Relationship of the Technical Development of Pulping and Bleaching to Effluent Quality and Aquatic Toxicity

摘要

Since the first of these five international conferences was held in 1991 in Sweden, technological and process changes within pulp mills have led to: 1) greatly reduced amounts of chlorinated and non-chlorinated organic compounds entering the final effluent; and 2) more and better external treatment of effluents. This has led to the near elimination of mortality of fish and invertebrates in short-term tests. Short-term tests and longer duration tests often measure growth effects on fish or algae, reproduction effects on fish or invertebrates, and effects on biochemical, physiological or morphological characteristics of organisms. Effluents from modernized mills with well-operated secondary treatment systems have usually shown the least effects. A continuously growing body of evidence suggests that chlorinated organic compounds are not involved in the current effects noted, and reducing components originating in the pulping process may have the greatest benefit in reducing biological effects measured in short or long duration bioassays.