Get access

Assessing the use of xylanase and laccases in biobleaching stages of a TCF sequence for flax pulp

Authors

  • Amanda Fillat,

    1. Textile and Paper Engineering Department, ETSEIAT, Universitat Politècnica de Catalunya, Colom 11, E-08222-Terrassa, Spain
    Search for more papers by this author
  • M. Blanca Roncero,

    1. Textile and Paper Engineering Department, ETSEIAT, Universitat Politècnica de Catalunya, Colom 11, E-08222-Terrassa, Spain
    Search for more papers by this author
  • Teresa Vidal

    Corresponding author
    1. Textile and Paper Engineering Department, ETSEIAT, Universitat Politècnica de Catalunya, Colom 11, E-08222-Terrassa, Spain
    • Textile and Paper Engineering Department, ETSEIAT, Universitat Politècnica de Catalunya, Colom 11, 08222-Terrassa, Spain.
    Search for more papers by this author

Abstract

BACKGROUND: In this study, two different laccases were used in combination with various mediators as biobleaching agents in a TCF sequence for flax fibre and pulp. Thus, non-commercial laccase from Pycnoporus cinnabarinus (PcL) was used with the synthetic mediator violuric acid (VA) or the natural mediator syringaldehyde (SA), and commercial laccase from Myceliophthora thermophila (MtL) was used with the natural mediator methyl syringate (MS). Each laccase–mediator treatment was used in the following TCF bleaching sequence: LQPo (Q denoting a chelating stage and Po a pressurized alkaline peroxide treatment). Also, a xylanase pretreatment was carried out for first time here to assess its effect on flax fibre. Pulp (kappa number, viscosity and brightness) and effluent properties (COD, colour, residual activity and toxicity) were determined after each bleaching stage. The hexenuronic acid (HexA) content of the pulp was also determined to assess its integrity.

RESULTS: The best L stage was PcL + VA, which provided a final brightness and kappa number of 81% ISO and 1.3, respectively. Using a xylanase pretreatment was found to efficiently remove HexA and enhance delignification by laccase (final kappa number 0.7).

CONCLUSIONS: These results warrant upscaling any of these biobleaching sequences for flax pulp as they provide environmentally sustainable flax fibre with a high cellulose content and brightness above 80% ISO. Copyright © 2011 Society of Chemical Industry

Ancillary