高产木聚糖酶对废新闻纸脱墨的补偿工艺研究

Compensation of High-activity Xylanase for ONP Deinking

为探讨实验室培养高产木聚糖酶(酶活1 792.67 IU/mL)在废新闻纸脱墨中的环境适应能力,在木聚糖酶脱墨适宜工艺基础上进行了酶用量补偿研究。研究发现,酶脱墨适宜条件为:酶用量5.0 IU/g、酶处理时间50 min、反应温度45℃、反应pH值5.0,此时脱墨浆料白度可提高2.04%ISO,残余油墨面积降低了17 324 mm^2/m^2。通过增加酶用量的方式来补偿实际应用中由于低温高碱环境对酶活造成的损失,研究结果表明在脱墨温度为20℃、pH值为7.0时的脱墨浆白度仍可提高1.94%ISO,残余油墨面积降低了17 546 mm^2/m^2,达到适宜脱墨工艺条件下的脱墨效果。

To get the environment adaptability in old news paper （ONP） deinking of the high production xylanse （xylanase activity was 1 792.67 IU/mL）, the enzyme dosage compensation was studied in detail based on the optimum processing conditions of the high activity xylanases. It was found that the optimum parameters of the enzymatic deinking process were as follows： The enzyme dosage was 5.0 IU/mL, enzymatic treatment time 50 min, deinking temperature 45 ℃ and pH5.0. In these conditions, the whiteness of deinked pulp could be increased by 2.04% ISO and its residual ink area reduced to 17 324 mm^2/m^2. With the method of increasing the xylanase dosage to compensate the loss of enzyme activity caused by low temperature and high alkali deinking environment in actual production environment, the whiteness of deinked pulp was increased by 1.94%ISO and its residual ink area reduced to 17 546 mm^2/m^2 when deinking was conducted at 20℃ of temperature with pH7.0. It was proved that the dosage compensation could get the same effect of deinking in the optimal deinking condition.