụ biofilms14 kpatara MIC corrosion.Electrogenic microorganisms na-erichapụ ọla iji nweta ume maka nlanarị17.Ọmụmụ MIC na nso nso a egosila na EET (nfefe elektrọn ọzọ) bụ ihe na-egbochi MIC site na microorganisms electrogenic.Zhang et al.18 gosipụtara na ndị mgbasa ozi elektrọn na-eme ka nnyefe elektrọn dị n'etiti mkpụrụ ndụ Desulfovibrio vulgaris sessile na 304 igwe anaghị agba nchara, na-ebute ọgụ MIC ka njọ.Anning et al.19 na Wenzlaff et al.20 egosila na biofilms nke nje bacteria na-ebelata sulfate na-emebi emebi (SRBs) nwere ike ịmịnye electrons ozugbo site na ihe ndị na-emepụta ígwè, na-ebute nnukwu nsị.
A maara DSS na ọ nwere ike ịnweta MIC na mgbasa ozi nwere SRB, nje bacteria na-ebelata ígwè (IRBs), wdg 21.Nje bacteria ndị a na-ebute nsị mpaghara n'elu DSS n'okpuru biofilm22,23.N'adịghị ka DSS, amachaghị ihe gbasara MIC HDSS24.
Pseudomonas aeruginosa bụ nje gram-adịghị mma, motile, nje nke yiri mkpanaka nke na-ekesa na okike25.Pseudomonas aeruginosa bụkwa isi microbiota maka MIC nke ígwè na gburugburu mmiri26.Ụdị Pseudomonas na-etinye aka na usoro corrosion ma bụrụ ndị a ghọtara dị ka ndị mbụ colonizers n'oge biofilm formation27.Mahat et al.28 na Yuan et al.29 gosipụtara na Pseudomonas aeruginosa na-achọ ịbawanye ọnụego corrosion nke ígwè dị nro na alloys na gburugburu mmiri.
Ebumnuche bụ isi nke ọrụ a bụ ịmụba njirimara MIC nke 2707 HDSS kpatara site na nje aerobic bacterium Pseudomonas aeruginosa site na iji usoro electrochemical, usoro nyocha elu na nyocha ngwaahịa corrosion.Ọmụmụ ihe elektrọnịkị gụnyere ike sekit mepere emepe (OCP), nguzogide polarization linear (LPR), electrochemical impedance spectroscopy (EIS) na ike polarization ka emere iji mụọ omume nke MIC 2707 HDSS.A na-eme nyocha ihe nleba anya mgbasawanye ike (EDS) iji chọpụta ihe kemịkalụ n'elu ebe mebiri emebi.Na mgbakwunye, nkwụsi ike nke ihe nkiri oxide passivation n'okpuru mmetụta nke gburugburu mmiri nwere Pseudomonas aeruginosa bụ nke X-ray photoelectron spectroscopy (XPS) kpebisiri ike.A tụrụ omimi nke olulu ndị ahụ n'okpuru microscope laser confocal (CLSM).
Isiokwu 1 na-egosi ihe mejupụtara kemịkalụ 2707 HDSS.Tebụl 2 na-egosi na 2707 HDSS nwere ihe eji arụ ọrụ mara mma yana ike mkpụrụ nke 650 MPa.Na fig.1 na-egosi microstructure ngwa anya nke okpomọkụ ngwọta 2707 HDSS.Enwere ike ịhụ eriri ogologo nke austenitic na ferritic na-enweghị usoro nke abụọ na microstructure nwere ihe dị ka 50% austenitic na 50% ferritic.
