ASTM D2652-22

Standard Terminology Relating to Activated Carbon

SIGNIFICANCE AND USE
2.1 This terminology ensures that terms peculiar to activated carbon are adequately defined so that other standards in which such terms are used can be understood and interpreted properly.  
2.2 This terminology is useful to those who are not conversant with the terms related to activated carbon. However, it is also a ready reference for those directly associated with activated carbon to resolve differences and ensure commonality of usage, particularly in the preparation of ASTM standards.  
2.3 Although this terminology is intended to promote uniformity in the usage of terms related to activated carbon, it can never be complete because new terms are constantly arising. The existence of this terminology does not preclude the use or misuse of any term in another context.
SCOPE
1.1 This terminology covers terms particularly related to activated carbon and encompasses finished products, applications, and testing procedures.  
1.2 When any of the definitions in this terminology is quoted or published out of context, editorially insert the limiting phrase “in activated carbon” after the dash following the term to properly limit the field of application of the term and definition.  
1.3 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

General Information

• Status: Published
• Publication Date: 31-Aug-2022
• ICS: 01.040.71 - Chemical technology (Vocabularies)
• ICS: 71.060.10 - Chemical elements
• Technical Committee: D28 - Activated Carbon
• Drafting Committee: D28.03 - Nomenclature and Editorial

Overview

ASTM D2652-22: Standard Terminology Relating to Activated Carbon provides a comprehensive set of definitions for terms specific to activated carbon technology. Published by ASTM International, this terminology standard is developed to ensure a common understanding among professionals, regulators, manufacturers, and users of activated carbon. A consistent language helps avoid ambiguity, streamlines communication, and ensures accuracy when applying related standards, performing testing, or specifying activated carbon products.

Key Topics

ASTM D2652-22 covers a broad range of terminology relevant to:

• Activated Carbon Characteristics: Definitions for physical and chemical properties such as abrasion resistance, adsorption, activity, density (apparent, bulk, particle), pore size (macropore, mesopore, micropore), hardness, and moisture content.
• Testing and Evaluation: Standardized terms for methods and procedures including accelerated adsorption tests, dynamic adsorptive capacity, equilibrium capacity, and breakpoint determinations.
• Applications and Processes: Concepts like fixed beds, fluidized beds, batch and continuous operations, reactivation, regeneration, and usage of powdered, granular, and pelleted activated carbon.
• Performance Metrics: Terms like service life, relative efficiency, retentivity, threshold concentration, and surface area (B.E.T.).
• Operational Phenomena: Key occurrences such as channeling, breakthrough, desorption, and equilibrium states.

These definitions are designed to be precise references “in activated carbon” to ensure correct interpretation across standards and documentation.

Applications

ASTM D2652-22 serves practical purposes for a variety of stakeholders in industries where activated carbon is utilized, including:

• Product Development & Selection: Assists manufacturers and users in specifying and selecting the correct type and grade of activated carbon by providing uniform property definitions.
• Testing & Quality Assurance: Laboratories and quality professionals rely on these terms to ensure clarity and consistency when interpreting test results or setting acceptance criteria.
• Standardization & Procurement: Specifications, purchase agreements, and technical standards reference these terms to eliminate misunderstandings and miscommunication in international trade and supply chains.
• Regulatory Compliance: Agencies and environmental professionals depend on consistent terminology when applying regulatory standards, reporting, and compliance documentation for activated carbon, especially in water, air, and process purification.
• Research & Education: Provides foundational vocabulary for academic, technical, and training materials related to adsorption science and activated carbon technology.

Related Standards

Professionals using ASTM D2652-22 may also reference other standards, including:

• ASTM D2866: Standard Test Method for Total Ash Content of Activated Carbon
• ASTM D3838: Standard Test Method for pH of Activated Carbon
• ASTM D3860: Standard Practice for Determination of Adsorptive Capacity of Activated Carbon by Aqueous Phase Isotherm Technique
• ISO 14454: Covers terminology and definitions related to carbonaceous adsorbents

These and other standards benefit from the standardized terminology in ASTM D2652-22, supporting accurate application and cross-referencing of test methods, safety guidelines, and product specifications in the activated carbon industry.

