ABSTRACT
The results of recent short-term and long-term laboratory tests with a variety of pulp and paper mill effluents were reviewed. In particular, attention was focused on the relationship between new bleaching technologies and the chronic toxicity of final mill effluents. The available data indicated that no generalizations could be made regarding the role of any specific pre-bleaching or bleaching process. Rather, there was limited evidence that the pulping side of mill operations could be a source of residual effluent toxicity. The extent to which laboratory tests have the ability to predict the actual impact of effluents on aquatic ecosystems is still an open question. Nevertheless, such approaches remain a cost-effective means of assessing effluent quality, especially effluents from technologies still in the developmental stage.
