DOI: https://doi.org/10.55373/mjchem.v28i3.173

Keywords: Kappa number, lignin, viscosity, bleaching, degree of polymerization

Abstract

Kraft pulps of Anthocephalus indicus of kappa number 39.49 and 24.76 were bleached adopting O/C/E/H/H, O/C/E/H/P and conventional C/E/H/H bleaching sequences. It was observed that bleached pulps possessed comparable strength properties; burst index,5.33 +0.27; tensile index,87.30 ± 1.55; tear index,4.95 ± 0.21 however, bleached pulp yield was about 7-8 % higher for kappa number 24.76. Intrinsic viscosity/degree of polymerization of pulps also holds the same trend. COD, BOD₅ and AOX values were 104.95,37.56 and 7.54 kg/tone of pulp (kg/tp) for O/C/E/H/H and minimum 45.25,14.79 2.56 kg/tp for O/C/E/H/P bleaching effluents of pulp of kappa number 36.49 COD, BOD₅ and AOX values were 74.56, 27.46 and 5.20 kg/tone for the C/E/H/H bleached pulp; 38.11,14.36 and 2.80 Kg/tp for the O/C/E/H/H 32.23,12.57 and 2.40 kg/tp bleaching effluents of pulp of kappa number 24.76. Thus, COD, BOD and AOX values were highest for C/E/H/H followed by O/C/E/H/H and minimum for O/C/E/H/P and appreciably decreased on oxygen treatment.