The Clarification of Paper Mill Effluents by
Activated Carbon Produced from Waste
Sulfite Liquor and Other Refuse
G. G. COPELAND, President
Copeland Systems, Inc.
Oak Brook, Illinois
G. R. SMITHSON, JR., Chief
M & M Division
Batteile Memorial Institute
Columbus Laboratories
Columbus, Ohio
INTRODUCTION
More than 5,000 establishments in the United States are engaged in the
manufacture of paper and allied products. The capacities of these installations, the
unit processes involved in converting the raw materials into finished products, and
the level of technology involved varies considerably from plant to plant. In most
cases, however, the establishments utilize a considerable number of wet operations in
the subprocesses which demand the use of large quantities of water because of the
necessity to eliminate from their circuits undesirable soluble and insoluble materials.
Furthermore, the auxiliary operations such as recovery systems, steam plants, etc.,
required by many of the subprocesses generate their own waste streams.
Over half of the paper products produced are made via the sulfate or Kraft
pulping process. An additional 18 per cent of the paper products utilize pulp made
by sulfite and semichemical pulping techniques. The general technological trends
within the industry include more efficient means of wood preparation, the use of
continuous digesters, and the utilization of liquor recovery systems wherever
possible. The general trend also is for greater reuse of water when this can be
accomplished without having a deleterious effect on the product. Some pulp and
paper mills segregate their liquid waste streams. Although the practice is not
common, it is used in special cases, usually to permit greater reuse of water in the
same or different processes. For example, bleach wash water may be reused in
repulping in chemical mills. Debarking effluent may be treated by screening for reuse
in flumes, sprays, etc.
Of the unit processes, the pulping operation is a consistent source of pollution.
Waste liquors from this operation have high BOD concentrations and are highly
colored. They also foam readily providing the visual evidence of pollution. The
suspended solids and dissolved solids contents of these liquors also are quite high.
Methods used in the treatment of waste water from pulp and paper mills
include   pretreatment,   primary   treatment,   secondary  treatment,  and  a growing
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