Significance of a Highly Alkaline Industrial
Waste in a Municipal Waste Water Treatment
Plant
RAY D. LEARY, Chief Engineer and General Manager
HENRY E. DEDINSKY, South Shore Plant Supervisor
LAWRENCE A. ERNEST, Director of Laboratories
Milwaukee Metropolitan Sewerage Commission
Milwaukee, Wisconsin
SUDARSHAN K. MALHOTRA, Assistant Professor
Marquette University
Milwaukee, Wisconsin
INTRODUCTION
An engineer at a municipal waste water treatment plant wants to know about
the different types of industrial wastes he can treat along with the domestic waste
water. In addition, a knowledge of the effect of an industrial waste on the plant
efficiency is useful to comprehend and overcome some of the observed abnormalities
during its treatment. This paper is intended to point out some of the observed effects
of a highly alkaline industrial waste, Peter Cooper Corporation's glue and gelatine
plant waste, on the performance of the South Shore Municipal Waste Water
Treatment Plant.
South Shore Waste Water Treatment Plant, designed by Alvord, Burdick and
Howson Consulting Engineers, is a branch of the Milwaukee Sewerage Commission
Jones Island Plant, and has been in operation since December, 1968. It is, at this
stage of development, a 60 MGD Primary Treatment Plant utilizing anaerobic
digesters for sludge stabilization. An addition presently under construction will
provide Secondary Activated Sludge Treatment by 1972, and will expand the plant
capacity to 120 MGD.
Prior to the acceptance of the Peter Cooper Corporation's glue and gelatine
plant waste, a laboratory evaluation was conducted to determine what effect this
industrial waste would have on the anaerobic digestion process. One of the major
concerns with this plant waste was its high chromium content and its possible toxic
effect on the anaerobic bacteria. Our laboratory studies indicated that the gas
production, the gas quality, and the digestion process were not effected when the
industry's sludge, mixed with sewage sludge, was digested. The requirements then
imposed on the industry were, 1) that the pH of the waste to equal 5.5 or higher, 2)
grease not to exceed 100 mg/1, 3) temperature not to exceed 140 F and, 4) the solids
should be discharged at a uniform rate.
The Peter Cooper Corporation involved in the manufacture of glue and gelatine
utilized raw materials consisting of chrome tanned leather scraps, hide trimmings,
cattle fleshings, calf trimmings, hide splits and  pig skins. The processes for the
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