CEDED bleach sequence
The procedure described by Reid et al.15 was applied and is
summarized as follows.
Pulps treated with inactivated enzyme preparations were chlorinated
at 6% chlorine charge (on pulp) while the enzyme-treated
pulps were given a 4% chlorine charge. For comparison, control
pulp samples treated with buffer were simultaneously chlorinated
at 4, 5, and 6% chlorine charge; for each sample, 30 g pulp was
used separately. Chlorination was performed in sealed plastic bags
with intermittent kneading for 45 min at room temperature and at
3% pulp consistency. Chlorination was followed by caustic extraction
on pulps at 10% consistency and incubated at 70°C for 90
min in sealed polythene bags with 3.5% NaOH (on pulp). First,
chlorine dioxide treatment was applied in sealed polythene bags
with intermittent kneading at 10% pulp consistency, incubated at
60°C for 3 h with 1% ClO2 1 0.45% NaOH followed by caustic
extraction at 3% NaOH charge on pulp. Second, chlorine dioxide
treatment was given similarly at 0.5% ClO2 but without NaOH.
Finally, the pulp samples were washed thoroughly in water.