Biological Degradation of
Tertiary Butyl Alcohol
J. A. HORN, Research Sanitary Engineer
J. E. MOYER, Supervisory Microbiologist
J. H. HALE, Chemist
Robert S. Kerr Water Research Center
Federal Water Quality Administration
U. S. Department of Interior
Ada, Oklahoma
INTRODUCTION
This investigation constitutes one segment of a research study involving the
development and testing of aerobic biological cultures capable of biodegrading classes
of reportedly "refractory chemicals."
Tertiary butyl alcohol (TBA) was chosen for investigation since it is a significant chemical waste constituent. For example, it is present as a by product from
production of propylene oxide by the direct oxidation process. This process is now
preferred for new plants since it is much cleaner than the older chlorohydrin process
regarding wastewaters generated. TBA is also a by product of isobutylene production. That TBA is highly resistant to biodegradation is shown by a review of literature.
During a Warburg study of 152 hr duration by Marion and Malaney (1)
oxygen uptake by TBA was approximately the same as the control. A pure culture of
Alcaligenes facaelis was utilized as the microbial seed. This species has been identified
as a member of activated sludge flora. The test mixture contained 500 mg of TBA
and 2,500 mg of bacterial cells per liter.
McKinney and Jeris found that only two per cent of the theoretical oxygen
demand of TBA was utilized during a 23 hr Warburg study (2). The substrate and
mixed liquor suspended solids concentrations (MLSS) were 500 and 170 mg/l, respectively. The microbial seed was developed from a sewage seed by gradual acclimation to TBA over a period of three to four weeks.
A 12 hr Warburg study by Buzzell (3) showed little oxygen uptake and only 4
per cent carbon removal. The nontoxic nature of TBA was demonstrated by the
dehydrogenase enzyme activity being greater than in the biocontrol unit at all times.
The initial TBA and MLSS concentrations were 180 mg/l as carbon, and 2,500 mg/l,
respectively. The microbial seed was a lyophilized sludge adatped to a glucose-
peptone feed. The above findings were substantiated during 20 gal/day pilot studies
of 8 hr duration having comparable feed and MLSS levels. Both studies were con
ducted primarily to develop a short term method for efficiently assessing the behavior of organic chemicals as shock loads on the activated sludge process.
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