ASTM_D_6807_-_02_2009.pdf

Designation:D680702(Reapproved 2009)Standard Test Method forOperating Performance of Continuous ElectrodeionizationSystems on Reverse Osmosis Permeates from2 to 100 S/cm1This standard is issued under the fixed designation D6807;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 test method covers the determination of the oper-ating characteristics of continuous electrodeionization(CEDI)devices,indicative of deionization performance when a deviceis applied to production of highly deionized water from theproduct water of a reverse osmosis system.This test method isa procedure applicable to feed waters containing carbonic acidand/or dissolved silica and other solutes,with a conductivityrange of approximately 2 to 100 microsiemens-cm-1.1.2 This test method covers the determination of operatingcharacteristics under standard test conditions of CEDI deviceswhere the electrically active transfer media therein is predomi-nantly regenerated.1.3 The test method is not necessarily indicative of:1.3.1 Long term performance on feed waters containingfoulants and/or sparingly soluble solutes;1.3.2 Performance on feeds of brackish water,sea water,orother high salinity feeds;1.3.3 Performance on synthetic industrial feed solutions,pharmaceuticals,or process solutions of foods and beverages;or,1.3.4 Performance on feed waters less than 2 S/cm,par-ticularly performance relating to organic solutes,colloidal orparticulate matter,or biological or microbial matter.1.4 The test method,subject to the limitations described,can be applied as either an aid to predict expected deionizationperformance for a given feed water quality,or as a method todetermine whether performance of a given device has changedover some period of time.It is ultimately,however,the usersresponsibility to ensure the validity of the test method for theirspecific applications.1.5 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.6 This standard may involve hazardous materials,operations,and equipment.This standard does not purport toaddress all of the safety concerns,if any,associated with itsuse.It is the responsibility of the user of this standard toestablish appropriate safety and health practices and deter-mine the applicability of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2D513 Test Methods for Total and Dissolved Carbon Dioxidein WaterD859 Test Method for Silica in WaterD1125 Test Methods for Electrical Conductivity and Resis-tivity of WaterD1129 Terminology Relating to WaterD1293 Test Methods for pH of WaterD2777 Practice for Determination of Precision and Bias ofApplicable Test Methods of Committee D19 on WaterD4194 Test Methods for Operating Characteristics of Re-verse Osmosis and Nanofiltration Devices3.Terminology3.1 DefinitionsFor definitions of general terms used inthese test methods,refer to Terminology D1129.3.2 For descriptions of terms relating to reverse osmosis,refer to Test Methods D4194.3.3 Definitions of Terms Specific to This Standard:3.3.1 cellan independently fed chamber formed by twoadjacent ion exchange membranes,or by a membrane and anadjacent electrode.3.3.2 continuous electrodeionization(CEDI)devicea de-vice that removes ionized and ionizable species from liquidsusing electrically active media and using an electrical potentialto influence ion transport,where the ionic transport propertiesof the active media are a primary sizing parameter.CEDI1This test method is under the jurisdiction of ASTM Committee D19 on Waterand is the direct responsibility of Subcommittee D19.08 on Membranes and IonExchange Materials.Current edition approved May 1,2009.Published June 2009.Originallyapproved in 2002.Last previous edition approved in 2002 as D6807 02.DOI:10.1520/D6807-02R09.2For 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 devices typically comprise semi-permeable ion exchangemembranes and permanently charged ion exchange media.Examples include continuous deionization,electrodiaresis,andpacked-bed or filled-cell electrodialysis.3.3.3 current effciencythe ratio,expressed in percent,ofthe net transfer of ionized and ionizable solutes per unit cellwithin a CEDI device,expressed in chemical equivalentstransferred per unit time,to the number of coulombs trans-ferred from an external DC power source to each electrodepair,expressed in faradays per unit time.Calculation of currentefficiency is described in 9