1、Designation: D4519 16Standard Test Method forOn-Line Determination of Anions and Carbon Dioxide inHigh Purity Water by Cation Exchange and Degassed CationConductivity1This standard is issued under the fixed designation D4519; the number immediately following the designation indicates the year oforig
2、inal 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 on-line test method includes hydrogen exchangeand degassin
3、g by heating or gas stripping and provides meansfor determining anions (such as Cl,SO4,NO3, and F)atlevels as low as 2 g/L (2 ppb) and carbon dioxide at the levelof 0.01 to 10 mg/L (ppm) at 25C in high purity water and insteam and water samples in power plants by measuringelectrical conductivity.1.2
4、 The conductivity of all anions (except OH) is deter-mined and not the conductivity of an individual anion if morethan one is present. If only one anion is present (such as ClorSO4), reference to Section 4, Table 1 and Table 2 or Figs.1-3 provides the chloride or sulfate and CO2concentration.1.3 Thi
5、s test method has been improved in accuracy byusing a modern microprocessor instrument for conductivityand temperature measurement and appropriate temperaturecompensation algorithms for compensation, by using finalsample cooling to 25C, or both.1.4 The values stated in either SI units or inch-pound
6、unitsare to be regarded separately as standard. The values stated ineach system may not be exact equivalents; therefore, eachsystem shall be used independently of the other. Combiningvalues from the two systems may result in non-conformancewith the standard.1.5 This standard does not purport to addr
7、ess 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:2D1066 Practice
8、 for Sampling SteamD1125 Test Methods for Electrical Conductivity and Resis-tivity of WaterD1129 Terminology Relating to WaterD1193 Specification for Reagent WaterD2777 Practice for Determination of Precision and Bias ofApplicable Test Methods of Committee D19 on WaterD3370 Practices for Sampling Wa
9、ter from Closed Conduits3. Terminology3.1 Definitions:3.1.1 For definitions of terms used in this standard, refer toTest Methods D1125 and Terminology D1129.4. Summary of Test Method4.1 This test method measures the anion concentration (suchas Cland SO4) by measuring the electrical conductivity ofth
10、e anions after passing the sample through a cation exchangerin the hydrogen form, then through a degasifier. Passagethrough the cation resin replaces cations (including ammoniaand other amines) in the water with hydrogen ions. Thiseliminates interference in the measurement of anions. Threeconductivi
11、ty cells located in the instrument provide measure-ments of the influent conductivity, cation conductivity at theincoming sample temperature, and the effluent conductivityafter acidic (volatile) gas removal. The sample is then eithercooled to 25C or conductivity values are compensated to25C. While t
12、he influent conductivity measurement is notnecessary in determining the total anion conductivity, itsdetermination provides a more complete evaluation of thesample, which can also include an estimation of the amine1This test method is under the jurisdiction of ASTM Committee D19 on Waterand is the d
13、irect responsibility of Subcommittee D19.03 on Sampling Water andWater-Formed Deposits, Analysis of Water for Power Generation and Process Use,On-Line Water Analysis, and Surveillance of Water.Current edition approved June 1, 2016. Published June 2016. Originallyapproved in 1985. Last previous editi
14、on approved in 2010 as D4519 10. DOI:10.1520/D4519-16.2For 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.Copyrig
15、ht ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1content. Measurement of the cation and degassed sampleconductivities are necessary in determining the composition ofthe influent (total anions and acidic gas content). Reference toTable 1 and T
16、able 2 or Figs. 1-3, or both, are then necessary tocomplete the determinations.4.2 In-depth studies provide additional background andupdated experience with the degassed cation conductivitytechnique (1).35. Significance and Use5.1 This test method can be a useful diagnostic tool inmeasuring the impu
