After the D0 stage, the pulp was treated by a hydrogen peroxide-reinforced alkali process (EP stage). Deionised water, sodium hydroxide (1.5% on oven-dried pulp) and hydrogen peroxide (0.6% on oven-dried pulp) were added to the bag containing the pulp (10% pulp consistency). After kneading, the bag was placed in a water bath (75 °C) and kneaded again after 10 and 30 minutes. After a total of 90 minutes of treatment, the pulp was washed using the same method as described for the OD process