1、Designation: D6807 02 (Reapproved 2009)D6807 17Standard 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 t
2、he 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
3、operating characteristics of continuous electrodeionization (CEDI) devices,indicative of deionization performance when a device is applied to production of highly deionized water from the product waterof a reverse osmosis system. This test method is a procedure applicable to feed waters containing c
4、arbonic acid and/or dissolvedsilica or dissolved silica, or both, and other solutes, with a conductivity range of approximately 2 to 100 microsiemens-cm-1.1.2 This test method covers the determination of operating characteristics under standard test conditions of CEDI devices wherethe electrically a
5、ctive transfer media therein is predominantly regenerated.1.3 TheThis test method is not necessarily indicative of:1.3.1 Long term performance on feed waters containing foulants and/oror sparingly soluble solutes;solutes, or both;1.3.2 Performance on feeds of brackish water, sea water, or other high
6、 salinity feeds;1.3.3 Performance on synthetic industrial feed solutions, pharmaceuticals, or process solutions of foods and beverages; or,or1.3.4 Performance on feed waters less than 2 S/cm, particularly performance relating to organic solutes, colloidal or particulatematter, or biological or micro
7、bial matter.1.4 TheThis 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 to determine whether performance of a given device has changed oversome period of time. It is ultimate
8、ly, however, the usersusers responsibility to ensure the validity of thethis test method for theirspecific applications.1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.6 This standard may involve hazardous materials, ope
9、rations, and equipment. This standard does not purport to address allof the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriatesafety safety, health, and healthenvironmental practices and determine the applicability of regu
10、latory limitations prior to use.1.7 This international standard was developed in accordance with internationally recognized principles on standardizationestablished in the Decision on Principles for the Development of International Standards, Guides and Recommendations issuedby the World Trade Organ
11、ization Technical Barriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2D513 Test Methods for Total and Dissolved Carbon Dioxide in WaterD859 Test Method for Silica in WaterD1125 Test Methods for Electrical Conductivity and Resistivity of WaterD1129 Terminology Relating to Wat
12、erD1293 Test Methods for pH of WaterD2777 Practice for Determination of Precision and Bias of Applicable Test Methods of Committee D19 on WaterD4194 Test Methods for Operating Characteristics of Reverse Osmosis and Nanofiltration Devices1 This test method is under the jurisdiction of ASTM Committee
13、D19 on Water and is the direct responsibility of Subcommittee D19.08 on Membranes and Ion ExchangeMaterials.Current edition approved May 1, 2009Dec. 15, 2017. Published June 2009February 2018. Originally approved in 2002. Last previous edition approved in 20022009 asD6807 02.D6807 02 (2009). DOI: 10
14、.1520/D6807-02R09.10.1520/D6807-17.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.This document is not an AS
15、TM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In a
16、ll cases only the current versionof the standard as published by ASTM is to be considered the official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States13. Terminology3.1 DefinitionsFor definitions of general terms used in thes
17、e test methods, refer to Terminology D1129.3.1 For descriptions of terms relating to reverse osmosis, refer to Test Methods D4194.Definitions:3.1.1 For definitions of terms used in this standard, refer to Terminology D1129.3.1.2 For descriptions of terms relating to reverse osmosis, refer to Test Me
18、thods D4194.3.2 Definitions of Terms Specific to This Standard:3.2.1 cellcell, nan independently fed chamber formed by two adjacent ion exchange membranes, or by a membrane and anadjacent electrode.3.2.2 continuous electrodeionization (CEDI) devicedevice, na device that removes ionized and ionizable
19、 species fromliquids using electrically active media and using an electrical potential to influence ion transport, where the ionic transportproperties of the active media are a primary sizing parameter. CEDI devices typically comprise semi-permeable ion exchangemembranes and permanently charged ion
20、exchange media. Examples include continuous deionization, electrodiaresis, andpacked-bed or filled-cell electrodialysis.3.2.2.1 DiscussionCEDI devices typically comprise semi-permeable ion exchange membranes and permanently charged ion exchange media.Examples include continuous deionization, electro
21、diaresis, and packed-bed or filled-cell electrodialysis.3.2.3 current effciencyeffciency, nthe ratio, expressed in percent, of the net transfer of ionized and ionizable solutes per unitcell within a CEDI device, expressed in chemical equivalents transferred per unit time, to the number of coulombs t
22、ransferred froman external DC power source to each electrode pair, expressed in faradays per unit time. Calculation of current efficiency isdescribed in 9.2.3.2.3.1 DiscussionCalculation of current efficiency is described in 9.2.4. Summary of Test Method4.1 This test method is used to determine perf
23、ormance capabilities of CEDI devices with regard to extent of ion removal,pressure/flow relationships and electrical power consumption at standard or nominal operating conditions, electrical currentcharacteristics, and the relative ability of the device to remove ionized and ionizable species when f
24、ed reverse osmosis permeatewater. On this type of feed, there is considerable water splitting and ion-exchange resin regeneration, causing certain species tobecome ionized within the device, either by the electromotive force or a localized pH shift. The This test method is applicable toboth new and
25、used devices.4.2 Pressure loss data is obtained. This information provides information relating to possible particulate plugging, fouling, orinternal damage of the device. Deionization performance, extent of silica and dissolved carbon dioxide removal, concentratingstream pH, and applied voltage are
26、 determined at a predetermined level of electrical current transfer. The ohmic (electrical)resistance is determined. This information in combination with concentrating stream pH provides basic design and performanceinformation.5. Significance and Use5.1 CEDI devices can be used to produce deionized
27、water from feeds of pretreated water. This test method permits themeasurement of key performance capabilities of CEDI devices using a standard set of conditions. The data obtained can beanalyzed to provide information on whether changes may have occurred in operating characteristics of the device in