Na fig.2a na-egosi ike sekit mepere emepe (Eocp) na oge ikpughe maka 2707 HDSS na 2216E abiotic medium na Pseudomonas aeruginosa broth maka ụbọchị 14 na 37°C.Achọpụtara na mgbanwe ndị kachasị akpọpụta na Eocp mere n'ime awa 24 mbụ.Ụkpụrụ Eocp n'ọnọdụ abụọ ahụ ruru ihe dịka -145 mV (na SCE) n'ihe dị ka awa 16 wee gbadaa nke ọma ruo -477 mV (karịa SCE) na -236 mV (karịa SCE) maka ihe ndị na-abụghị nke ndu na P maka ikwu. SCE) patina na-ahapụ, n'otu n'otu.Mgbe awa 24 gachara, uru Eocp nke Pseudomonas aeruginosa 2707 HDSS nọgidere na-akwụsi ike na -228 mV (tụnyere SCE), ebe uru dabara adaba maka nlele na-abụghị nke ndu bụ ihe dịka -442 mV (tụnyere SCE).Eocp n'ihu Pseudomonas aeruginosa dị obere.
Nnwale electrochemical nke 2707 HDSS sample na abiotic media na Pseudomonas aeruginosa broth na 37°C:
(a) Mgbanwe na Eocp na oge mkpughe, (b) ntụgharị polarization na ụbọchị 14, (c) mgbanwe na Rp na oge mkpughe, (d) mgbanwe na corr na oge mkpughe.
Tebụl 3 na-egosi paramita corrosion electrochemical nke 2707 HDSS sample ekpughere na abiotic na P. aeruginosa inoculated media n'ime oge nke 14 ụbọchị.Tangential extrapolation nke anodic na cathodic curves ruo n'ókè nke intersection kwere ka mkpebi nke corrosion ugbu density (icorr), corrosion ikike (Ecorr) na Tafel mkpọda (βα na βc) dị ka ọkọlọtọ usoro30,31.
Dị ka e gosiri na foto 2b, ngbanwe elu nke P. aeruginosa curve mere ka e nwee mmụba na Ecorr ma e jiri ya tụnyere usoro abiotic.Ọnụ ego icorr nke ihe nlele ahụ nwere Pseudomonas aeruginosa, nke dabara na ọnụ ọgụgụ corrosion, mụbara ruo 0.328 µA cm-2, nke dị okpukpu anọ karịa nke ihe nlele na-abụghị nke ndu (0.087 µA cm-2).
LPR bụ usoro eletrọkị kemịkalụ kpochapụrụ maka nyocha nke corrosion na-adịghị emebi emebi.Ejikwala ya mụọ MIC32.Na fig.2c na-egosi mgbanwe na nguzogide polarization (Rp) dabere na oge ikpughe.Uru Rp dị elu pụtara obere corrosion.N'ime awa 24 mbụ, Rp 2707 HDSS gbagoro na 1955 kΩ cm2 maka ụdị na-abụghị nke ndu yana 1429 kΩ cm2 maka ụdị Pseudomonas aeruginosa.Ọgụgụ 2c na-egosikwa na uru Rp gbadara ngwa ngwa ka otu ụbọchị gachara wee nọgide na-agbanweghị agbanwe n'ime ụbọchị iri na atọ sochirinụ.Uru Rp maka ihe nlere ule Pseudomonas aeruginosa dị ihe dịka 40 kΩ cm2, nke dị obere karịa uru 450 kΩ cm2 maka ụdị nnwale na-abụghị nke ndu.
Uru nke icorr dabara na ọnụego corrosion otu.Enwere ike gbakọọ ọnụ ahịa ya site na ngụkọ Stern-Giri:
Dị ka Zoe et al.33 A na-ewere mkpọda Tafel B dị ka uru nke 26 mV / dec na ọrụ a.Na fig.2d na-egosi na icorr nke ụdị abiotic 2707 ka kwụsiri ike, ebe icorr nke Pseudomonas aeruginosa band gbanwere nke ukwuu site na nnukwu mwụli elu mgbe awa 24 mbụ gasịrị.Uru icorr nke ihe nlele Pseudomonas aeruginosa bụ usoro dị elu karịa nke njikwa na-abụghị nke ndu.Omume a kwekọrọ na nsonaazụ nke nguzogide polarisation.
