ASTM D1291-01

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Designation:D 1291–01
Standard Practice for
Estimation of Chlorine Requirement or Demand of Water, or
1
Both
This standard is issued under the fixed designation D 1291; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope 3. Terminology
1.1 This practice provides a means of estimating the quan- 3.1 Definitions of Terms Specific to This Standard:
tity of chlorine required to be added to a unit volume of water 3.1.1 chlorine demand—the amount of chlorine that must
to accomplish a predetermined treatment objective or to be added to a unit volume of water under specified conditions
completely react with all chlorine reactable substances in the of pH, temperature, and contact time to completely react with
water, or both. all chlorine-reactable substances in the water. It is defined as
1.2 Temperature, pH, and initial chlorine dosage are all the difference between the amount of chlorine applied and the
variables in estimating the optimum chlorination practice. The amount of free chlorine remaining at the end of the contact
effects of these variables can be evaluated using this practice. period.
1.3 Chlorine residual is determined using Test Method 3.1.2 chlorine requirement—the amount of chlorine that
D 1253. must be added to a unit volume of water under specified
1.4 This practice is applicable to all types of water in which conditions of pH, temperature, and contact time to achieve the
the stated treatment objective can be evaluated or residual objectives of chlorination.
chlorine can be measured, or both. 3.2 Definitions—For definitions relating to this practice, see
1.5 This standard does not purport to address all of the Terminology D 1129.
safety concerns, if any, associated with its use. It is the
4. Summary of Practice
responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica- 4.1 Known amounts of chlorine are added to a series of 500
mL aliquots of sample. The treated sample aliquots are
bility of regulatory limitations prior to use. For a specific
permitted to stand for a specified contact time (or a variety of
hazard statement, see Note 1.
different specified contact times) under specified conditions of
2. Referenced Documents
pH and temperature.At the end of the contact time, the sample
2.1 ASTM Standards: aliquots are either analyzed for chlorine content by Test
2
D 1129 Terminology Relating to Water Method D 1253 or subjected to whatever evaluative technique
2
D 1193 Specification for Reagent Water is required to establish accomplishment of the treatment
2
D 1253 Test Method for Residual Chlorine in Water objective, or both.
2
D 1293 Test Methods for pH of Water
5. Significance and Use
D 3370 Practices for Sampling Water from Closed Con-
2
5.1 Chlorine is added to potable water, waste water, and
duits
industrial water for a variety of purposes. Some of these
purposes are:
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5.1.1 To eliminate or reduce the growth of microorganisms
This practice is under the jurisdiction of ASTM Committee D19 on Water and
is the direct responsibility of Subcommittee D19.03 on Sampling of Water and
in water,
Water-Formed Deposits, Surveillance of Water, and Flow Measurement of Water.
5.1.2 To destroy or modify decomposable organic sub-
Current edition approved June 10, 2001. Published July 2001. Originally
e1 stances so as to reduce the biochemical oxygen demand of the
published as D 1291 – 53T. Last previous edition D 1291 – 89 (1994) .
2
Annual Book of ASTM Standards, Vol 11.01. water,
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
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D 1291–01
5.1.3 To eliminate or reduce taste, odors, and color in the a solution containing from 0.5 to 10 mg available chlorine per
water, millilitre, depending upon the maximum expected chlorine
5.1.4 To separate grease in waste water by eliminating the requirement for the sample.This solution must be standardized
protective colloidal effect of proteins present, and before use.
5.1.5 To destroy or modify substances in the waste water
7.5.3 Standardize the chlorine water or sodium hypochlorite
that react directly by oxidation, such as ammonia, cyanates,
solution, standard, as follows:
cyanides, ferrous iron, nitrites, phenol, phosphorus, sulfides,
7.5.3.1 Transfer 10 mL of the solution to be standardized to
sulfites, thiocyanates, and other oxidizable constituents.
a porcelain dish.
5.2 It is important to avoid over-chlorination in order to
7.5.3.2 Add 10 mL of acetic acid (1 + 1) (see 7.3) and 1
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