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Keywords: ASTM D2652-22, activated carbon terminology, adsorption, adsorbent, granular activated carbon, powdered activated carbon, carbon testing standards, activated carbon applications, ASTM International.

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: D2652 − 22
Standard Terminology Relating to
Activated Carbon
This standard is issued under the fixed designation D2652; 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 (´) indicates an editorial change since the last revision or reapproval.
1. Scope absorption—a process in which fluid molecules are taken up
by a liquid or solid and distributed throughout the body of
1.1 This terminology covers terms particularly related to
that liquid or solid.
activated carbon and encompasses finished products,
applications, and testing procedures.
accelerated adsorption tests—adsorption tests in which the
end point is hastened by testing at conditions more severe
1.2 When any of the definitions in this terminology is
than those anticipated in service.
quoted or published out of context, editorially insert the
limiting phrase “in activated carbon” after the dash following
acid-extractable material—substances dissolved by an acid
the term to properly limit the field of application of the term
under specified conditions.
and definition.
activated carbon—a family of carbonaceous substances
1.3 This international standard was developed in accor-
manufactured by processes that develop adsorptive proper-
dance with internationally recognized principles on standard-
ties.
ization established in the Decision on Principles for the
Development of International Standards, Guides and Recom-
activation—any process whereby a substance is treated to
mendations issued by the World Trade Organization Technical
develop adsorptive properties.
Barriers to Trade (TBT) Committee.
activity—for activated carbon, the adsorptive capacity of an
adsorbent, usually as measured by a standard test.
2. Significance and Use
adsorbate—any substance that is adsorbed.
2.1 This terminology ensures that terms peculiar to acti-
vated carbon are adequately defined so that other standards in
adsorbent—any solid having the ability to concentrate signifi-
which such terms are used can be understood and interpreted
cant quantities of other substances on its surface.
properly.
adsorption—a process in which fluid molecules are concen-
2.2 This terminology is useful to those who are not conver-
trated on a surface by chemical or physical forces, or both.
sant with the terms related to activated carbon. However, it is
also a ready reference for those directly associated with
adsorption zone—see mass transfer zone.
activated carbon to resolve differences and ensure commonal-
ash—residue after the combustion of a substance under speci-
ityofusage,particularlyinthepreparationofASTMstandards.
fied conditions.
2.3 Although this terminology is intended to promote uni-
as-is basis—as received.
formity in the usage of terms related to activated carbon, it can
breakpoint—the appearance in the effluent of a specified
never be complete because new terms are constantly arising.
concentration of an adsorbate.
The existence of this terminology does not preclude the use or
misuse of any term in another context.
breakthrough, n—the first appearance in the effluent of an
adsorbate of interest under specified conditions.
3. Terminology
channeling—the preferential flow of fluid through passages of
abrasion resistance—the property of a particle to resist
lower resistance that can occur in fixed beds or columns of
attrition or wearing away by friction.
particles owing to nonuniform packing, irregular sizes and
shapes of the particles, gas pockets, wall effects, and other
causes.
This terminology is under the jurisdiction of ASTM Committee D28 on
Activated Carbon and is the direct responsibility of Subcommittee D28.03 on
chemical adsorption—see chemisorption.
Nomenclature and Editorial.
chemisorption (chemical adsorption)—the binding of an
Current edition approved Sept. 1, 2022. Published October 2022. Originally
adsorbate to the surface of a solid at strengths approximating
approved in 1967. Last previous edition approved in 2021 as D2652 – 21. DOI:
10.1520/D2652-22. those of a chemical bond.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D2652 − 22
coadsorption—the adsorption of two or more components on effective size—the particle size, in SI units, which corresponds
an adsorbent, each affecting the adsorbability of the other. to 10 percent finer on the cumulative particle size distribu-
tion curve.
contact batch operation—an adsorption process in which an
adsorbent is dispersed in a fluid to be treated and then
end point—the occurrence in the effluent of the maximum
separated when practical equilibrium is attained.
permissible concentration of an adsorbate of interest.
continuous moving bed—an adsorption process characterized
equilibrium adsorptive capacity—the quantity of a given
