1、Designation: D 3375 95a (Reapproved 2001)Standard Test Method forColumn Capacity of Particulate Mixed Bed IonExchange Materials1This standard is issued under the fixed designation D 3375; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revis
2、ion, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the determination of the perfor-mance of particulate mixed bed ion exchange
3、materials in theregenerated form when used for deionization. It is intended foruse in testing unused mixed bed materials and samples ofregenerated mixed beds from operating units.1.2 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is therespon
4、sibility 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:D 1125 Test Methods for Electrical Conductivity and Re-sistivity of Water2D 1129 Terminology R
5、elating to Water2D 1193 Specification for Reagent Water2D 1293 Test Methods for pH of Water2D 1782 Test Methods for Operating Performance of Par-ticulate Cation-Exchange Materials3D 2687 Practices for Sampling Particulate Ion-ExchangeMaterials3D 2777 Practice for Determination of Precision and Bias
6、ofApplicable Methods of Committee D19 on Water23. Terminology3.1 DefinitionsFor definitions of terms related to water,refer to Terminology D 1129.4. Summary of Test Method4.1 This test method consists of exhausting a column ofregenerated mixed bed ion exchange material to a specific endpoint with an
7、 influent solution of known composition andvolume.5. Significance and Use5.1 This test method can be used to evaluate unused mixedbed ion exchange materials for conformance to specifications.When a representative sample of the mixed bed can beobtained from an operating unit, this test method can be
8、usedto evaluate the regeneration efficiency by comparison with thesame data obtained with new material from the same manu-factured lots, or retained samples of the in-place products.5.2 This test method provides for the calculation of capacityin terms of the volume of water treated to a conductivity
9、 endpoint.5.3 The test method as written assumes that the cationexchange material has been regenerated to the hydrogen formwith acid and the anion exchange material has been regener-ated with alkali to the hydroxide or free-base form. In certainapplications a cation exchange material in the potassiu
10、m,ammonium, or other monovalent form may be encountered.Such materials may be tested following this procedure usingTest Water A (Test Methods D 1782) as the influent andsubstituting the hardness end point (Test Methods D 1782) forthe end points prescribed herein.5.4 In most cases the product tested
11、will be properly mixedand will contain the correct proportions of anion and cationexchange materials. However, if the pH as well as theconductivity of the effluent is measured, the test method willindicate which of the components is present in excess; an acideffluent at breakthrough indicating an ex
12、cess of regeneratedcation exchange groups and an alkaline effluent an excess ofregenerated anion exchange groups. In such cases the volumesof the two components obtained in the final backwash willindicate whether this imbalance arises from improper regen-eration or from an improper ratio of the two
13、components. Itshould be noted, however, that not all units are charged with abalanced ratio of anion-exchanging and cation-exchanginggroups. Hence, wherever possible, a field sample should beevaluated in comparison with a retained sample of the originalcharge.5.5 This test method provides for the ca
14、lculation of capacityon either a wet weight basis or a volume basis. Although suchmaterials are normally bought and sold in terms of cubic feet,they are actually packaged in wet pounds. Therefore, it is the1This test method is under the jurisdiction of ASTM Committee D19 on Waterand is the direct re
15、sponsibility of Subcommittee D19.08 on Membranes and IonExchange Materials.Current edition approved Sept. 10, 1995. Published November 1995. Originallypublished as D 3375 75. Last previous edition D 3375 95.2Annual Book of ASTM Standards, Vol 11.01.3Annual Book of ASTM Standards, Vol 11.02.1Copyrigh
16、t ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.capacity on a wet weight basis that is directly correlatable tothe amount of material in a given shipment.5.6 Calculation of a volume capacity is based on theexhausted, separated volume of the c
17、omponents after back-washing and resettling the bed. This volume is chosen becauseit is difficult, if not impossible, to pack a sample of regeneratedmixed bed material in a small-diameter column reproducibly.5.7 This test method may be used to test mixed bed resincartridges. In such cases the flow r
