ASTM D4692-01(2006)e1

Standard Practice for Calculation and Adjustment of Sulfate Scaling Salts (CaSO₄, SrSO₄, and BaSO₄) for Reverse Osmosis and Nanofiltration

SIGNIFICANCE AND USE
In the design and operation of reverse osmosis and nanofiltration installations, it is important to predict the CaSO4, SrSO 4, and BaSO4 scaling properties of the concentrate stream. Because of the increase in total dissolved solids and the increase in concentration of the scaling salts, the scaling properties of the concentrate stream will be quite different from those of the feed solution. This practice permits the calculation of the scaling potential for the concentrate stream from the feed water analyses and the reverse osmosis or nanofiltration operating parameters.
Scaling by CaSO4, SrSO4, and BaSO4 will adversely affect the reverse osmosis or nanofiltration performance. This practice gives various procedures for the prevention of scaling.
SCOPE
1.1 This practice covers the calculation and adjustment of calcium, strontium, and barium sulfates for the concentrate stream of a reverse osmosis or nanofiltration system. The calculations are used to determine the need for scale control in the operation and design of reverse osmosis and nanofiltration installations. This practice is applicable for all types of reverse osmosis devices (tubular, spiral wound, and hollow fiber) and nanofiltration devices.
1.2 This practice is applicable to both brackish waters and seawaters.

General Information

• Status: Historical
• Publication Date: 14-Dec-2006
• ICS: 71.120.99 - Other equipment for the chemical industry
• Technical Committee: D19 - Water
• Drafting Committee: D19.08 - Membranes and Ion Exchange Materials

Relations

• Replaces: ASTM D4692-01 - Standard Practice for Calculation and Adjustment of Sulfate Scaling Salts (CaSO₄, SrSO₄, and BaSO₄) for Reverse Osmosis and Nanofiltration
• Effective Date: 15-Dec-2006
• Replaced By: ASTM D4692-01(2010) - Standard Practice for Calculation and Adjustment of Sulfate Scaling Salts (CaSO₄, SrSO₄, and BaSO₄) for Reverse Osmosis and Nanofiltration
• Effective Date: 01-May-2010

