Optimization of Extraction Conditions for Production of Halophyte-based Biocides for Microbiologically Influenced Corrosion (MIC) MitigationJakob L. Stein, Tanmay Chaturvedi, Torben L. Skovhus*, Mette H. ThomsenAalborg University, Esbjerg, Denmark*VIA University College, DenmarkMicrobiologicallyinfluencedCorrosionMICcanbecomeaprobleminmostwaterinfrastructure.Theoffshoreoilandgasindustryareespeciallypronebecauseofinjectionofsulfaterichseawater.Sulfate-reducingprokaryotesutilizesulfateforenergy.Assulfateisreduced,pipelinesteelisoxidized.Thisproblemisacceleratedbyformationofbiofilmexcretedfrommicroorganisms.Biofilmsprotectthemicroorganismsandkeepthematthepipelinewalls,causinglocalizedpittingcorrosion.CurrentmitigationofbiofilmSyntheticbiocidessuchasTetrakisHydroxymethylPhosphoniumSulfate(THPS)areaddedintheoilandgasindustrytoreducetherateofMIC.Whenthatisnotsufficientphysicalscraping(pigging)isdone.HalophytesHalophytes(salt-tolerantplants),produceavarietyofbioactivecompounds.Someofthesecompoundshaveantimicrobialactivity.Theyarealsosomeoftheonlyfoodcropsthatcanwithstandtheincreasingsoilsalinityoffarmlandacrosstheworld.Byvaryingtheextractionmethodandconditions,itispossibletooptimizetheantimicrobialeffectofanextract,whilereducinggrowth-promotingfactorssuchasnaturallypresentsugars.CouponWeightLossWeightofcoupons(1018low-alloysteel)werenotedbeforeandaftertheexperiment.Theweightlosswascalculatedintocorrosionrate.(n=3)CouponSurfaceScanningEachcoupon(1018low-alloysteel)wassandedwithP500SiCsandingpaperbeforethestartoftheexperiment.Attheend,thecouponswerescannedwitha3Dopticalprofilometer.(n=3)AgoodcorrelationbetweentheH2Sconcentration,weightlossandsurfaceroughnesswasfound.Preventedcorrosionisgenerallypittingcorrosion.H2SandATPMeasurementsDuringtheexperiments,liquidsamplesweretakenwithasyringe.FromthesesamplesH2SandATPweremeasured.(n=3)H2SisonlygeneratedbySRBduringthesulfatereductionprocess,whileATPisgeneratedbyallmicroorganisms.AcknowledgementTheproject“CleanBiocide”isfinanciallysupportedbyDTUOffshore**TheCleanBiocideproductionprocessispendingapatentMethod•Fivewater-basedbiocideswereproduced**fromalignifiedhalophyteatincreasinglysevereconditions(1=lowest,5=highest).•AnaerobicPostgatemedium(3.2%NaCl)wasinoculatedwithseasedimentatleftat22Cfor4weeks.•Toeachflask,10%or20%ofoneofthebiocideswasadded.un-inoculatedblinds,andaninoculatedcontrolswerealsoincluded.•All12samplevariationswererunintriplicate.00.511.522.510%20%10%20%10%20%10%20%10%20%BlindControl12345Arithmetic Mean Height (Sa) [µm]Average coupon surface roughnessControl2 –10%4 –10%Biocidescurrentlyusedthe oiland gas industryPlanktonicbacteriaSessilebacteriaBiofilmEnvironmentalimpactToxic: heavilyregulated110100100007142128µmol/L (LOG Scale)DayH2S1 - 10%1 - 20%2 - 10%2 - 20%3 - 10%3 - 20%4 - 10%4 - 20%5 - 10%5 - 20%ControlBlind0.111010010001000007142128RLU (10,000 RLU = 1 µmol/L)DayATP1 - 10%1 - 20%2 - 10%2 - 20%3 - 10%3 - 20%4 - 10%4 - 20%5 - 10%5 - 20%ControlBlind0.00.10.20.30.40.50.60.70.80.910%20%10%20%10%20%10%20%10%20%BlindControl12345mm/yearCorrosion Rate