1、Designation:D458210Standard Practice forCalculation and Adjustment of the Stiff and Davis StabilityIndex for Reverse Osmosis1This standard is issued under the fixed designation D4582;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,th
2、e 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 and adjustment ofthe Stiff and Davis Stability Index(S&DSI)for the concen-tr
3、ate stream of a reverse osmosis device.This index is used todetermine the need for calcium carbonate scale control in theoperation and design of reverse osmosis installations.Thispractice is applicable for concentrate streams containing morethan 10 000 mg/L of total dissolved solids.For concentrates
4、treams containing less than 10 000 mg/L of total dissolvedsolids,refer to Practice D3739.1.2 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 a
5、nd determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2D511 Test Methods for Calcium and Magnesium In WaterD1067 Test Methods for Acidity or Alkalinity of WaterD1129 Terminology Relating to WaterD1293 Test Methods for pH of WaterD1888 Methods
6、 Of Test for Particulate and Dissolved Matterin Water(Withdrawn 1989)3D3739 Practice for Calculation and Adjustment of theLangelier Saturation Index for Reverse OsmosisD4194 Test Methods for Operating Characteristics of Re-verse Osmosis and Nanofiltration DevicesD4195 Guide for Water Analysis for Re
7、verse Osmosis andNanofiltration ApplicationD6161 Terminology Used for Microfiltration,Ultrafiltration,Nanofiltration and Reverse Osmosis Membrane Processes3.Terminology3.1 DefinitionsFor definitions of terms used in thepractice,refer to Terminology D1129 and D6161.3.2 Definitions of Terms Specific t
8、o This Standard:3.2.1 For description of terms relating to reverse osmosis,refer to Test Methods D4194.3.2.2 Stiff and Davis Stability Index(S&DSI)4an indexcalculated from total dissolved solids,calcium concentration,total alkalinity,pH,and solution temperature that shows thetendency of a water solu
9、tion to precipitate or dissolve calciumcarbonate.4.Summary of Practice4.1 This practice consists of calculating the S&DSI indexfor a reverse osmosis concentrate stream from the totaldissolved solids,calcium ion content,total alkalinity,pH,andtemperature of the feed solution and the recovery of the r
10、everseosmosis system.4.2 This practice also presents techniques to lower the S&DSI by decreasing the recovery;decreasing the calcium andalkalinity concentrations;or by changing the ratio of totalalkalinity to free carbon dioxide in the feedwater.5.Significance and Use5.1 In the design and operation
11、of reverse osmosisinstallations,it is important to predict the calcium carbonatescaling properties of the concentrate stream.Because of theincrease in total dissolved solids in the concentrate stream andthe differences in salt passages for calcium ion,bicarbonateion,and free CO2,the calcium carbonat
12、e scaling properties ofthe concentrate stream will generally be quite different fromthose of the feed solution.This practice permits the calculationof the S&DSI for the concentrate stream from the feed wateranalyses and the reverse osmosis operating parameters.1This practice is under the jurisdictio
13、n of ASTM Committee D19 on Water andis the direct responsibility of Subcommittee D19.08 on Membranes and IonExchange Materials.Current edition approved May 1,2010.Published June 2010.Originallyapproved in 1986.Last previous edition approved in 2005 as D4582 05.DOI:10.1520/D4582-10.2For referenced AS
14、TM 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.3The last approved version of this historical standard is referenced onwww.astm.org.
15、4Stiff,H.A.and Davis,L.E.,“A Method for Predicting the Tendency of OilField Waters to Deposit Calcium Carbonate,”Petroleum Transactions,Vol 195,1952.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 5.2 A positive S&DSI indicates the tenden
16、cy to form acalcium carbonate scale,which can be damaging to reverseosmosis performance.This practice gives procedures for theadjustment of the S&DSI.6.Procedure6.1 Determine the calcium concentration in the feed solu-tion in accordance with Test Methods D511 and express asCaCO3as demonstrated in section 6.6.6.2 Determine the total dissolved solids of the feed solutionusing Test Methods D1888.6.3 Determine the total alkalinity of the feed solution usingTest Methods D1067 and express as CaCO3.6.4