EIS bụ ụzọ ọzọ anaghị emebi emebi ejiri mara mmeghachi omume electrochemical na interface corrosion34.Ihe nleba anya nke impedance na capacitance nke ibe ekpughere na mgbasa ozi abiotic na ngwọta nke Pseudomonas aeruginosa, Rb bụ nguzogide nke passive / biofilm kpụrụ n'elu nke warara, Rct bụ nguzogide nnyefe ụgwọ, Cdl bụ okpukpu abụọ eletrik.) na QCPE mgbe niile nkeji mmewere (CPE).A na-enyochakwa ihe ndị a site n'iji data ahụ tụnyere ụdị sekit eletrik (EEC).
Na fig.3 na-egosi atụmatụ Nyquist (a na b) na Bode (a' na b') nke 2707 HDSS sample na abiotic media na Pseudomonas aeruginosa broth n'oge nnabata dị iche iche.N'ihu Pseudomonas aeruginosa, dayameta nke Nyquist loop na-ebelata.Atụmatụ Bode (Fig. 3b') na-egosi mmụba na mkpokọta mgbochi.Enwere ike nweta ozi gbasara oge izu ike mgbe niile site na usoro maxima.Na fig.4 na-egosi nhazi anụ ahụ na EEC kwekọrọ na nke dabeere na otu oyi akwa (a) na okpukpu abụọ (b).A na-ewebata CPE n'ime ụdị EEC.Ekwuputara nnabata ya na mgbochi ya dị ka ndị a:
Ụdị anụ ahụ abụọ na sekit ndị kwekọrọ na ya maka ịkwado 2707 HDSS coupon impedance spectrum:
Ebe Y0 bụ ịdị ukwuu nke CPE, j bụ ọnụọgụ echiche ma ọ bụ (-1) 1/2, ω bụ ugboro angular, na n bụ ihe ike CPE na-erughị otu35.Ntugharị nguzogide mbufe ụgwọ (ya bụ 1/Rct) dabara na ọnụego corrosion.Uru Rct dị ala pụtara ọnụego corrosion dị elu27.Mgbe ụbọchị iri na anọ nke incubation gasịrị, Rct nke ihe nlele nke Pseudomonas aeruginosa ruru 32 kΩ cm2, nke na-erughị 489 kΩ cm2 nke nlele ule na-abụghị nke ndu (Table 4).
Onyonyo CLSM na onyonyo SEM na fig.5 gosiri n'ụzọ doro anya na mkpuchi biofilm n'elu HDSS sample 2707 dị oke oke mgbe ụbọchị asaa gachara.Otú ọ dị, mgbe ụbọchị 14 gasịrị, mkpuchi biofilm bịara dị ntakịrị ma ụfọdụ mkpụrụ ndụ nwụrụ anwụ pụtara.Tebụl 5 na-egosi ọkpụrụkpụ biofilm nke ihe atụ 2707 HDSS mgbe ụbọchị 7 na 14 nke ikpughe na Pseudomonas aeruginosa.Ọkpụrụkpụ biofilm kachasị gbanwere site na 23.4 µm mgbe ụbọchị 7 gachara ruo 18.9 µm mgbe ụbọchị iri na anọ gachara.Nkezi ọkpụrụkpụ biofilm gosikwara omume a.Ọ gbadara site na 22.2 ± 0.7 μm mgbe ụbọchị 7 gachara ruo 17.8 ± 1.0 μm mgbe ụbọchị iri na anọ gachara.
(a) onyonyo 3-D CLSM na ụbọchị 7, (b) onyonyo 3-D CLSM na ụbọchị iri na anọ, (c) onyonyo SEM na ụbọchị asaa, yana (d) onyonyo SEM na ụbọchị iri na anọ.
EMF kpughere kemịkalụ kemịkalụ na biofilm na ngwaahịa corrosion na nlele ekpughere na Pseudomonas aeruginosa maka ụbọchị iri na anọ.Na fig.Ihe osise 6 na-egosi na ọdịnaya nke C, N, O, P na ngwaahịa biofilm na corrosion dị elu karịa na metal dị ọcha, ebe ọ bụ na ihe ndị a jikọtara ya na biofilm na metabolites ya.Microorganisms chọrọ naanị ọnụọgụ Cr na Fe.Ọdịnaya dị elu nke Cr na Fe na biofilm na ngwaahịa corrosion n'elu ihe nlele na-egosi mfu nke ihe dị na matrix metal n'ihi mmebi.
