1、April 2009DEUTSCHE NORM Normenausschuss Materialprfung (NMP) im DINDIN-SprachendienstEnglish price group 10No part of this translation may be reproduced without prior permission ofDIN Deutsches Institut fr Normung e. V., Berlin. Beuth Verlag GmbH, 10772 Berlin, Germany,has the exclusive right of sal
2、e for German Standards (DIN-Normen).ICS 71.100.40!$a5j“1621871www.din.deDDIN 54403Testing of ion exchangers Determination of the total capacity of cation exchangersEnglish translation of DIN 54403:2009-04Prfung von Ionenaustauschern Bestimmung der Totalen Kapazitt von KationenaustauschernEnglische b
3、ersetzung von DIN 54403:2009-04Essai des changeurs dions Dtermination de la capacit totale des changeurs de cationsTraduction anglaise de DIN 54403:2009-04SupersedesDIN 54403:2001-12www.beuth.deDocument comprises pages1608.11 DIN 54403:2009-04 2 A comma is used as the decimal marker. Contents Page F
4、oreword. 3 1 Scope . 4 2 Normative references. 4 3 Terms and definitions 4 4 Unit. 4 5 Principle. 4 5.1 General. 4 5.2 Strongly acidic exchangers. 5 5.2.1 General. 5 5.2.2 Total capacity 5 5.3 Weakly acidic exchangers . 5 5.3.1 General. 5 5.3.2 Total capacity 5 6 Designation . 5 7 Apparatus 6 8 Reag
5、ents 8 9 Sampling 8 10 Sample preparation 8 10.1 Strongly acidic cation exchangers . 8 10.1.1 General (see flowcharts 1 and 2) 8 10.2 Weakly acidic cation exchangers . 8 11 Volume adjustment. 8 12 Determination and evaluation of the total capacity of strongly acidic cation exchangers (method A). 9 1
6、3 Determination and evaluaation of total capacity of weakly acidic cation exchangers (method B). 11 14 Rapid method of determining total capacity of strongly acidic cation exchangers (method C). 13 14.1 Reagents 13 14.1.1 Sample preparation 13 14.1.2 Determining the total capacity 13 14.2 Apparatus
7、13 14.2.1 Sample preparation 13 14.2.2 Determining the total capacity 13 14.3 Apparatus settings . 13 14.3.1 Sample preparation 13 14.3.2 Determining the total capacity 13 14.4 Procedure 14 14.4.1 Sample preparation 14 14.4.2 Determining the total capacity (KTin mol/l) 14 14.5 Calculation of total c
8、apacity KT(in mol/l). 14 15 Test report . 16 DIN 54403:2009-04 3 Foreword This standard has been prepared by Working Committee NA 062-08-95 AA Prfung von Ionenaus-tauschern of the Normenausschuss Materialprfung (Materials Testing Standards Committee). The symbol % is used in this standard to mean pe
9、rcentage by mass. Amendments This standard differs from DIN 54403:2001-12 as follows. a) Figure 2 “Flowchart 1” has been corrected. b) The standard has been editorially revised. Previous editions DIN 54403: 1980-11, 1982-11, 2001-12 DIN 54403:2009-04 4 1 Scope This standard specifies methods for det
10、ermining the total capacity of cation exchangers (in this standard referred to as “excangers”, for short). The methods A, B and C according to this standard can be applied to all granular types of strongly and weakly basic resins, but not to powdered or liquid cation-exchange material. Determination
11、 of total capacity enables the external observation of cation-exchange material that is used in water treatment equipment using laboratory tests to evaluate changes and decide whether it has undergone any alterations. The parameters determined in the analyses provide information about the total numb
12、er of groups capable of exchange, about their acidity and about any changes in these characteristics. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the la
13、test edition of the referenced document (including any amendments) applies. DIN 54400, Ion exchange Terminology DIN 54401, Testing of ion exchangers (bead form) Sampling DIN 54402, Testing of ion exchangers Determination of the total capacity of anion exchangers 3 Terms and definitions For the purpo
14、ses of this standard, the terms and definitions given in DIN 54400 apply. 4 Unit The unit in which all capacities in this standard are expressed is mol per litre. 5 Principle 5.1 General Method A (see Clause 12) and method B (see Clause 13) specified in this standard, serve to characterize and test
15、cation exchangers, make use of the following reactions: the regeneration, with varying efficiency, of groups of different acidity with hydrochloric acid; the conversion of neutral salts into free acids by strongly acidic groups in the hydrogen form; the displacement of the hydrogen ions from the exc
16、hanger by sodium ions; the binding of cations in alkaline solution by weakly acidic groups (equivalent to the acidity of weakly acidic groups after regeneration with a stronger acid). DIN 54403:2009-04 5 To determine the capacity of strongly acidic cation exchangers, it is necessary to start either
17、from the hydrogen form prepared by regeneration with acid or from the equally common sodium form as the reference form. In the case of weakly acidic cation exchangers, the starting point is always the hydrogen form. If the exchanger is loaded with other ions, anomalous capacities will be obtained be
