title: Xylanase and laccase based enzymatic kraft pulp bleaching reduces adsorbable organic halogen (AOX) in bleach effluents: a pilot scale study.
abstract: In present study, xylanase and laccase were produced in a cost-effective manner up to 10 kg substrate level and evaluated in elemental chlorine free bleaching of Eucalyptus kraft pulp. Compared to the pulp pre-bleached with xylanase (15%) or laccase (25%) individually, the ClO2 savings were higher with sequential treatment of xylanase followed by laccase (35%) at laboratory scale. The sequential enzyme treatment when applied at pilot scale (50 kg pulp), resulted in improved pulp properties (50% reduced post color number, 15.71% increased tear index) and reduced AOX levels (34%) in bleach effluents. The decreased AOX level in effluents will help to meet AOX discharge limits, while improved pulp properties will be value addition to the paper.
authors.affiliation: Lignocellulose Biotechnology Laboratory, Department of Microbiology, University of Delhi South Campus, Benito Juarez Road, New Delhi 110021, India.
authors.forename: Abha
authors.initials: A
authors.lastname: Sharma
authors.affiliation: Central Pulp and Paper Research Institute, Saharanpur, U.P., India.
authors.forename: Vasanta Vadde
authors.initials: VV
authors.lastname: Thakur
authors.affiliation: Lignocellulose Biotechnology Laboratory, Department of Microbiology, University of Delhi South Campus, Benito Juarez Road, New Delhi 110021, India.
authors.forename: Anita
authors.initials: A
authors.lastname: Shrivastava
authors.affiliation: Central Pulp and Paper Research Institute, Saharanpur, U.P., India.
authors.forename: Rakesh Kumar
authors.initials: RK
authors.lastname: Jain
authors.affiliation: Central Pulp and Paper Research Institute, Saharanpur, U.P., India.
authors.forename: Rajeev Mohan
authors.initials: RM
authors.lastname: Mathur
authors.affiliation: Lignocellulose Biotechnology Laboratory, Department of Microbiology, University of Delhi South Campus, Benito Juarez Road, New Delhi 110021, India.
authors.forename: Rishi
authors.initials: R
authors.lastname: Gupta
authors.affiliation: Lignocellulose Biotechnology Laboratory, Department of Microbiology, University of Delhi South Campus, Benito Juarez Road, New Delhi 110021, India. Electronic address: kuhad85@gmail.com.
authors.forename: Ramesh Chander
authors.initials: RC
authors.lastname: Kuhad
mesh_terms: D000327:Adsorption; D057886:Bleaching Agents / Q000737:chemistry*; D043364:Endo-1,4-beta Xylanases / Q000378:metabolism*; D004795:Enzyme Stability; D005052:Eucalyptus / Q000737:chemistry; D006219:Halogens / Q000302:isolation & purification*; D042845:Laccase / Q000378:metabolism*; D055620:Optical Phenomena; D009930:Organic Chemicals / Q000302:isolation & purification*; D010209:Paper; D010865:Pilot Projects; D014865:Waste Disposal, Fluid
chemical_list: D057886:Bleaching Agents; D006219:Halogens; D009930:Organic Chemicals; D042845:Laccase; D043364:Endo-1,4-beta Xylanases
keywords: Adsorbable organic halogen; Bleaching; Laccase; Post color number; Xylanase