Mgbe ụbọchị 14 gachara, a hụrụ olulu nwere na enweghị P. aeruginosa na ọkara 2216E.Tupu incubation, elu nke samples bụ ire ụtọ na-enweghị ntụpọ (Fig. 7a).Mgbe incubation na mwepụ nke biofilm na corrosion ngwaahịa, a na-enyocha olulu miri emi n'elu ihe nlele ahụ site na iji CLSM, dị ka egosiri na Fig. 7b na c.Ọnweghị olulu doro anya ahụrụ n'elu njikwa na-abụghị nke ndu (oke omimi olulu 0.02 µm).Omimi olulu kachasị nke Pseudomonas aeruginosa kpatara bụ 0.52 µm mgbe ụbọchị 7 gasịrị na 0.69 µm mgbe ụbọchị 14 gasịrị, dabere na nkezi omimi olulu kachasị site na ihe atụ 3 (a na-ahọrọ olulu 10 kachasị maka nlele ọ bụla) wee ruo 0. 42 ± 0.12 µm. .na 0.52 ± 0.15 µm, n'otu n'otu (Table 5).Ụkpụrụ omimi dimple ndị a dị ntakịrị mana ọ dị mkpa.
(a) tupu ikpughe;(b) ụbọchị iri na anọ na gburugburu ebe obibi abiotic;(c) 14 ụbọchị na P. aeruginosa broth.
Na fig.Tebụl 8 na-egosi ụdịdị XPS dị iche iche nke ihe nlele dị iche iche, na kemịka nyochara maka elu ọ bụla ka a chịkọtara na Tebụl 6. Na tebụl 6, pasent atọ nke Fe na Cr dị obere karịa n'ihu P. aeruginosa (nlere A na B). ) karịa na ibe njikwa na-abụghị nke ndu.(ihe atụ C na D).Maka ihe atụ nke Pseudomonas aeruginosa, Cr 2p core level spectral curve dabara na akụkụ anọ kachasị elu nwere ike ike (BE) nke 574.4, 576.6, 578.3 na 586.8 eV, nke ekenyere Cr, Cr2O3, CrO3 na Cr. 3, n'otu n'otu (Fig 9a na b).Maka nlele ndị na-abụghị ihe ndụ, ụdịdị nke isi ọkwa Cr 2p na fig.9c na d nwere ọnụ ọgụgụ isi abụọ nke Cr (BE 573.80 eV) na Cr2O3 (BE 575.90 eV), n'otu n'otu.Ihe dị iche iche dị ịrịba ama n'etiti coupon abiotic na P. aeruginosa coupon bụ ọnụnọ nke Cr6 + na obere akụkụ dị elu nke Cr (OH) 3 (BE 586.8 eV) n'okpuru biofilm.
Ihe nlere anya XPS sara mbara nke 2707 HDSS n'ime mgbasa ozi abụọ maka ụbọchị 7 na 14, n'otu n'otu.
(a) 7 ụbọchị P. aeruginosa ikpughe, (b) ụbọchị 14 P. aeruginosa ikpughe, (c) ụbọchị 7 ikpughe abiotic, (d) ụbọchị 14 abiotic.
HDSS na-egosipụta ọkwa dị elu nke nguzogide corrosion n'ọtụtụ gburugburu.Kim et al.2 kọrọ na HDSS UNS S32707 chọpụtara dị ka DSS nke ukwuu doped na PREN karịrị 45. Uru PREN nke HDSS sample 2707 na ọrụ a bụ 49. Nke a bụ n'ihi nnukwu ọdịnaya Cr na ọkwa dị elu nke Mo na Ni, nke bara uru na gburugburu acidic na gburugburu nwere nnukwu ọdịnaya nke chlorides.Na mgbakwunye, ihe mejupụtara nke ọma na microstructure na-enweghị ntụpọ na-enye nkwụsi ike nhazi na nguzogide corrosion.N'agbanyeghị ezigbo nguzogide kemịkalụ, data nnwale na ọrụ a na-egosi na 2707 HDSS anaghị egbochicha ya na Pseudomonas aeruginosa biofilm MIC.
