Section Fourteen
MEATPACKING WASTES
49    START-UP AND OPERATION RESULTS FROM SBR
TREATMENT OF A MEAT PROCESSING WASTEWATER
Kenneth L. Norcross, III, Vice President
Sam Petrie, Project Engineer
Jet Tech, Inc.
Industrial Airport, Kansas 66031
Rick Bair, Project Director
Mid-Kansas Engineering Corporation
Wichita, Kansas 67226
Gorden Beaushaw, Plant Operator
Doskocil Sausage Company
South Hutchison, Kansas 67505
INTRODUCTION
The Doskocil Sausage Company supplies precooked pizza toppings to most of the major pizza
retailers. In 1985, a total of 79 million pounds of meat were processed at the facility. Approximately
20% of the mass is lost during the cooking process. The result is a highly concentrated waste stream
with the following characteristics.
Flow
150,000 to 400,000 GPD
BOD
10,000 mg/L
TSS
150 mg/L
Grease
13,000 mg/L
PH
4.5 to 11
The existing pretreatment plant was an activated sludge plant with fine bubble diffused aeration.
Due to the high F:M loadings, the diffusers slimed over continuously, and the plant operated for years
under extreme filamentous bulking conditions. Effluent quality was extremely poor, and little BOD
reduction was achieved. In June of 1984, the City of South Hutchinson, Kansas passed a sewer
disposal charge ordinance which assessed the industry lie per pound of BOD, lit per pound of
grease, and 10« per pound of suspended solids. This resulted in an annual cost to Doskocil of $1.34
million. It was determined that a functional wastewater treatment plant with grease recovery could be
constructed for under $1.5 million. The prime consideration was that the plant be capable of eliminating the filamentous bulking problem. A substantial recovery of renderable grease was estimated to be
worth as much as $0.5 million annually. Dissolved air flotation was selected for grease recovery. The
sequencing batch reactor (SBR) version of the activated sludge process was selected for BOD, suspended solids, and additional grease removal. The SBR's apparent capability to control filaments,
flexibility and overall simplicity were the basis of selection.
SEQUENCING BATCH REACTOR PROCESS DESCRIPTION
The conventional, continuous flow activated sludge process is as follows: influent feeds continuously, proceeds through a sequence of separate dedicated unit process tanks, and discharges continuously. Steady state conditions are attempted, but rarely achievable. In contrast, the basic operational
steps of the batch reactor process are shown in Figure 1. As is evident from the sketch, all process
steps (Fill, React, Settle and Decant) are completed in a single tank. In the SBR Process, the influent
still feeds continuously, but batch-wise to each SBR process tank. The unit process steps proceed
through a similar sequence of dedicated process periods instead of separate tanks. The effluent
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