Water Re-Use and Black
Liquor Oxidation by the Container-
Copeland Process
C. G. COPELAND, Chief Engineer
Process Developments
Container Corporation of America
Carthage, Indiana
INTRODUCTION
Pulp and paper mills across the country have, in recent years, been subject to
increasing pressures to reduce the amount and character of wastes discharged into
adjacent waterways on which they are normally located. Many mills have been
working at and improving the problem, but many will find the problem next to
impossible to solve for reasons which I will try to describe. Financial considerations of the total problem are immense, and time is certainly not in favor of the
mills.
Stream pollution, as attributed to pulp and paper mills, generally is due to a
discharge of that wood fraction which is digested or cooked out of the basic pulp
wood in the preparation of fibers for paper making. This fraction is organic in
chemical make up and consists of wood sugars, hemi-celluloses and a cementing
material of complex structure, which binds the cellulose fibers in a tree together,
called lignin.    In combination with the sulfur bearing chemicals used in the di-
festion, the wasted material is dark brown or black in color and pollutes largely
ecause of its reducing character and consequent oxygen demand on the receiving
waters. To compare pulp and paper mill effluents with a population equivalent of
domestic sewage is unjust and technically unsupportable.
Pulp and paper mills are usually located in areas close to a raw material supply, i. e. wood, reclaimed fibers or waste paper, and water. Most other considerations of location have been secondary.
Early recognition was given by the industry to the fact that wood reserves were
fundamental to continued operation and mucn effort and cost has gone into forest
land acquisition, wood conservation, and reforestation. The progress made in replanting of trees or reforestation is one of the great scientific achievements of the
industry.
The development ofthe waste paper or reclaimed fiber segment ofthe industry
has been an important adjunct to conservation of wood supplies and fills an important need where less costly secondary materials can be used.
Water is used by the industry to wash lignin, etc. out of the wood pulp and
generally as a conveying fluid for transportation of wood fibers through the process
of manufacture of paper. In many cases, the efficiency of operations can be
measured in terms of total water pumped through the pulp and paper mills. Water
supplies have, therefore, been considered "ipso facto" a low cost key to successful operation.
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