ENZYME-ASSISTED DEINKING AND FIBER MODIFICATION OF MIXED OFFICE WASTE

INTRODUCTIONIn the past 20 years, more and more waste papers were recycled because of the shortage of raw materials and increasing pressure of environment protection. Among those recycled waste paper, MOW, which contains xerographic and laser printed pape…     

旧报纸的酸性生物酶法脱墨

研究了一种新的废纸脱墨工艺，它是用酸性纤维素酶处理旧报纸浆，然后在酸性条件下进行浮选脱墨，此工艺化学药品用量少，有利于环境保护；所得脱墨浆白度高，黄度低；具有较好的滤水性能和相近的强度性能。利用过氧化氢进行漂白时，酶法脱墨浆的可漂性优于化学法脱墨浆。     

纤维素酶对纤维素纤维酶解动力学的研究

提出了纤维素酶对纤维素纤维的酶解率与处理时间和酶的初始浓度的经验关系式,以及纤维素酶对纤维水解反应的动力学解示方程,该方程能有效地预测和控制生化处理中纤维素酶对织物的加工过程。利用动力学方程,能够得到酶浓度无限大时纤维经过t时间处理后的最大酶解量（Ymax）和半最大酶解常数K‘。实验结果表明,在相同的实验条件下,SF纤维素酶对纤维的酶解极限程度为粘胶>棉>亚麻纤维,而要达到相同的酶解率,亚麻纤维所需的酶用量最高,棉其次,而粘胶最低。纤维的酶解速率与纤维素酶的浓度有很大的关系,在低浓度的情况下,酶解速率与酶浓度近似成正比,而在高浓度的情况下,酶浓度的增加对酶解的促进作用逐渐减弱,因此,在实际的工艺处理过程中,选择过高的酶浓度是不合理的。     

THE DEINKING OF NON-IMPACT PRINTED PAPER BY COMBINING ENZYME WITH MECHANICAL ACTION

We studied an enzymatic deinking process of non-impact printed paper which was carried out in batch equipment, similar to Valley beater. The equipment can provide suitable forces to cause toner separation from fiber rather than fiber damage. The factors that influenced the deinking efficiency included beating time, pressure between rotating bars and bottom bars, enzyme properties such as dosage,cellulase activity, temperature, pH, etc. Beating time and enzyme type and enzyme dosage was investigated in detail. The deinked pulp was brighter and cleaner. The drainage property also can be controlled by adjusting enzyme dosage and mechanical action strength. Combining enzyme with mechanical action provides the best deinking effects,not enzyme alone. In the meantime, mechanism of enzymatic deinking was discussed depending on the deinked pulp properties.     

ENZYMATIC DEINKING OF NONIMPACT PRINTED WASTES

INTRODUCTIONNonimpact printed wastes include laser printed and xerographic papers. These wastes are increasing with the increasing utilization of computer printout and photocopiers. It is difficult for us to deink these wastes. The pigments in these inks are carbon black mixed with thermo-plastic resin binders,for example, styrene-acrylate copolymers that will crosslink at 100℃during fusing stage of the copying process①. These hard cross linked, stringly bound systems will only be fragm…     

用碱性脂肪酶消除磨木浆的树脂障碍的探索

用碱性脂肪酶对磨木浆及其沉积树脂进行水解和树脂沉积试验 .结果表明 :碱性脂肪酶能够消除树脂沉积 .加酶水解产物为较低粘性的组分 .加酶处理不会影响纸浆和纸的质量 .     

纤维素酶在废纸脱墨中的应用

采用纤维素酶对废书刊纸进行了脱墨探索,实验结果表明,酶法脱墨较佳的工艺条件为pH 5～6、浆料浓度5.5%、酶用量0.1%～0.15%、处理时间40min～50min、处理温度50℃～60℃。同时,酶法脱墨还能改善浆料的物理强度,提高其可漂白性。     

