ASTM D4189-07

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation: D4189 − 07 AnAmerican National Standard
Standard Test Method for
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Silt Density Index (SDI) of Water
This standard is issued under the fixed designation D4189; 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 4. Summary of Test Method
4.1 Water is passed through a 0.45-µm membrane filter at a
1.1 This test method covers the determination of the silt
constant applied gage pressure of 207 kPa (30 psi), and the rate
density index (SDI) of water. This test method can be used to
of plugging of the filter is measured.
indicate the quantity of particulate matter in water and is
applicable to relatively low (<1.0 NTU) turbidity waters such
4.2 The SDI is calculated from the rate of plugging.
as well water, filtered water, or clarified effluent samples. Since
the size, shape, and nature of particulate matter in water may
5. Significance and Use
vary, this test method is not an absolute measurement of the
5.1 The SDI can serve as a useful indication of the quantity
quantity of particulate matter.
of particulate matter in water.
1.2 This test method is not applicable for reagent grade
5.2 The SDI can be used to determine effectiveness of
water Types I, II, and III of Specification D1193, or effluents
various processes such as filtration or clarification used to
from most reverse osmosis and ultrafiltration systems.
remove particulate matter.
1.3 This standard does not purport to address all of the
5.3 The SDI has been empirically correlated with the
safety concerns, if any, associated with its use. It is the
fouling tendency of some water treatment equipment such as
responsibility of the user of this standard to establish appro-
reverse osmosis devices.
priate safety and health practices and determine the applica-
5.4 The SDI may vary as a function of water temperature,
bility of regulatory limitations prior to use.
and values obtained at different temperatures may not neces-
sarily be comparable.
2. Referenced Documents
2 5.5 The SDI will vary with the membrane filter manufac-
2.1 ASTM Standards:
turer. Thus, SDI values obtained with filters from different
D1129 Terminology Relating to Water
membrane manufacturers cannot be comparable.
D1193 Specification for Reagent Water
D3370 Practices for Sampling Water from Closed Conduits
6. Apparatus
E1 Specification for ASTM Liquid-in-Glass Thermometers
6.1 SDI Assembly, as schematically described in Fig. 1. All
wetted parts should be made of high-quality stainless steel or
3. Terminology
plastic to prevent contamination by corrosion products. Do not
3.1 Definitions—For definitions of terms used in this test
usereactivematerialssuchascarbonsteelorcastiron.Suitable
method, refer to Terminology D1129.
filter holders, designed to withstand an operating gage pressure
3.2 Definitions:
of 350 kPa (50 psi) can be obtained from suppliers of
membrane filters.
3.2.1 silt density index (SDI)—an index calculated from the
rate of plugging of a 0.45-µm membrane filter.
6.2 Membrane Filter:
6.2.1 Membrane—white hydrophillic, mixed cellulose ni-
trate (50–75 %) and cellulose acetate (MCE).
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This test method is under the jurisdiction of ASTM Committee D19 on Water 6.2.2 Mean Pore Size— 0.45 µm.
and is the direct responsibility of Subcommittee D19.08 on Membranes and Ion
6.2.3 Diameter—47 mm nominal, plain.
Exchange Materials.
6.2.4 Thickness—115–180 µm.
Current edition approved June 15, 2007. Published June 2007. Originally
6.2.5 Pure Water Flow Time—25–50 seconds/500 mL.
approved in 1982. Last previous edition approved in 2002 as D4189 – 95 (2002).
DOI: 10.1520/D4189-07.
6.2.6 Pressure—91.4–94.7 kPa (13.3–13.8 psi).
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
6.2.7 Bubble Point— 179–248 kPa (26.0–36.0 psi).
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
6.2.8 Use only filters that are packaged in the same orien-
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. tation.
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D4189 − 07
NOTE 3—Time (t) to collect 500 mL should be within6 10 % of the
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time to collect 500 mL using nonplugging reference water at the same
water temperature. The nonplugging reference water can be obtained by
filtering distilled water through a 0.2-µm pore size membrane filter.
NOTE 4—If t is less than 90 % of the nonplugging time, the filter may
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be cracked and a new filter should be used. If t is more than 110 % of the
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nonplugging t
...