Nsonaazụ electrochemical gosiri na ọnụ ọgụgụ corrosion nke 2707 HDSS na broth Pseudomonas aeruginosa mụbara nke ukwuu mgbe ụbọchị 14 gachara ma e jiri ya tụnyere gburugburu ebe obibi.Na eserese 2a, a hụrụ mbelata nke Eocp ma na usoro abiotic yana na broth P. aeruginosa n'ime awa 24 mbụ.Mgbe nke ahụ gasị, biofilm ahụ kpuchiri elu nke ihe nlele ahụ ma Eocp na-adịwanye mma.Agbanyeghị, ọkwa biotic Eocp dị elu karịa ọkwa abiotic Eocp.Enwere ihe mere ị ga-eji kwere na ọdịiche a jikọtara ya na nhazi nke P. aeruginosa biofilms.Na fig.2g, uru icorr nke 2707 HDSS ruru 0.627 µA cm-2 n'ihu Pseudomonas aeruginosa, nke bụ usoro dị elu karịa nke njikwa na-abụghị nke ndu (0.063 µA cm-2), nke kwekọrọ na Rct. ọnụ ahịa EIS tụrụ.N'ime ụbọchị ole na ole mbụ, ụkpụrụ impedance na broth P. aeruginosa mụbara n'ihi ntinye nke sel P. aeruginosa na nhazi biofilm.Otú ọ dị, ihe mgbochi ahụ na-ebelata mgbe biofilm na-ekpuchi ihe nlele ahụ kpamkpam.A na-awakpo oyi akwa mkpuchi ahụ n'ụzọ bụ isi n'ihi nhazi biofilm na metabolites biofilm.Ya mere, nguzogide corrosion na-ebelata ka oge na-aga, na nkwụnye ego nke Pseudomonas aeruginosa na-akpata corrosion mpaghara.Usoro na gburugburu abiotic dị iche.Nguzogide corrosion nke njikwa na-abụghị nke ndu dị elu karịa uru kwekọrọ ekwekọ nke ihe nlele ekpughere na broth Pseudomonas aeruginosa.Na mgbakwunye, maka ihe atụ abiotic, uru Rct 2707 HDSS ruru 489 kΩ cm2 n'ụbọchị 14, nke dị okpukpu 15 dị elu karịa ọnụnọ Pseudomonas aeruginosa (32 kΩ cm2).Ya mere, 2707 HDSS nwere ezigbo nguzogide corrosion na gburugburu ebe adịghị mma, mana echebeghị ya na MIC ọgụ site na Pseudomonas aeruginosa biofilm.
Enwere ike ịhụ nsonaazụ ndị a site na mkpọda polarization na fig.2b.Ejikọtara alaka anodic na nhazi biofilm Pseudomonas aeruginosa na mmeghachi omume oxidation metal.N'otu oge ahụ, mmeghachi omume cathodic bụ mbelata oxygen.Ọnụnọ nke P. aeruginosa budata ụbara njupụta corrosion ugbu a, nke bụ ihe dị ka usoro dị elu karịa na njikwa abiotic.Nke a gosiri na Pseudomonas aeruginosa biofilm kwalitere corrosion mpaghara nke 2707 HDSS.Yuan et al.29 chọpụtara na njupụta corrosion ugbu a nke 70/30 Cu-Ni alloy ka Pseudomonas aeruginosa biofilm mụbara.Nke a nwere ike ịbụ n'ihi biocatalysis nke mbelata oxygen site na Pseudomonas aeruginosa biofilm.Nlebanya a nwekwara ike ịkọwa MIC 2707 HDSS n'ọrụ a.Aerobic biofilms nwekwara ike ibelata ikuku oxygen dị n'okpuru ha.Ya mere, ọjụjụ iji oxygen na-emegharị elu igwe ahụ nwere ike ịbụ ihe na-enye aka na MIC na ọrụ a.
