Factors to Consider When Selecting
Granular Activated Carbon for Wastewater Treatment
PASCHAL B. DeJOHN, Project Leader
Specialty Chemicals Division
ICI America Inc.
Wilmington, Delaware 19899
INTRODUCTION
Granular carbons produced from medium volatile bituminous coal or lignite have been
found to be the most feasible products for use in wastewater treatment. How does one
choose between the two if one were attempting to treat a particular waste stream? How does
one determine if the information obtained from a granular activated carbon column study is
sufficiently reliable to design a carbon system? These are two of the many questions that one
must answer when attempting to solve wastewater treatment problems with granular
activated carbon.
This paper is written to answer these and other questions about granular activated
carbon. If you have ever attempted to obtain information about the use of granular carbon
in wastewater^treatment, you have probably discovered that there is little of this type of
information available. Solving wastewater treatment problems with granular activated
carbon is nothing more than applied science in action. Hopefully, this paper will lift the
shroud that presently exists concerning this subject.
COMPARATIVE ADSORPTION OF LIGNITE AND BITUMINOUS COAL
CARBONS IN MUNICIPAL WASTES
In selecting a granular activated carbon, one should seek the most economical product
that provides 1) ability to adsorb impurities so that allowable effluent standards can be met;
2) losses during carbon regeneration that are reasonable (5-10% total); 3) minimal pressure
drop and operating problems; and 4) the lowest operating cost.
During the past four years, ICI America has conducted more than 50 comparative
granular carbon studies on various types of municipal and industrial wastewaters. The
work was done to determine what differences, if any exist in the performance of the two
carbon types.
TRICKLING
FILTER
6.9 gpm/. t'
I
(down.low)
SAND
TUTER
(tip. low.
1             1
LIGNITE
CARBON
10'
BITUMINOUS
COAL
CARBON
10'
t
Figure 1 — Flow diagram of the Marshall, Tx., plant.
Figures 1,2 and 3 are flow diagrams of three plants (Marshall, Texas; Cortland, N.Y.;
and Colorado Springs, Col.) where comparative studies on domestic wastewater were
conducted. Figures I and 2 also show the flow scheme of the pilot plant portion at the
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