Horseradish peroxidase (HRP) treatment could effectively cause the removal of the dissolved and colloidal lignin from the wood pre-hydrolysis liquor (PHL). At the optimized conditions, the HRP treatment caused the dissolved lignin and turbidity removal of the PHL were 33.3% and 47.9%, respectively.
For the current technologies removing lignin from PHL, the lignin removal efficiency of the single stage processes such as cationic polymers flocculation and acidification is not satisfied. For the processes containing adsorption stage using adsorbents such as ion exchange resin and activated carbon, the reusing of the adsorbents or the further separation and utilization of the removed lignin is the big problem. For the purpose of effective lignin removal from PHL and high availability of the removed lignin, in the present work, the HRP was used to treat the aspen PHL and the treatment conditions for lignin removal was optimized, and the novel processes combined HRP and cationic polymer treatment or acidification for lignin removal was proposed and evaluated.