漆酶协同活性炭处理脱除桉木预水解液中木素的研究

Study on the Removal of Lignin from Eucalyptus Pre-hydrolysis Liquid by Laccase Combined with Activated Carbon Treatment

关键词:  桉木  预水解液  漆酶  活性炭  小分子木素

Key Words:Eucalyptus  pre-hydrolysis liquid  laccase  active carbon  small molecular lignin

摘要:为了脱除桉木预水解液中的小分子木素，采用漆酶协同活性炭处理方法，对经过Ca(OH)₂和活性炭分别处理过的二级桉木预水解液进行脱木素处理，探讨漆酶处理过程中pH值、处理温度、漆酶用量和处理时间对木素脱除效率的影响。采用单因素实验结合响应面法对上述主要因素进行了模型分析与验证，建立了小分子木素脱除的数学模型。结果表明，经过漆酶处理后的二级处理液，其木素脱除率比未用漆酶处理的提高了12.8个百分点。二级处理液中木素脱除率的4个因素影响大小的顺序为：pH值＞漆酶用量＞处理温度＞处理时间。漆酶协同活性炭处理的较优工艺条件为：pH值为5.23、处理温度45.3℃、漆酶用量5.68 U/g（相对于处理液质量）、处理时间190 min，此条件下二级处理液中木素脱除率的预测值为65.1%，实际测定平均值为65.1%，木素脱除率为桉木预水解液所含木素的90.5%。

Abstract:In this work, laccase combined with activated carbon were used to remove small molecular lignin from secondary Eucalyptus pre-hydrolysis liquid which was treated with Ca(OH)₂ and activated carbon successively. The effects of pH value, treatment temperature, laccase dosage and treatment time on lignin removal efficiency were analyzed. The main factors were analyzed and verified by single factor experiment and response surface method, and a mathematical model for the removal of small molecule lignin was established. The results showed that compared with secondary purified liquid without laccase treatment, the lignin removal rate increased by 12.8 percentage points after laccase treatment. And the 4 main factors affecting lignin removal rate from strong to weak were: pH treatment value of laccase ＞laccase dosage＞ treatment temperature＞treatment time. Under the optimum treatment condition (pH=5.23, temperature 45.3℃， laccase dosage 5.68 U/g purified liquid and treatment time 190 min)， the predicted maximum lignin removal rate in the liquid solution was 65.1%, and the actual measured value 65.1%. The lignin removal rate was 90.5% based on the Eucalyptus pre-hydrolysate.