Dickinson et al.38 tụrụ aro na ọnụego mmeghachi omume kemịkalụ na electrochemical na-adabere ozugbo na ọrụ metabolic nke nje bacteria jikọtara n'elu ihe nlele yana na ọdịdị nke ngwaahịa corrosion.Dị ka egosiri na eserese 5 na tebụl 5, ọnụ ọgụgụ nke mkpụrụ ndụ na ọkpụrụkpụ biofilm belatara mgbe ụbọchị iri na anọ gasịrị.Enwere ike ịkọwa nke a n'ụzọ ezi uche dị na ya na mgbe ụbọchị 14 gasịrị, ọtụtụ n'ime mkpụrụ ndụ arịlịka na elu 2707 HDSS nwụrụ n'ihi ụkọ nri na 2216E ọkara ma ọ bụ ntọhapụ nke ion metal na-egbu egbu site na 2707 HDSS matrix.Nke a bụ mmachi nke nnwale ogbe.
N'ime ọrụ a, Pseudomonas aeruginosa biofilm kwalitere mmebi mpaghara nke Cr na Fe n'okpuru biofilm n'elu 2707 HDSS (Fig 6).Na Tebụl 6, Fe na Cr belatara na nlele D ma e jiri ya tụnyere C, na-egosi na mgbasa nke Fe na Cr kpatara site na P. aeruginosa biofilm ka edobere mgbe ụbọchị 7 mbụ gasịrị.A na-eji gburugburu 2216E mee ka ebe obibi mmiri dị.O nwere 17700 ppm Cl-, nke a na-atụnyere ọdịnaya ya na mmiri oke osimiri.Ọnụnọ nke 17700 ppm Cl- bụ isi ihe kpatara mbelata Cr na ụbọchị 7 na ụbọchị 14 na-abụghị nke ndu nke XPS nyochara.E jiri ya tụnyere ihe nlele nke Pseudomonas aeruginosa, mgbasa nke Cr na nlele abiotic dị ntakịrị n'ihi nguzogide siri ike nke 2707 HDSS na chlorine na gburugburu abiotic.Na fig.9 na-egosi ọnụnọ Cr6+ na ihe nkiri na-agafe agafe.Nke a nwere ike jikọta na mwepụ nke Cr site na nchara nchara site na P. aeruginosa biofilms, dịka Chen na Clayton39 tụrụ aro.
N'ihi uto nke nje bacteria, ụkpụrụ pH nke ọkara tupu na mgbe incubation bụ 7.4 na 8.2, n'otu n'otu.Ya mere, corrosion nke organic acid adịghị ele anya na ọ ga-enye aka na ọrụ a n'okpuru P. aeruginosa biofilms n'ihi pH dị elu dị elu na nnukwu ihe.PH nke usoro nchịkwa na-abụghị nke ndu agbanwebeghị nke ọma (site na 7.4 mbụ ruo 7.5 ikpeazụ) n'oge ule ụbọchị 14.Mmụba nke pH na ọkara inoculum mgbe emechara ya na arụ ọrụ metabolic nke Pseudomonas aeruginosa, a chọtara otu mmetụta ahụ na pH na enweghị mpempe ule.
Dị ka e gosiri na fig.7, omimi olulu kachasị nke Pseudomonas aeruginosa biofilm kpatara bụ 0.69 µm, nke dị ukwuu karịa na usoro abiotic (0.02 µm).Nke a kwekọrọ na data electrochemical dị n'elu.N'okpuru otu ọnọdụ ahụ, omimi olulu nke 0.69 µm karịrị okpukpu iri pere mpe karịa uru 9.5 µm akọwapụtara maka 2205 DSS40.Data ndị a na-egosi na 2707 HDSS na-egosipụta nguzogide dị mma na MIC karịa 2205 DSS.Nke a abụghị ihe mgbagwoju anya ebe 2707 HDSS nwere ọkwa Cr dị elu, nke na-enye ohere ịgafe ogologo oge, na-eme ka Pseudomonas aeruginosa sie ike ịda mbà n'obi, ma malite usoro ahụ na-enweghị mmiri ozuzo nke abụọ na-emerụ ahụ Pitting41.
