The Impact of Elemental Chlorine Free Bleaching on Effluent Characteristics

Abstract

The amendment of Air Pollution Control Law that required pulp and paper mills to reduce discharge of chloroform was promulgated in 1996. Since then, Japanese pulp and paper companies have gradually been introducing elemental chlorine free (ECF) bleaching. In 2006, the production of ECF pulps exceeded 80 percent of Japanese bleached chemical pulp production.
Generations of chloroform, chlorinated phenolic compounds, and chlorinated dioxins were decreased dramatically with ECF bleaching. The AOX level in ECF bleaching mill effluent was less than 0.2 kg per ton of bleached pulp. On the contrary, chlorate discharges were increased with chlorine dioxide bleaching.
Whether ECF conversion decreases the adverse effects of mill effluents on aquatic organisms is evaluating in Japan Pulp and Paper Research Institute.
It can be concluded that misgivings about the discharge of organic chlorine compounds from Japanese pulp and paper mills were practically eliminated by ECF conversion.