A PAPER MILL WATER TREATMENT AND REUSE SYSTEM
FOR ZERO DISCHARGE
M. M. Schirtzinger, President
M. M. Schirtzinger & Associates, Limited
Consulting Environmental Engineers
Chillicothe, Ohio 45601
INTRODUCTION
One of the stated goals of Public Law 92-500 is zero discharge of pollutants to the
environment by the year 1985. Of course, anyone with practical knowledge of our interdependent society realizes that the goal of zero discharge of pollutants is not possible,
since man's activity involves the rearrangement of natural resources to fit his own desired
environmental requirements. This will result in contaminants discharged to one of three
possible environs, that is, water, land or air.
The choice for manufacturing industries must be made based upon the minimized
damage to the environment at a cost which is affordable and technically possible.
Initial EPA emphasis was on improvement of water quality with requirements established based on stream water standards. Later effluent standards for the residual waterborne
waste discharges were adopted and, in some cases, the effluent standards provided water
quality which far exceeded the quality of the receiving stream and approached the quality
of water needed for use in the paper mill process. Thus, to treat the residual water from
the paper mill to these qualities and then discharge it to the receiving stream makes less
sense than to take the effluent and treat it for process use in the mill.
After all, in the paper industry, water is merely a conveyor of materials in the same
way that conveyor belts or assembly lines are used. Water is used not only to transport
but to break down the raw materials, to dissolve and disperse the chemical additives, and
to provide the medium for formation of the sheet on the machine.
In this process, the water becomes contaminated with fiber fines, inorganic suspended
solids and all the materials which are soluble and were present in the original stock preparation. Although reused to some degree in all paper mills, residual water ultimately
finds it way to the effluent sewer for treatment at an end-of-sewer treatment plant.
QUANTITY OF WATER USE FOR PAPERMAKING
Tracing the water use (and effluent generated) by paper mills through publications will
reveal that prior to 1940 the use of water in fine paper mills and board mills often exceeded 20,000 gal/ton of production. By the 1950s, savealls  of all types were introduced
which resulted in reuse of clarified water from saveall systems, and fresh water use dropped
to 10,000 gal/ton of production. Many paper mills are still operating at this level while
others have conservation programs and have achieved levels as low as 3000 gal/ton of
production.
Most often difficulties with the reuse of water centers around grade changes, particularly on colored runs. For mills or machines which have long runs of one grade, a closed
water system is an affordable reality.
ECONOMICS
Sewer use charges for effluent treatment at remote locations by municipal or by regional agencies often cost $0.5-$ 1/1000 gal of effluent discharged. Therefore, a paper mill
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