1、Designation: D6302 98 (Reapproved 2017)Standard Practice forEvaluating the Kinetic Behavior of Ion Exchange Resins1This standard is issued under the fixed designation D6302; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year
2、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 is intended to evaluate changes in kineticperformance of ion exchange resins used in mixed beds topro
3、duce high purity water. Within strict limitations, it also maybe used for comparing resin of different types. This standarddoes not seek to mimic actual operating conditions. Specificchallenge solutions and conditions are specified. At the optionof the user, other conditions may be tested.1.2 The va
4、lues stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.3 This standard does not purport to address the safetyconcerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety an
5、dhealth practices and determine the applicability of regulatorylimitations prior to use.1.4 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards,
6、 Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2D1129 Terminology Relating to WaterD1193 Specification for Reagent WaterD2187 Test Methods for Physical and Chemical Propertiesof Particulate Ion-
7、Exchange ResinsD2687 Practices for Sampling Particulate Ion-Exchange Ma-terialsD5391 Test Method for Electrical Conductivity and Resis-tivity of a Flowing High Purity Water Sample3. Terminology3.1 Definitions:3.1.1 For definitions of terms used in this standard, refer toTerminology D1129.4. Summary
8、of Practice4.1 An apparatus is described in which a specified volumeof regenerated resin sample is mixed with a corresponding newresin. The mixed bed then is operated at a controlled high flowrate on an influent of known composition, and the quality of theeffluent is measured by conductivity, and if
9、 agreed upon, otherappropriate analytical procedures.5. Significance and Use5.1 This practice is intended to evaluate changes in theperformance of ion exchange resins used in mixed bedsoperating as polishing systems for solutions of low ionicstrength, typically, 17.5 M (see 8.3).NOTE 1Pressure relie
10、f should be provided for this system to allow nomore pressure than the materials can tolerate, typically 50 psig or less.8. Reagents8.1 Purity of ReagentsReagents meeting the specificationsof the Committee on Analytical Reagents of the AmericanChemical Society may not be suitable for use in this pra
11、ctice.All reagents used should be of the highest grade commerciallyavailable and should be tested for both anionic and cationicimpurities by ion chromatography after the feed solutions havebeen prepared.3,48.2 Purity of WaterUnless otherwise indicated, referencesto water shall be understood to mean
12、reagent water conformingto Specification D1193, Type I. It shall be checked by ionchromatography at the ppb level prior to use, if ion chroma-tography will be used for analysis.8.3 Standard Cation ResinNew hydrogen-form, strongacid, cation resin is to be used; nuclear grade is preferred. Donot regen
13、erate this resin. This resin should be stored inimpermeable containers at temperatures that do not exceed25C. Backwash the resin with water at 100 % expansion for atleast 15 min. The resin should be rinsed thoroughly with waterto 17.5 M resistivity before being used in a kinetics test.Thesame cation
14、 resin may be used in the test column, as well as thecation column. It is recommended that a specific type andbrand of resin be used consistently where results are to becompared.8.4 Standard Anion ResinUse new, hydroxide-form,strong base anion resin; nuclear grade preferred. Follow otherrequirements
15、 as given in 8.3.8.5 Test SolutionsTest solutions can be modified for spe-cific systems, however, the following are recommended forroutine testing. Although a target feed injection rate of 0.5mL/min is used here, the feed concentrations and meteringpump flows can be altered, so long as the test colu
16、mn influentconcentrations and flow rate are nominal as specified.8.5.1 Ammonia Feed Solution (3.0 g/L as NH3) Optional forUse with Ammoniated SystemsTare a beaker with about 50mL of water on an analytical balance with 0.01-g sensitivity.Add 20.9 g of concentrated ammonium hydroxide (sp. gr. 0.90)fro
17、m a dropping bottle. Transfer to a 2-L volumetric flask, anddilute to volume. Mix well. When delivered at the rate of 0.5mL/min into 1 L/min flow, the concentration in the influentshould be 1.5 mg NH3/L.NOTE 2Ammonium hydroxide generates irritating ammonia vapors.8.5.2 Sodium Sulfate Feed Solution (
