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Lal, M., Dutt, D., Tyagi, C. H., Kaur, H., and Kumar, A. (2011). "Bio-conventional bleaching of kraft-AQ pulp of A. cadamba by crude xylanases from Coprinellus disseminatus MLK-03 and effect of residual enzyme on effluent load," BioRes. 6(2), 1019-1028.

Abstract

A new thermo-alkali-tolerant crude xylanase from Coprinellus disseminatus decreased kappa number by 34.38% and improved brightness and viscosity by 1.6 and 6.47% respectively after XE1-stage during prebleaching of Anthocephalus cadamba kraft-AQ pulp. At 2.4% chlorine demand, crude xylanase in a XECEHH (X= enzymatic prebleaching stage, E= extraction stage, C= chlorination stage, H= hypochlorite stage) bleaching sequence improved pulp brightness, tensile index, burst index, and double fold numbers by 3.66%, 4.78%, 6.38%, and 11.11%, respectively with a reduction in viscosity (10.59%) and tear index (10.77%) compared to the control. Combined bleach effluent of the XECEHH sequence mitigated adsorable organic halides (AOX) by 21% and increased chemical oxygen demand (COD), bio-chemical oxygen demand (BOD), and colour by 67.18%, 84.78%, and 97.53%, respectively, compared to the control. Residual enzymes that entered during enzymatic prebleaching stage decreased AOX, COD, BOD, and colour of combined effluent of the XECEHH bleaching sequence progressively and on 6th day, and these were reduced by 23.78%, 0.04%, 15.00%, and 0.61%, respectively, compared to the control.
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