1、Designation: D6529 11Standard Test Method forOperating Performance of Continuous ElectrodeionizationSystems on Feeds from 501000 S/cm1This standard is issued under the fixed designation D6529; the number immediately following the designation indicates the year oforiginal adoption or, in the case of
2、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 electr
3、odeionization (CEDI)devices using synthetic feed solutions and is not necessarilyapplicable to natural waters. This test method is a procedureapplicable to solutions with a conductivity range from approxi-mately 50 to 1000 S/cm.1.2 This test method covers the determination of operatingcharacteristic
4、s under standard test conditions of CEDI deviceswhere the electrically active transfer media therein is predomi-nantly unregenerated. This results in more rapid achievementof steady state and shorter test time than when performing atest which requires the active media be predominantly regen-erated.1
5、.3 This test method is not necessarily indicative of thefollowing:1.3.1 Long-term performance on feed waters containingfoulants or sparingly soluble solutes, or both,1.3.2 Performance on feeds of brackish water, sea water, orother high-salinity feeds,1.3.3 Performance on synthetic industrial feed so
6、lutions,pharmaceuticals, or process solutions of foods and beverages,or,1.3.4 Performance on feed waters less than 50 S/cm,particularly performance relating to organic solutes, colloidalor particulate matter, or biological or microbial matter.1.4 This test method, subject to the limitations previous
7、lydescribed, can be applied as either an aid to predict expecteddeionization performance for a given feed water quality, or asa test method to determine whether performance of a givendevice has changed over some period of time. It is ultimately,however, the users responsibility to ensure the validit
8、y of thistest method for their specific applications.1.5 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 o
9、r regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D1125 Test Methods for Electrical Conductivity and Resis-tivity of WaterD1129 Terminology Relating to WaterD1193 Specification for Reagent WaterD1293 Test Methods for pH of WaterD2777 Practice for Determination of Preci
10、sion and Bias ofApplicable Test Methods of Committee D19 on WaterD4189 Test Method for Silt Density Index (SDI) of Water3. Terminology3.1 DefinitionsFor definitions of general terms used inthis test method, refer to Terminology D1129.3.2 Definitions of Terms Specific to This Standard:3.2.1 cellan in
11、dependently fed ion-depleting chamberformed by two adjacent ion-exchange membranes, or by amembrane and an adjacent electrode.3.2.2 continuous electrodeionization (CEDI) devicea de-vice that removes ionized and ionizable species from liquidsusing electrically active media and using an electrical pot
12、entialto influence ion transport, where the ionic transport propertiesof the active media are a primary sizing parameter. The CEDIdevices typically comprise semipermeable ion-exchange mem-branes and permanently charged ion-exchange media. Ex-amples include continuous deionization, electrodiaresis, a
13、ndpacked-bed or filled-cell electrodialysis.3.2.3 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 extern
14、al dc power source to each electrode pair,expressed in faradays per unit time. Calculation of currentefficiency is described in 9.2.1This test method is under the jurisdiction of ASTM Committee D19 on Waterand is the direct responsibilities of Subcommittee D19.08 on Membranes and IonExchange Materia
15、ls.Current edition approved Oct. 15, 2011. Published May 2000. Originallyapproved in 2000. Last previous edition approved in 2009 as D652900 which waswithdrawn January 2008 and reinstated in October 2011. This reinstatement datematches the year date after the designation. DOI: 10.1520/D6529-11.2For
16、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.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700,
17、 West Conshohocken, PA 19428-2959, United States.4. Summary of Test Method4.1 This test method is used to determine performancecapabilities of CEDI devices with regard to extent of ionremoval, pressure/flow relationships and electrical power con-sumption at standard or nominal operating conditions,
18、electri-cal current characteristics, and the relative ability of the deviceto remove ionized species when fed pretreated tap water. Onthis type of feed there is little water splitting or resin regen-eration, thus only ionized species are removed. This testmethod is applicable to both new and used de
