Abstract: Cellulase blended with xylanase at certain ratio was used for deinking of the used newsprint to obtain their optimal ratio and compared with chemical deinking.Results showed 50/50 was the optimum ratio, under which the brightness of deinked pulp is 3.2 percentages higher and ink removal rate is 73.8% lower respectively than the contrast, and 0.4 percentages higher and 8.6% lower respectively than the xylanase deinked pulp.Breaking length, bursting index and tearing index were 3.8%, 5.9% and 8.6% higher than those of cellulase deinked pulp respectively.Enzyme dosages were saved 50% for cellulase and xylanase both, too.Compared with chemical deinked pulp, enzymatic deinked pulp had higher yield and lower postcolor number.

Key words: cellulase, xylanase, C/X blended, deinking, used newsprint