Section 9. FOOD WASTES
TREATMENT OF SOFT DRINK BOTTLING WASTEWATER
FROM BENCH-SCALE TREATABILITY TO FULL-SCALE OPERATION
Frederic C. Blanc, Professor
James C. O'Shaughnessy, Assistant Professor
Department of Civil Engineering
Northeastern University
Boston, Massachusetts 02115
Steven H. Corr, Vice President
Peter M. Smith, Engineer
Weston & Sampson Engineers, Inc.
Wakefield, Massachusetts 01880
INTRODUCTION
When a soft drink bottling plant on Cape Cod decided to construct a new bottling plant in Sandwich, Massachusetts, a wastewater treatment and disposal system was required by the Commonwealth
of Massachusetts since there was no municipal sewer system available. This paper presents the treatability investigation, design, and construction of the wastewater facility for this soft drink bottling
plant.
The bottling plant bottles Cola, Diet Cola, Orange Soda, Root Beer, and other flavors for distribution on Cape Cod and surrounding areas. The Company bottles 2 liter, 32 ounce, 16 ounce and 10
ounce returnable bottles, and 5-gallon transfer tanks. All of the operations are bottling operations.
No canning is done. The process is operated year-round, normally one 8-hour shift per day. However,
in the summer when production more than doubles, this may be increased to 10-hours per day.
There are two production bottling lines located in the plant: Line Number 1 is for all sizes except 2
liter while Line Number 2 is for the 2 liter size only. Transfer tanks are washed and filled in a separate
area. All of the existing equipment was moved to the new facility. The wastewater sampling and characterization was conducted at the old facility.
The Bottling Process and Wastewater Generation
A process schematic, with the bottling operation, uses of water, and the sources of wastewater, is
shown on Figure 1. Wastewater is generated in several locations in the operation.
Production Line Number 1 fills new and returnable bottles. When new bottles are being filled, a
prerinse with a flow rate of approximately 10 gallons per minute (gpm) precedes the filling operation.
Additional wastewater is generated by soap, conveyor belt lubricant and the disposal of the contents
of improperly filled bottles.
When returnable bottles are on Production Line 1, the bottles pass through the bottle washing
machine. The machine washes the returnable bottles in a hot caustic solution which includes the following: 1) Pre-rinse; 2) Caustic active soak; 3) Rinse; 4) Warm water rinse; and 5) Final fresh water
rinse. The rinses from the bottle washer are discharged to the floor drain at a flow rate of approximately 35 gpm.
Transfer containers are 5-gallon containers filled with either premixed soft drink or a soft drink
concentrate to be mixed with carbonated water in a soft drink dispensing machine. Containers are
reused and washed in a special washing machine prior to refilling. Rinse water from this machine is
discharged as wastewater. In addition, any contents remaining in a returned can are emptied to the
floor drain.
Production Line Number 2 bottles only new 2-liter bottles in the same manner as Production Line
Number 1. Bottles are pre-rinsed and post-rinsed after bottling for a total flow of 15 to 20 gpm.
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