ASTM D1782-95(2009)
(Test Method)Standard Test Methods for Operating Performance of Particulate Cation-Exchange Materials
Standard Test Methods for Operating Performance of Particulate Cation-Exchange Materials
SIGNIFICANCE AND USE
Cation exchange materials are frequently used in the sodium form to exchange divalent and trivalent ions in the influent water for sodium ions on the resin sites. This process is commonly referred to as softening water since it removes those ions that form a “hard” curd of insoluble salts with the fatty acids used in some soaps and that also precipitate when water is boiled. In such a process, sodium chloride is used as the regenerant to return the cation-exchanging groups to the sodium form.
This test method is intended to simulate the performance of such materials in actual usage. It may be used either to compare the performance of new materials or to compare the performance of a material that has been used with its original performance.
Regenerant concentrations and dosages used herein are typical for the types of materials used in this application. If different concentrations or amounts of regenerant are agreed upon by parties using this test method, this fact should be stated when the results are reported. Similarly, the test water specified is the agreed upon standard. Where other test waters or the water to be treated are used in the test, the analysis of the water in terms of total solids, sodium, calcium, magnesium, other di- or trivalent metals as well as the major anions present should be reported with the test results.
SCOPE
1.1 These test methods cover the determination of the operating capacity of particulate cation-exchange materials when used for the removal of calcium, magnesium, and sodium ions from water. It is intended for use in testing both new and used materials. The following two test methods are included:
Sections Test Method A—Sodium Cycle 8 to 14 Test Method B—Hydrogen Cycle15 to 21
1.2 The values given in SI units are to be regarded as the standard. The inch-pound units given in parentheses are for information only.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
8.1 This test method is designed to simulate operating conditions on a sodium cycle used for the removal of calcium and magnesium and other divalent ions from water.
15.1 This test method is designed to simulate operating conditions on a hydrogen cycle used for the removal of all other cations from water.
General Information
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Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation: D1782 − 95 (Reapproved 2009)
Standard Test Methods for
Operating Performance of Particulate Cation-Exchange
Materials
This standard is issued under the fixed designation D1782; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 3.2.1 Certain terms in these test methods that relate specifi-
cally to ion exchange are defined as follows:
1.1 These test methods cover the determination of the
3.2.2 free mineral acidity—the quantitative capacity of
operating capacity of particulate cation-exchange materials
aqueous media to react with hydroxyl ions to pH 4.3.
whenusedfortheremovalofcalcium,magnesium,andsodium
ions from water. It is intended for use in testing both new and 3.2.3 hydrogen cycle—the operation of a cation-exchange
used materials. The following two test methods are included: cycle wherein the removal of specified cations from influent
water is accomplished by exchange with an equivalent amount
Sections
Test Method A—Sodium Cycle 8 to 14
of hydrogen ion from the exchange material.
Test Method B—Hydrogen Cycle 15 to 21
3.2.4 theoretical free mineral acidity—thefreemineralacid-
1.2 The values given in SI units are to be regarded as the
ity that would result from the conversion of the anions of
standard. The inch-pound units given in parentheses are for
strong acids in solution to their respective free acids.
information only.
1.3 This standard does not purport to address all of the
4. Summary of Test Methods
safety concerns, if any, associated with its use. It is the
4.1 Test MethodAconsists of repeated cycles of backwash,
responsibility of the user of this standard to establish appro-
brine regeneration, rinse, and exhaustion of the sample in the
priate safety and health practices and determine the applica-
form of a bed in a transparent column.The exhausting medium
bility of regulatory limitations prior to use.
used is an ion-exchange test water.
2. Referenced Documents 4.2 Test Method B consists of repeated cycles of backwash,
2 acid regeneration, rinse, and exhaustion of the sample in the
2.1 ASTM Standards:
form of a bed in a transparent column.The exhausting medium
D1067 Test Methods for Acidity or Alkalinity of Water
used is an ion-exchange test water.
D1126 Test Method for Hardness in Water
D1129 Terminology Relating to Water
5. Apparatus
D1193 Specification for Reagent Water
D2687 PracticesforSamplingParticulateIon-ExchangeMa- 5.1 Test Assemble (see Fig. 1), consisting of the following:
terials
5.1.1 Column, transparent, vertically supported, 25.4 6 2.5
mm (1.0 6 0.1 in.) in inside diameter and approximately 1500
3. Terminology mm(60in.)long.Thebottomofthecolumnshallbeclosedand
provided with an outlet of approximately 6-mm inside diam-
3.1 Definitions—For definitions of terms used in these test
eter. Connections shall be provided at top and bottom for
methods, refer to Terminology D1129
admission and removal of solutions as described in Section 10.
3.2 Definitions of Terms Specific to This Standard:
Adequate means for measuring and regulating flow shall be
provided. Calibrate the column in such a manner that the
volume readings required by the test method can be made.
These test methods are under the jurisdiction of ASTM Committee D19 on Make all measurements at 25 6 5°C.