18、ate of test water and thefrequency of sampling must be varied to compensate for theapproximate volume of resin in the test sample. The test aswritten assumes a resin volume of approximately 330 mL.6. Apparatus6.1 Test Assembly (Fig. 1), consisting of the following:6.1.1 Column, transparent supported
19、 25 6 2.5-mm (1 60.1-in.) inside diameter and approximately 1500 mm (60 in.)long. The bottom of the column shall be closed and providedwith an outlet of about 6-mm inside diameter. Connectionsshall be provided at the top and the bottom for the admissionand removal of the exhausting solution as descr
20、ibed in 7.4.Adequate means of regulating and measuring flow shall beprovided. Support for the sample shall be provided so that thedistance from the sample to the column outlet is at least 50mm. Calibrate the column in such a manner that the volumereadings required by the test method can be made. Mak
21、e allcalibration measurements at 25 6 5C.6.1.2 Sample Support, so designed that the distance from thesample to the column outlet is at least 50 mm. A suggestedsupporting bed utilizes quartz, gravel, glass beads, or othermaterial 1.5 to 3.5 mm in diameter, insoluble in the reagentsused, and retained
22、on a corrosion-resistant screen.6.2 Measuring circuit and in-line conductivity cells asdescribed in Test Methods D 1125. A continuous recorder isrecommended.6.3 pH Meter, with associated electrodes as described inTest Methods D 1293. A continuous recorder is recommended.7. Reagents7.1 Purity of Reag
23、entsReagent grade chemicals shall beused in all tests. Unless otherwise indicated, it is intended thatFIG. 1 Typical Arrangement of Apparatus for Performance Testing of Ion Exchange MaterialsD 3375 95a (2001)2all reagents shall conform to the specifications of the Commit-tee on Analytical Reagents o
24、f the American Chemical Society,where such specifications are available.4Other 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 WaterAll reference to water in this tes
25、tmethod shall be understood to mean Reagent Water Type I orII conforming to Specification D 1193, with the additionalrequirement that the silica concentration is less than 0.1 mg/L.7.3 Ammonium Hydroxide Solution (1 + 19)Carefullypour 50 mL of concentrated ammonium hydroxide (NH4OH,sp gr 0.90) into
26、500 mL of water, stirring constantly. Cool to 256 5C and dilute to 1 L with water. Mix well.7.4 Ion Exchange Test Water D (10 meq/L)Prepare a testwater containing, in each litre, 0.585 g of oven-dried (105C)sodium chloride (NaCl). Approximately 25 L of this solutionare required for a single test.7.4
27、.1 To standardize for chloride content, pipet three100-mL portions. Add 1 drop of methyl orange indicatorsolution and 1 drop of phenolphthalein indicator solution toeach and neutralize, if required, by dropwise addition ofHNO3(1 + 9) until the color changes from yellow to orangefollowed by dropwise
28、addition of NH4OH (1 + 19) to restorethe yellow color. Pipet in 1 mL of K2CrO4solution (50 g/L)and titrate each with standard 0.1 N AgNO3solution until thecolor of the supernatant solution changes from yellow tored-orange and persists for 30 s with vigorous swirling. Recordthe average number of mill
29、ilitres of AgNO3solution used to60.02 mL.7.4.2 Calculate the strength of the solution in meq ofchloride as follows:Chloride, meq/L 5 V 3 N 3 10 (1)where:V = millilitres of AgNO3solution required for titration,andN = normality of the AgNO3solution.The test solution used should have a concentration of
30、 10 60.5 meq/L of chloride.NOTE 1Because of the large quantities of this reagent that arerequired, it is usually made up semi-quantitatively in large batches andthen standardized per the above procedure. If desired, it is acceptable toprepare this reagent quantitatively (as for a primary standard) a
31、nd theneliminate the above standardization.7.5 Methyl Orange Indicator Solution (1.0 g/L)Dissolve0.10 g of methyl orange in water and dilute to 100 mL withwater.7.6 Nitric Acid (1 + 9)Pour 1 volume of nitric acid(HNO3, sp gr 1.42) into 9 volumes of water and mix thor-oughly.7.7 Phenolphthalein Indic
32、ator Solution (10.0 g/L)Dissolve 1.0 g of phenolphthalein in 100 mL of 95 % ethanol.NOTE 2In most cases certain denatured alcohols such as speciallydenatured Formula Nos. 3A, 30, or 2B may be substituted for ethanol.7.8 Potassium Chromate Solution (50 g/L)Dissolve 5.0 gof potassium chromate (K2CrO4)
33、 in 50 mL of water. Dilute to100 mL with water.7.9 Silver Nitrate Solution, Standard (0.10 N)Dry crys-talline silver nitrate (AgNO3) at 105C for 1 h and cool in adesiccator. Weigh out 17 6 0.05 g. Transfer to a 1-Lvolumetricflask with water. Dissolve in 500 mL of water and mixthoroughly. Dilute to 1
34、 L with water at 25 6 5C. Mix well.Store the solution in a tightly stoppered amber glass bottle.7.9.1 To standardize, dry approximately5gofreagentsodium chloride (NaCl) in a glass container at 105C for 2 h.Cool in a desiccator. Weigh accurately three 0.2500 60.0100-g portions of the dried NaCl and t
