ASTM G29-96(2010)
(Practice)Standard Practice for Determining Algal Resistance of Plastic Films
Standard Practice for Determining Algal Resistance of Plastic Films
SIGNIFICANCE AND USE
Bodies of water, such as swimming pools, artificial ponds, and irrigation ditches often are lined with plastic films. Algae tend to grow in such bodies of water under the proper atmospheric conditions, and they can produce slimy and unsightly deposits on the film. The method described herein is useful in evaluating the degree and permanency of protection against surface growth of algae afforded by various additives incorporated in the film.
SCOPE
1.1 This practice covers the determination of the susceptibility of plastic films to the attachment and proliferation of surface-growing algae.
1.2 The values in SI units are to be regarded as the standard. The inch-pound units given in parentheses are for information only.
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 and health practices and determine the applicability of regulatory limitations prior to use.
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Standards Content (Sample)
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Designation: G29 − 96 (Reapproved 2010)
Standard Practice for
Determining Algal Resistance of Plastic Films
This standard is issued under the fixed designation G29; 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.Asuperscript
epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 4. Apparatus
1.1 This practice covers the determination of the suscepti- 4.1 Propagation Tank (see Fig. 1):
bility of plastic films to the attachment and proliferation of 4.1.1 A small fish tank (10 gal) is used to contain a
surface-growing algae.
simulated cooling tower, made of redwood slats, over which
culturemediumisrecirculatedthroughaplastictubewithholes
1.2 The values in SI units are to be regarded as the standard.
punched in the bottom. This design was developed in order to
The inch-pound units given in parentheses are for information
provide ideal conditions for propagation of the algae that serve
only.
as inocula for each test. Three redwood slats are joined by two
1.3 This standard does not purport to address all of the
supports in such a way that water cascades over each slat in
safety concerns, if any, associated with its use. It is the
turn from a distributor tube above the upper slat.Asmall, fully
responsibility of the user of this standard to establish appro- 3
immersed recirculating pump rests on the bottom of the tank
priate safety and health practices and determine the applica-
and operates continuously to deliver the tank contents to the
bility of regulatory limitations prior to use.
distributor tube. The light required for algal propagation is
provided by a 100-W bulb placed 300 mm (12 in.) away from
2. Summary of Practice
the redwood slats. A timing device turns the light on for 12 h
each day.
2.1 In this practice, test strips of plastic film are suspended
4.1.2 The propagation tank, that is used as the permanent
in glass jars maintained at room temperature.The test strips are
source of inoculum, is filled to approximately one-third capac-
exposed to fluorescent light and in direct contact with a
ity with the culture medium. Heavy growth of Oscillatoria
standardized inoculum of the filamentous blue-green alga
rapidly develops on the redwood tower and, at different phases,
Oscillatoria in culture medium. The sample test jars are
this growth appears light green, dark green, or black.
reinoculated with fresh alga every second or third day. A
control using untreated plastic film is used as a basis of
4.2 Test Chambers (see Fig. 2):
comparison. The inoculum is prepared with the help of a
4.2.1 One-litre (1-qt) wide-mouth glass jars, 170 mm (6 ⁄4
propagation apparatus made from a small fish tank. The test is
in.) high by 76 mm (3 in.) in inside diameter serve as test
terminated at the end of two weeks, or whenever the test film
chambers wherein water containing an inoculum of the algal
shows dense algal growth.
organisms and strips of the plastic film are maintained in
contact.
3. Significance and Use
4.2.2 The jars in 4.2.1 are placed in a 38-L (10-gal) fish
3.1 Bodies of water, such as swimming pools, artificial tank, 508 by 267 by 305 mm (20 by 10 ⁄2 by 12 in.) high, that
ponds, and irrigation ditches often are lined with plastic films. is illuminated by four 20-W “cool white” fluorescent bulbs,
Algae tend to grow in such bodies of water under the proper arranged two on each long side of the tank, at the level of the
atmospheric conditions, and they can produce slimy and
growing algae in the jars. The lamps are mounted on a bracket
unsightly deposits on the film. The method described herein is that holds the outer surface of the bulbs 25 mm (1 in.) from the
useful in evaluating the degree and permanency of protection wall of the tank. The tank is filled with water to within 25 mm
against surface growth of algae afforded by various additives of the top of the exposure jars in order to create uniform
incorporated in the film. temperature conditions for all jars.
1 2
This practice is under the jurisdiction ofASTM Committee G03 on Weathering The redwood tower should be soaked in water before use, until the water is
andDurabilityandisthedirectresponsibilityofSubcommitteeG03.04onBiological colorless. Water is changed daily.
Deterioration. Model 1 MA manufactured by the Little Giant Corp., 3800 N. Tulsa Ave.,
Current edition approved June 1, 2010. Published June 2010. Originally Oklahoma City, OK 73107, has been found suitable for this purpose.
approved in 1971. Last previous edition approved in 2002 as G29 – 96 (2002). DOI: Culture medium in the propagation tank is discarded, and the tank is refilled
10.1520/G0029-96R10. with fresh medium at monthly intervals.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
G29 − 96 (2010)
where such specifications are available. Other grades may be
used, provided it is first ascertained that the reagent is of
sufficiently high purity to permit its use without lessening the
accuracy of the determination.
5.2 Purity of Water—Unless otherwise indicated, references
to water shall be understood to mean distilled water or water of
equal purity.
5.3 Culture Medium for Propagation Apparatus—Prepare
this medium by dissolving in 15 L of water the designated
amounts of the following reagen
...
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