Technical Bulletin No. 0494: A Laboratory Study of Pre-Biological Treatment Color Reduction Technology Effectiveness for Selected Kraft Streams

During the course of the laboratory investigation three different caustic extraction stage filtrates, bleached kraft primary, bleach kraft secondary, and two unbleached kraft primary effluents were treated for color reduction using lime, polymer, peroxide and chlorine, respectively, and with the exception of the one secondary effluent were then provided biological treatment. All the biologically treated effluents were subjected to long term storage to simulate actual field or receiving water conditions. The study showed that no increase in color occurred during biological treatment or long term storage of any of the effluents previously treated with lime or a polymer.