酶改善二次纤维结合性能的研究

以二次纤维为研究对象，分别用半纤维素酶和纤维素酶对其进行处理，以改善二次纤维的结合性能，寻找酶处理的最佳条件．并用扫描电镜(SEM)观察二次纤维处理前后表面形态的变化．研究结果表明，提高纸页强度主要靠改善二次纤维的结合性能．半纤维素酶处理时半纤维素与纤维表面的木聚糖反应，打开半纤维素之间氢键的联结，使纤维表面细纤维化并增加润胀，改善了其结合性能．纤维素酶处理时其C1酶破坏纤维素链的结晶结构，使纤维易于润胀，因此增强了二次纤维的结合性能．     

六甲基二硅胺烷改善二次纤维造纸性能

以烘干漂白麦草浆为原料,用六甲基二硅胺烷(HMDS)进行处理,观察处理前后二次纤维的角质化程度和强度性能,扫描电镜(SEM)观察纤维表面形态,并抄纸比较纸页性能变化.发现经HMDS处理能降低二次纤维的角质化程度,增强纤维的结合力和强度,大大提高纸页的强度性能.本法所用药品容易回收,且可循环使用,成本低而无污染.为二次纤维的推广使用提供了行之有效的解决办法,可缓解我国目前造纸原料短缺的矛盾,因此有一定的经济效益和社会效益.     

KRAFT WOOD PULP TCF AND ECF BLEACHING WITH ENZYME PRETREATMENT *

针叶木硫酸盐浆用木聚糖酶Ｉｒｇａｚｙｍｅ４０＿Ｘ４进行预处理,然后进行各种无元素氯（ＥＣＦ）和全无氯（ＴＣＦ）漂白．实验结果表明,酶预处理能提高后续漂白效果,提高白度,降低卡伯值,并改善纸浆的粘度,在不用元素氯的情况下,能将纸浆漂白到８８％ＩＳＯ以上的白度     

Study on the Structure and Properties of Polynosic Fiber Treated by Alkali

The regenerated cellulose fibers, made from wood pulp, have excellent physical properties like cotton fiber. Especially polynosic fibers can be mercerized by alkali, but conventional Viscose fiber can not be treated or mercerized by alkali. The paper studies on behavior of polynosic fibers treated by alkali, including physical properties, such as weight loss, tensile strength and elongation, and fiber structures properties. In this paper, on the basis of study on polynosic fibers treated by alkali, the conclusions were drawn as following. Firstly, polynosic fiber is good at alkali resistance. Secondly, the changes of fiber structure and physical properties begin declining at 5 wt% NaOH concentration and reverse changes take place at 10 wt%.     

白腐菌改性桉木CTMP浆的漂白研究

利用白腐菌改性处理可以显著提高机械浆的强度性能,有利于拓宽机械浆的应用范围.本文采用白腐菌Trametes hirsute 196对桉木CTMP浆进行改性处理,并探讨了白腐菌处理后纸浆的漂白工艺.研究结果表明:白腐菌处理使桉木CTMP浆白度值从49.6%下降到37.8%,且这种改性后纸浆的可漂性较差,H2O2和Na2S2O4单段漂后纸浆白度均在60%以下,但采用Na2S2O4—H2O2两段组合漂白工艺可以使漂后Bio-CTMP浆白度达到71.3%.     

桉木浆纤维多孔结构的分形分析

采用低温氮吸附法测量了桉木浆纤维的内部孔隙结构。结果表明,桉木浆纤维表面密布孔洞,孔隙分布以中孔为主,有一定量的大孔,微孔数量有限。原子力显微镜（AFM）观察也证实这一点。在低温氮吸附实验的基础上,把分形理论用于分析桉木浆纤维的孔结构,发现桉木浆纤维具有分形特征,其分形维数为2.82,分维数接近3,说明植物纤维表面较为粗糙,是密布孔洞。桉木浆纤维分形维数与其保水值等宏观性质有密切的关系。     

酶制剂在玉米秸秆双菌种固态发酵生产微生物油脂中的应用

以玉米秸秆为原料,利用纤维素酶和康宁木霉将玉米秸秆转化为可发酵糖,皮状丝孢酵母利用可发酵糖生产微生物油脂。采用正交试验,分别通过检测发酵物中还原糖含量和油脂产量,确定微生物油脂生产的最佳条件。研究结果表明：利用纤维素酶和康宁木霉处理玉米秸秆,在纤维素酶添加量为0.15％,康宁木霉接种量为10％,处理温度为26℃,处理时间为6 d的条件下,可获得还原糖含量为4.852 g/L的玉米秸秆降解物。利用皮状丝孢和酵母发酵玉米秸秆降解物生产微生物油脂,在皮状丝孢酵母接种量为9％,培养温度为26℃,培养时间为7 d的条件下,每100 g发酵产物中,可获得微生物油脂3.321 g。     

