Pilot Studies of Biological Alternatives for
Petrochemical Waste Treatment
J. C. HOVIOUS, Research Engineer
R. A. CONWAY, Group Leader
Research and Development Department
Union Carbide Corporation
South Charleston, West Virginia
Z. B. HARVEY, Engineer
Texas City Plant
Union Carbide Corporation
Texas City, Texas
INTRODUCTION
Due to major problems encountered in treating petrochemical wastes by the
conventional air-based activated sludge process, a developmental effort was undertaken by the Chemicals and Plastics Divison of Union Carbide to evaluate currently
available process alternatives. Emphasis was placed upon alternatives applicable to
warm, spacious locations where a need for additional treatment facilities was
impending. Laboratory studies were conducted at the South Charleston, West
Virginia Technical Center and pilot studies at the Texas City, Texas, Plant of Union
Carbide. The studies described are entirely separate from and not associated with the
UNOX system developed and currently being marketed by Union Carbide's Linde
Division for oxygen treatment of both municipal and industrial (including petrochemical) wastes. By way of illustration, air was used as the oxygen source in this
study, where at least 90 percent pure oxygen is preferred in the UNOX system. The
UNOX system was not available at the time this study was conducted.
The ideal process combination would use proven technology insofar as possible
and provide long-term reliability in treatment of a hot waste characterized by a
rapidly changing load of synthetic, soluble organics. The petrochemical wastes
involved have a high pH and are low in available nutrients. Major chemical
constitutents are listed in Table I. Inhibitory effects on various microbial groups, e.g.
nitrifiers, protozoa, floe formers, are periodically encountered.
Biological systems studied included 1) completely mixed activated sludge, 2)
anaerobic contact digestion, 3) anaerobic packed beds, 4) anaerobic lagoons, 5) series
anaerobic lagoon-activated sludge, and 6) series anaerobic lagoon-aerated stabilization-facultative lagoons.
A research grant providing partial support of anaerobic treatment studies was
awarded in late 1968 by the Water Quality Office of the Environmental Protection
Agency. Studies covered were anaerobic contact digestion, anaerobic packed bed,
and the latter phase of the anaerobic lagoon pilot study. A large demonstration unit
was constructed under the grant to study series anaerobic lagooning-aerated
stabilization-facultative lagooning.
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