Optimization of laccase-mediator system in producing biobleached flax pulp

Area of Science:

• Pulp and Paper Manufacturing
• Biotechnology
• Environmental Science

Background:

• Traditional pulp bleaching often involves chlorine compounds, raising environmental concerns.
• Flax pulp offers a sustainable alternative, but efficient bleaching methods are needed.
• Totally-chlorine-free (TCF) sequences are increasingly preferred for eco-friendly pulp production.

Purpose of the Study:

• To optimize a short TCF biobleaching sequence for high-quality flax pulp.
• To evaluate the effectiveness of a laccase-mediator system (L stage) followed by a hydrogen peroxide stage (P stage).
• To assess the environmental impact, specifically effluent toxicity, of the optimized biobleaching process.

Main Methods:

• A sequential statistical plan was used to optimize operating conditions for the laccase-HBT mediator system.
• Four key variables were analyzed to determine their influence on pulp properties after the P stage.
• Mathematical models were developed to predict pulp properties based on optimized variables.
• Toxicity measurements of effluents from the L stage were conducted.

Main Results:

• The optimized biobleaching sequence achieved a 40% increase in ISO brightness.
• Delignification reached 80% with the developed TCF process.
• Mathematical models accurately predicted pulp properties under optimized conditions.
• Toxicity tests confirmed no negative environmental impact from the L stage effluents.

Conclusions:

• The optimized flax pulp biobleaching sequence is highly effective in enhancing pulp brightness and delignification.
• The process is adaptable to industrial applications and can be easily integrated into existing systems.
• This TCF biobleaching method presents a sustainable and environmentally sound approach to flax pulp production.