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Combined Enzymatic and Physical Deinking Methodology for Efficient Eco-Friendly Recycling of Old Newsprint
- Source :
- PLoS ONE, PLoS ONE, Vol 8, Iss 8, p e72346 (2013)
- Publication Year :
- 2013
- Publisher :
- Public Library of Science, 2013.
-
Abstract
- BACKGROUND: The development in the deinking process has made recycled fiber a major part of the raw material for pulp and paper industry. Enzymes have revolutionized the deinking process obtaining brightness levels surpassing conventional deinking processes. This study explores the deinking efficiencies of bacterial alkalophilic laccase (L) and xylanase (X) enzymes along with physical deinking methods of microwaving (MW) and sonication (S) for recycling of old newsprint (ONP). METHODS AND RESULTS: The operational parameters viz. enzyme dose, pH and treatment time for X and L deinking were optimized statistically using Response Surface Methodology. Laccase did not require any mediator supplementation for deinking. Deinking of ONP pulp with a combination of xylanase and laccase enzymes was investigated, and fiber surface composition and morphological changes were studied using X-ray diffraction, fourier transform infrared spectroscopy and scanning electron microscopy. Compared to the pulp deinked with xylanase (47.9%) or laccase (62.2%) individually, the percentage reduction of effective residual ink concentration (ERIC) was higher for the combined xylanase/laccase-deinked pulp (65.8%). An increase in brightness (21.6%), breaking length (16.5%), burst factor (4.2%) tear factor (6.9%), viscosity (13%) and cellulose crystallinity (10.3%) along with decrease in kappa number (22%) and chemical consumption (50%) were also observed. Surface appeared more fibrillar along with changes in surface functional groups. A combination of physical and enzymatic processes (S-MW-XL) for deinking further improved brightness (28.8%) and decreased ERIC (73.9%) substantially. CONCLUSION: This is the first report on deinking of ONP with laccase without any mediator supplementation. XL pretreatment resulted in marked improvement in paper quality and a new sequence being reported for deinking (S-MW-XL) will contribute further in decreasing chemical consumption and making the process commercially feasible.
- Subjects :
- Applied Microbiology
lcsh:Medicine
Bacillus
Industrial Ecology
Biochemistry
law.invention
chemistry.chemical_compound
law
Lignin
Recycling
Biomacromolecule-Ligand Interactions
lcsh:Science
Conservation Science
Multidisciplinary
Ecology
Deinking
Pulp and paper industry
Bioeconomy
Environmentally friendly
Enzymes
visual_art
visual_art.visual_art_medium
Xylanase
Biodegradation
Printing
Ink
Gammaproteobacteria
Research Article
Biotechnology
Paper
Raw material
Microbiology
Industrial Microbiology
Environmental Biotechnology
Bacterial Proteins
Humans
Cellulose
Biology
Bioinorganic Chemistry
Laccase
Endo-1,4-beta Xylanases
business.industry
lcsh:R
Proteins
Green Chemistry Technology
chemistry
Newsprint
Biocatalysis
Environmental science
lcsh:Q
business
Factor Analysis, Statistical
Environmental Protection
Subjects
Details
- Language :
- English
- ISSN :
- 19326203
- Volume :
- 8
- Issue :
- 8
- Database :
- OpenAIRE
- Journal :
- PLoS ONE
- Accession number :
- edsair.doi.dedup.....56301f58088c7bc7cd4c02357dcea181