氨基二氧化硅固定化纤维素酶及其特性

以氨基化二氧化硅为载体, 戊二醛为交联剂, 采用共价交联法制备固定化纤维素酶, 最佳条件为交联剂浓度4% (体积比), 交联时间60分钟, 给酶量35 U/g载体, 固定化反应时间5小时。所得固定化酶对pH和温度的敏感性降低, 时间稳定性和热稳定性均优于游离酶。热动力学研究表明, 固定酶的失活活化能(Ed)、失活焓(ΔH^*)和失活自由能(ΔG^*)均高于自由酶, 固定化减小酶失活反应速率, 降低酶失活反应趋势。     

纤维素酶在棉织物生物抛光中的应用

阐述纤维素酶的作用机理,并简述纤维素酶对棉织物的抛光整理工艺;分析影响纤维素酶抛光效果的各种因素,包括酶用量、温度、pH值、处理时间等对织物失重率、起毛气球外观的影响;指出纤维素酶在绿色染整工艺中的重要性。     

Alkyl Ketene Dimer (AKD) Paper Sizing Efficiency in Term of Fiber Surface Charge

The charge density of cellulose fibers is a key parameter in the papermaking systems,and this is particularly true for the Alkyl Ketene Dimer( AKD) paper sizing.Zeta potential and cationic demand are often used to characterize these charges.Generally,a similar sizing performance would be obtained when the fibers with similar morphology and charge characteristics are used.However,in a mill trial,it was shown that three bleached birch pulp samples,with similar fiber morphology,and zeta potential,had different AKD sizing behaviors.In this study,the surface charges of these pulp samples,measured using the polyelectrolyte titration methods,were investigated.The results showed that lower sizing efficiency of fibers were due to their lower surface charges.It was concluded that the direct measurement of surface charge of cellulose fibers can be more appropriate to evaluate the AKD paper sizing efficiency.     

不同糖对纤维素酶保护的机理研究

旨在通过测量海藻糖、葡萄糖、蔗糖、葡聚糖、纤维素酶以及纤维素酶分别与这些糖的混合物的红外光谱和差示扫描量热谱图，研究糖和纤维素酶分子间的相互作用，推测海藻糖对纤维素酶保护的机理。结果表明，海藻糖的羟基同酶分子以氢键的形式结合提高了酶的热变性温度，增加了酶的热稳定性。另一方面，海藻糖分子包裹在酶分子周围，或填充在酶分子的空间结构内，特别是酶的活性部位附近，并形成玻璃态，将酶蛋白的空间结构固定住而避免酶的失活。     

氨基功能化SBA-15分子筛的制备及对纤维素酶的固定化

采用共缩聚法制备了氨基功能化SBA-15介孔分子筛,以此为载体,戊二醛作交联剂,进行了纤维素酶固定化.考察了戊二醛浓度、给酶量、pH、固定化时间等因素对固定化的影响,确定了固定化最佳条件,并对固定化酶的酶学性质进行了研究.结果表明,固定化酶最适作用温度60℃,最适作用pH为4;固定化酶Km值3.61 mg·mL-1;固定化酶的热稳定性、操作稳定性、贮存稳定性均明显高于游离酶.     

几种糖对纤维素酶热稳定性影响的研究

研究了几种糖对纤维素酶热稳定性的影响。研究发现，20℃下海藻糖和葡萄糖都能较好地保护酶的活性，蔗糖次之，而葡聚糖则不起作用。高温下葡萄糖和蔗糖不但不能保护酶的活性，反而起到破坏作用，而海藻糖和葡聚糖则对酶有较强的保护作用。初步分析，海藻糖作用机理是羟基能替代水分子同酶结合，并且能在酶分子空隙中和酶分子周围形成玻璃态，将酶分子支撑和包裹起来。因此海藻糖能在较宽的温度范围内阻止酶分子空间结构发生变化，从而提高了酶的热稳定性。