Two Treatment Installations for
Pharmaceutical Wastes
R. W. HERION, JR., Project Engineer
H. O. LOUGHHEAD, Manager Process Division
Wyeth Laboratories, Inc.
Paoli, Pennsylvania
Wyeth Laboratories has two major waste treatment facfiities. Both are aeration type biological processes. The larger plant, located in West Chester, Pennsylvania, pretreats penicillin fermentation and fine chemical wastes from bulk
production and is presently removing approximately 6,000 lbs of BOD per day, discharging effluent to the municipal sewer.
The second plant, located near PaoU, Pennsylvania, completely treats all
wastes from a pharmaceutical packaging and drug formulation plant, discharging
effluent to a trout stream.
The details of the plants wiU be discussed separately, beginning with the pre-
treatment plant at the West Chester laboratories.
WEST CHESTER LABORATORIES
The peniciUin production faculties always had two major disposal problems
— that of spent acid culture medium and mycelial solids. Disposal of the solids
has been primarily by plowing and disking into the grounds. InitiaUy, the liquid
wastes were disposed of by lagooning. New faciUties for penicillin production
were constructed in 1952, at which time we entered into a contract with the
Borough of West Chester to treat lime neutralized fermentation wastes. Further
increases in production and the inability of the municipal plant to treat these
wastes led to spray irrigation of a portion of the waste to limit the sewer load.
Spray irrigation was to be only a temporary measure, since the ground soon became impervious.
At this time our initial studies to pretreat the fermentation waste were begun.
AmenabiUty studies were conducted in the fermentation pilot plant units prior to
design of a continuous activated sludge pilot plant. Figure 1 shows the main aeration vessel of 45-gal capacity, water jet exhauster and supply pump aspirating air
from the atmosphere, and feed rotameter. Connected to the aerator is a clarifier
with air lift return. At the experimental loadings denitrification and air entrain-
ment practicaUy made the clarifier inoperative; clarification was handled manu-
aUy, returning sludge intermittently after settling. A continuously operating unit
was established with a feed rate of 38 gal/day at a pH of 3.1 and a detention of 21
hrs.   A neutral effluent was produced with 95 per cent reduction in BOD.
Figure 2 shows the relation of influent to effluent BOD at various intervals
during continuous operation. As the data show, the MLVSS are quite high due to
no withdrawal of sludge other than that in the effluent. Effluent of this quaUty,
when combined with the remaining plant wastes, would have a BOD of less than
300 ppm. A combined plant waste BOD of 300 ppm was one limiting feature
established by the municipal authorities in the Sewage Premium Charge Formula.
The fact that the system was self-neutralizing when operated at these loadings,
that is, 500 lbs BOD removed/1000 cu ft of aeration, was also significant as elim-
- 218  -