1、Designation: D4189 07 (Reapproved 2014)Standard Test Method forSilt Density Index (SDI) of Water1This standard is issued under the fixed designation D4189; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision.
2、A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the determination of the siltdensity index (SDI) of water. This test method can be used toindicate the quanti
3、ty of particulate matter in water and isapplicable to relatively low (276 kPa (40 psi).7.3 Measure the temperature of the water.7.4 Open the membrane filter holder and place a 0.45-mmembrane filter (47 mm in diameter) on the support plate ofthe holder. Some filter holders include a foam support pad,
4、which should be used. Place the filter grid side up. Handle themembrane filter only with dull tweezers to avoid puncturing.Avoid touching the membrane filter with the fingers.NOTE 1Other membrane filter sizes, that is, 25 mm or 90 mmdiameter, can be used.NOTE 2Record the manufacturer of the membrane
5、 filter and themanufacturers identification for the membrane filter.7.5 Make sure the O-ring is in good condition and properlyplaced. Replace the top half of the filter holder and closeloosely.7.6 Bleed out trapped air by cracking the ball valve. Closethe valve and tighten the filter holder.7.7 Open
6、 the ball valve. Simultaneously, using a stopwatch,begin measuring the time required for the flow of 500 mL.Record the time (ti). Leave the valve open for continued flow.NOTE 3Time (ti) to collect 500 mL should be within 610 % of thetime to collect 500 mL using nonplugging reference water at the sam
7、ewater temperature. The nonplugging reference water can be obtained byfiltering distilled water through a 0.2-m pore size membrane filter.NOTE 4If tiis less than 90 % of the nonplugging time, the filter maybe cracked and a new filter should be used. If tiis more than 110 % of thenonplugging time, th
8、en a smaller sample size, that is, 250 mL or 100 mLshould be used.NOTE 5The 500-mL sample size is based on a 47-mm diameter filter.If a different filter size is used, adjust the sample size in direct proportionto the filter area.7.8 Measure and record the times to collect additional500-mL (Note 6) v
9、olumes of sample, starting the collection at5, 10, and 15 min of total elapsed flow time. Measure the watertemperature and check the pressure as each sample is collected(Note 7 and Note 8).NOTE 6If the initial size was not 500 mL, use the same sample sizeas used in 7.7.NOTE 7The pressure must remain
10、 at 207 6 7 kPa (30 6 1 psi)throughout the test.NOTE 8The water temperature must remain constant (61C) through-out the test. This is necessary because flow rate changes by about 3 %/C.7.9 After completion of the test, the membrane filter may beretained for future reference.8. Calculation8.1 Calculat
11、e the silt density index (SDIT) as follows:SDIT5% P30T5F1 2titfG100Twhere:%P30= percent at 207 kPa (30 psi) feed pressure,T = total elapsed flow time, min (usually 15 min, seeNote 9),ti= initial time required to collect 500 mL of sample, s,andtf = time required to collect 500 mL of sample after test
12、time T (usually 15 min, see Note 9), s.NOTE 9For this test method, % P30 should not exceed 75 %. If % P30exceeds this value, use a shorter time for T; that is, 5 or 10-minmeasurements in 7.8.If%P30exceeds 75 % after 5 min, other testmethods should be used to analyze for particulate matter.9. Report9
13、.1 Report the following information:9.1.1 The SDI, with a subscript indicating the total elapsedflow time (T) in minutes,9.1.2 The water temperature before and after the test, and9.1.3 The manufacturer of the 0.45-m membrane filterused for the test, as well as the manufacturers identification forthe
14、 membrane filter.10. Precision and Bias310.1 The interlaboratory test was performed by nine opera-tors from five laboratories using test waters of their choice,whose SDI values varied from 0.4 to 15. Waters used included3Supporting data have been filed at ASTM International Headquarters and maybe ob
15、tained by requesting Research Report RR:D19-1151. ContactASTM CustomerService at serviceastm.org.FIG. 1 Apparatus for Measuring the Silt Density IndexD4189 07 (2014)2RO permeate, deionized water, tap water, and undefinedprocess water. The pooled single operator precision is 0.43.10.2 Only pooled sin
16、gle operator precision was determinedfor this test method. The test method is very sensitive to bothquantity and size of suspended particles, which contribute tothe plugging of the membrane filter. Maintenance of theintegrity of the samples cannot be guaranteed through prepa-ration of the bulk mix,
17、subsampling for testing, shipping, andholding. Moreover, approximately 5 gal of sample are requiredfor each SDI test run. Thus, if large stock solutions exhibitingdifferent SDI values could be prepared and if representative 30to 55-gal subsamples could be drawn, shipping two or three ofthese samples
18、 to each of six or more laboratories for full-scaletesting was not considered to be practical.10.3 The bias of this test method cannot be determinedbecause the test method is based upon waters of choice, whichmay differ with each source.10.4 It is the users responsibility to ensure the validity ofth
19、is test method for waters of untested matrices.11. Keywords11.1 RO; reverse osmosis; SDI; silt density indexASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised t
20、hat determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapp
21、roved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you
22、feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual r
23、eprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).D4189 07 (2014)3
