ASTM D4189-23

Standard Test Method for Silt Density Index (SDI) of Water

SIGNIFICANCE AND USE
5.1 The SDI can serve as a useful indication of the quantity of particulate matter in water.  
5.2 The SDI can be used to determine effectiveness of various processes such as filtration or clarification used to remove particulate matter.  
5.3 The SDI has been empirically correlated with the fouling tendency of some water treatment equipment such as reverse osmosis devices.  
5.4 The SDI may vary as a function of water temperature, and values obtained at different temperatures may not necessarily be comparable.  
5.5 The SDI can vary with the membrane filter manufacturer. Thus, SDI values obtained with filters from different membrane manufacturers might not be comparable.
SCOPE
1.1 This test method covers the determination of the silt density index (SDI) of water. This test method can be used to indicate the quantity of particulate matter in water and is applicable to relatively low (  
1.2 This test method is not applicable for reagent grade water Types I, II, and III of Specification D1193, or effluents from most reverse osmosis and ultrafiltration systems.  
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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

General Information

• Status: Published
• Publication Date: 31-Oct-2023
• Technical Committee: D19 - Water
• Drafting Committee: D19.08 - Membranes and Ion Exchange Materials

Relations

• Replaces: ASTM D4189-07(2014) - Standard Test Method for Silt Density Index (SDI) of Water (Withdrawn 2023)
• Effective Date: 01-Nov-2023
• Referred By: ASTM D5091-23 - Standard Guide for Water Analysis for Electrodialysis/Electrodialysis Reversal Applications
• Effective Date: 01-Nov-2023
• Referred By: ASTM D4195-23 - Standard Guide for Water Analysis for Reverse Osmosis and Nanofiltration Application
• Effective Date: 01-Nov-2023
• Referred By: ASTM D4188-17 - Standard Practice for Performing Pressure In-Line Coagulation-Flocculation-Filtration Test in Water
• Effective Date: 01-Nov-2023
• Referred By: ASTM D8002-15e1 - Standard Test Method for Modified Fouling Index (MFI-0.45) of Water
• Effective Date: 01-Nov-2023
• Referred By: ASTM D6529-22 - Standard Test Method for Operating Performance of Continuous Electrodeionization Systems on Feeds from 50 μS/cm to 1000 μS/cm
• Effective Date: 01-Nov-2023
• Referred By: ASTM D5131-23 - Standard Guide for Record Keeping for Electrodialysis/Electrodialysis Reversal Systems
• Effective Date: 01-Nov-2023

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: D4189 − 23
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 3. Terminology
3.1 Definitions—For definitions of terms used in this test
1.1 This test method covers the determination of the silt
method, refer to Terminology D1129.
density index (SDI) of water. This test method can be used to
indicate the quantity of particulate matter in water and is
3.2 Definitions:
applicable to relatively low (<1.0 NTU) turbidity waters such
3.2.1 silt density index (SDI), n—an index calculated from
as well water, filtered water, or clarified effluent samples. Since
the rate of plugging of a 0.45 μm membrane filter.
the size, shape, and nature of particulate matter in water may
vary, this test method is not an absolute measurement of the 4. Summary of Test Method
quantity of particulate matter.
4.1 Water is passed through a 0.45 μm membrane filter at a
constant applied gauge pressure of 207 kPa (30 psi), and the
1.2 This test method is not applicable for reagent grade
rate of plugging of the filter is measured.
water Types I, II, and III of Specification D1193, or effluents
from most reverse osmosis and ultrafiltration systems.
4.2 The SDI is calculated from the rate of plugging.
1.3 This standard does not purport to address all of the
5. Significance and Use
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro- 5.1 The SDI can serve as a useful indication of the quantity
priate safety, health, and environmental practices and deter- of particulate matter in water.
mine the applicability of regulatory limitations prior to use.
5.2 The SDI can be used to determine effectiveness of
1.4 This international standard was developed in accor-
various processes such as filtration or clarification used to
dance with internationally recognized principles on standard-
remove particulate matter.
ization established in the Decision on Principles for the
5.3 The SDI has been empirically correlated with the
Development of International Standards, Guides and Recom-
fouling tendency of some water treatment equipment such as
mendations issued by the World Trade Organization Technical
reverse osmosis devices.
Barriers to Trade (TBT) Committee.
5.4 The SDI may vary as a function of water temperature,
and values obtained at different temperatures may not neces-
2. Referenced Documents
sarily be comparable.
2
2.1 ASTM Standards:
5.5 The SDI can vary with the membrane filter manufac-
D1129 Terminology Relating to Water
turer. Thus, SDI values obtained with filters from different
D1193 Specification for Reagent Water
membrane manufacturers might not be comparable.
D3370 Practices for Sampling Water from Flowing Process
Streams
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
plastic to prevent contamination by corrosion products. Do not
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This test method is under the jurisdiction of ASTM Committee D19 on Water
use reactive materials such as carbon steel or cast iron. Suitable
and is the direct responsibility of Subcommittee D19.08 on Membranes and Ion
filter holders, designed to withstand an operating gauge pres-
Exchange Materials.
Current edition approved Nov. 1, 2023. Published November 2023. Originally
sure of 350 kPa (50 psi) can be obtained from suppliers of
approved in 1982. Last previous edition approved in 2014 as D4189 – 07 (2014)
membrane filters.
which was withdrawn July 2023 and reinstated in November 2023. DOI: 10.1520/
D4189-23.
6.2 Membrane Filter:
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
6.2.1 Membrane—White hydrophilic, mixed cellulose ni-
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
trate (50 % to 75 %) and cellulose acetate (MCE).
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. 6.2.2 Mean Pore Size—0.45 μm.
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D4189 − 23
7.5 Make sure the O-ring is in good condition and properly
placed. Replace the top half of the filter holder and close
loosely.
7.6 Bleed out
...