Na mmechi, a chọtara pitting MIC na 2707 HDSS na-ebupụta na broth Pseudomonas aeruginosa, ebe ọ bụ ihe na-adịghị mma na mgbasa ozi abiotic.Ọrụ a na-egosi na 2707 HDSS nwere nguzogide dị mma na MIC karịa 2205 DSS, mana ọ bụghị kpamkpam na MIC n'ihi Pseudomonas aeruginosa biofilm.Nsonaazụ ndị a na-enyere aka na nhọrọ nke igwe anaghị agba nchara kwesịrị ekwesị na ndụ ndụ maka gburugburu mmiri.
Ụlọ akwụkwọ nke Metallurgy, Northeast University (NEU), Shenyang, China nyere ihe atụ 2707 HDSS.E gosipụtara ihe mejupụtara nke 2707 HDSS na Tebụl 1, nke nyochara ihe nyocha ihe na ngalaba nnwale nke Mahadum Northeast.A na-edozi ihe nlele niile maka ngwọta siri ike na 1180 ° C maka 1 hour.Tupu nnwale corrosion, 2707 HDSS nchara nchara nke nwere oghere ekpughere nke 1 cm2 ka chara chara na 2000 grit na silicon carbide sandpaper wee jiri slurry 0.05 µm Al2O3 na-ehicha ya.A na-echebe akụkụ na ala na agba inert.Mgbe ihichachara, a na-asacha ihe atụ ndị ahụ na mmiri mmiri na-adịghị mma na sterilized na 75% (v / v) ethanol maka 0,5 h.A na-akpọsa ha n'ikuku n'okpuru ọkụ ultraviolet (UV) maka awa 0,5 tupu ejiri ya.
Azụtara eriri mmiri Pseudomonas aeruginosa MCCC 1A00099 site na mkpokọta Xiamen Marine Culture Collection (MCCC), China.A na-eji mmiri mmiri 2216E mmiri mmiri (Qingdao Hope Biotechnology Co., Ltd., Qingdao, China) mee omenala Pseudomonas aeruginosa na 250 ml flasks na 500 ml electrochemical cell cell n'okpuru ọnọdụ ikuku na 37 ° C.Ọkara nwere (g/l): 19.45 NaCl, 5.98 MgCl2, 3.24 Na2SO4, 1.8 CaCl2, 0.55 KCl, 0.16 Na2CO3, 0.08 KBr, 0.034 SrCl2, 0.034 SrCl2, 0.02, 3.0.2, H30r.0.0, BO. 0.008, 0.008 Na4F0H20PO.1.0 yist wepụ na 0.1 citrate ígwè.Autoclave na 121 Celsius C maka nkeji 20 tupu inoculation.A na-agụ mkpụrụ ndụ sessile na planktonic n'okpuru microscope ọkụ site na iji hemocytometer na mmụba 400x.Nleba mbụ nke sel planktonic P. aeruginosa ozugbo a gwọchara ya bụ ihe dịka sel 106 / ml.
Emere ule kemịkalụ elektrọnik n'ime cell iko iko atọ nke nwere oke nha nke 500 ml.Ejikọtara mpempe akwụkwọ platinum na calomel electrode juru eju (SCE) na reactor site na Luggin capillary jupụtara na akwa nnu wee jee ozi dị ka counter na electrodes, n'otu n'otu.Iji mepụta electrode na-arụ ọrụ, a na-ejikọta waya ọla kọpa roba na nke ọ bụla ma jiri epoxy kpuchie ya, na-ahapụ ihe dịka 1 cm2 nke elu elu n'otu akụkụ maka electrode na-arụ ọrụ.N'oge nha electrochemical, a na-etinye ihe nlele ahụ na etiti 2216E ma debe ya na okpomọkụ mgbe niile (37 Celsius) na mmiri ịsa ahụ.A tụrụ OCP, LPR, EIS na data nwere ike ịdị ike site na iji Autolab potentiostat (Ntụaka 600TM, Gamry Instruments, Inc., USA).Edere ule LPR n'ogo nyocha nke 0.125 mV s-1 na oke -5 na 5 mV yana Eocp nwere ọnụego nlele nke 1 Hz.Emere EIS na steeti Eocp kwụ ọtọ site na iji voltaji etinyere nke 5 mV nwere sinusoid n'ogo ugboro nke 0.01 ruo 10,000 Hz.Tupu enwere ike ịsachapụ ahụ, electrodes nọ na ọnọdụ sekit mepere emepe ruo mgbe enwere ike imebi ihe n'efu nke 42.Ya na.Emegharịrị ule ọ bụla ugboro atọ na enweghị Pseudomonas aeruginosa.