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information.
´1
Designation: D4692 – 01 (Reapproved 2006)
Standard Practice for
Calculation and Adjustment of Sulfate Scaling Salts (CaSO ,
SrSO , and BaSO ) for Reverse Osmosis and Nanofiltration
4 4
This standard is issued under the fixed designation D4692; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
´ NOTE—Sections 2 and 3.1 were updated editorially in February 2007.
1. Scope 3.2 Definitions of Terms Specific to This Standard:
3.2.1 For definitions of terms relating to reverse osmosis,
1.1 This practice covers the calculation and adjustment of
refer to Test Methods D4194.
calcium, strontium, and barium sulfates for the concentrate
stream of a reverse osmosis or nanofiltration system. The
4. Summary of Practice
calculations are used to determine the need for scale control in
4.1 This practice consists of calculating the potential for
the operation and design of reverse osmosis and nanofiltration
scaling by CaSO , SrSO , and BaSO in a reverse osmosis or
4 4 4
installations.This practice is applicable for all types of reverse
+
nanofiltrationconcentratestreamfromtheconcentrationofCa
osmosis devices (tubular, spiral wound, and hollow fiber) and
++ ++ 5
+,Sr ,Ba , and SO in the feed solution and the recovery of
nanofiltration devices. 4
the reverse osmosis or nanofiltration system.
1.2 This practice is applicable to both brackish waters and
4.2 This practice also presents techniques to eliminate
seawaters.
++
scaling by decreasing the recovery, by decreasing the Ca ,
++ ++
2. Referenced Documents
Sr , and Ba concentrations in the feed water, and by
addition of scale inhibitors.
2.1 ASTM Standards:
D511 Test Methods for Calcium and Magnesium In Water
5. Significance and Use
D516 Test Method for Sulfate Ion in Water
5.1 In the design and operation of reverse osmosis and
D1129 Terminology Relating to Water
nanofiltrationinstallations,itisimportanttopredicttheCaSO ,
D3352 Test Method for Strontium Ion in Brackish Water, 4
SrSO , and BaSO scaling properties of the concentrate
4 4
Seawater, and Brines
stream.Becauseoftheincreaseintotaldissolvedsolidsandthe
D4194 Test Methods for Operating Characteristics of Re-
increase in concentration of the scaling salts, the scaling
verse Osmosis and Nanofiltration Devices
propertiesoftheconcentratestreamwillbequitedifferentfrom
D4195 Guide for Water Analysis for Reverse Osmosis and
thoseofthefeedsolution.Thispracticepermitsthecalculation
Nanofiltration Application
ofthescalingpotentialfortheconcentratestreamfromthefeed
D4382 Test Method for Barium in Water, Atomic Absorp-
water analyses and the reverse osmosis or nanofiltration
tion Spectrophotometry, Graphite Furnace
operating parameters.
D6161 Terminology Used for Microfiltration, Ultrafiltra-
5.2 Scaling by CaSO , SrSO , and BaSO will adversely
4 4 4
tion, Nanofiltration and Reverse Osmosis Membrane Pro-
affect the reverse osmosis or nanofiltration performance. This
cesses
practicegivesvariousproceduresforthepreventionofscaling.
3. Terminology
6. Procedure
3.1 Definitions—For definitions of terms used in this prac-
++ ++ ++
6.1 Determine the concentrations of Ca ,Sr ,Ba , and
tice, refer to Terminology D1129 and D6161.
SO inthefeedstreaminaccordancewithTestMethodsD511,
D3352, D4382, and D516, respectively.
This practice is under the jurisdiction ofASTM Committee D19 on Water and
is the direct responsibility of Subcommittee D19.08 on Membranes and Ion NOTE 1—If H SO is used for control of CaCO scale, measure the
2 4 3
Exchange Materials.
SO after acid addition.
Current edition approved Dec. 15, 2006. Published February 2007. Originally
6.2 Determine the concentration of all major ions using the
approved in 1987. Last previous edition approved in 2001 as D4692–01. DOI:
10.1520/D4692-01R06E01.
appropriatemethodsgiveninGuideD4195.Ataminimum,the
–
For referenced ASTM standards, visit the ASTM website, www.astm.org, or ++ + −
concentrations of Mg ,Na , HCO , and Cl must be
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
determined.
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
´1
D4692 – 01 (2006)
FIG. 1 K for CaSO versus Ionic Strength
sp 4
7. Calculation
where:
I = ionic strength of concentrate stream,
7.1 Calculate the calcium concentration in the concentrate
c
m¯ = molal concentration of ion, i (moles/1000 g of
stream from the calcium concentration in the feed solution, i
water) in the concentrate stream, and
from the recovery of the reverse osmosis or nanofiltration
Z = ionic charge of ion, i.
i
system, and from the calcium ion passage as follows:
NOTE 3—The molal concentration is calculated as follows:
1 2 Y ~SP !
Ca
Ca 5Ca 3
c f
1 2 Y
C 1000 C
i i
m 5 5
i
6 6
10 2 TDS MW 10 2 TDS
~ !
i
where:
1000 MW
iF 6 G
Ca = calcium ion concentration in concentrate, mg/L,
c
Ca = calcium ion concentration in feed, mg/L,
f
where:
Y = recovery of the reverse osmosis system, expressed
C = concentration of ion, i, in concentrate stream, mg/L,
i
as a decimal, and
MW = molecular weight of ion, i, and
i
SP = calcium ion passage, expressed as a decimal.
TDS = total dissolved solids in concentrate stream, mg/L.
Ca
NOTE 2—SP canbeobtainedfromthesupplierofthereverseosmosis
Ca 7.5 Calculate the ion product (IP ) for CaSO in the
c 4
or na
...