Bleaching of pulp fibers by supersaturated oxygen

In this study, a new bleaching method using supersaturated oxygen is explored to bleach kraft pulp. The supersaturated oxygen is produced by the electrolysis of water in the pulp solution by using a microfibrous nickel anode. The supersaturated oxygen bleaching is applied to two physical forms of kraft pulp, i.e., a pulp suspension and a paper piece. For the pulp suspension, no evidence of significant bleaching could be found even after prolonged experimental duration presumably due to low consistency and poor contact. For the paper pieces, significant bleaching effect was observed and these results seemed to be superior to those obtainable in a typical oxygen bleaching process. It seems that this new approach with a better design of bleaching system is to be more applicable to a practical bleaching process.