Water and are the direct responsibility of Subcommittee D19.08 on Membranes and
5.1.2 Support, for the sample, so designed that the distance
Ion Exchange Materials.
from the sample to the column outlet is at least 50 mm. A
Current edition approved May 1, 2009. Published June 2009. Originally
suggested supporting bed utilizes quartz, glass beads, or other
approved in 1960. Last previous edition approved in 2007 as D1782 – 95 (2007).
DOI: 10.1520/D1782-95R09.
material 1.5 to 3.5 mm in diameter, insoluble in the reagents
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
used, and retained on a corrosion-resistant screen. However,
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
other supports such as fritted glass or polyester screens may be
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. used at the discretion of the interested parties.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D1782 − 95 (2009)
FIG. 1 Typical Arrangement of Apparatus for Performance Testing of Ion-Exchange Materials
6. Reagents the manufacturer’s original packages or from a bed of used
material, refer to Practices D2687.
6.1 Purity of Reagents—Reagent grade chemicals shall be
used in all tests. Unless otherwise indicated, it is intended that 7.2 Transfer the laboratory sample to a 2-L beaker and add
all reagents shall conform to the specifications of the Commit- enough water to bring the water level up to that of the
tee onAnalytical Reagents of theAmerican Chemical Society, ion-exchange material and soak for 1 h (see Note 1). Mix the
where such specifications are available. Other grades may be sample thoroughly and transfer a sufficient representative
used, provided it is first ascertained that the reagent is of portion to fill a 400-mL beaker. Use this portion of sample in
sufficiently high purity to permit its use without lessening the the procedure.
accuracy of the determination.
NOTE 1—Where new materials are shipped dry, follow the manufac-
turer’s instructions for preconditioning.
6.2 Purity of Water—Unlessotherwiseindicated,references
to water shall be understood to mean reagent water, Type IV,
TEST METHOD A—SODIUM CYCLE
conforming to Specification D1193.
8. Scope
7. Sampling
8.1 This test method is designed to simulate operating
7.1 To obtain a representative sample of particulate ion-
conditions on a sodium cycle used for the removal of calcium
exchange material, either from a shipment of new product in
and magnesium and other divalent ions from water.
9. Significance and Use
Reagent Chemicals, American Chemical Society Specifications , American
Chemical Society, Washington, DC. For suggestions on the testing of reagents not
9.1 Cation exchange materials are frequently used in the
listed by the American Chemical Society, see Analar Standards for Laboratory
sodium form to exchange divalent and trivalent ions in the
Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia
influent water for sodium ions on the resin sites. This process
and National Formulary, U.S. Pharmaceutical Convention, Inc. (USPC), Rockville,
MD. is commonly referred to as softening water since it removes
D1782 − 95 (2009)
those ions that form a “hard” curd of insoluble salts with the 11. Procedure
fatty acids used in some soaps and that also precipitate when
11.1 Adjust the temperature of the water and all solutions to
water is boiled. In such a process, sodium chloride is used as
be used in this procedure to 25 6 5°C and maintain this
the regenerant to return the cation-exchanging groups to the
temperature throughout the test.
sodium form.
11.2 Fill the column approximately half full of water and
9.2 Thistestmethodisintendedtosimulatetheperformance
add sufficient sample to give a bed height of 750 6 75 mm
of such materials in actual usage. It may be used either to
above the top of the support. To avoid drying out of the
compare the performance of new materials or to compare the
ion-exchange material, maintain a layer of liquid at least 20 to
performance of a material that has been used with its original
30 mm deep above the top of the bed at all times during the
performance.
procedure.
9.3 Regenerant concentrations and dosages used herein are
11.3 Backwash with water for 10 min using a flow rate that
typical for the types of materials used in this application. If
will maintain a 50 % expansion of the bed. If the supernatant
different concentrations or amounts of regenerant are agreed
liquid is clear at this point, proceed to 11.4. If the liquid is
upon by parties using this test method, this fact should be
cloudy (indicating the presence of light, insoluble, extraneous
stated when the results are reported. Similarly, the test water
material), adjust the backwash outlet tube to a height above the
specified is the agreed upon standard. Where other test waters
bed equal to 75 % of the bed height. Continue backwashing at
orthewatertobetreatedareusedinthetest,theanalysisofthe
the same rate until the effluent is clear.
water in terms of total solids, sodium, calcium, magnesium,
11.4 Allow the bed to settle and then drain at a rate of
other di- or trivalent metals as well as the major anions present
approximately100mL/minuntilthewaterlevelis20to30mm
should be reported with the test results.
above the top of the bed. Do not jar. Record the volume, in
millilitres, of ion-exchange material. Repeat the 10-min back-
10. Reagents and Materials
wash until two successive readings of volume agree within 5
10.1 Brine Regenerants: mL. The average of these two readings shall be the sample
10.1.1 For synthetic organic ion-exchange materials: volume for new materials shipped in the sodium form.
10.1.1.1 Sodium Chloride (100 g/L)—Dissolve enough so-
11.5 Exhaust the ion exchanger with cation-exchange test
dium chloride (NaCl) in water to make a solution containing in
water A at a flow rate of 0.33 mL/min/mL of exchanger, as
each litre 100.0 g of NaCl.
measured in 11.4. Maintain a head of liquid not less than 50
10.1.2 For all other ion-exchange materials:
mmabovethetopofthebed.Continuetherununtiltheeffluent
10.1.2.1 Sodium Chloride (50 g/L)—Dissolve enough NaCl
shows 0.2 meq/L (or other agreed-upon hardness level) when
in water to make a solution containing in each litre 50.0 g of
tested in accordance with Test Method D1126. Record the
NaCl.
volume of test water used.
