摘要 |
Use of oxygen, oxygen containing gases or substances giving off oxygen in reduction or inhibition of the dark colouring of pulp or paper in white water systems, especially closed ones, in production of pulp and paper, these substances being added to the white water system in such an amount that aerobic conditions are maintained substantially permanently in at least a part of the white water system, i.e. the redox potential is higher than -100mV. |