19、vices.4.2 Pressure loss data is obtained. This information providesinformation relating to possible particulate plugging, fouling,or internal damage of the device. Deionization performance,concentrating stream pH, and electrical current transfer ismonitored as a function of applied voltage. The init
20、ial ohmic(electrical) resistance, rate of change of ohmic resistance, andmaximal ohmic resistance is determined. Also the electricalcurrent efficiency as a function of deionization performanceand voltage is determined. This information in combinationwith concentrating stream pH as a function of appl
21、ied voltageprovides basic design and performance information.5. Significance and Use5.1 The CEDI devices can be used to produce deionizedwater from feeds of pretreated water. This test method permitsthe relatively rapid measurement of key performance capabili-ties of CEDI devices using standard sets
22、 of conditions. Thedata obtained can be analyzed to provide information onwhether changes may have occurred in operating characteris-tics of the device independently of any variability in feed watercharacteristics or operating conditions. Under specific circum-stances, this test method may also prov
23、ide sufficient informa-tion for plant design.6. Apparatus6.1 Description:6.1.1 The test apparatus is schematically represented in Fig.1. Feed water to the apparatus may be passed through a heatexchanger or other accessories, or both, to modify or controlfeed water temperature, or both, as desired. A
24、lternately, dataobtained from the operation of the apparatus may be normal-ized for temperature if normalization factors are known.6.1.2 Feed water to the apparatus enters a holding tank(open or vented) of volume sufficient to maintain good controlof water level and solute concentrations. The tank i
25、s unpres-surized, ported to be capable of occasional cleanings orsanitizations, and incorporates needed safety features such astemperature and overflow protection. The tank also incorpo-rates a drain valve. During operation of the apparatus, the drainvalve may be used in combination with a valve con
26、trolling therate of feed water to the apparatus to aid in control of soluteconcentrations, water level, and temperature within the tank.The tank supplies water to a recirculation pump designed tofeed water to the CEDI device at a flow rate and pressureconsistent with the ratings of the CEDI device.
27、A recirculationline with a shut off valve from the pump discharge to the tankmay be incorporated as required for proper pump operation.6.1.3 The concentration and pH of the feed water to theCEDI device is controlled by metering pumps that meter acontrolled flow of concentrated aqueous sodium chlorid
28、e, andeither sodium hydroxide or hydrochloric acid as needed intothe feed water to maintain the desired feed water soluteconcentration and pH.6.1.3.1 The concentrated reagents may be metered into thedischarge line of the pump or alternately may be metered intothe tank. In either case, mixing means a
29、re required to ensurethat the feed water concentrations do not fluctuate. Meteringpump assemblies and controllers should be designed withproper safety interlocks and controls configured so as to be“fail safe.” Suitable instrumentation must be provided tomonitor solute concentration (by means of elec
30、trical conduc-tivity or resistivity, see Test Methods D1125), pH (TestMethods D1293), and temperature of the feed water to theCEDI device. Instrumentation may be in-line or alternately,appropriate sample taps may be incorporated to allow fordetermination off-line.6.1.4 Feed water provided to the CED
31、I device should beplumbed as specified by the supplier, with appropriate flow andpressure controls, internal recirculations, drains, interlocks,safety controls, and other features as required. Pressure at theinlet and outlet and flow rates of each of the streams of interestmust be monitored (for exa
32、mple, deionized water stream,concentrate stream, and electrode feed stream).6.1.5 The CEDI device should be powered as specified bythe supplier, with equipment and wiring to provide appropriatesupply dc voltage and amperage, controls, interlocks, ground-ing, and safety features. Supply voltage and s
33、upply amperageto the CEDI device should be monitored at positions within thedevice or device assembly as specified by the supplier.6.1.6 Streams leaving the CEDI device may be returned tothe tank by means of return lines. Alternately, one or more ofthe streams may be sent either completely or partia
34、lly to drainby means of appropriate valving if such operation provideseasier control of desired feed water conditions. The outletdeionization stream is monitored for electrical conductivity orresistivity and optionally pH, and the outlet concentratingstream is monitored for pH and optionally electri
