ENHANCEMENT OF OIL REFINERY ACTIVATED SLUDGE
BY ADDITION OF POWDERED ACTIVATED CARBON
Michael K. Stenstrom, Research Engineer
Colin G. Grieves, Research Engineer
Research and Development Center
Amoco Oil Company
Naperville, Illinois 60540
INTRODUCTION
The National Pollutant Discharge Elimination System (NPDES), as created by PL-92-500,
requires all industries in the United States to reduce water pollution to essentially zero by
1985.  The first phase of the reduction program is to be implemented by mid-1977 and
required industries to operate best practicable control technology currently available (BPT)
wastewater treatment plants.   The second objective is to develop, construct, and operate
best available technology, economically achievable (BAT) treatment plants by 1983.  The
development program, and experience in operating the BPT and BAT treatment plants,
will result in further progress toward the final goal of the program, which is elimination of
all pollutant discharges, if such elimination is technologically and economically achievable.
Attainment of BPT treatment requires the implementation of best practicable technology.
The U.S. EPA has suggested in their guideline document [1] the treatment sequence shown
in Figure 1.   Although other suitable treatment methods are available, many other refiners
as well as Amoco have followed the general outline.   Modifications in the suggested treatment have been made in many instances to utilize existing facilities or improve the process
Refinery
Waste-	
water
Gravity
Separator
Stop Otl
to
Treatment
Dissolved
Air
Flotation
Equalization
Aeration
Tank
Sludge
Recycle
Granular
Media
Filter
Final
-Effluent
Sludge
to
Treatment
Figure 1.  Schematic of refinery BPT wastewater treatment system.
due to peculiarities of each installation.   Granular activated carbon columns have been
proposed for BAT treatment.   The add-on columns would utilize the existing treatment
BPT facilities and would, in theory, provide an economical method of achieving 1983
standards.   An alternate technique, and the subject of this paper, is powdered activated
carbon enhancement of the activated sludge process shown in Figure 1.   If the technique
were successful, no additional equipment would be required other than the carbon handling and, in some cases, regeneration facilities, which would also be required of the granular
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