An ecofriendly cost effective enzymatic methodology for deinking of school waste paper

Efficiency of xylano-pectinolytic enzymes in deinking of school waste paper for its reuse has been investigated in the present study. Enzymatic deinked pulp decreased the requirement of chemicals to nearly 50% and gave same optical properties of pulp as obtained by conventional deinking process. This biodeinking plus chemical deinking approach resulted in a decrease of 20.15% and 22.64% in BOD and COD values of effluents and a gain of 10.71% in viscosity, 7.49% in breaking length, 10.52% in burst factor and 6.25% in tear factor as compared to conventional chemical deinking. This is the first report mentioning the use of xylanase and pectinase produced from a cellulase free alkalo-thermotolerant bacterial strain in the same cost effective agricultural residues based production medium for deinking and will help in making the process ecofriendly with 50% reduction in chemicals, commercially viable with better paper quality.

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► Enzyme dose of 15.0 IU xylanase and 3.0 IU pectinase per gram of pulp was sufficient for ink removal.
► Peformance of enzymes at alkaline conditions showed their suitability for paper industries.
► Enzymatic plus chemical deinking approach decreased the requirement of chemicals to nearly 50%.
► This combined methodology resulted in decrease of 20.15% and 22.64% in BOD and COD of effluents.
► This deinking approach also improved the various physical properties of handsheets.