Effect of Xylanase-Assisted Treatment of Oxygen-Delignified Eucalypt Kraft Pulp on ECF Bleaching
The effects of treating industrial (laboratory-unwashed) oxygen-delignified eucalypt kraft pulp with a commercial endo-xylanase (X) on ECF bleaching performance were evaluated. Changes in fibre morphology, pulp bleachability and quality, and bleaching effluent parameters were assessed. Although no s...
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| Format: | Article |
| Language: | English |
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MDPI AG
2023-02-01
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| Series: | Forests |
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| Online Access: | https://www.mdpi.com/1999-4907/14/2/396 |
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| author | José M. S. Matos Dmitry V. Evtuguin António P. M. Sousa Maria Graça V. S. Carvalho |
| author_facet | José M. S. Matos Dmitry V. Evtuguin António P. M. Sousa Maria Graça V. S. Carvalho |
| author_sort | José M. S. Matos |
| collection | DOAJ |
| description | The effects of treating industrial (laboratory-unwashed) oxygen-delignified eucalypt kraft pulp with a commercial endo-xylanase (X) on ECF bleaching performance were evaluated. Changes in fibre morphology, pulp bleachability and quality, and bleaching effluent parameters were assessed. Although no significant morphological changes were observed, fibres showed some external fibrillation. The X stage reduced both the amount and the integrity of xylans remaining in the fibres, causing their redistribution inside the cell wall. In bleaching, the X treatment allowed the reduction of ClO<sub>2</sub> and NaOH loads by 20 and 10%, respectively. Furthermore, the brightness stability of enzyme-treated bleached pulps was improved, which was assigned to the decrease in the content of hexenuronic acid residues. The X treatment did not affect the cellulosic counterpart of pulp and did not cause a significant impact on the papermaking properties, even when xylan degradation was somewhat excessive. The enzymatic treatment caused a significant increase in the chemical oxygen demand (COD) of the respective effluent. The realistic conditions used provide a better insight into the overall impact of this technology at a pulp mill. |
| first_indexed | 2024-03-11T08:49:02Z |
| format | Article |
| id | doaj.art-9a99fd9ef214491cbabfc809e2c5f86c |
| institution | Directory Open Access Journal |
| issn | 1999-4907 |
| language | English |
| last_indexed | 2024-03-11T08:49:02Z |
| publishDate | 2023-02-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Forests |
| spelling | doaj.art-9a99fd9ef214491cbabfc809e2c5f86c2023-11-16T20:35:23ZengMDPI AGForests1999-49072023-02-0114239610.3390/f14020396Effect of Xylanase-Assisted Treatment of Oxygen-Delignified Eucalypt Kraft Pulp on ECF BleachingJosé M. S. Matos0Dmitry V. Evtuguin1António P. M. Sousa2Maria Graça V. S. Carvalho3CIEPQPF, Department of Chemical Engineering, University of Coimbra, 3030-790 Coimbra, PortugalCICECO, Department of Chemistry, University of Aveiro, 3810-193 Aveiro, PortugalForest and Paper Research Institute (RAIZ), 3800-783 Eixo, PortugalCIEPQPF, Department of Chemical Engineering, University of Coimbra, 3030-790 Coimbra, PortugalThe effects of treating industrial (laboratory-unwashed) oxygen-delignified eucalypt kraft pulp with a commercial endo-xylanase (X) on ECF bleaching performance were evaluated. Changes in fibre morphology, pulp bleachability and quality, and bleaching effluent parameters were assessed. Although no significant morphological changes were observed, fibres showed some external fibrillation. The X stage reduced both the amount and the integrity of xylans remaining in the fibres, causing their redistribution inside the cell wall. In bleaching, the X treatment allowed the reduction of ClO<sub>2</sub> and NaOH loads by 20 and 10%, respectively. Furthermore, the brightness stability of enzyme-treated bleached pulps was improved, which was assigned to the decrease in the content of hexenuronic acid residues. The X treatment did not affect the cellulosic counterpart of pulp and did not cause a significant impact on the papermaking properties, even when xylan degradation was somewhat excessive. The enzymatic treatment caused a significant increase in the chemical oxygen demand (COD) of the respective effluent. The realistic conditions used provide a better insight into the overall impact of this technology at a pulp mill.https://www.mdpi.com/1999-4907/14/2/396cellulose technologychlorine dioxide savingsECF biobleachingeucalypt kraft pulpgreen industryxylanase |
| spellingShingle | José M. S. Matos Dmitry V. Evtuguin António P. M. Sousa Maria Graça V. S. Carvalho Effect of Xylanase-Assisted Treatment of Oxygen-Delignified Eucalypt Kraft Pulp on ECF Bleaching Forests cellulose technology chlorine dioxide savings ECF biobleaching eucalypt kraft pulp green industry xylanase |
| title | Effect of Xylanase-Assisted Treatment of Oxygen-Delignified Eucalypt Kraft Pulp on ECF Bleaching |
| title_full | Effect of Xylanase-Assisted Treatment of Oxygen-Delignified Eucalypt Kraft Pulp on ECF Bleaching |
| title_fullStr | Effect of Xylanase-Assisted Treatment of Oxygen-Delignified Eucalypt Kraft Pulp on ECF Bleaching |
| title_full_unstemmed | Effect of Xylanase-Assisted Treatment of Oxygen-Delignified Eucalypt Kraft Pulp on ECF Bleaching |
| title_short | Effect of Xylanase-Assisted Treatment of Oxygen-Delignified Eucalypt Kraft Pulp on ECF Bleaching |
| title_sort | effect of xylanase assisted treatment of oxygen delignified eucalypt kraft pulp on ecf bleaching |
| topic | cellulose technology chlorine dioxide savings ECF biobleaching eucalypt kraft pulp green industry xylanase |
| url | https://www.mdpi.com/1999-4907/14/2/396 |
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