18、cause of the difference in the swelling characteristics of the individual ionic forms. It should be noted that there is a marked difference between hydrogen and sodium forms because of their difference in volume. Contamination of the exchangers by deposits, adsorbed oil or other organic substances d
19、uring operation may alter their total capacity. Laboratory determination of the capacity prior to and after cleaning treatment provides information about the cleaning efficiency and the improvement in the parameters achieved. To assess the damage to the ion-exchange material as a result of degradati
20、on of the matrix structure or of the functional groups, the cleaned sample shall always be compared with a sample of unused exchanger from the same batch. 5.2 Strongly acidic exchangers 5.2.1 General All the functional groups of strongly acidic exchangers shall be converted to the hydrogen form by t
21、reatment with an adequate quantity of acid. 5.2.2 Total capacity After treatment with hydrochloric acid under specified conditions and rinsing with deionized water, a reference volume shall be measured out (reference parameter for the hydrogen form). If the sodium form is chosen for reference purpos
22、es, the volume shall be measured after treatment with sodium chloride solution (see 10.1.3), but prior to regeneration with hydrochloric acid. Excess sodium chloride solution shall then be passed through the exchanger and the hydrochloric acid in the effluent shall be determined. The total capacity
23、shall be calculated from the quantity of hydrogen ions liberated. 5.3 Weakly acidic exchangers 5.3.1 General Only the total capacity of weakly acidic cation exchangers is of interest. Since the volumes of the salt form and the hydrogen form of some weakly acidic exchangers vary considerably owing to
24、 exchanger swelling and shrinkage, they are always converted to the hydrogen form using hydrochloric acid before testing. 5.3.2 Total capacity After the exchanger has been regenerated with excess hydrochloric acid and rinsed with deionized water, its volume shall be measured. The exchanger is then t
25、reated with excess sodium hydroxide solution and the weak acid capacity calculated from the quantity of sodium hydroxide bound. 6 Designation Designation of the method of determining the total capacity of cation exchangers by method A: Test DIN 54403-A DIN 54403:2009-04 6 7 Apparatus In addition to
26、calibrated measuring instruments and standard laboratory equipment, the following shall be used: Glass filter tube (1) (as shown in Figure 1), with an internal diameter of about 20 mm, about 400 mm long, having a permanently fitted glass frit G0 (2) with a pore size of 150 m to 200 m, a ground socke
27、t (3) and a connecting piece (4) about 20 mm long with an internal diameter of 4 mm and an external diameter of about 8 mm. PE tube (5), having an internal diameter of 6 mm and about 450 mm long, connected to the connecting piece (4); the other end of the PE tube is fitted with a shaped glass piece
28、(6) having an internal diameter of 4 mm and about 100 mm long; a glass tube is fused to the centre of the glass piece extending initially at an angle of about 45 and then at about 20; if the glass piece is suspended in the opening of a vessel (e.g. a volumetric flask) placed on a platform whose heig
29、ht can be adjusted, the liquid level above the ion exchange resin packed into the filter tube (1) can be adjusted as necessary (e.g. 1 cm deep) by raising and lowering the shaped glass piece (6). Dropping funnel (7), having a capacity of 500 ml or 1 000 ml is mounted on the filter tube (1) and has a
30、 stopcock with a PTFE tap (8) and a conical ground socket. It is advantageous if the extension of this funnel (9), about 60 mm long, is either tapered down to an opening of 1 mm to 2 mm diameter at its end or is a capillary of the same internal diameter over its entire length. NOTE The apparatus des
31、cribed here is identical to that specified in DIN 54402. Shaking table, for mechanically adjusting the volume. DIN 54403:2009-04 Dimension in millimetres Key 1 Filter tube 2 Glass frit 3 Ground socket 4 Connecting piece 5 PE tube 6 Shaped glass piece 7 Dropping funnel 8 Stopcock with tap 9 Extension
32、 Figure 1 Filter tube 7 DIN 54403:2009-04 8 8 Reagents Reagents shall be of analytical grade and the water used shall be fully demineralized using ion exchangers. Unless otherwise specified, the solutions of reagents shall be prepared with deionized water. 0,1 % solution of methyl orange in ethanol;
33、 10 % sodium chloride solution, prepared by dissolving 100 g of sodium chloride, NaCl, in water and making up to 1 000 ml; 2,5 % sodium chloride solution, prepared by dissolving 25 g of sodium chloride, NaCl, in water and making up to 1 000 ml; c(NaOH) = 1 mol/l sodium hydroxide solution; c(NaOH) =
