Technical Bulletin No. 0131: Removal of Color Bodies from Bleachery Effluents through Modification of Kraft Recovery Process

The attached Technical Bulletin, which was presented at the Annual Meeting of Members, of the National Council for Stream Improvement, held in New York on February 24, 1960, describes a new experimental method designed to remove color from kraft bleach effluents, The process was developed by the National Council research project at Louisiana State University and integrates color removal into the recovery process by using the lignin-containing lime sludge directly to recausticize green liquor. Laboratory data have shown this procedure to be feasible. Color removals greater than 90 percent and ROD removals of about 45 percent were obtained in the laboratory. There are still a number of important questions regarding the process that are not completely answered, and pilot plant experiments are being conducted at Southern kraft mills in an attempt to resolve them.