35、ransfer to separate250-mL conical flasks. Add 100 mL of water and swirl todissolve the NaCl. Pipet in 1 mL of K2CrO4solution (50 g/L)and titrate with the 0.1 N AgNO3solution with vigorousswirling until the color of the solution changes from yellow tored-orange and persists for 30 s.7.9.2 Calculate t
36、he normality of the AgNO3solution asfollows:N 5 D/0.05845 3 E (2)where:N = normality of the AgNO3solution,D = actual weight of NaCl used, andE = millilitres of AgNO3solution used.8. Sampling8.1 For sampling refer to Practices D 2687.8.2 When sampling new mixed bed materials the drum-to-drum uniformi
37、ty of the mixing is an important factor, particu-larly if the material is to be repackaged into small cartridges.Hence, if samples are taken from three or more separate drumsor bags of a given lot a composite sample is not prepared butone column is run from each container sampled. Where thesequence
38、of filling is known such samples should include thefirst and the last container filled.9. Procedure9.1 Weigh 270 6 1 g of the moist, as received, mixed bedion exchange material, and record weight to the nearest 0.1 g.Introduce through the backwash line about 25 mm of water tothe column. Place about
39、25 mL of the sample in a large-stemmed plastic funnel inserted in the top of the column. Washthe portion of sample into the column with a minimum ofwater. Repeat until all the sample is transferred into thecolumn. Care must be exercised that no stratification takesplace during the filling procedure.
40、 Maintain the water level inthe column about 10 mm over the bed level to minimize airtrapping.9.2 When all the mixed bed ion exchange material has beentransferred slowly introduce test water D at the top of thecolumn. Increase the flow rate to 100 mL/min, adjusting therate as required with a clamp i
41、n the effluent line.4Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For suggestions on the testing of reagents notlisted by the American Chemical Society, see Analar Standards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the Unit
42、ed States Pharmacopeiaand National Formulary, U.S. Pharmaceutical Convention, Inc. (USPC), Rockville,MD.D 3375 95a (2001)39.3 Measure and record the effluent conductivity every 2 L.Continue until the 1.0 mhos/cm value is passed, then recordreadings for each 500 mL of effluent until two successiverea
43、dings greater than 50 S/cm (20 000 Vcm) are obtained.9.4 When the effluent conductivity exceeds 1.0 S/cm (1MVcm), measure the pH of the effluent. Continue the pHmeasurements at the same frequency as the conductivitymeasurements.9.5 When the conductivity exceeds 50 S/cm (20 000Vcm), stop the flow of
44、test water and record the total volume(V) of test water used in litres.9.6 Open the backwash valves and backwash the bed withwater for 10 min at a flow rate sufficient to maintain a 50 %expansion of the bed. Stop the flow of water and allow the bedto settle. Drain at the rate of 100 mL/min until the
45、 water levelis 20 to 30 mm above the bed. Do not jar. Record the bedvolume in millilitres. Repeat the backwash and drain procedureuntil two successive readings agree within 5 mL. Record theaverage volume as S mL.10. Calculation10.1 The operating capacity may be calculated on either avolume or wet we
46、ight basis using a conductivity end point.10.2 Calculate the operating capacity to the conductivityend point on a volume basis as follows:Capacity, meq/mL 5 C 3 V/S (3)where:C = total electrolytes in test water D expressed in mil-liequivalents per litre as determined in 7.4.2,V = volume of test wate
47、r used, litres, andS = volume of sample measured in 9.6.This capacity may be converted to kilograins per cubic footas CaCO3by multiplying by 21.8.10.3 Calculate the operating capacity to the conductivityend point on a wet weight basis as follows:Capacity, meq/g wet 5 C 3 V/270 (4)where C and V are d
48、efined as in 10.2.NOTE 3Other end points may be agreed upon. When this is done thespecies and level selected should be specified with the results.11. Report11.1 The report of results of this test method should includenot only the capacity as calculated above but the end pointused. For certification
49、purposes the averaging of results fromthree separate samples is customary. However, when samplesfrom individual drums are analyzed the individual results aswell as the average should be reported.12. Precision and Bias12.1 The collaborative study for this test method involvedsix laboratories, six operators, and three replicate determina-tions on one material, IRN-150 mixed bed resin. The analysisof a single material was judged to be sufficient to represent thevarious mixed resins in general use, since they would beexpected to fall in a relatively narrow ran