35、cal conduc-tivity or resistivity. For CEDI devices with internal recircula-tion and “feed and bleed” features, solute concentrations mustbe measured at locations that are indicative of conditionswithin the CEDI module prior to mixing of recirculation flows.6.2 Installation:6.2.1 Materials of constru
36、ction shall be as specified by thesupplier of the CEDI device and in conformance to standardengineering practice.6.2.2 Controls and monitors should be calibrated and main-tained in accordance with the suppliers requirements andstandard engineering practice.7. Reagents7.1 Purity of ReagentsReagent gr
37、ade chemicals shall beused in all tests. Unless otherwise indicated, it is intended thatall reagents shall conform to the specifications of the Commit-tee on Analytical Reagents of the American Chemical Society,D6529 112FIG. 1 Process Flow Schematic Test Method for Operating Performance of Continuou
38、s Electrodeionization Systems on Feeds from 501000 S/cmD6529113where such specifications are available.3Other grades may beused, provided it is first ascertained that the reagent is ofsufficiently high purity to permit its use without lessening theaccuracy of the determination.7.2 Purity of WaterUnl
39、ess otherwise indicated, referenceto water shall be understood to mean Type III reagent con-forming to Specification D1193 and meeting the followingadditional minimum quality specifications:- SDI15 4 (Test Method D4189)7.3 Sodium Chloride Feed SolutionDissolve enough so-dium chloride to make a conce
40、ntrated solution suitable forproper control of salinity fed to the device.7.4 Sodium Hydroxide SolutionDissolve or dilute enoughconcentrated sodium hydroxide to make a solution suitable forproper control of water pH fed to the device.7.5 Hydrochloric Acid SolutionDilute enough concen-trated hydrochl
41、oric acid solution to make a solution suitable forproper control of water pH fed to the device.8. Procedure8.1 Startup:8.1.1 Ensure that the tank and reagent feed reservoirs aresufficiently full, with adequate feed water rate to accommodateany losses of water caused by the positioning of the various
42、drain valves. Control valves to the CEDI device should beclosed and the device should be unpowered.8.1.2 Turn on the recirculation pump and then slowly openthe feed water throttling valves and various valves and recir-culation devices on the CEDI device until the device isoperating at nominal or sup
43、plier-recommended flow condi-tions. Modify throttling valves to adjust inlet and outletpressures of the various device streams in accordance withsupplier recommendations.8.1.3 Operate the system with no dc power applied for asufficient time to ensure adequate removal of any residual airfrom the pipi
44、ng and device. During this time, flows, pressures,feed solute concentrations, pH, and temperature should beadjusted until a desirable steady-state device feed water con-dition has been attained. Operation should be continued untilfeed, deionization stream and concentrating stream soluteconcentration
45、s, pH values, and temperatures are all approxi-mately the same. This ensures that the device is at equilibriumwith the test solution, so that the results will not be affected bythe feed stream on which the device was previously operated.8.1.4 Feed pH should be maintained in a range from 6.0 to8.0 an
46、d feed solute conductivity should be maintained at somespecific value (610 %) in the 50 to 1000 S/cm range. Thespecific value depends on the device being tested, for instanceto match the capacity of the dc power supply or to duplicate theconditions for which the CEDI device was designed.8.2 Pressure
47、 Drop MeasurementsOnce steady state isachieved, as described in 8.1, measure and record pressures ofthe various inlet and outlet streams of the device. If necessary,normalize pressure differentials for temperature and compareto the suppliers specifications. If operating pressure specifica-tions cann
48、ot be met, consult the supplier for the recommendedcourse of action prior to proceeding with the collection ofadditional data.8.3 Electrical Property and Deionization PerformanceMeasurements:8.3.1 Once steady state is achieved, as described in 8.1 and8.2, turn on the dc power supply to the CEDI devi
49、ce, beginningat a low voltage. Initial applied dc voltage should be approxi-mately 0.5 V per unit cell within the device (consult thesupplier for the recommended values). A cell is the repeatingunit of the device, and operating voltage expressed per celltherefore applies to devices with different numbers of cells.Continue to operate until steady state is achieved.8.3.2 Measure and record dc voltage, dc amperage, devicefeed water temperature, deionizing stream inlet and outletconductivity or resistivity, deionizing or concentrating streamoutlet pH, or both, and d
