漆酶介体体系脱墨机理的研究

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1、山东轻工业学院 硕士学位论文 漆酶/介体体系脱墨机理的研究 姓名：谭丽萍 申请学位级别：硕士 专业：制浆造纸工程 指导教师：徐清华 2011-05-28 山东轻工业学院硕士学位论文 I 摘 要 如今，造纸工业面临最大的三个问题就是能源紧张、环境污染及资源短缺， 而废纸回收利用具有节约原料，增加生产；减少污染，保护环境；节省能源，降 低能耗，比磨木浆、化学浆节省投资等优点。鉴于废纸回用的众多优点，近十几 年来，世界各国都已经高度重视废纸资源的回收利用，废纸的回收率和利用率也 在逐年的增长。废纸回用技术的关键是脱墨，与传统的化学法脱墨相比，酶法脱 墨能降低能耗，减轻环境污染，改善纸浆的物理特性（如

2、滤水性能） ，脱墨效率也 高于化学法脱墨。 漆酶（Laccase EC 1.10.3.2）是一种含铜多酚氧化酶，在某些具有传递电子能 力的介体及氧气的存在下，可以使木素发生氧化降解，这具有很广阔的应用前景。 漆酶及漆酶/介体体系在制浆造纸工业中主要是应用在纸浆漂白、生物制浆、酶法 脱墨、纤维改性、造纸废水处理等方面。 前期的研究结果表明，漆酶/介体体系能够对废新闻纸进行油墨的脱除，且脱 墨过程中存在部分木素的溶出和破坏。但油墨脱除是因为纤维表面木素的溶出， 还是因为漆酶对印刷油墨连结料的直接降解，亦或是二者共同作用的结果，尚不 能确定，值得做进一步更加深入的研究。本课题对漆酶/介体体系脱墨机理

3、进行系 统研究。 本文选取木素含量少的废旧书刊纸为原料，利用漆酶/介体体系对其进行脱墨 处理。首先探讨了最佳的脱墨工艺条件；然后用环境扫描电镜（ESEM） 、傅立叶 变换红外光谱（FT-IR） 、纤维质量分析仪（FQA）等现代分析技术分析对照浆、漆 酶脱墨浆及后续漂白浆的纤维表面性能；选取常用的油墨连结料，如酚醛树脂 （PF） 、松香改性酚醛树脂（RM-PR） 、苯乙烯-马来酸酐共聚物（SMA）作为模型 物， 研究漆酶/介体体系对三者的氧化降解性能， 从而揭示漆酶/介体体系脱墨机理。 采用漆酶/介体体系对废旧书刊纸进行脱墨，最佳的工艺条件为：漆酶用量 20 LAMU/g 浆，碎浆浆浓 12%，

4、温度 55-60，pH5.5-6.5，通氧气；脱墨浆再进行后 续的过氧化氢漂白，得到的漂白浆与对照浆相比白度、物理强度都有所增加。用 ESEM、FQA 等分析技术对其进行纤维表面性能分析，结果显示，与对照脱墨浆相 比，漆酶/介体脱墨浆表面比较粗糙，并且有丝状的微细纤维出现；细小纤维的含 量稍有降低，纤维平均长度稍微有所升高，纤维的粗度和纤维宽度都有所增加等。 漆酶/介体体系与常用的油墨连结料-酚醛树脂进行反应，用各种现代分析手段 对降解后的酚醛树脂进行表征。紫外-可见光谱分析结果表明，酚醛树脂经漆酶/ 介体处理之后其紫外特征吸收值有一定程度的下降，说明漆酶/介体体系使酚醛树 脂发生了降解；傅里

5、叶红外光谱分析结果表明，酚醛树脂的功能基有一定程度的 摘 要 II 变化，其中包括苯环、酚羟基、叔丁基等特征吸收峰的相对强度都有一定程度的 降低，说明酶处理导致上述功能基的降解；GPC 的分析结果表明，经漆酶/介体处 理之后，酚醛树脂的平均分子量有所升高，而分子量分布却减小，可以推测漆酶 处理主要是降解酚醛树脂中低分子量的聚合物；对降解产物进行 GC-MS 分析，结 果表明漆酶/介体处理之后产生了许多的小分子物质，如 1-叔丁基-3, 5-二甲基苯， 2, 5-二叔丁基苯酚等物质。 用漆酶/介体与松香改性酚醛树脂进行反应，产物的紫外可见光谱分析结果表 明，树脂经漆酶/介体处理之后其紫外特征吸收

