Packing House Waste Processing
Applied Improvement of
Conventional Methods
K. M. GARRISON, Chemical Engineering
R. J. GEPPERT, Manager Research Engineering
Rath Packing Company
Waterloo, Iowa
SUMMARY
A study was made of various types of waste handling equipment in an effort to recover valuable materials and reduce the strength and volume of packing house wastes. The processes studied included air-flotation, liquid-solid
cyclone classification, vacuum-drum filtration, and centrifugation. It was
found that each process could be applied for reducing the biological load and
solids content of packing house wastes. However, for the plant under study,
the high capital investment and operating costs or low rates of material recovery precluded their application. The most effective methods for reducing valuable material losses were determined by a thorough study of each plant waste
process.
Modification of the methods of handling hasher wash waters and interceptor bottom sludge resulted in increased grease and tankage recovery as well as
reduced hydraulic and biological load of the plant sewage. During the tests,
it was observed that seeding of the raw sewage may prove important in material recovery and the purification of waters polluted with grease and protein-
aceous solids.
The use of plastic as a filter media in a biological filter tower resulted in
BOD removals of 70 per cent at very high rates of filter loading. These latter
experiments will be continued so that more detailed information can be obtained.
INTRODUCTION
Waste processing in the meat packing industry is becoming more important every day. Inedible grease and animal tissue represent a large portion of
the recoverable products in the packing house, (1,2,3). Loss of these valuable materials can result in heavy pollutional loads to rivers and streams.
Waste processing is of additional importance in order to reduce municipal
sewage charges, prevent in-plant odors, and to prevent over loading at municipal treatment plants.
A detailed study of waste production within the packing house will provide
data on inefficient plant operations in the recovery of profitable materials
from the waste water discharged to the sewers. For the past seven years, such
a study has been made at The Rath Packing Company in Waterloo, Iowa. This
study has resulted in modifications which have reduced excessive losses of
valuable materials.
The facilities at The Rath Packing Company for waste treatment consist
of four interceptor basins of approximately 400,000 gal capacity. These
basins were designed in 1940 for primary sedimentation and grease recovery
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