Pulp and paper technologies and improvements in environmental emissions to aquatic environments

In recent years, there has been considerable study on the environmental impacts of kraft bleached pulp mills on the aquatic environment. These studies have focused on the discharge and toxicity of chlorinated organic compounds of AOX. Data from Scandinavian and North American mills show that the discharge of polychlorinated organic compounds can be significantly reduced with modern bleaching and effluent treatment technologies. An important step is to reduce the use of elemental chlorine (Cl₂) and to substitute other oxidizing agents, including, for example, chlorine dioxide, peroxide, and oxygen. These steps halt the formation of recently discovered by‐products such as dioxins, as well as other highly chlorinated materials. In certain circumstances (e.g., fluff pulp mills), total AOX discharges have been reduced by over 90%, to as little as 0.1 kg/t. Analyses of effluents from these facilities also show that, contrary to lay expectations, remaining chlorinated materials have low chlorine substitution, are water soluble (will not bioaccumulate), and are easily degradable. Chronic toxicity testing in both laboratory tests, as well as environmental models (e.g., mesocosms) demonstrate that these modern processes virtually eliminate toxic effects in the receiving waters. These multiple technologies are being rapidly implemented by most Scandinavian and North American mills.

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Current address: Procter & Gamble Company, 6100 Center Hill Road, Cincinnati OH 45224.