Use of Sand Filter-Activated Carbon System
for Refinery Wastewater Treatment
P. KRISHNAN, Senior Project Engineer
R. F. PEOPLES, Project Manager
Roy F. Weston, Inc.
West Chester, Pennsylvania
R. N. SIMONSEN, Consultant
Air and Water Conservation
Standard Oil Company (SOHIO)
Cleveland, Ohio
INTRODUCTION
B. P. Oil Corporation, a subsidiary of the Standard Oil Co. (Ohio), operates a
105,000 barrels/day refinery in Marcus Hook, Pennsylvania. The refinery is located
directly on the lower Delaware River and, thus, the effluent discharges are subject to
the jurisdiction of the Delaware River Basin Commission (DRBC).
Wastewater dischargers into the Delaware River have been given individual
pounds/day allocation of FSUOD (First Stage Ultimate Oxygen Demand). For B. P.
Oil's Marcus Hook Refinery, this allocation was established as 2,650 lbs/day. To help
meet this limit, B. P. Oil has undertaken a program to provide more complete
segregation of clean water from the Process Sewer and the API Separator and to
eliminate minor contamination of the clean water sewer system. At the same time, an
investigation was initiated to determine the most suitable method of treating the
process wastewaters.
A combination of pilot work and desk top analysis was used to define the
required facilities for both a conventional activated sludge system and an aerated
lagoon system. The presence of significant amounts of oil, mostly in emulsified form
in the API Separator effluent indicated the need for pretreatment of API Separator
effluent prior to biological treatment. With proper pretreatment, either the activated
sludge or the aerated lagoon system could accomplish the primary objective of
meeting DRBC's discharge allocation; however, other considerations prompted
further treatability investigation. Of great concern to B. P. was the considerable land
area required for either type of biological system but especially for the aerated
lagoon. The commitment of prime riverfront real estate to wastewater treatment by
biological methods, thus eliminating it from future use for refinery purposes, was not
attractive. In addition, expensive relocation of utilities and rerouting of some in-plant
sewers would be required.
Furthermore, biological units are often sensitive to variations in influent loads
(i.e., temperature, pH, oil, and other contaminants), and the effluent normally
reflects   these   fluctuations.   The   biological  treatment   process  also   produces  a
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