18、0.9 g Na2SO4/L)Drythe Na2SO4for1hat100105C, then store in a desiccator.Weigh 0.900 g of the anhydrous sodium sulfate, and dissolve itin 1 L of water. Mix well. When delivered at the rate of 0.5mL/min into 1 L/min flow, the concentration of the influentshould be 0.145 mg/L Na and 0.300 mg/L SO4.8.6 R
19、egenerant, Sodium Hydroxide Solution (87 g/L)Add345 g NaOH to 3.5 L of water with stirring. Cool and dilute to4.0 L. This solution is caustic and liberates heat duringdissolution. This is equivalent to 8 % NaOH by weight.NOTE 3This solution is intentionally stronger than typical fieldprocesses so th
20、at maximum percent regeneration is achieved.Reagent grade 50 % NaOH (763 g NaOH/L) also can beused and would require 456 mL to make 4.0 L.8.7 Regenerant, Hydrochloric Acid Solution (1 + 9)Carefully pour 200 mL of hydrochloric acid (HCl, sp. gr. 1.19)into 1800 mL of water, stirring constantly. Cool t
21、o 256 5C.NOTE 4For field cation samples, sulfuric acid typically would besubstituted for HCl, since H2SO4is the usual regenerant in the field.9. Sampling9.1 Collect the sample in accordance with Practices D2687.It is extremely important that the resin sample properlyrepresent the entire bed being ev
22、aluated. Core sampling isrequired. A sample containing at least 300 mL of anion, orcation resin, or both, must be provided. The sample may betaken before or after separation of a mixed bed, so long as it isrepresentative. Use a plastic or glass container with a water-tight cap and label in accordanc
23、e with Practices D2687.9.2 Subsamples taken in the laboratory also must be takenby careful coring to preserve the representativeness of thesample.10. Backwash and Separation Procedure10.1 Place about 800 mL of mixed bed resin sample orabout 500 mL of individual resin sample in the backwash/separatio
24、n apparatus. Backwash with water at a flow sufficientto give about 50 % bed expansion. This should allow crud torinse away while separating any cation from the anion in thesample.3Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For suggestions o
25、n the testing of reagents 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.4McNulty, J.T., Bevan, C.A., et al.,
26、“Anion Exchange Resin KineticTesting:AnIndispensable Tool for Condensate Polisher Troubleshooting,” Proceedings of the47th International Water Conference, Engineers Society of Western Pennsylvania,October 1986.D6302 98 (2017)310.2 Using a siphon or aspiration assembly, remove andcollect the resin of
27、 interest, anion resin (above the interface) orcation resin. Try to minimize cross-contamination by leavingbehind or wasting resin as needed. This, however, must beminimized in order to avoid sample bias. Inspection of theinterface with a hand lens may show a bead size variation at theinterface. If
28、less than 300 mL of the resin of interest isrecovered, repeat 10.1 with another portion of sample.10.3 Remove a small amount of the separated resin to aplastic petri dish and examine under low power (1215)magnification to estimate the percentage of whole beads. If theresin is less than about 90 % wh
29、ole beads, this practice shouldnot be continued.NOTE 5Ion exchange kinetics are affected by particle size and shape.10.4 After decanting excess water, measure, by coring, 300mL of the separated resin in a graduated cylinder under water.Tap gently to settle before measuring resin. Disconnect theregen
30、eration column, and transfer the resin as a slurry to thecolumn. Keep a small amount of water above the resin and tryto minimize air bubbles. Leave the bottom effluent line shut offwhile filling the column. Open it and immediately begin theflow of regenerant. Regenerate the resin as follows. For ani
31、on,use NaOH regenerant solution at a flow rate of 25 mL/min for60 min, maintaining a temperature of 50C either by jacketingthe column or warming the regenerant. For cation resin, use theHCl regenerant with the same conditions, except that ambienttemperatures are used.10.5 Make sure that the water le
32、vel is no more than about 5mm above the top of the resin before beginning the rinse step.Rinse the regenerated resin with water at 25 mL/min for 15min, then increase flow to about 100 mL/min, and rinse untilthe effluent conductivity is 20 S/cm or less. Rinsing shouldtake no more than a total of 1 h.
