Use of chlorine dioxide for the bleaching of pulp: A re-evaluation of ecological risks based on scientific progress since 1993

A scientific review was conducted of studies published since 1993 to assess the ecological risks associated with final effluents from pulp mills using 100% ClO2 in bleaching processes. AU available data indicate that chlorina ted compounds in effluents from pulp mills that employ 100% ClO2 bleaching are of very limited persistence and not strongly bioaccumulative. Chlorinat ed compound concentrations in final effluent (following secondary treatment ) comprise a negligible risk to aquatic organisms in comparison with the kn own toxicological thresholds.