TREATMENT AND RECYCLING OF WASTEWATERS FROM A
CORRUGATED BOX MANUFACTURING PLANT
James C. O'Shaughnessy, Associate Professor
Frederic C. Blanc, Associate Professor
Department of Civil Engineering
Northeastern University
Boston, Massachusetts 02115
INTRODUCTION
This paper deals with the treatment of wastewaters from corrugated boxboard and
box manufacturing, an industry which by the nature of its products and service areas
is geographically spread throughout the country. The volume of wastewaters generated
by boxboard and box manufacture is small. However, the wastewaters are high strength
and not easily treated. Generally the wastewaters are a combination of starch, glue and
inks. Both total and suspended solids concentrations are high, giving the wastewater
a slurry consistency so that it appears similar to a heavy paint. The wastewaters contain
a high concentration of soluble organics with accompanying high biochemical oxygen
demand and chemical oxygen demand values. Significant concentrations of metals, namely aluminum, calcium, chromium, iron, sodium, magnesium, lead and zinc are present in
the wastewater due to the ink. Because the amounts of wastewater are small, the treatment or pretreatment system generally is a batch-type process, consisting of a series of
physical/chemical operations.
PLANT OPERATIONS AND WASTEWATER GENERATION
The plant receives paper in roll form and produces corrugated board in combining
machines. This process uses a soluble starch to bind the outer layers of paper to the
corrugated sheet. From the periodic cleaning of the combining machines and the starch
solution supply system, an estimated 3,500 gallons per week of starch washwater were
generated in the facility studied.
Corrugated sheets are cut to size in the next step and fed into printing machines
which print, fold, and trim the boxboard into the final box products. Most of the boxes
are printed in machines termed Flexo presses. The cleaning of the Flexo presses generated 5,000 gallons per week of Flexo washwater which is composed of water-soluble
ink residue in water. Flexographic inks are composed of coloring matter, resin, alcohol
and ether solvents, water, wax compounds and surfactants. The coloring matter of flexographic water inks is similar to printing inks composed of inorganic pigments of titanium,
lead, chromium, iron and other metals, carbon black and organic dye pigments. A small
percentage of the production is printed in a press-line box printing machine which uses
a slightly different type of ink termed Press Line Ink. The washing of this machine
produces 150 gallons per week of Press Line Ink washwater.
One remaining operation, the gluing of the box seams, generates about 150 gallons
per week of glue washwater.
In total, the plant had 8,800 gallons of washwater requiring treatment.
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