Sorption Properties of Flax Fibers Depending on Pretreatment Processes and their Environmental Impact

The purpose of this research was to investigate the influence of different pre-treatment processes, on the sorption properties of flax fibers and the impact of residual treatment baths on environmental pollution. Flax fibers were subjected to different scouring processes (alkaline, acidic and enzymatic scouring) and, subsequently, oxidative bleaching, with and without application of ultrasound energy. The sorption properties of differently pre-treated flax fibers were defined by iodine sorption value, moisture sorption, and water retention power. The residual pre-treatment baths were ecologically analyzed using total organic carbon, chemical oxygen demand, biochemical oxygen demand and biological degradability. The obtained results indicated that the alkaline, acidic and enzymatic scourings of flax fibers have a significant effect on their sorption properties and, consequently, on the bleaching process. The application of ultrasound in the scouring and bleaching bath increased the fiber weight loss and water retention power of the flax fibers, as well as improving the ecological parameters. The optimal pre-treatment process was enzymatic bioscouring because it provided a lower weight loss, a better absorptivity of the flax fibers, and is less environmentally harmful.