Biobleaching of pulp from agricultural residues with enzymes

Pulp from agricultural residues (wheat straw) was bleached with the DE(P)D (chlorine dioxide-extraction with soda and hydrogen peroxide-chlorine dioxide) or P sequence (hydrogen peroxide) after enzymatic pretreatment with cartazyme HS. The enzymatic pretreatment increases the final brightness of the pulp after bleaching with the P and DE(P)D sequences (+3.7%) and saves bleaching reagents (from 3.5 to 5.2%); however, it also decreases the pulp yield (from 9.3 to 14.1%) and breaking length (from 20.2 to 13.2%), burst index (from 13.1 to 8.2%) and tear index (from 4.2% to 16.8%) of the paper sheets formed from the pulp.