Technical Bulletin No. 0149: Use of Molecular Oxygen in Treating Semi-chemical Pulp Mill Wastes

The attached National Council Technical Bulletin No. 149 is a summary of research conducted at Virginia Polytechnic Institute employing biological oxidation for the treatment of semi-chemical pulping effluent and using molecular oxygen in the process. Interest in the use of oxygen is increasing as this gas is becoming more readily available and lower in cost. Its use could provide lower capital investment in treatment works and reduce power requirements, as well as facilitate the treatment of more concentrated wastes by biological oxidation than is possible by common aeration techniques. The results obtained to date in these studies indicate that high BOB loadings are obtainable in aerators applying the activated sludge process to semi-chemical waste, and that relatively strong waste can be treated in this manner. Further investigation is indicated to explore the effect of high seed sludge concentrations on efficiency of the process, as well as to determine if stronger effluents than those investigated to date can be handled.