6、值有一定程度的降低，说明松香改 性酚醛树脂发生了降解；红外光谱分析结果表明，树脂的功能基有一定程度的变 化，其中包括苯环、酯基等的特征吸收峰的相对强度有一定程度的降低，说明酶 处理导致上述功能基的降解；由 GC-MS 分析结果表明，与漆酶/介体反应之后产 生了许多的小分子物质，如 2-乙基-1, 4-二甲基苯，1, 2, 4, 5-四甲基苯等。漆酶/介 体与苯乙烯-马来酸酐共聚物进行反应，产物的紫外可见光谱分析结果表明，树脂 经漆酶处理之后其紫外特征吸收值有一定程度的降低，说明苯乙烯-马来酸酐共聚 物可以被漆酶/介体体系降解；由红外光谱分析结果表明，树脂的功能基有一定程 度的变化，其中包括苯环

7、、酸酐等特征吸收峰的相对强度有一定程度的降低，说 明酶处理导致树脂上述功能基的降解。 上述实验结果并结合前面对漆酶/介体脱墨过程中木素结构的变化，可以推断 出，漆酶/介体体系对废纸的脱墨作用主要是由两个方面共同作用的结果。其一是 漆酶/介体体系能够使得纤维表面木素溶出，从而使附着在上面的油墨脱除；其二 是漆酶对印刷油墨连结料的直接降解导致油墨的脱除。 关键词：关键词：漆酶/介体；废旧书刊纸；酚醛树脂；松香改性酚醛树脂；苯乙烯-马来酸 酐共聚物 山东轻工业学院硕士学位论文 I ABSTRACT Today, paper-making industry is faced with three im

8、portant problems，which are energy scarcity, resource shortage and environmental pollution. Waste paper has become an important source of material for papermaking and the use of recycled fibers has increased greatly. As we all know, the key step in fiber recycling is deinking. Compared the newly deve

9、loped enzymatic deinking to a conventional alkaline one, there are many benefits in enzymatic deinking, including reduced COD, brightness increase, reduced chemical cost, physical properties enhancement, improved dirt removal efficiency and so on. Laccases (EC 1.10.3.2) are multicopper inducible oxi

10、dases. They are capable of reducing oxygen to water and simultaneously oxidizing lignin with the presence of mediator. Because of their oxidation capability of lignin and phenolic compounds, they are considered as enzymes in various applications, such as pulp bleaching, wood fiber modification, bio-

11、pulping, deinking, remediation of contaminated effluents and so on. In the previous work, the deinking of old-newspaper waste with Laccase/Mediator System (LMS) was explored. The experimental results showed that LMS had the ability to deink. However, until now, the mechanism of LMS-deinked stayed un

12、known. In this study, we try to reveal the mechanism of LMS-deinked. Post Consumer Printing Paper (PCPP), which had a little lignin was deinked. The optimum pulping process was obtained. Then, surface properties of the control pulp, LMS-deinked pulp and bleaching pulp were studied by ESEM, FT-IR and

13、 FQA. The widly used ink vehicles, Phenol Formaldehyde Resin (PF), Rosin Modified Phenolic Resin (RM-PR) and Styrene Maleic Anhydride (SMA) were selected as model substances to react with LMS, and the substances after reaction were characterized. The optimum process was obtained. PCPP was pulped wit

14、h 20 LAMU/g laccase and 0.5% of violuric acid, keeping the temperature 55-60, pH5.5-6.5. Then the deinking-pulps were bleached by H2O2. The results showed that the brightness and physical strength of the LMS-deinked pulp was increased, respectively. Surface properties of the control LMS-deinked pulp

15、 were analysed. The results showed that the controlled fibres were smooth, while the fibres of the LMS-deinked pulp became rough. Relative to the control pulp, the average length and coarseness of the LMS-deinked pulp fibres incrased. The oxidation of ink vehicles by laccase in the presence of violu

16、ric acid were ABSTRACT II studied. To study the changes in the reaction, ink vehicles were characterized by spectroscopic and chromatographic methods. The molecular weight change of ink vehicles were tracked by gel permeation chromatogram (GPC), and structural changes in ink vehicles extracted from the mixture were characterized by fourier transform infrared spectrometer (FT-IR), gas chromatography-mass spectrum (GC-MS). In