by flow of a fluid through a continuously moving bed of
component adsorbed per unit of adsorbent from a fluid or
granular adsorbent with continuous withdrawal of spent
fluid mixture at equilibrium temperature and concentration,
adsorbent and continuous addition of reprocessed or virgin
or pressure.
adsorbent.
expanded bed—a bed of granular particles through which a
countercurrent adsorption—an adsorption process in which
fluid flows upward at a rate sufficient to slightly elevate and
the flow of fluid is in a direction opposite to the movement
separate the particles without changing their relative posi-
of the adsorbent.
tions.
critical bed depth—the minimum depth of an adsorbent bed
fine mesh activated carbon—activated carbon in particle
required to contain the mass transfer zone.
sizes predominantly between 80 mesh and 325 mesh.
crushing strength—the property of a particle to resist physical
breakdown when contained and subjected to a slowly
fines, n—particles smaller than the smallest nominal specified
increasing continuously applied force. particle size.
degassing—removal of gases.
fixed bed—a stationary bed of granular particles.
density, absolute or true—the mass under specified condi-
floaters—the material floating on the surface of water into
tions of a unit volume of a solid sorbent excluding its pore
which carbon has been added and has been thoroughly
volume and inter-particle voids.
wetted.
density, apparent (density, bulk, packing)—the mass under
fluidized bed—a bed of particles in which the fluid flows
specified conditions of a unit volume of a solid sorbent
upward at a rate sufficient to suspend the particles com-
including its pore volume and inter-particle voids.
pletely and randomly in the fluid phase.
density, block—see density, particle.
Freundlich adsorption isotherm—a logarithmic plot of quan-
density, bulk—see density, apparent.
tity of component adsorbed per unit of adsorbent versus
density, packing—see density, apparent.
concentration of that component at equilibrium and at
density, particle (density, block)—the mass under specified
constant temperature, which approximates the straight line
conditions of a unit volume of a solid sorbent including its
postulated by the Freundlich adsorption equation
pore volume but excluding inter-particle voids.
n
X/M 5 kC
density, tamped—the density of packed bed of powdered
carbon.
where:
X = quantity adsorbed,
desiccant—a substance such as silica gel or activated alumina
M = quantity of adsorbent,
or molecular sieve or similar material that has a high affinity
C = concentration, and
for water and is used as a drying agent.
k and n = constants.
desorption—the separation of an adsorbate as such from a
granu
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This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: D2652 − 21 D2652 − 22
Standard Terminology Relating to
Activated Carbon
This standard is issued under the fixed designation D2652; 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 (´) indicates an editorial change since the last revision or reapproval.
1. Scope
1.1 This terminology covers terms particularly related to activated carbon and encompasses finished products, applications, and
testing procedures.
1.2 When any of the definitions in this terminology is quoted or published out of context, editorially insert the limiting phrase “in
activated carbon” after the dash following the term to properly limit the field of application of the term and definition.
1.3 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Significance and Use
2.1 This terminology ensures that terms peculiar to activated carbon are adequately defined so that other standards in which such
terms are used can be understood and interpreted properly.
2.2 This terminology is useful to those who are not conversant with the terms related to activated carbon. However, it is also a
ready reference for those directly associated with activated carbon to resolve differences and ensure commonality of usage,
particularly in the preparation of ASTM standards.
2.3 Although this terminology is intended to promote uniformity in the usage of terms related to activated carbon, it can never
be complete because new terms are constantly arising. The existence of this terminology does not preclude the use or misuse of
any term in another context.
3. Terminology
abrasion resistance—the property of a particle to resist attrition or wearing away by friction.
absorption—a process in which fluid molecules are taken up by a liquid or solid and distributed throughout the body of that
liquid or solid.
accelerated adsorption tests—adsorption tests in which the end point is hastened by testing at conditions more severe than
those anticipated in service.
This terminology is under the jurisdiction of ASTM Committee D28 on Activated Carbon and is the direct responsibility of Subcommittee D28.03 on Nomenclature and
Editorial.
