Champion International Corporation is a leading producer of paper and forest
products. The company's Canton mill manufactures high-quality printing and
writing paper and employs about 1,500 people.
Prior to 1989, the discharge from the mill caused the water in the Pigeon River to
take on a brown color and emit odors typical of Kraft pulp mill wastewater. In
response to new NPDES permit requirements and objections from the downstream
neighbors in North Carolina and Tennessee, the company began a 3-year, $300
million modernization of the mill. The goal of the project was the installation of
environmental technology designed to minimize the effluent and river color,
significantly reduce water use, and eliminate molecular chlorine from the bleaching
process. This last change further reduces dioxin formation.
P2 Application:
Water Recycling and Reuse
The existing mill water system was modified to reduce fresh water consumption
and excess thermal loading on the river through water reuse. Computer
monitoring of water consumption now ensures minimum usage whenever
possible.
Further water conservation is achieved through installation of a new 3-cell cooling
tower and basin which, by receiving the water and reducing its temperature to 85 degrees
F, enables reuse of all excess hot water generated by the pulp mill. Previously,
this water was discharged into the river.
Water conservation is also achieved on two fine-printing and writing paper
machines via mesh filtration of process and cooling tower water. The water is
then reused on the machines.
Effluent Color
The modernization of a fiber line reduced fiber losses, effluent color, and water
consumption. A cornerstone of the modifications is the new pulp bleaching
process called OD100 which utilizes an oxygen delignification step prior to
the chlorine bleach step. Oxygen delignification significantly reduces the lignin
content of the pulp prior to bleaching, thereby reducing chemical usage and
effluent color.
Comments: Annual savings from these waste reduction activities have not yet been calculated.
Details of Reductions
Chloroform
Comments: Many environmental benefits were realized from the project. Effluent color
discharges to the Pigeon River have fallen by 75 percent. The facility now generates
57 pounds of effluent color per ton of pulp produced, down from 222 pounds at
the start of the project in August 1990. Also, virtually all chloroform has been
eliminated from the wastewater.
Dioxin
Comments: Molecular chlorine as a bleaching chemical has been eliminated and replaced
with chlorine dioxide. A special design, the new 3-stage bleach plant uses only
chlorine dioxide and caustic as bleaching chemicals in a chlorine dioxide - caustic
extraction - chloride dioxide sequence. While dioxins had not been detected in
the mill effluent for more than 4 years, this new sequence ensures that the
formation of these toxic by-products of the bleaching process is even more
unlikely. The mill was one of the first in the country to completely replace
molecular chlorine in favor of chlorine dioxide as a bleaching agent.
Water use
Comments: Water usage is down from 45 million gallons per day before the modifications to
current usage of less than 29 million gallons per day, a 35% reduction.
