ASTM D6530-00(2013)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation: D6530 − 00 (Reapproved 2013)
Standard Test Method for
Total Active Biomass in Cooling Tower Waters (Kool Kount
Assay; KKA)
This standard is issued under the fixed designation D6530; 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 3.3 Symbols:
3.3.1 cfu/mL—colony forming units per millilitre.
1.1 This test method covers the determination of viable
active biomass in cooling tower water in the range from 10 to
8 4. Summary of Test Method
10 cfu/mL (1). It is a semiquantitative test method.
4.1 Thistestmethodconsistsofaddingaspecificvolumeof
1.2 This test method was used successfully with reagent
water to nutrients and a color indicator contained in a glass
water, physiologic saline, and cooling tower waters. It is the
vial. The contents of the vial are then mixed and incubated at
user’s responsibility to ensure the validity of this test method
95°F (35 6 3°C; that is, in a shirt pocket, incubator, or heat
for waters of untested matrices.
block). The color of the sample after addition into the vial
1.3 This standard does not purport to address all of the
containing the nutrients and color indicator is yellow. Viable
safety concerns, if any, associated with its use. It is the
active biomass in the sample replicates using the nutrients
responsibility of the user of this standard to establish appro-
provided and reduces the color indicator.At a critical biomass
priate safety and health practices and determine the applica-
concentration, sufficient quantities of the color indicator are
bility of regulatory limitations prior to use. For specific hazard
reduced resulting in a visible change in the indicator from the
statements, see Section 9.
original yellow sample color to orange. The time required for
conversion of the oxidized indicator to the reduced indicator
2. Referenced Documents
resulting in an orange color as directly correlated with the
2.1 ASTM Standards:
concentration of viable active biomass in the water sample
D1129Terminology Relating to Water
tested. High concentrations of active biomass in the sample
D1192Guide for Equipment for Sampling Water and Steam
produce the positive orange color more rapidly than low
in Closed Conduits (Withdrawn 2003)
concentrations of viable biomass.
D1193Specification for Reagent Water
D3370Practices for Sampling Water from Closed Conduits
5. Significance and Use
5.1 This test method is useful for rapid determination of
3. Terminology
viable active biomass concentrations in cooling tower waters.
3.1 Definitions—For definitions of terms used in this test
The efficiency of cooling towers is directly affected by the
method, refer to Terminology D1129.
concentration of biomass in the cooling tower waters. As
3.2 Definitions of Terms Specific to This Standard:
biomass concentrations increase, biofilm formation occurs
3.2.1 snapping cup—container provided for holding the
resulting in a decrease in the efficiency of heat exchange in the
sample and snapping tip of the vial.
tower. Current tests for monitoring the biomass concentration
in cooling towers require at least 36 h for growth of the
3.2.2 vial—sealed glass ampoule under vacuum containing
microorganisms on a solid agar surface for counting. Replica-
reagents for the Kool Kount Test.
tion of microorganisms over the 36-h period before results are
available creates an aqueous environment which is no longer
This test method is under the jurisdiction of ASTM Committee D19 on Water
representedbythedatagenerated.Timelytestresultscanassist
and is the direct responsibility of Subcommittee D19.24 on Water Microbiology.
CurrenteditionapprovedJune1,2013.PublishedJuly2013.Originallyapproved in minimizing biocide addition to control biomass concentra-
in 2000. Last previous edition approved in 2006 as D6530– 00 (2006). DOI:
tions.KoolKountprovidesdatawithinhourstoallowformore
10.1520/D6530-00R13.
precise control of active biomass concentrations in the waters.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on 6. Interferences
the ASTM website.
6.1 Halogens interfere with this test method by inhibiting
The last approved version of this historical standard is referenced on
www.astm.org. microbialgrowthresultinginlengthyincubationperiodsbefore
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D6530 − 00 (2013)
a positive orange color is produced suggesting better water 11. Procedure
quality.Addition of thiosulfate eliminates this interference and
11.1 Rinse snapping cup at least twice with water to be
allows for testing of waters previously treated with halogens
tested. Place at least 20 mL of the sample to be tested in the
(not immediately prior to testing).
snapping cup. Add two drops of the thiosulfate solution
6.2 Reducing agents (that is, beta mercaptoethanol) may
provided. Mix and allow sample to sit quiescently in the
interfere in this test method by reducing the color indicator
snapping cup for 15 min.
chemically. Rapid color development upon filling of the vials
11.2 Submerge the tip of glassVialAcontaining reagents in
suggests a chemical rather than a biological reaction. Waters
the sample to be tested (in the snapping cup). Place the tip in
containingreducingagentswhichreactwiththecolorindicator
oneofthegroovesinthebottomofthesnappingcup.Carefully
are not suitable for testing with Kool Kount.
press the vial toward the opposite wall of the cup to snap the
6.3 Avoidprolongedexposure(greaterthan30min)offilled
tip allowing the vial to fill as a result of the vacuum in the vial.
or unopened KKA vials to sunlight to avoid false positive
11.3 Submerge the tip of control glass Vial B (no glass rod)
reactions.
in the same sample. Place the tip in one of the grooves in the
6.4 Testing must not take place within 24 h of biocide
bottomofthesnappingcup.Carefullypressthevialtowardthe
addition.
wall of the cup to snap the tip allowing the vial to fill.
7. Apparatus
11.4 Place a protective sleeve on the neck of each vial to
cover the sharp edges. Carefully invert vials several times to
7.1 TheschematicarrangementoftheKKAtestkitisshown
completely mix the reagent powders with the water sample.
in Fig. 1.
11.5 Prepare the label with the sample designation, sample
7.2 (Parts) of the KKA Test K—VialA(test vial), vial under
pH, sample temperature, and the time at which test was
vacuum containing nutrient and reagent on glass rod; Vial B
initiated. Place the sample label on the appropriate vial and
(control vial), vial under vacuum containing nutrient only
label the control vial. Incubate vials at approximately 95°F (35
(does not contain a glass rod); snapping cup; and plastic safety
6 3°C; heat block, shirt pocket, incubator).
sleeve.
11.6 Examine Vials A and B after 10 to 15 min for
8. Reagents and Materials
development of pink to red color indicative of chemical
8.1 Purity of Reagents—Reagent grade chemicals shall be
reaction, not biological activity.
used in all tests. Unless otherwise indicated, it is intended that
11.7 Examine sample Vial A for color change (yellow
all reagents shall conform to the specifications of the Commit-
[negative] to orange [positive]) after 30 min of incubation by
tee on Analytical Reagents of the American Chemical S
...