Clarification of the Lime Bearing Wastes
from a Sole Leather Tannery
J. DAVID EYE, Professor
LAWRENCE LIU, Research Assistant
Environmental Health Engineering
University of Cincinnati
Cincinnati, Ohio
INTRODUCTION
The tanning industry long has been recognized as a major contributor to water
pollution because of the highly pollutional nature of the water borne components of
untreated tannery effluents. The overall volume of tannery wastes, however, amounts
to only about 16 bil gal/yr, a rather small volume when compared with some of the
other wet industries.
It is of interest to note that some of the earliest work on indsutrial waste treatment in the United States was devoted to finding acceptable means for treating tannery wastes. The annual reports of the Massachusetts State Board of Health describe
laboratory and pilot plant studies on tannery waste treatment from 1850 to about
1910. The Public Health Service performed extensive waste treatment studies at various tanneries in the period from 1912-1914 (1). Following the Public Health Service work, investigators for the tanning industry, both in the United States and abroad,
conducted many studies on the treatment of tannery wastes alone and in combination
with domestic wastes (2,3,4,5,6,7,8,9,10,11 and 12).
While the research effort in tannery waste treatment has been extensive, the
industry has been slow in translating the laboratory and pilot plant findings into
workable waste management systems. Since 1965, however, a renewed effort has
been underway and the present level of activity in waste treatment in all segments of
the tanning industry probably ranks with that of any other industrial group. For
example five demonstration projects have been sponsored by the Federal Water Pollution Control Administration to investigate the feasibility of various treatment procedures for tennery wastes. In addition a number of tanneries currently are constructing full scale treatment facilities and many others are conducting laboratory and
pilot studies to provide design data. The outlook in early 1969, therefore, is
extremely encouraging and it is probably safe to predict that this industry will be one
of the first to resolve problems of waste management in a satisfactory manner.
TYPES OF TANNING
The basic objective of all tanning processes is the conversion of animal skins
into useful end products. The raw materials are derived from all types of animals,
from reptiles, and even include the feathers from birds. The end products likewise are
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