ASTM D3838-80(1999)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation: D 3838 – 80 (Reapproved 1999)
Standard Test Method for
pH of Activated Carbon
This standard is issued under the fixed designation D 3838; 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
1.1 This test method covers determination of the pH of a
water extract of activated carbon.
1.2 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 appro-
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use. For specific hazard
statements, see Section 6.
2. Referenced Documents
2.1 ASTM Standards:
D 1193 Specification for Reagent Water
D 1293 Test Methods for pH of Water
D 2867 Test Method for Moisture in Activated Carbon
E 300 Practice for Sampling Industrial Chemicals
3. Summary of Test Method
3.1 An activated carbon sample is boiled in reagent water
using a reflux condenser to recycle water vapor. The particles
of carbon are filtered out, the filtrate cooled to 50°C and the pH
of the filtrate determined by electrometic measurement.
4. Significance and Use
4.1 When a fluid containing an adsorbate is passed through
a bed of activated carbon, chemical reactions may take place
between the activated carbon, its other noncarbonaceous con-
FIG. 1 Boiler-Reflux Condenser Apparatus
stituents, and the adsorbate containing fluid. The pH of the
carbon may be a significant parameter of such a reaction and
supply houses. The “all-glass” elements, with standard-taper
therefore may be an important characteristic of the carbon.
and ball joints, provide freedom from contamination and
5. Apparatus and Materials
maintenance. A check valve in the position shown is essential
to relieve pressure buildup while minimizing loss of vapor.
5.1 Analytical Balance, capacity 100 g, precision 6 0.01 g.
5.4 Thermometer, glass, approximately 0 to 120°C, long
5.2 Hot Plate.
enough to be read at 100°C when inserted to bottom of
5.3 Glassware for Boiler-Reflux Condenser Apparatus (Fig.
Erlenmeyer flask in Fig. 1.
1)—Itemsshownareforguidanceonly,providingaconvenient
5.5 Thermometer, glass, approximately 20 to 55°C.
set of equipment available off-the-shelf from many laboratory
5.6 Graduated Cylinder, 100-mL.
5.7 Beaker, 200-mL.
1 5.8 Filter Funnel.
This test method is under the jurisdiction of ASTM Committee D-28 on
5.9 Filter Paper, qualitative, medium flow rate, 12.5 cm or
Activated Carbon and is the direct responsibility of Subcommittee D28.04 on Gas
Phase Evaluation Tests.
larger in diameter.
Current edition approved Jan. 3, 1980. Published March 1980.
5.10 Timer.
Annual Book of ASTM Standards, Vol 11.01.
5.11 pH Meter, in accordance with Test Methods D 1293,
Annual Book of ASTM Standards, Vol 15.01.
Annual Book of ASTM Standards, Vol 15.05. Type II (automatic thermal compensation preferred).
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D 3838
5.12 Reagent Water, in accordance with Specification 10. Calculation
D 1193, Type II.
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
6. Hazards
equation from the Terminology section of Test Methods
D 1293.
6.1 The test method involves transfer of boiling water
between containers; appropriate tongs or gloves should be
11. Report
used. In addition, the use of an electric hot plate and pH meter
11.1 Report the following information:
(if line-powered) poses a shock hazard. This equipment must
11.1.1 Source
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