ASTM D1252-06 (2020) PDF

Full title and description

Designation: D1252 − 06 (Reapproved 2020) — Standard Test Methods for Chemical Oxygen Demand (Dichromate Oxygen Demand) of Water. This ASTM test-method standard describes two procedures for determining chemical oxygen demand (COD) in water and wastewater: Test Method A (macro COD by reflux digestion and titration) and Test Method B (micro COD by sealed digestion and spectrometry).

Abstract

ASTM D1252 specifies dichromate-based test methods to measure the maximum quantity of oxygen that impurities in a water sample could consume. The standard includes procedures for both macro and micro determinations, reagent and apparatus requirements, sample handling, performance limits (including chloride interference considerations), and safety notes for use of strong acids and toxic catalysts. It is intended for routine laboratory monitoring of municipal, industrial, and environmental waters.

General information

• Status: Published (reapproved).
• Publication date: Reapproved January 1, 2020 (original adoption 2006).
• Publisher: ASTM International.
• ICS / categories: 13.060.50 — Examination of water for chemical substances.
• Edition / version: D1252-06 (Reapproved 2020).
• Number of pages: 12 pages (typical published PDF length).

Key bibliographic details and designation notes are provided in the reapproved 2020 edition.

Scope

These test methods cover determination of the quantity of oxygen that certain impurities in water will consume, based on reduction of potassium dichromate in sulfuric acid under specified conditions. The standard contains two test methods: Test Method A — Macro COD using reflux digestion and titration; Test Method B — Micro COD using sealed digestion and spectrometric measurement. The methods include optional modifications for low-COD waters and address chloride interference (general application limited without pretreatment to about 1000 mg/L Cl−; techniques to remove higher chloride are described). Safety considerations for corrosive acid and toxic reagents (for example, silver sulfate and mercuric sulfate) are provided.

Key topics and requirements

• Principle: Oxidation of organic and oxidizable inorganic matter by potassium dichromate in 50% sulfuric acid; COD calculated from dichromate consumed.
• Two test methods: Macro reflux digestion with titration (Method A) and sealed digestion with spectrometric measurement (Method B).
• Reagents and catalysts: Use of mercuric sulfate to complex chloride and silver sulfate as catalyst for refractory organics (with associated toxic-hazard controls).
• Operational limits: Typical method validity up to specified chloride and COD ranges (procedures for dilutions and chloride removal described in appendices).
• Apparatus and sample handling: Reflux apparatus, sealed digestion vessels, standardization procedures for titrants and indicators, and sampling practices referenced.
• Precision, accuracy, and check standards: Guidance on expected recoveries, precision ranges, and recommended quality controls for method verification.
• Safety and waste: Specific hazard warnings for concentrated sulfuric acid and toxic metal salts and recommendations for disposal and laboratory safety practices.

These are the primary technical requirements and recommended controls for laboratory implementation.

Typical use and users

Used by environmental and wastewater testing laboratories, municipal and industrial water quality groups, regulatory compliance laboratories, research institutions, and consultants involved in routine monitoring, process control, and method validation for organic load in water and wastewater. The standard is commonly applied for discharge monitoring, treatment performance evaluation, and comparative laboratory studies.

Related standards

Commonly referenced and related documents include ASTM D1129 (terminology relating to water), ASTM D1193 (specifications for reagent water), sampling practices such as Practice D3370, and practices for substitute wastewater preparation (e.g., D5905). The standard also cross-references other ASTM and internationally recognized methods and standard practices for wastewater analysis and laboratory quality control.

Keywords

Chemical Oxygen Demand, COD, dichromate oxygen demand, potassium dichromate, reflux digestion, sealed digestion, titration, spectrometry, wastewater analysis, water quality, mercuric sulfate, silver sulfate, analytical method.

FAQ

Q: What is this standard?

A: ASTM D1252 is a set of standardized test methods for measuring Chemical Oxygen Demand (COD) of water using dichromate oxidation; designated D1252-06 and reapproved in 2020.

Q: What does it cover?

A: It covers two primary procedures — a macro method using reflux digestion and titration (Method A) and a micro method using sealed digestion and spectrophotometric measurement (Method B) — plus reagent, apparatus, sampling, interference, precision, and safety guidance. It addresses chloride interference and includes modifications/appendices for low-COD waters and high-chloride samples.

Q: Who typically uses it?

A: Environmental and wastewater testing laboratories, municipal and industrial monitoring programs, environmental consultants, regulators, and researchers involved in water quality and effluent monitoring.

Q: Is it current or superseded?

A: The 2006 designation was reapproved in 2020 (D1252-06 (Reapproved 2020)). As of the reapproval date it is the current reapproved edition; users should check for any later revisions or reapprovals after 2020 if absolute currency is required.

Q: Is it part of a series?

A: It is part of ASTM's D19 committee output (Water) and is commonly used alongside related water-analysis standards and practices (terminology, reagent water specifications, sampling practices, and wastewater preparation practices). It is not a multi-part numbered series but does cross-reference several companion ASTM methods.

Q: What are the key keywords?

A: COD, chemical oxygen demand, dichromate, reflux digestion, titration, spectrometry, wastewater, water analysis, mercuric sulfate, silver sulfate.