A na-eji akwụkwọ 2000 grit wet SiC chara nke ọma n'ụdị maka nyocha metallographic wee jiri 0.05 µm Al2O3 ntụ ntụ slurry maka nlele anya.A na-eme nyocha ihe gbasara ihe site na iji microscope anya.Edebere ihe nlele ahụ na 10 wt% potassium hydroxide solution43.
Mgbe incubation gasịrị, saa 3 ugboro na phosphate buffered saline (PBS) (pH 7.4 ± 0.2) wee dozie ya na 2.5% (v / v) glutaraldehyde maka awa 10 iji dozie biofilm.Mmiri mmiri na-esote ya na ethanol na usoro steepụ (50%, 60%, 70%, 80%, 90%, 95% and 100% by volume) tupu ihicha ikuku.N'ikpeazụ, a fesa ihe nkiri ọla edo n'elu ihe nlele ahụ iji nye ihe omume maka nlele SEM44.Ihe oyiyi SEM na-elekwasị anya na ebe nwere mkpụrụ ndụ P. aeruginosa kachasị guzosie ike n'elu ihe nlele ọ bụla.Emere nyocha EMF iji chọpụta ihe kemịkal.Iji tụọ omimi nke olulu ahụ, a na-eji microscope Zeiss confocal laser scanning (CLSM) (LSM 710, Zeiss, Germany).Iji hụ olulu corrosion n'okpuru biofilm, a na-ebu ụzọ kpochaa ihe nlele ahụ dị ka Chinese National Standard (CNS) GB/T4334.4-2000 iji wepụ ngwaahịa corrosion na biofilm n'elu ihe nlele ule.
Nyocha X-ray fotoelectron spectroscopy (XPS, ESCALAB250 Surface Analysis System, Thermo VG, USA) nyocha site na iji isi iyi X-ray monochromatic (Akara Al Kα nwere ike nke 1500 eV na ike nke 150 W) n'ọtụtụ ike na-ekekọta ike. 0 n'okpuru ọkọlọtọ ọnọdụ -1350 eV.Dekọọ ụdị nhụsianya dị elu site na iji ike ngafe 50 eV yana nha nzọụkwụ 0.2 eV.
Wepu ihe nlele agbakwunyere ma jiri nwayọọ sachaa ya na PBS (pH 7.4 ± 0.2) maka 15 s45.Iji hụ ịdị irè nke nje nke biofilm na ihe nlele ahụ, a na-emetọ biofilm site na iji LIVE/DEAD BacLight BacLight Viability Kit (Invitrogen, Eugene, OR, USA).Ngwa ahụ nwere akwa fluorescent abụọ: SYTO-9 green fluorescent dye na propidium iodide (PI) na-acha uhie uhie.Na CLSM, ntụpọ akwụkwọ ndụ akwụkwọ ndụ na fluorescent na-anọchi anya sel dị ndụ na nke nwụrụ anwụ, n'otu n'otu.Maka ntụpọ, tinye 1 ml nke ngwakọta nwere 3 µl nke SYTO-9 na 3 µl nke ngwọta PI na ụlọ okpomọkụ (23ºC) n'ime ọchịchịrị maka nkeji 20.Mgbe nke ahụ gasịrị, a na-ahụ ihe nlele ahụ nwere ntụpọ n'ogologo abụọ (488 nm maka sel ndụ na 559 nm maka mkpụrụ ndụ nwụrụ anwụ) site na iji ngwa Nikon CLSM (C2 Plus, Nikon, Japan).Tulee ọkpụrụkpụ biofilm na ọnọdụ nyocha 3-D.
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Oge nzipu: Jan-09-2023