Sulfite Pulping Process Wastewater Treatment
by Activated Sludge
W. A. EBERHARDT, Manager
J. J. FEDRO, Process Engineer
The Charmin Paper Products Company
Mehoopany, Pennsylvania
J. S. KEEL, JR., Environmental Engineer
C. A. BARTON, Engineer
The Procter and Gamble Company
Cincinnati, Ohio
INTRODUCTION
The Charmin Paper Products Company has demonstrated at its Mehoopany,
Pennsylvania Plant that a sulfite pulp mill can be operated in harmony with the
environment. Almost three years following the start-up of an integrated pulp and
paper mill on the North Branch Susquehanna River, this waterway in the
Mehoopany-Tunkhannock area continues to be a highly productive warm water
fishery and is considered one of the most beautiful stretches of recreational water in
the nation.
A successful ecological-industrial balance was achieved by integrated planning
and operation of the production and environmental control facilities. The ammonia
base sulfite pulp making process used is described briefly elsewhere (1). The
associated water resource protection facilities are shown schematically in Figure 1.
They consist of high recovery multi-stage counter-current washing, a vapor
recompression evaporator, specially designed liquor handling boilers and an activated
sludge plant including emergency holding and diversion basins. The activated sludge
facility was the first of its kind to treat wastes from a sulfite pulp mill. The
development, start-up, operation and performance of this biological treatment plant
are the subjects of this paper.
PRELIMINARY FEASIBILITY STUDIES
Two primary areas of biological concern required early consideration: 1)
activated sludge process development, and 2) possible effects on the Susquehanna
River aquatic community.
Since there were no known activated sludge facilities treating sulfite pulping
wastes, treatability studies were undertaken. Using 15 liter batch units, Polkowski
and Boyle (2) demonstrated amenability of the waste to treatment and of major
significance, that biological flocculation and clarification could be achieved.
Process design batch and continuous laboratory investigations were undertaken
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