ABSTRACT
Pulp and paper mill effluents pose a unique challenge to treatment plant operators who have to deliver discharges to the environment with negligible impact. The pulp and paper industry generates large volumes of effluents which contain a broad variety of compounds. These compounds are added, formed or dissolved during the process of manufacturing pulp. The volume of discharged water per ton of manufactured pulp varies over a broad range and depends on the pulping process used, the operating practices, the equipment and the production rate. In the pulp and paper industries, internal measures have been undertaken to reduce wastewater discharges (e.g., dry debarking, prolonged cooks, countercurrent washing, chemical charges, substitution of chlorine with chlorine dioxide, oxygen delignification, and hydrogen peroxide bleaching) (McCubbin, 1984).
