Pulp brightness gains obtained by fungal biobleaching are often decreased by dark MnO2 deposits which are formed by the biologically- mediated oxidation of Mn(II). Oxalic acid extraction of O2-delignified kraft pulps bleached by several white-rot fungi was found to increase pulp brightness by up to 9.7 ISO points due to MnO2 dissolution. These results indicate that pulp extraction with oxalic acid can be used in order to accurately assess the net brightness gains achieved by fungal biobleaching.
ASJC Scopus subject areas
- Applied Microbiology and Biotechnology