The delignification efficiency of different laccase enzymes was examined on the eucalyptus Kraft pulp. The laccase enzyme from Trametes versicolor showing the highest delignification efficiency was selected and used in the elemental chlorine-free bleaching sequence for improving the pulp bleachability. An appreciable reduction in chlorine dioxide consumption was also obtained. Further reduction...

This work aims to fill gaps in the present knowledge of the structures of wood polysaccharides of potential importance in mechanical and chemical pulping. The detailed structures of the polysaccharide components from wood that dissolve during mechanical pulping were determined. The structures of polysaccharide components linked to residual lignin in chemical pulp were also determined. Methylati...

Effectiveness of ozonation before and after biological treatment for removal of recalcitrant organic matter in bleached kraft pulp effluents was compared. Two industrial ECF bleached eucalypt kraft pulp effluents (E1 and E2) were pretreated with 100 mg O3/L. Raw and pretreated effluents were treated biologically in bench-scale sequencing batch reactors, under constant conditions. Following biol...

It has been found that polyoxometalates (POMs) can act as mediators in the electrochemical oxidation of lignin in pulps. An electrochemical cell, with a Nafion membrane separating the anode and cathode compartments, was used in the delignification experiments. A softwood kraft pulp was placed in the anode compartment with a buffered 0.01M solution of the polyoxometalate Na5[SiVW11O40]. During e...

oxygen delignified kraft pulp from eucalyptus (e. urophylla × e. grandis) was catalytically pretreated in aerobic condition using ammonium persulfate in present of catalists like cupric acetate and/or cobalt acetate in acetic acid-water solution, i. e. s2o82--cu2+, s2o82--co2+ and s2o82--(cu2++co2+). final bleached pulp after pretreatment with the three catalytic systems showed higher delignifi...

Kraft pulp mill effluents contain elevated concentrations of resin acids, chiefly abietic and dehydroabietic acid, and other lipophilic wood constituents. Resin acids, if not efficiently removed during wastewater treatment, can be responsible for chronic toxicity in aquatic systems. The objective of this study was to investigate the biological removal of abietic acid (AbA) during the treatment ...