Technical Bulletin No. 0157: A Process for Removal of Color from Bleached Kraft Effluents Through Modification of the Chemical Recovery System

The attached Technical Bulletin was first distributed in June 1962 as the final report on a study of the treatment of kraft bleaching effluents for the removal of color and BOD by lime precipitation, completed in 1961 at the National Council's Southern Regional Center which was then located at Louisiana State University. This process was developed for possible integration with the kraft recovery process and was carried successfully through the semi-pilot plant stage in this study. The process was found capable of removing over 95 percent of the color of caustic stage bleachery effluents, as well as from 35 to 57 percent of the BOD. Practically all the lima employed is recoverable in the normal re-causticizing process. The clarified water appeared suitable for reuse in some processes within the mill.