17、rities and detecting their sources in highpurity water, boiler feed water and steam condensate of highpressure power plants, and in the process water of certainindustries requiring high purity water.5.2 The measurement of such impurities is most importantto these industries since plant outages or pr
18、oduct contaminationcan result from events such as condenser leakage. Also, waterquality deviations can occur from condensate polishing andmakeup water equipment malfunctions.5.3 The continuous measurement and trends provided bythis test method are of particular interest and can indicate theneed for
19、corrections in water treating or operating proceduresand equipment. The equipment for this test method can beconsidered more rugged and adaptable to installation under3The boldface numbers in parentheses refer to a list of references at the end ofthis standard.TABLE 1 Increase in Conductivity of Pur
20、e Water Expressed asChloride Ion or Sulfate IonConductivity due toChloridesConcentrationChlorides (PPB)Conductivity due toSulfatesConcentrationSulfates (PPB)0.0548 0.0 0.0548 0.00.0595 1 0.0608 10.0651 2 0.0669 20.0717 3 0.0732 30.0791 4 0.0797 40.0872 5 0.0862 50.0958 6 0.0929 60.1049 7 0.0997 70.1
21、145 8 0.1066 80.1243 9 0.1137 90.1344 10 0.1208 100.2427 20 0.1969 200.3560 30 0.2780 300.4709 40 0.3616 400.5865 50 0.4455 500.7023 60 0.5320 600.8183 70 0.6181 700.9345 80 0.7044 801.0507 90 0.7909 901.1669 100 0.8775 1002.2209 200 1.7470 2005.8252 500 4.362 500TABLE 2 25C Conductivity of the Samp
22、le Immediately After theCation Column, Relating to the CO2Concentration with the AnionComponent Subtracted Out (See 11.7)Conductivitys/cmCarbon Dioxideppm ppb0.0548 0 00.09 0.01 100.12 0.02 200.16 0.03 300.19 0.04 400.21 0.05 500.24 0.06 600.26 0.07 700.28 0.08 800.3 0.09 900.32 0.1 1000.48 0.2 2000
23、.61 0.3 3000.71 0.4 4000.81 0.5 5000.89 0.6 6000.97 0.7 7001.04 0.8 8001.11 0.9 9001.17 1.0 .1.69 2.0 .2.09 3.0 .2.42 4.0 .2.72 5.0 .2.98 6.0 .3.23 7.0 .3.46 8.0 .3.67 9.0 .3.88 10 .5.46 20 .FIG. 1 Chloride Ion vs. ConductivityD4519 162plant operating conditions than the more accurate laboratorymeth
24、ods, such as ion chromatography and atomic absorption.6. Interferences6.1 It is important to devote particular attention to accurateflow and temperature control as variations can cause inaccu-racies. See AnnexA1, AnnexA2, and AnnexA3 for additionalinformation.7. Apparatus7.1 Degassed Cation Conducti
25、vity System, may be providedas a complete panel or may be assembled from components.7.1.1 Constant Head Device or Other Means, for providingconstant sample flow through the apparatus.7.1.2 Constant Temperature Equipment, for adjusting theinfluent temperature to 25 6 0.5C.7.1.3 Flow or Temperature Sa
26、fety Shutoff, as needed toprotect the degasifier heater.7.1.4 Conductivity Instrument(s) and Sensors, for measur-ing the conductivity of the sample to determine the concentra-tion of anions and carbon dioxide. Use of instruments that havea specialized temperature compensation for high purity water(t
27、o 25C) based on a trace acid contaminant such as HCl orH2SO4is required for this test method. Instrumentation mayalso include software to automate the determination of anionsand carbon dioxide based on Table 1 and Table 2.7.1.5 Hydrogen Ion Exchange Cartridge, 158 in. insidediameter, 12 in. height,
28、containing 1 lb of 8 % cross-linkedstyrene-divinylbenzene, strong acid gel cation exchange resinin the H+form; U.S. standard mesh 16 by 50 (1190 by 297 m)may be used. Regenerate with 1500 mL of hydrochloric acid(1 + 6) at a flow rate of 40 to 50 mL/min, followed by rinsingwith 300 mL of Type II wate
29、r at the same flow rate. Then rinsewith 3500 mL of Type II water at a flow rate of 100 to 150mL/min. Rinse down when placing in service.NOTE 1The column inside diameter, resin bed height, inlet sampletemperature (11.3), and service flowrate (11.4) have been standardized toprovide comparable results.
