Bleach boosting and direct brightening by multiple xylanase treatments during peroxide bleaching of kraft pulps
| Autor: | John N. Saddler, Lori A. Martin, F. Miguel Gama, Ed de Jong, Ken K. Y. Wong |
|---|---|
| Přispěvatelé: | Universidade do Minho |
| Jazyk: | angličtina |
| Rok vydání: | 1997 |
| Předmět: |
xylanase
genetic structures Bleach Xylanase Peroxide bleaching Bioengineering Instituut voor Agrotechnologisch Onderzoek Pulp and paper industry Applied Microbiology and Biotechnology Peroxide chemistry.chemical_compound chemistry Kraft process Solubilization kraft pulp Trembling aspen Agrotechnological Research Institute Organic chemistry Lignin peroxide bleaching Kraft pulp sense organs Kraft paper Biotechnology |
| Zdroj: | CIÊNCIAVITAE Repositório Científico de Acesso Aberto de Portugal Repositório Científico de Acesso Aberto de Portugal (RCAAP) instacron:RCAAP Scopus-Elsevier Biotechnology and Bioengineering 54 (1997) Biotechnology and Bioengineering, 54, 312-318 |
| ISSN: | 0006-3592 |
| DOI: | 10.1002/(sici)1097-0290(19970520)54:4<312::aid-bit3>3.0.co;2-n |
| Popis: | The effects of multiple xylanase treatments were assessed during the peroxide bleaching of three pulps: Douglas-fir (kraft); Western hemlock (oxygen delignified kraft); and trembling Aspen (kraft). The addition of a xylanase treatment stage, either before or after the peroxide bleaching stage(s), resulted in the enhanced brightening of all pulps. A higher brightness was achieved using two enzyme treatments, one before and one after the peroxide stage(s). Both bleach boosting and direct brightening seemed to contribute to the enhancement of peroxide bleaching. Compared to xylanase prebleaching, xylanase posttreatment of the peroxide bleached pulps solubilized less lignin and chromophores and made smaller amounts of these materials alkaline soluble. Nevertheless, the final brightness achieved by xylanase posttreatment was similar or superior to that achieved with xylanase prebleaching of the corresponding unbleached pulps. (undefined) |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Plný text