PITCH CONTROL WITH MICROORGANISM WITH PREVENTED DETERIORATION OF DEGREE OF WHITENESS OF PULP

摘要

PROBLEM TO BE SOLVED: To prevent the deterioration of the degree of whiteness of a pulp and carry out the pitch control by adding a microorganism and a reducing bleaching agent to a mechanical pulp slurry and conducting a biochemical reaction. SOLUTION: A bacterium of the genus Pseudomonas is added to a mechanical pulp slurry and a reducing bleaching agent selected from the group of a thiourea deoxide, a hydrosulfite or a mixture thereof is added in an amount of 0.067-1.667 g based on 1 g of the bacterial cell and 0.002-0.050 g based on 1 g of the pulp thereto in the case of the thiourea deoxide. A biochemical reaction is then conducted to perform the pitch control.