Current edition approved June 1, 2021Sept. 1, 2022. Published June 2021October 2022. Originally approved in 1967. Last previous edition approved in 20202021 as
D2652 – 11 (2020).D2652 – 21. DOI: 10.1520/D2652-21.10.1520/D2652-22.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D2652 − 22
acid-extractable material—substances dissolved by an acid under specified conditions.
activated carbon—a family of carbonaceous substances manufactured by processes that develop adsorptive properties.
activation—any process whereby a substance is treated to develop adsorptive properties.
activity—for activated carbon, the adsorptive capacity of an adsorbent, usually as measured by a standard test.
adsorbate—any substance that is adsorbed.
adsorbent—any solid having the ability to concentrate significant quantities of other substances on its surface.
adsorption—a process in which fluid molecules are concentrated on a surface by chemical or physical forces, or both.
adsorption zone—see mass transfer zone.
ash—residue after the combustion of a substance under specified conditions.
as-is basis—as received.
breakpoint—the appearance in the effluent of a specified concentration of an adsorbate.
breakthrough, n—the first appearance in the effluent of an adsorbate of interest under specified conditions.
channeling—the preferential flow of fluid through passages of lower resistance that can occur in fixed beds or columns of
particles owing to nonuniform packing, irregular sizes and shapes of the particles, gas pockets, wall effects, and other causes.
chemical adsorption—see chemisorption.
chemisorption (chemical adsorption)—the binding of an adsorbate to the surface of a solid at strengths approximating those
of a chemical bond.
coadsorption—the adsorption of two or more components on an adsorbent, each affecting the adsorbability of the other.
contact batch operation—an adsorption process in which an adsorbent is dispersed in a fluid to be treated and then separated
when practical equilibrium is attained.
continuous moving bed—an adsorption process characterized by flow of a fluid through a continuously moving bed of granular
adsorbent with continuous withdrawal of spent adsorbent and continuous addition of reprocessed or virgin adsorbent.
countercurrent adsorption—an adsorption process in which the flow of fluid is in a direction opposite to the movement of the
adsorbent.
critical bed depth—the minimum depth of an adsorbent bed required to contain the mass transfer zone.
crushing strength—the property of a particle to resist physical breakdown when contained and subjected to a slowly increasing
continuously applied force.
D2652 − 22
degassing—removal of gases.
density, absolute or true—the mass under specified conditions of a unit volume of a solid sorbent excluding its pore volume
and inter-particle voids.
density, apparent (density, bulk, packing)—the mass under specified conditions of a unit volume of a solid sorbent including
its pore volume and inter-particle voids.
density, block—see density, particle.
density, bulk—see density, apparent.
density, packing—see density, apparent.
density, particle (density, block)—the mass under specified conditions of a unit volume of a solid sorbent including its pore
volume but excluding inter-particle voids.
density, tamped—the density of packed bed of powdered carbon.
desiccant—a substance such as silica gel or activated alumina or molecular sieve or similar material that has a high affinity for
water and is used as a drying agent.
desorption—the separation of an adsorbate as such from a sorbent.
differential heat of adsorption—the heat evolved during the adsorption of an incremental quantity of adsorbate at a given level
of adsorption.
dosage—the quantity of substance applied per unit weight or volume of the fluid being treated.
dry basis—exclusive of any moisture which may be present.
dust—an imprecise term referring to particulates capable of temporary suspension in air or other gases; also, particles smaller
than an arbitrarily selected size.
dynamic adsorptive capacity—the quantity of a given component adsorbed per unit of adsorbent from a fluid, or fluid mixture
moving through a fixed bed at the breakpoint for that component.
effective size—the particle size, in SI units, which corresponds to 10 percent finer on the cumulative particle size distribution
curve.
end point—the occurrence in the effluent of the maximum permissible concentration of an adsorbate of interest.
equilibrium adsorptive capacity—the quantity of a given component adsorbed per unit of adsorbent from a fluid or fluid
mixture at equilibrium temperature and concentration, or pressure.
expanded bed—a bed of granular particles through which a fluid flows upward at a rate sufficient to slightly elevate and separate
the particles without changing their relative positions.
D2652 − 22
fine mesh activated carbon—activated carbon in particle sizes predominantly between 80 mesh and 325 mesh.
fines, n—particles smaller tha
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