Swedish Environmental Regulations for Bleached Kraft Pulp Mills

In Sweden, the discharge of chlorinated organic substances from pulp mills has received considerable attention since the late 1970s. The large research project Environment/Cellulose demonstrated detrimental effects in the receiving waters outside pulp mills. Several of these effects were suspected to be related to exposure to chlorinated organics. Furthermore, chlorinated organic substances have been widely distributed throughout the Baltic Sea. The first steps to reduce bleach plant effluents were taken in the early 1970s when oxygen delignification stages began to be installed. Discharges of AOX at Swedish mills at that time were estimated to have been 8–10 kg AOX tonne pulp⁻¹. Recent implementation of process modifications including the elimination of molecular Cl has reduced discharges of AOX to <1 kg tonne pulp⁻¹. Additional process changes (best available technology) could reduce AOX levels at Swedish mills to less than 0.1-0.2 kg tonne pulp⁻¹.