Section Six
INDUSTRIAL WASTES
A. PHARMACEUTICAL
57    START-UP OF THE BIOLOGICAL NITRIFICATION PROCESS
FOR THE FERMENTATION WASTEWATER
TREATMENT PLANT AT ELI LILLY AND COMPANY
Lisa M. Pantea, Environmental Engineer
Eli Lilly and Company
Tippecanoe Laboratories
Lafayette, Indiana
INTRODUCTION
A biological nitrification wastewater treatment plant has been designed and constructed to treat a
wastewater from fermentation processes at Tippecanoe Laboratories, located in Lafayette, Indiana.
The driving force in the project was the need to remove ammonia in this particular wastestream. There
are three wastestreams from the plantsite, all combining at the outfall to total 12 MGD. The major
ammonia load is from the fermentation production wastestream; hence, the ammonia reduction was
targeted for the fermentation wastewater treatment plant. The current NPDES permit has a 2000
pounds/day daily average limit of ammonia at the outfall. The proposed limit in the permit, expected
to be issued late in 1993, is likely to be significantly less than the current limit. The pre-existing
treatment plant could not meet the proposed limit; hence the nitrification process was pursued and
has been implemented.
Construction of the nitrification plant started in spring of 1990 and was completed in the fall of
1991. The nitrification process started up in the fourth quarter of 1991 and has been in operation since
that time. This chapter will describe the basic treatment process, the seeding scale-up process that
occurred before full scale start-up, first year performance of the treatment process, operational issues
confronted during the first year of operation, and a brief summary of denitrification start-up in
March, 1993.
PROCESS FLOW AND DESIGN CRITERIA
The nitrification process was designed and installed within a pre-existing activated sludge process.
The old treatment plant consisted of an equalization basin, five aeration basins in series, intermediate
clarification, followed by additional aeration basins with final clarifiers. The nitrification process
replaced the second set of aeration basins in the process flow. A flow diagram incorporating the new
nitrification facility into the old activated sludge system is shown in Figure 1.
The nitrification design begins with temperature reduction of the incoming wastewater using plate
and frame heat exchangers and a closed-loop cooling tower. The pre-existing activated sludge system
operates in the thermophilic range, with waste temperatures of 120-130°F. During feasibility studies
done at Purdue University, it was found that biological nitrification could not be successfully operated in this temperature range. Therefore, design criteria included temperature reduction to 75°F.
Basic design criteria is listed in Table I. Loading conditions vary greatly with production schedules,
and fluctuations are common due to batch scheduling. Equalization greatly benefits the process, but
does not totally eliminate daily variability.
BIOLOGICAL SEEDING PROCESS
The seeding process began in July, 1991, utilizing approximately one liter of mixed liquor from the
pilot reactors that had been running at Purdue University. This bacterial population had been accli-
48th Purdue Industrial Waste Conference Proceedings, 1993 Lewis Publishers, Chelsea, Michigan 48118. Printed in
U.S.A.
569