Technical Bulletin No. 0119: The Surface Reaction Method for Color Removal from Kraft Bleachery Effluents
Laboratory and bench-scale pilot plant tests on the surface reaction process, developed by National Council engineers at Louisiana State University, are described in the attached TAPPI reprint of a paper delivered by Herbert F. Berger and Richard I. Brown at the last Alkaline Pulping Conference. This process is capable of affecting a high degree of color removal from caustic extract bleaching effluents. In the experiments described by the authors, the effluent was filtered through a hydrated lime pre-coat on a vacuum filter and the color bodies were deposited on the surface of the lime, from which they could be doctored in a thin film. The doctored lime-organic film was sufficiently dry to allow its direct feed to a lime kiln with the usual causticizing mud. Larger scale tests of the process are now being made at a southern mill to determine the practical and economic feasibility of the process.