ASTM_D_4328_-_08_2013.pdf

Designation:D432808(Reapproved 2013)Standard Practice forCalculation of Supersaturation of Barium Sulfate,StrontiumSulfate,and Calcium Sulfate Dihydrate(Gypsum)inBrackish Water,Seawater,and Brines1This standard is issued under the fixed designation D4328;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This practice covers the calculation of supersaturation ofbarium sulfate,strontium sulfate,and calcium sulfate dihydrate(gypsum)in brackish water,seawater,and brines in whichbarium,strontium,and calcium ions either coexist or existindividually in solution in the presence of sulfate ions.1.2 This practice is not applicable for calculating calciumsulfate dihydrate supersaturation if the temperatures of salinewaters under investigation exceed 95C.At temperatures above95C,hemianhydrate and anhydrite would be major insolubleforms.1.3 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.4 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2D511 Test Methods for Calcium and Magnesium In WaterD512 Test Methods for Chloride Ion In WaterD513 Test Methods for Total and Dissolved Carbon Dioxidein WaterD516 Test Method for Sulfate Ion in WaterD1129 Terminology Relating to WaterD3352 Test Method for Strontium Ion in Brackish Water,Seawater,and BrinesD3370 Practices for Sampling Water from Closed ConduitsD3561 Test Method for Lithium,Potassium,and SodiumIons in Brackish Water,Seawater,and Brines by AtomicAbsorption SpectrophotometryD3651 Test Method for Barium in Brackish Water,Seawater,and BrinesD3986 Test Method for Barium in Brines,Seawater,andBrackish Water by Direct-Current Argon Plasma AtomicEmission Spectroscopy3.Terminology3.1 DefinitionsFor definitions of terms used in thispractice,refer to Terminology D1129.4.Significance and Use4.1 This practice covers the mathematical calculation of thesupersaturation of three principal sulfate scaling compoundsfound in industrial operations.Application of this standardpractice to the prediction of scale formation in a given system,however,requires experience.The calculations tell the user ifa water,or mixture of waters,is in a scaling mode.Whether ornot scale will in fact form,how quickly it will form,where itwill form,in what quantities,and what composition are subjectto factors beyond the scope of this practice.However,based onhow supersaturated a given water or mixture of waters is,anobjective evaluation of the relative likelihood of scale forma-tion can be made.NOTE1There are several personal computer(PC)type programs thatare both available commercially and publicly that will perform thesecalculations.5.Procedure5.1 Collect water samples for compositional analysis inaccordance with Practices D3370.5.2 Determine the calcium and magnesium concentrationsin accordance with Test Methods D511.5.3 Determine the barium concentration in accordance withTest Methods D3651 or D3986.5.4 Determine the strontium concentration in accordancewith Test Method D3352.1This practice is under the jurisdiction of ASTM Committee D19 on Water andis the direct responsibility of Subcommittee D19.05 on Inorganic Constituents inWater.Current edition approved June 1,2013.Published July 2013.Originally approvedin 1984.Last previous edition approved in 2008 as D4328 08.DOI:10.1520/D4328-08R13.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 5.5 Determine sodium and potassium concentrations inaccordance with Test Method D3561.5.6 Determine sulfate ion concentration in accordance withTest Method D516.5.7 Determine chloride ion concentration in accordancewith Test Methods D512.5.8 Determine carbonate and bicarbonate ion concentrationsin accordance with Test Methods D513.5.9 Determine the concentrations of all other major inor-ganic constituents that may be present in the water underinvestigation in accordance with appropriate test methods inAnnual Book of ASTM Standards,Vols 11.01 and 11.02.5.10 Determine temperature and pressure of the watersystem under investigation.6.Calculation of Ionic Strength6.1 Calculate the ionic strength of the water under investi-gation as follows:512(CiZi2(1)where:=ionic strength,Ci=molal concentration of each i