ASTM D3838-05

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation: D3838 – 05
Standard Test Method for
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pH of Activated Carbon
This standard is issued under the fixed designation D3838; 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 carbon may be a significant parameter of such a reaction and
therefore may be an important characteristic of the carbon.
1.1 This test method covers determination of the pH of a
water extract of activated carbon.
5. Apparatus and Materials
1.2 This standard does not purport to address all of the
5.1 Analytical Balance, capacity 100 g, precision 6 0.01 g.
safety concerns, if any, associated with its use. It is the
5.2 Hot Plate.
responsibility of the user of this standard to establish appro-
5.3 Glassware for Boiler-Reflux Condenser Apparatus (Fig.
priate safety and health practices and determine the applica-
1)—Itemsshownareforguidanceonly,providingaconvenient
bility of regulatory limitations prior to use. For specific hazard
set of equipment available off-the-shelf from many laboratory
statements, see Section 6.
supply houses. The “all-glass” elements, with standard-taper
2. Referenced Documents and ball joints, provide freedom from contamination and
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maintenance. A check valve in the position shown is essential
2.1 ASTM Standards:
to relieve pressure buildup while minimizing loss of vapor.
D1193 Specification for Reagent Water
5.4 Thermometer, glass, approximately 0 to 120°C, long
D1293 Test Methods for pH of Water
enough to be read at 100°C when inserted to bottom of
D2867 Test Methods for Moisture in Activated Carbon
Erlenmeyer flask in Fig. 1.
D6851 Test Method for Determination of Contact pH with
5.5 Thermometer, glass, approximately 20 to 55°C.
Activated Carbon
5.6 Graduated Cylinder, 100-mL.
E300 Practice for Sampling Industrial Chemicals
5.7 Beaker, 200-mL.
3. Summary of Test Method
5.8 Filter Funnel.
5.9 Filter Paper, qualitative, medium flow rate, 12.5 cm or
3.1 An activated carbon sample is boiled in reagent water
larger in diameter.
using a reflux condenser to recycle water vapor. The particles
5.10 Timer.
of carbon are filtered out, the filtrate cooled to 50°C and the pH
5.11 pH Meter, in accordance with Test Methods D1293,
of the filtrate determined by electrometic measurement.
Type II (automatic thermal compensation preferred).
4. Significance and Use
5.12 Reagent Water, in accordance with Specification
D1193, Type II.
4.1 When a fluid containing an adsorbate is passed through
a bed of activated carbon, chemical reactions may take place
6. Hazards
between the activated carbon, its other noncarbonaceous con-
6.1 The test method involves transfer of boiling water
stituents, and the adsorbate containing fluid. The pH of the
between containers; appropriate tongs or gloves should be
used. In addition, the use of an electric hot plate and pH meter
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This test method is under the jurisdiction of ASTM Committee D28 on
(if line-powered) poses a shock hazard. This equipment must
ActivatedCarbonandisthedirectresponsibilityofSubcommitteeD28.02onLiquid
be grounded and insulated in accordance with UL standards
Phase Evaluation.
and electrical codes.
Current edition approved April 1, 2005. Published April 2005. Originally
approved in 1980. Last previous edition approved in 1999 as D3838 – 80 (1999).
DOI: 10.1520/D3838-05.
7. Sampling
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For referenced ASTM standards, visit the ASTM website, www.astm.org, or
7.1 Guidance in sampling activated carbon is given in
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on Practice E300.
the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
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D3838 – 05
500-mL vacuum filter flask, being careful to prevent carbon-
fines from overrunning into the flask.
9.7 Cool the filtrate to 50 6 5°C.
9.8 Measure pH as described in Test Methods D1293.
10. Calculation
10.1 If the pH meter is calibrated in pH units, read value
from pH meter. If the meter reading is in voltage units, use the
equation from the Terminology section of Test Methods
D1293.
11. Report
11.1 Report the following information:
11.1.1 Source of sample,
11.1.2 Type or designation of activated carbon,
11.1.3 Supplier name,
11.1.4 Supplier grade designation,
11.1.5 Supplier lot and batch number,
11.1.6 Moisture content in accordance with Test Method
D2867,
11.1.7 pH to the nearest 0.1 unit,
11.1.8 Temperature of measurement to the nearest 1°C,
11.1.9 Date of test,
11.1.10 Name and signature of technician
...