30、 They may not be the optimum values. Theuser should realize that those parameters affect the measurement.7.1.6 Degasifier, for removing carbon dioxide from thesample. The degasifier may operate by heating the sample tonear boiling temperature with a reboiler or by sparging with aCO2-free gas such as
31、 nitrogen. Following a reboiler, a coolermay be used to reduce the sample temperature and potentialerrors in temperature compensation. (Membrane gas strippinghas been used experimentally for degassing but this techniquehas not been standardized.) (2)8. Reagents8.1 Purity of ReagentsReagent grade che
32、micals shall beused in all tests. Unless otherwise indicated, it is intended thatall reagents shall conform to the specifications of theAmericanFIG. 2 Sulfate Ion vs. ConductivityFIG. 3 Carbon Dioxide vs. ConductivityD4519 163Chemical Society, where such specifications are available.4Other grades ma
33、y be used, provided it is first ascertained thatthe reagent is of sufficiently high purity to permit its usewithout lessening the accuracy of the determination.8.2 Purity of WaterUnless otherwise indicated, referencesto water that is used for reagent preparation, rinsing or dilutionshall be understo
34、od to mean water that conforms to thequantitative specifications of Type II reagent water of Specifi-cation D1193.8.3 Chloride Solution, Stock (1 mL = 0.1 mg Cl)Dissolve in water 0.1649 g of sodium chloride (NaCl) dried toconstant weight at 105C, and dilute to 1 L in a thoroughlycleaned polyethylene
35、 flask.8.4 Chloride Solution, Standard (1.00 mL = 0.001 mg)Dilute 10.00 mL of chloride stock solution (8.3) to 1 L withwater.8.4.1 This standard chloride solution is to be used in thecalibration of the instrument if desired, or reference can bemade to the instruction booklet furnished with the instr
36、ument.8.5 Hydrochloric Acid (1+6)Add 100 mL concentratedHCl (sp. gr. 1.19) to 600 mL water.9. Sampling9.1 Establish sampling conditions in accordance with theapplicable ASTM standards: Practice D1066 and PracticesD3370.10. Calibration10.1 The instrument may be calibrated by pumping solu-tions of kno
37、wn concentrations of Cl(in NaCl form) or SO4(in Na2SO4form) through the instrument and observing theconductivity increases. It may be preferred to use the calibra-tion charts shown in the instruction book accompanying theinstrument or in referenced articles (3-6).10.2 If it is desired to calibrate t
38、he instrument using knownchloride solutions, the range of 0.001 to 0.010 mg/L (1 to 10ppb) of chloride may be covered by application of 0.2 to 2.0mL/min of the standard chloride solution (8.4.1) to the 200mL/min flow by injecting the flow from a small peristalticpump to a hypodermic needle inserted
39、in a plastic tubingconnection.11. Procedure11.1 Flush out the piping thoroughly by flow of high puritywater through the instrument before starting the flow of waterto be tested.11.2 Refer to the manufacturers instruction booklet beforestarting the instrument. Because of the nature of this measuringt
40、echnique, it is very important to follow the manufacturersinstructions very carefully in order to achieve accurate results.See Annex A1 Annex A4 for a discussion on the effectscaused by variations in operating conditions and interferingsubstances.11.3 Connect the sample line to be tested to the inst
41、rumentinfluent connection. This water should preferably be at atemperature of 25 6 0.5C. The flow shall first pass throughthe flow control device, then into the instrument through thehydrogen ion exchanger and degasifier (Fig. 4).11.4 Adjust the flow through the instrument to the properflow rate (20
42、0 mL/min), or as specified by the instrumentmanufacturer. It is important to use a constant head device orother means to maintain a stable flow rate, otherwise changesin cation resin exchange and degassing efficiencies may occurwith changes in the flow rate.11.5 Clean up the system by maintaining th
43、e recommendedflow rate through the instrument for 24 h or longer to approacha minimum value of 0.055 S/cm reading for pure water at thefinal effluent conductivity. On restart, several hours of opera-tion may be required before this minimum conductivity valueis obtained.11.6 Refer to Table 1,orFig. 1
44、 and Fig. 2, or both, todetermine the equivalent concentration of chloride ion orsulfate ion based on the conductivity reading of the finalconductivity cell.4Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For suggestions on the testing of reage
45、nts notlisted by the American Chemical Society, see Analar Standards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmaceutical Convention, Inc. (USPC), Rockville,MD.FIG. 4 Block Diagram of Measurement ApparatusD4519 16411.7
46、In order to obtain the volatiles expressed as carbondioxide in Table 2, subtract the conductivity of pure water(0.055 S/cm) from the conductivity of the final effluent cell.Then deduct this value from the cation conductivity obtainedfrom the cell immediately after the cation exchange resin. Usethis
47、adjusted conductivity value to look up the concentration ofvolatiles expressed as a concentration of carbon dioxide inTable 2,orFig. 3, or both. Alternatively, use instrumentationcontaining software to make these conversions automaticallyand providing continuous real time readout.11.7.1 Example: Bas
48、ed on a final cell conductivity readingof 0.087 S/cm (equivalent to 5 ppb of Clin a systempredominant in chloride ion), 0.055 S/cm is deducted for theconductivity of pure water to obtain a value of0.087 0.055 = 0.032 S/cm. Then deduct this number (0.032)from the cation conductivity (0.242 0.032) = 0
49、.21 Scm dueto volatiles, which corresponds to 50 g/L (ppb) of carbondioxide, as read from Table 2. This deduction is necessary toaccount for the anion conductivity (other than carbon dioxide)obtained in the cation conductivity measurement.11.8 The service life of the cation cartridge may vary fromone month to several months depending on the amine concen-tration in the influent and the sample flow rate.12. Report12.1 Report the results as g/L (ppb) Cl,orSO4, or both,and CO2as obtained from Table 1 and Table 2,orFigs. 1-3,orboth w
copyright@ 2008-2019 麦多课文库（www.mydoc123.com）网站版权所有
备案/许可证编号：苏ICP备17064731号-1