Pretreatment by ceriporiopsis subvesmispora and phlebia subserialis of wheat straw and its impact on subsequent soda-AQ and kraft-AQ pulping

Abstract

Pretreatments of wheat straw with two different lignindegrading fungal cultures Ceriporiopsis subvesmispora and Phlebia subserialiswere carried out and their effects on sodaAQ and kraftAQ pulping were studied. After two weeks of biotreatment of the wheat straw, both fungus were found to be suitable for biochemical pulping. The fungal pretreatment decreased the kappa number by as much as 24% and the unbleached pulp brightness increased by about 7% at a constant yield. Furthermore, the biopretreatment increased the brightness of the fully bleached pulp by about 1 ISO% point. This can apparently reduce the amount of the chemicals used in the bleaching process. The results on the sugar analysis of the pulps showed that in terms of carbohydrate composition, there were no significant differences between the biotreated and control pulps. However, the strength properties of the unbleached and bleached chemical straw pulps decreased slightly after the fungal pretreatment. This is different from reported results that the strength properties of mechanical pulps were improved after the fungal pretreatment. There was no difference of the two whiterot fungal species, Ceriporiopsis subvesmispora and Phlebia subserialis in term of their effect on the strength properties. © 2008 Bucharest University Printed in Romania.