纤维素酶处理后造纸白水微细胶黏物失稳特性研究

Analysis of the Instability Characteristics of Microstickies in Papermaking White Water Treated with Cellulase

采用激光、流式技术结合荧光示踪剂示踪法,对纤维素酶处理后的办公废纸造纸白水微细胶黏物的失稳特性进行研究。通过检测分析微米级胶黏物粒子尺寸分布特点及纤维素酶处理后白水体系阳离子需求量和浊度值的变化规律,探讨时间、温度和搅拌转速对纤维素酶处理后微细胶黏物粒子失稳特性的影响。结果表明,纤维素酶处理后的微细胶黏物,随时间的持续延长可能趋于聚集也可能趋于分散,具体与纤维素酶用量有关;随温度的升高,胶黏物微粒分散和聚集同时发生,且聚集的趋势相对较强,最终微细胶黏物粒子平均粒径增大;搅拌转速对微细胶黏物的影响与纤维素酶用量有关,用量40 U/L的纤维素酶处理后微细胶黏物微粒分散效果明显,而用量80 U/L的纤维素酶处理后微细胶黏物在剪切作用弱时分散、在剪切作用强时聚集。纤维素酶处理后的微细胶黏物粒子受时间和温度影响的变化与白水系统阳离子需求量变化基本一致,纤维素酶处理后胶黏物粒子受时间、温度和转速影响的变化可通过浊度值的变化间接体现。

By using a method combing laser, flow cytometric technology and fluorescent tracers, which can capture the microstickies＇ information in micro level, the instability characteristics of the microstickies in white water from papermaking process using mixed office waste paper （MOP） as raw material and treated with cellulase were investigated in this study. The influences of the time, temperature and shear strength of the stirring action of cellulase treatment on the instability characteristics of the microstickies were studied by measuring the its size distribution, cationic demand and turbidity value of the white water system. The results showed that the microstickies with cellulase treatment might disperse or agglomerate depending on the dosage of the cellulase. Moreover, both of the dispersion or the agglomeration of these microstickies particles happened with the increase of the temperature. However, the aggregation tendency was superior to the dispersion. Therefore, the average size of these particles increased with temperature rise. Besides, the influence of the shear strength depended on the dosage of the cellulase applied in the white water. The mierostickies particles dispersed obviously with the 40 U/L enzyme dosage. When the 80 U/L dosages was applied, these particles dispersed under the weak shear action and aggregated under the strong shearing. These characteristic changes of the microstickies affected by time and temperature kept the same variation tendency with the cationic demand of the white water system, and all of these characteristic changes could display indirectly by the turbidity value.