Disposal of Paper Wastes from a
Sveen-Pedersen Floatation Unit
J. H. WALTER, Engineer,
R.  C. PETERSON,  Pollution Control Engineer,
and
J. F. BYRD, Chemical Engineer
Procter and Gamble Company
Cincinnati, Ohio
White water originating as drainage through the Fourdrinier wire of a
paper machine or in the felt wash water contains valuable fibre as well as
fibres too short to use in paper. Rotary vacuum screens are used as primary
save-alls to separate the good fibre from the water so this fibre may be returned to the system.
A Sveen-Pedersen floatation save-all (1),(2) is used at the Charmin Paper
Products Co. mill at Cheyboygan, Michigan, to further clarify the Whitewater
from the primary save-all so that the water may be reused. Through the use
of alum and glue as flocculating agents, the introduction of air ahead of the
feed end causes the floes of short fibre to float to the top. The froth containing these waste fibres is continuously skimmed off the discharge end. The
skimmings run one-half per cent to two per cent consistency, depending on
the operation of the floatation unit.
This paper is concerned with the disposal of the waste skimmings from
the Sveen-Pedersen floatation unit.
DISPOSAL TO THE RIVER
Before the days when stream pollution became a definite problem, a
waste of this sort might have been discharged without a second thought to the
nearest watercourse. Now, however, both government bodies and industry are
conscious of the effects of pollution. In Michigan, the Water Resources Commission has an order restricting the discharge of fibre waste to a stream to no
more than one lb per 1, 000 gals of water and suspended solids to no more than
30 lbs per ton of production. The Sveen-Pedersen wastes might have exceeded
these restrictions under peak conditions but even if they had not, Charmin
would not have considered any waste discharge which might cause pollution
problems in the clear Cheboygan River.
COMBINED TREATMENT WITH DOMESTIC WASTES
In the fall of 1958 Charmin began production of toilet tissue at its
Cheboygan Mill. Starting then, the Sveen solids were sent to the city sewer
and thence to the city's treatment plant. Although paper waste has been
digested successfully elsewhere when combined with domestic sewage, the
city soon experienced difficulties. Charmin engaged expert professional help,
who, together with the representatives of the State Department of Health,
made recommendations for improving the operation of the city treatment
plant.
Preliminary results of studies by Rohlich and Polkowski (3) at the University of Wisconsin show that digestion of a 30 to 70 ratio of these particular
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