10.2 Cation-Exchange Test Water A (10 meq/L)—Dissolve
11.6 Repeat the 10-min backwash and drain as described in
enough calcium chloride (CaCl ·2H O) and magnesium sulfate
2 2 11.3 and 11.4. When testing new material shipped in the
(MgSO ·7H O) in water to make a solution containing, in each
sodium form, only one backwash is necessary at this point
4 2
litre, 0.49 g of CaCl ·2H O and 0.415 g of MgSO ·7H O.
2 2 4 2 because a determination of volume has already been made.
Adjust the pH to 7.5 by the addition of Na CO (30 g/L) and
However, used material other than in the sodium form must
2 3
determine the hardness of the solution in accordance with Test
have a volume determination made here as described in 11.4.
Method D1126. The hardness of the test water will be 10.0 6
Use this sample volume determined on the exhausted material
0.5 meq/L. Use the determined hardness in calculating operat-
in calculating the capacity of used ion-exchange materials.
ing capacity as indicated in 12.1. This test water shall be used
11.7 Determine the amount of brine regenerant and rate
for all tests.
required, from Table 1. For use with Table 1, the volume
10.3 Hardness Test Reagents—For reagents used in deter-
sample for new material shall be that determined in accordance
mining hardness, refer to Test Method D1126. This reagent is
with 11.4 and for used material shall be that determined in
used only in preparation of test water (see 10.2).
accordance with 11.6.
10.4 Sodium Carbonate Solution(30g/L)—Dissolve30gof 11.8 Pass the specified volume of brine regenerant through
sodium carbonate (Na CO ) in water and dilute to 1 L. the bed at the specified rate until only a 20 to 30-mm layer of
2 3
TABLE 1 Amount of Brine Regenerant Required for Use in Test Method A
Type of Exchange Brine Regenerant, Rate of Flow, mL Contact Time,
Regeneration Level
Material g/L brine/min/mL of Exchanger min
lb/ft g/L
Synthetic organic 100 0.032 30 6.00 96.1
Greensand 50 0.027 15 1.25 20.0
Synthetic siliceous 50 0.080 20 3.00 80.1
Carbonaceous 50 0.067 15 3.15 50.5
D1782 − 95 (2009)
liquid remains above the bed. Rinse the bed with water, using 14.2 The precision of the test method varies with the
the same rate, until one bed-volume of liquid has been operating capacity of the material tested and may be expressed
displaced. Increase the rinse rate to approximately 100 mL/ as follows:
min. Test for hardness at 3-min intervals by adding 0.5 mL of
S 5 0.058 C
t
buffer solution to 50 mLof the effluent followed by three drops
S 5 0.024 C
o
of hardness indicator and 0.5 mL of sodium ethylendiamine
tetraacetate solution (1 mL = 1.0 mg CaCO ), with stirring. If
where:
a blue color develops, the effluent contains 0.2 meq/L or less
S = overall precision, meq/mL,
t
hardness and the rinse is completed. If the color is red, the end
S = single operator precision, meq/mL, and
o
point has not been reached. Continue the rinse until the effluent
C = operating capacity, meq/mL.
shows 0.2 meq/L or less hardness.
14.3 Bias—Because materials with known operating capac-
11.9 Repeat the service run described in 11.5.
ity cannot be prepared, bias cannot be determined.
11.10 Repeat the cycle, beginning with a single backwash
TEST METHOD B—HYDROGEN CYCLE
(see 11.6), omitting the determination of bed volume. Continue
with a regeneration and rinse (see 11.8), and end with a service
15. Scope
run (see 11.5). Repeat the cycle until each of three successive
15.1 This test method is designed to simulate operating
runs agrees within 65 % of their average capacity as calcu-
conditions on a hydrogen cycle used for the removal of all
lated in accordance with Section 12.
other cations from water.
12. Calculation
16. Significance and Use
12.1 Calculate the operating capacity, in milliequivalents
16.1 Cation exchange materials containing sulfonic acid
per millilitre, of the ion exchange material as
groups are frequently used in the hydrogen form to exchange
capacity, meq/mL 5 A 3B /S
~ !
hydrogen ions from the resin sites for all the cations in the
influent water. They are then regenerated with acid to restore
where:
the sites to the hydrogen form for reuse. This test is designed
A = hardness of test water, meq/L,
to simulate such usage.
B = volume of test water used in service run, L, and
S = volume of sample in the bed, mL. For new materials,
16.2 Since each cation has a specific and different exchange
this refers to the average volume of the material in the equilibrium with hydrogen form exchange groups, the effi-
sodium form as determined in 11.4. For used materials,
ciency of the process will vary with the nature and concentra-
itistheaveragevol
...
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