34、0,1 mol/l sodium hydroxide solution; 15 % hydrochloric acid c(HCl) = 1 mol/l hydrochloric acid solution. 9 Sampling According to DIN 54401. 10 Sample preparation 10.1 Strongly acidic cation exchangers 10.1.1 General (see flowcharts 1 and 2) Convert strongly acidic exchangers to the hydrogen form or
35、sodium form for determining the total capacity. 10.1.2 To convert the exchanger to the hydrogen form, fill the filter tube with deionized water and introduce about 100 ml of sample in any chemical form without allowing bubbles to form and pass about 600 ml of 15 % hydrochloric acid through it at a f
36、low rate of 10 ml/min. Then, pass deionized water at the same flow rate until the base capacity of the effluent at a pH value of 4,3 (KB4,3) is 0,1 mmol/l. The exchanger will then be in the hydrogen form. Determine the capacity of the sample within 24 hours. 10.1.3 To convert the exchanger to the so
37、dium form, fill the filter tube with deionized water and introduce about 100 ml of the sample in any chemical form without allowing bubbles to form and pass about 1 000 ml of 10 % sodium chloride solution through it at a flow rate of 10 ml/min. Then pass 1 000 ml of deionized water at the same flow
38、rate. The exchanger will then be in the sodium form. Determine the capacity of the sample within 24 hours. 10.2 Weakly acidic cation exchangers To determine the total capacity, pretreat the sample as described in 10.1.2 and convert the cation exchanger to the hydrogen form. DIN 54403:2009-04 11 Volu
39、me adjustment Shake the exchanger pretreated as described in clause 10 under deionized water in a measuring cylinder manually or, preferably, on a shaking table until the volume is constant, taking care to remove any air bubbles. The final volume of the exchanger after shaking shall be (50 1) ml. 12
40、 Determination and evaluation of the total capacity of strongly acidic cation exchangers (method A) See flowchart 1 (see Figure 2). Transfer the exchanger shaken to a constant volume of (50 1) ml as described in clause 11 using deionized water quantitatively to a filter tube filled with deionized wa
41、ter and lower the liquid level to about 1 cm above the exchanger, taking care to avoid air bubbles. If the exchanger is in the hydrogen form, no regeneration will be necessary. Treat exchangers in the sodium form with 300 ml of 15 % hydrochloric acid at a flow rate of 5 ml/min. Finally, wash with de
42、ionized water at the same flow rate until the base capacity of the effluent at a pH value of 4,3 (KB4,3) is 0,1 mmol/l or less. Then pass 950 ml of 2,5 % sodium chloride solution through the exchanger column at a flow rate of 10 ml/min and collect the effluent in a 1 000 ml volumetric flask. Continu
43、e rinsing with deionized water until the contents are made up to the mark, and then mix the liquid thoroughly. Titrate 10 ml of this solution with sodium hydroxide (c(NaOH) = 0,1 mol/l), using methyl orange as indicator. Calculate the total capacity, KT, in mol/l of exchanger, using equation (1): 01
44、,0HaT=VcVK (1) where Vais the volume of sodium hydroxide solution required for the titration, in ml; c is the concentration of the sodium hydroxide solution, in mol/l; VHis the exchanger volume, in ml; 0,01 is the aliquot part of the solution to be titrated. If c = 0,1 mol/l and VH= 50 ml, then equa
45、tion (1) becomes: 5aTVK = (2) 9 DIN 54403:2009-04 Flowchart 1 Determination of total capacity of strongly acidic cation exchangers (method A) Figure 2 Flowchart 1 10 DIN 54403:2009-04 13 Determination and evaluation of total capacity of weakly acidic cation exchangers (method B) See flowchart 2 (see
46、 Figure 3). After shaking the exchanger to a constant volume of (50 1) ml as described in Clause 11, pour 100 ml of sodium hydroxide (c(NaOH) = 1 mol/l) solution over it in a beaker and mix thoroughly. After 15 minutes, rinse the contents of the beaker quantitatively into the filter tube, taking car
47、e to avoid air bubbles. Lower the liquid level to about 1 cm above the exchanger and collect the effluent in a 1 000 ml volumetric flask. Pass a further 500 ml of sodium hydroxide solution (c(NaOH) = 1 mol/l) over the exchanger at a flow rate of 5 ml/min. Then, rinse with 200 ml of deionized water a
48、t the same flow rate. Combine all the effluents in the 1 000 ml volumetric flask, make up to the mark with deionized water and mix thoroughly. After adding about 50 ml of deionized water, titrate 50 ml of this solution with hydrochloric acid (c(HCl) = 1 mol/l) with methyl orange as indicator. Calcul
49、ate the total capacity, KT, in mol/l of exchanger, using equation (3): 05,005,0H2a1bT=VcVcVK (3) where Vais the volume of hydrochloric acid required for titration, in ml; Vb is the volume of sodium hydroxide solution passed through the exchanger, in ml; c1 is the concentration of the sodium hydroxide solution, in mol/l; c2 is the concentration of the hydrochloric acid solution, in mol/l; VH is the exchanger volume, in ml; 0,05 is the aliquot part of the solution to be titrated. If Vb= 600 ml, c1= 1 mol/l, c2= 1 mol/l and VH=