28、dependentlyof any variability in feed water characteristics or operating conditions. Under specific circumstances, the this test method may alsoprovide sufficient information for plant design.6. Apparatus6.1 Description:6.1.1 The test apparatus is schematically represented in Fig. 1. Feed water to t
29、he apparatus may be passed through a heatexchanger and/oror other accessories to modify and/oror control feed water temperature as desired.Alternately, data obtained fromthe operation of the apparatus may be normalized for temperature if normalization factors are known.6.1.2 Feed water to the appara
30、tus enters a holding tank (open or vented) of volume sufficient to maintain good control of waterlevel and solute concentrations. The tank is unpressurized, ported to be capable of occasional cleanings or sanitizations, andincorporates needed safety features such as high temperature and overflow pro
31、tection. The tank also incorporates a drain valve.During operation of the apparatus, the drain valve may be used in combination with a valve controlling the rate of feed water toD6807 172FIG. 1 Process Flow SchematicD6807173the apparatus to aid in control of solute concentrations, water level, and t
32、emperature within the tank. The tank supplies water toa recirculation pump designed to feed water to the CEDI device at a flow rate and pressure consistent with the ratings of the CEDIdevice. A recirculation line with shut off valve from the pump discharge to the tank may be incorporated as required
33、 for properpump operation.6.1.3 Adjustment of feed water solute concentration is not required. Adjust feed water pH as required by the manufacturer ofthe CEDI device. Feed water to the CEDI device must be monitored for solute concentrations, pH (Test MethodMethods D1293),and temperature. Solute conc
34、entration may be monitored via electrical conductivity or resistivity (Test MethodMethods D1125) incombination with silica (Test MethodMethods D513) and carbon dioxide (Test Method D859) concentration measurement, oralternately may be monitored for individual ionic species and dissolved carbon dioxi
35、de and silica, depending on the feed watersupplied to the tank and the solutes of interest.6.1.4 Feed water provided to the CEDI device should be plumbed as specified by the supplier, with appropriate flow andpressure controls, internal recirculations, drains, interlocks, safety controls, and other
36、features as required. Pressure at the inlet andoutlet and flow rates of each the streams of interest must be monitored (for example, deionized water stream, concentrate stream,and electrode feed stream).6.1.5 The CEDI device should be powered as specified by the supplier, with equipment and wiring t
37、o provide appropriate supplyDC voltage and amperage, controls, interlocks, grounding, and safety features. Supply voltage and supply amperage to the CEDIdevice should be monitored at positions within the device or device assembly as specified by the supplier.6.1.6 Streams leaving the CEDI device may
38、 be returned to the tank via return lines.Alternately, one or more of the streams maybe sent either completely or partially to drain via appropriate valving if such operation provides easier control of desired feed waterconditions. The outlet deionization stream is monitored for the same solutes as
39、for the feed water. The outlet concentrating streamis also monitored for the same solutes as for the feed water. Control of temperature is not required. For CEDI devices with internalrecirculation and “feed and bleed” features, solute concentrations must be measured at locations that are indicative
40、of conditionswithin the CEDI module prior to mixing of recirculation flows.6.1.7 Feed water to the tank of the test apparatus shall be prepared using reverse osmosis apparatus. The pretreatmentrequirements for the RO are optional depending on the application, but should, at minimum, conform to the m
41、anufacturersspecifications for the particular system.6.2 Installation:6.2.1 Materials of construction shall be as specified by the supplier of the CEDI device and in conformance to standardengineering practice.6.2.2 Controls and monitors should be calibrated and maintained according with suppliers r
42、equirements and standardengineering practice.7. Reagents7.1 Specific chemical reagents are not required for this test method. However, chemical modification such as pH adjustment,addition of trace solutes, and the addition of dissolved carbon dioxide may be applicable under certain circumstances. Un
43、lessotherwise indicated, it is intended that all reagents shall conform to the specifications of the Committee on Analytical Reagentsof the American Chemical Society, where such specifications are available.3 Other grades may be used, provided it is firstascertained that the reagent is of sufficient
44、ly high purity to permit its use without lessening the accuracy of the determination.8. Procedure8.1 Start Up:8.1.1 Ensure that the tank and reagent feed reservoirs are sufficiently full, with adequate feed water rate to accommodate anylosses of water caused by the positioning of the various drain v
45、alves. Control valves to the CEDI device should be closed and thedevice should be unpowered.8.1.2 Turn on the recirculation pump and then slowly open the feed water throttling valves and various valves and recirculationdevices on the CEDI device until the device is operating at nominal or supplier r
46、ecommended flow conditions. Modify throttlingvalves to adjust inlet and outlet pressures of the various device streams in accordance with supplier recommendations.8.1.3 Operate the system with no DC power applied for a sufficient time to ensure adequate removal of any residual air fromthe piping and
47、 device. During this time, flows, pressures, feed solute concentrations, and temperature, should be adjusted until adesirable steady state device feed water condition has been attained.8.2 Electrical Property and Deionization Performance Measurements:8.2.1 Turn on the DC power supply to the CEDI dev
48、ice, beginning at a low voltage. Raise the applied DC voltage until DCamperage between electrode pairs attains a pre-determined electrical current efficiency, typically below 20 %, but do not apply avoltage or amperage that exceeds suppliers recommendations (consult supplier for recommended values).
49、 Current efficiency3 Reagent Chemicals, American Chemical Society Specifications, American Chemical Society, Washington, DC, www.chemistry.org. For suggestions on the testing ofreagents not listed by the American Chemical Society, see Analar Standards for Laboratory Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville, MD.MD, http:/www.usp.org.D6807 174should be calculated as described in 9.2 using as Ndi the total combined normality of all ionized and ioniza
