Technical Bulletin No. 0056: Selective-Solvent Concentration of Semi-Chemical Waste Liquors

The enclosed National Council Technical Bulletin deals with selective solvent treatment of spent neutral sulfite semi-chemical pulping liquor. This study was undertaken as one of the first steps in exploring the possibilities of recovering acetic acid economically from such liquors in which they are quite rich. Complete removal of acetic acid from these liquors would result in an oxygen demand reduction approaching 75 percent and since this oxygen demand is the major objection to the discharge of such wastes, removal or oxidation of a portion of this fatty acid is essential to improvement in this respect. While no specific economical process was evolved by these studies they have provided considerable fundamental data which will prove invaluable to continuing investigations now in progress at the Council's Virginia Polytechnic Institute project.