33、10.6 Transfer the regenerated resin from the column to abeaker. Transfer, by coring, a 75-mL portion to a graduatedcylinder, containing 1015 mL of water. Cover to protect fromCO2until resin is to be used. If mass transfer coefficient is tobe calculated according to Appendix X1, use the rest of there
34、generated resin sample, at least 200 mL, to measure theparticle size distribution as directed in Test Methods D2187,Test Method D. No other pretreatment is required prior tosieving. Measurement of particle size distribution is recom-mended for all samples to verify the representativeness ofsamples a
35、nd comparability of results; however, be cautious inusing this measurement to compare to specifications for sizesince some resin may be lost in this procedure.11. Preparation of Column and Rinse Down11.1 Transfer, by coring, 150 mL of the hydrogen-formcation resin either new or regenerated sample in
36、 a graduatedcylinder under water. Tap the graduated cylinder gently whenmeasuring the resin volume to get an accurate reading.Transferthe cation and the 75 mL of new or regenerated sample anionresin to a 400-mL beaker, and decant excess water, then mixwell with a glass rod.11.2 Disconnect the test c
37、olumn (see Fig. 1), decant excesswater from the resin, and transfer the mixed resin as a slurry tothe rinsed, drained test column. Keep only a very small amountof water above the resin, so the resins do not stratify, and try tominimize air pockets. Leave the bottom effluent line shut offwhile fillin
38、g the column, except that a small amount of liquidcan be drained off while liquid is being added. A small amountof demineralized water can be used to rinse resin off the sidesof the column, but keep only about 5 mm of free liquid abovethe resin to keep resins from separating out. If mass transfercoe
39、fficient will be calculated, measure the inside diameter ofthe test column with a micrometre, divide this by two, andconvert to metres.11.3 An alternative is to drain the test column as above, buttransfer the mixed resin in 25-mL portions, about onetablespoon, to a long-stemmed plastic funnel insert
40、ed in the topof the test column. Again, a minimum amount of rinse watercan be used to facilitate the transfer.NOTE 6If the resin is poorly mixed or contains air pockets, test resultswill be erroneous. If resin stratification or air bubbles can be seen in thecolumn, remove the resin to the beaker, an
41、d repeat the mixing and transfersteps.11.4 Fill the cation column to a depth of at least 15 cm withthe new hydrogen-form cation resin (8.4), then reconnect it inthe test apparatus. This column is not used if the sample testedis cation resin.11.5 Before connecting to the test apparatus, turn on thewa
42、ter supply system and allow it to recirculate or flush to drainuntil the conductivity indicator reads 0.06 S/cm or less.Adjustthe valves to allow flow to the test column, and connect theinfluent and effluent lines to the column.12. Column Test ProcedureNOTE 7Normally this test is conducted at labora
43、tory temperatures, butother temperatures can be used if they can be maintained uniformly duringthe test. In either case, record the temperature at which the test isconducted, and for comparative purposes, data must be generated attemperatures within a 10C range.12.1 Turn on the water source and adju
44、st the flow ratethrough the column with the resin in place until it measures 1L/min on the discharge side.12.2 Turn on the recorder and continue the water flow untila stable reading is obtained. This should require a minimum of15 min but usually less than 1 hour. It may be useful to recordthe rinse
45、down time for comparison purposes. Although areading of less than 0.06 S/cm is expected, an occasional testsample will not attain this. Repeat the entire procedurecarefully, but if the conductivity is still too high, try todetermine the cause of the poor rinse down before proceeding.It may be helpfu
46、l to check for the presence of other ions. Ifmass transfer coefficient is to be calculated, measure the testcolumn resin bed depth.12.3 If analysis other than conductance is to be made, openthe effluent sample tap and take a sample of the water, as abackground blank, with care to minimize its contam
47、ination.Sample containers should be suitable for high purity water.Close the effluent sample tap.12.4 If the optional ammonia solution is to be used, turn onthe feed pump calibrated to feed the ammonia feed solutionD6302 98 (2017)4reagent at the chosen flow rate. Continue to feed this reagentuntil t
48、he reading on the conductivity recorder restabilizes. A12-h run time is recommended.Asample(s) may be taken at theinfluent sample tap if desired to verify the ammonia concen-tration.12.5 Turn on the sodium sulfate feed pump for the sodiumsulfate solution and continue running as in 12.4, taking sampl
49、esat the influent and effluent sample taps for analysis if required.Again, the conductivity should stabilize within a12-h.12.6 Verify that the test column effluent and cation conduc-tivities are being recorded, or record manually.12.7 Shutdown of the feed pumps in reverse order until thesample is again running on water alone. Record the conduc-tance. Shut down the system.13. Reporting13.1 Tabulate the data from the test, including run time, testtemperature, flow velocity, influent concentrations,conductivities, and analysis of specific ions if
