2    INDUSTRIAL WASTE PRETREATMENT USING A CELROBIC
ANAEROBIC REACTOR
Donald F.«DeAngelis, Environmental Process Supervisor
Louis Giokas, Senior Environmental Engineer
Badger Engineers, Inc.
Cambridge, Massachusetts 02142
James M. Nelson, Assistant City Engineer
David L. Welsh, Wastewater Plant Superintendent
City of Beloit
Beloit, Wisconsin 53511
INTRODUCTION
The purpose of this chapter is to present a case history for the Celrobic anaerobic pretreatment
plant located in Beloit, Wisconsin.
A Celrobic anaerobic wastewater pretreatment plant has been constructed and is pretreating industrial wastewater prior to discharge into the municipal wastewater collection system. The pretreatment
plant is an excellent example of cooperative effort by private industry and a municipality to solve a
wastewater handling problem.
A new enzyme production facility was planned for construction by Enzyme Bio-Systems Ltd. in the
Beloit, Wisconsin Industrial Park. The increased organic wastewater load from the enzyme plant
would have utilized all the reserve capacity of the existing municipal wastewater treatment plant. To
alleviate this problem, the decision was made by Enzyme Bio-Systems Ltd. and the City of Beloit to
pretreat the enzyme plant wastewater along with all the other wastewater from the industrial park.
The pretreatment plant greatly reduces the organic load to the municipal wastewater treatment plant
(POTW), thereby reserving plant capacity for further growth in the greater Beloit area.
The case history presented herein defines the need for wastewater pretreatment, explains the development of the design basis, summarizes wastewater characteristics and laboratory treatability tests,
describes the Celrobic anaerobic process, discusses engineering, procurement, construction and
start-up of the facility, and summarizes operating results.
BACKGROUND
During 1983, Enzyme Bio-Systems Ltd., an enzyme producer and subsidiary of CPC International
executed a site selection survey for a Midwestern site. The proposed enzyme plant was to manufacture
enzymes used for the processing of various carbohydrates. The enzyme products from the plant were
to be produced by fermentation followed by recovery and purification.
As in most fermentation processes, the disposal of fermentation liquor after the desired products
have been recovered, is an issue which must be addressed due to the high strength of the wastewater.
After an extensive review of various plant sites, Enzyme Bio-Systems Ltd. selected a site at the Beloit
Industrial Park in Beloit, Wisconsin adjacent to Interstate 90.
The industrial park consists of a diversified cross-section of commercial/industrial users as shown
in Table I. All the users discharge process and/or sanitary wastewater into the municipal collection
system for treatment in the City's treatment plant. The municipal primary and secondary plant treats
wastewater from the industrial park as well as servicing the rest of the City's residential, commercial,
and industrial users. The municipal plant has a maximum capacity of 9.5 mgd and 27,000 Ib/d of
BOD.
Since the City POTW was operating near its maximum capacity, a moratorium on the addition of
new wastewater sources was in affect.
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