ASTM D4692-01(2010)
(Practice)Standard Practice for Calculation and Adjustment of Sulfate Scaling Salts (CaSO4, SrSO4, and BaSO4) for Reverse Osmosis and Nanofiltration
Standard Practice for Calculation and Adjustment of Sulfate Scaling Salts (CaSO<sub>4</sub>, SrSO<sub>4</sub>, and BaSO<sub>4</sub>) 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, SrSO4, 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.
1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
General Information
Relations
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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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
Designation:D4692 −01 (Reapproved 2010)
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.
1. Scope 3. Terminology
3.1 Definitions—For definitions of terms used in this
1.1 This practice covers the calculation and adjustment of
practice, refer to Terminology D1129 and D6161.
calcium, strontium, and barium sulfates for the concentrate
stream of a reverse osmosis or nanofiltration system. The
3.2 Definitions of Terms Specific to This Standard—For
calculations are used to determine the need for scale control in
definitions of terms relating to reverse osmosis, refer to Test
the operation and design of reverse osmosis and nanofiltration
Methods D4194.
installations.This practice is applicable for all types of reverse
4. Summary of Practice
osmosis devices (tubular, spiral wound, and hollow fiber) and
nanofiltration devices.
4.1 This practice consists of calculating the potential for
scaling by CaSO , SrSO , and BaSO in a reverse osmosis or
4 4 4
1.2 This practice is applicable to both brackish waters and
nanofiltration concentrate stream from the concentration of
seawaters.
++ ++ ++
Ca ,Sr ,Ba ,and SO inthefeedsolutionandtherecovery
1.3 The values stated in SI units are to be regarded as
of the reverse osmosis or nanofiltration system.
standard. No other units of measurement are included in this
4.2 This practice also presents techniques to eliminate
standard. ++
scaling by decreasing the recovery, by decreasing the Ca ,
++ ++
Sr , and Ba concentrations in the feed water, and by
2. Referenced Documents
addition of scale inhibitors.
2.1 ASTM Standards:
5. Significance and Use
D511Test Methods for Calcium and Magnesium In Water
D516Test Method for Sulfate Ion in Water 5.1 In the design and operation of reverse osmosis and
D1129Terminology Relating to Water nanofiltrationinstallations,itisimportanttopredicttheCaSO ,
D3352Test Method for Strontium Ion in Brackish Water, SrSO ,andBaSO scalingpropertiesoftheconcentratestream.
4 4
Seawater, and Brines Because of the increase in total dissolved solids and the
increase in concentration of the scaling salts, the scaling
D4194Test Methods for Operating Characteristics of Re-
propertiesoftheconcentratestreamwillbequitedifferentfrom
verse Osmosis and Nanofiltration Devices
thoseofthefeedsolution.Thispracticepermitsthecalculation
D4195Guide for Water Analysis for Reverse Osmosis and
ofthescalingpotentialfortheconcentratestreamfromthefeed
Nanofiltration Application
water analyses and the reverse osmosis or nanofiltration
D4382TestMethodforBariuminWater,AtomicAbsorption
operating parameters.
Spectrophotometry, Graphite Furnace
D6161TerminologyUsedforMicrofiltration,Ultrafiltration,
5.2 Scaling by CaSO , SrSO , and BaSO will adversely
4 4 4
Nanofiltration and Reverse Osmosis Membrane Processes
affect the reverse osmosis or nanofiltration performance. This
practicegivesvariousproceduresforthepreventionofscaling.
6. Procedure
This practice is under the jurisdiction ofASTM Committee D19 on Water and
++ ++ ++
is the direct responsibility of Subcommittee D19.08 on Membranes and Ion
6.1 Determine the concentrations of Ca ,Sr ,Ba , and
Exchange Materials.
SO in the feed stream in accordance withTest Methods D511,
Current edition approved May 1, 2010. Published May 2010. Originally
ε1
D3352, D4382, and D516, respectively.
approved in 1987. Last previous edition approved in 2006 as D4692–01 (2006) .
DOI: 10.1520/D4692-01R10.
NOTE1—IfH SO isusedforcontrolofCaCO scale,measuretheSO
2 4 3 4
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
after acid addition.
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
6.2 Determine the concentration of all major ions using the
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. appropriatemethodsgiveninGuideD4195.Ataminimum,the
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D4692−01 (2010)
FIG. 1K for CaSO versus Ionic Strength
sp 4
++ + −
concentrations of Mg ,Na , HCO , and Cl must be deter- 1
I 5 m¯ Z
c i i
(
mined. 2
where:
7. Calculation
I = ionic strength of concentrate stream,
c
7.1 Calculate the calcium concentration in the concentrate
m¯ = molal concentration of ion, i (moles/1000 g of water)
i
stream from the calcium concentration in the feed solution,
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
1000 C
Ca 5 Ca 3 C
i
c f i
1 2 Y
m 5 5
6 6
i
10 2 TDS MW 10 2 TDS
~ !
i
1000 MW
F G
i 6
where:
Ca = calcium ion concentration in concentrate, mg/L,
c
where:
Ca = calcium ion concentration in feed, mg/L,
f
C = concentration of ion, i, in concentrate stream, mg/L,
i
Y = recovery of the reverse osmosis system, expressed
MW = molecular weight of ion, i, and
i
as a decimal, and
TDS = total dissolved solids in concentrate stream, mg/L.
SP = calcium ion passage, expressed as a decimal.
Ca
7.5 Calculate the ion product (IP ) for CaSO in the
c 4
NOTE2—SP canbeobtainedfromthesupplierofthereverseosmosis
Ca
concentrate stream as follows:
or nanofiltration system. For most
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.