Designation:D3875−15StandardTestMethodforAlkalinityinBrackishWater,Seawater,andBrines1ThisstandardisissuedunderthefixeddesignationD3875;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope*1.1Thistestmethodcoversthedeterminationofalkalinityinbrackishwater,seawater,andbrines.1.2ThevaluesstatedinSIunitsaretoberegardedasstandard.Nootherunitsofmeasurementareincludedinthisstandard.1.3Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafetyandhealthpracticesanddeterminetheapplica-bilityofregulatorylimitationspriortouse.2.ReferencedDocuments2.1ASTMStandards:D1129TerminologyRelatingtoWaterD1193SpecificationforReagentWaterD2777PracticeforDeterminationofPrecisionandBiasofApplicableTestMethodsofCommitteeD19onWaterD3370PracticesforSamplingWaterfromClosedConduitsD5847PracticeforWritingQualityControlSpecificationsforStandardTestMethodsforWaterAnalysisE200PracticeforPreparation,Standardization,andStorageofStandardandReagentSolutionsforChemicalAnalysis3.Terminology3.1Definitions—Fordefinitionsoftermsusedinthistestmethod,refertoTerminologyD1129.4.SummaryofTestMethod4.1AnelectrotitratororpHmeterisusedtodeterminetheamountofacidnecessarytoreachpH8.1and4.5,respectively.ThepHvaluesapproximatethepointswherethehydroxideandbicarbonateionsareneutralized.5.SignificanceandUse5.1Alkalinityascarbonateandbicarbonateofsalinewaterisveryimportantinchemicalwaterfloodingortertiaryrecov-eryprocessesforrecoveringpetroleum.Alkalinewatersofferbetterwettingtotheformationrockandimproveoilrelease.Asanadditionalbenefit,ionsthatprovidealkalinityadsorbonrocksurfacesoccupyingadsorptionsitesanddecreasethelossofrecoverychemicalbyadsorption.Determinationofalkalin-ityinwatersusedintertiaryrecoveryproces...
