ASTM D1252-06

Standard Test Methods for Chemical Oxygen Demand (Dichromate Oxygen Demand) of Water

SIGNIFICANCE AND USE
These test methods are used to chemically determine the maximum quantity of oxygen that could be consumed by biological or natural chemical processes due to impurities in water. Typically this measurement is used to monitor and control oxygen-consuming pollutants, both inorganic and organic, in domestic and industrial wastewaters.
The relationship of COD to other water quality parameters such as TOC and TOD is described in the literature. 3
SCOPE
1.1 These test methods cover the determination of the quantity of oxygen that certain impurities in water will consume, based on the reduction of a dichromate solution under specified conditions. The following test methods are included: Equation 1 -  Test Method A-Macro COD by Reflux Digestion and TitrationEquation 2 - Test Method B-Micro COD by Sealed Digestion and Spectrometry
1.2 These test methods are limited by the reagents employed to a maximum chemical oxygen demand (COD) of 800 mg/L. Samples with higher COD concentrations may be processed by appropriate dilution of the sample. Modified procedures in each test method (Section 15 for Test Method A and Section 24 for Test Method B) may be used for waters of low COD content ( 50 mg/L).
1.3 As a general rule, COD results are not accurate if the sample contains more than 1000 mg/L Cl. Consequently, these test methods should not be applied to samples such as seawaters and brines unless the samples are pretreated as described in Appendix X1.
1.4 This test method was used successfully on a standard made up in reagent water. It is the user's responsibility to ensure the validity of these test methods for waters of untested matrices.
1.5 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. For specific hazard statements, see Sections 8, 15.6, and 24.5.

General Information

• Status: Historical
• Publication Date: 14-Feb-2006
• ICS: 13.060.50 - Examination of water for chemical substances
• Technical Committee: D19 - Water
• Drafting Committee: D19.06 - Methods for Analysis for Organic Substances in Water

Relations

• Replaces: ASTM D1252-00 - Standard Test Methods for Chemical Oxygen Demand (Dichromate Oxygen Demand) of Water
• Effective Date: 15-Feb-2006
• Replaced By: ASTM D1252-06(2012) - Standard Test Methods for Chemical Oxygen Demand (Dichromate Oxygen Demand) of Water
• Effective Date: 15-Jun-2012
• Referred By: ASTM D8084-17 - Standard Test Method for Photoelectrochemical Oxygen Demand of Freshwater Sources for Drinking Water Treatment Plants and Treated Drinking Water
• Effective Date: 15-Feb-2006
• Referred By: ASTM D3223-17 - Standard Test Method for Total Mercury in Water
• Effective Date: 15-Feb-2006
• Referred By: ASTM D3694-96(2017) - Standard Practices for Preparation of Sample Containers and for Preservation of Organic Constituents
• Effective Date: 15-Feb-2006

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: D1252 − 06
StandardTest Methods for
Chemical Oxygen Demand (Dichromate Oxygen Demand) of
1
Water
This standard is issued under the fixed designation D1252; 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.
This standard has been approved for use by agencies of the Department of Defense.
1. Scope 2. Referenced Documents
2
2.1 ASTM Standards:
1.1 These test methods cover the determination of the
D1129Terminology Relating to Water
quantity of oxygen that certain impurities in water will
D1193Specification for Reagent Water
consume, based on the reduction of a dichromate solution
D2777Practice for Determination of Precision and Bias of
under specified conditions. The following test methods are
Applicable Test Methods of Committee D19 on Water
included:
D3223Test Method for Total Mercury in Water
TestMethodA 2MacroCODbyRefluxDigestionandTitration
D3370Practices for Sampling Water from Closed Conduits
D5905Practice for the Preparation of SubstituteWastewater
TestMethodB 2MicroCODbySealedDigestionandSpectrometry
E60Practice for Analysis of Metals, Ores, and Related
Materials by Spectrophotometry
1.2 Thesetestmethodsarelimitedbythereagentsemployed
E275PracticeforDescribingandMeasuringPerformanceof
to a maximum chemical oxygen demand (COD) of 800 mg/L.
Ultraviolet and Visible Spectrophotometers
SampleswithhigherCODconcentrationsmaybeprocessedby
appropriate dilution of the sample. Modified procedures in
3. Terminology
eachtestmethod(Section15forTestMethodAandSection24
for Test Method B) may be used for waters of low COD
3.1 Definitions—For definitions of other terms used in these
content (< 50 mg/L). test methods, refer to Terminology D1129.
3.2 The term “oxygen demand” (COD) in these test meth-
1.3 As a general rule, COD results are not accurate if the
−
ods is defined in accordance with Terminology D1129 as
samplecontainsmorethan1000mg/LCl .Consequently,these
follows:
test methods should not be applied to samples such as
3.2.1 oxygen demand— the amount of oxygen required
seawaters and brines unless the samples are pretreated as
underspecifiedtestconditionsfortheoxidationofwaterborne
described in Appendix X1.
organic and inorganic matter.
1.4 This test method was used successfully on a standard
made up in reagent water. It is the user’s responsibility to
4. Summary of Test Methods
ensure the validity of these test methods for waters of untested
4.1 Most organic and oxidizable inorganic substances pres-
matrices.
ent in water are oxidized by a standard potassium dichromate
1.5 This standard does not purport to address all of the
solution in 50% sulfuric acid (vol/vol). The dichromate
safety concerns, if any, associated with its use. It is the
consumed (Test Method A) or tri-valent chromium produced
responsibility of the user of this standard to establish appro-
(Test Method B) is determined for calculation of the COD
priate safety and health practices and determine the applica-
value.
bility of regulatory limitations prior to use. For specific hazard
4.2 The oxidation of many otherwise refractory organics is
statements, see Sections 8, 15.6, and 24.5.
facilitated by the use of silver sulfate that acts as a catalyst in
the reaction.
1
These test methods are under the jurisdiction of ASTM Committee D19 on
Water and are the direct responsibility of Subcommittee D19.06 on Methods for
2
Analysis for Organic Substances in Water. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved Feb. 15, 2006. Published February 2006. Originally contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
approved in 1953. Last previous edition approved in 2000 as D1252–00. DOI: Standards volume information, refer to the standard’s Document Summary page on
10.1520/D1252-06. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

---------------------- Page: 1 ----------------------
D1252 − 06
TABLE 1 Test Method A, Recovery of Theoretical COD for
4.3 These test methods provide for combining the reagents
Various Organic Material
and sample in a manner that minimizes the loss of volatile
Reactivity, Percent of Theoretical
organic materials, if present.
Component
A B C D E
1 2 3 4 5
4.4 The oxidation of up to 1000 mg/L of chloride ion is
Aliphatic Compounds
inhibited by the addition of mercuric chloride to form stable
Acetone 98 . 96 94 .
and soluble mercuric sulfate complex. A technique to remove Acetic acid 92 92 98 . .
Acrolein 62 . . . .
up to 40 000 mg/Lchloride is shown
...