STUDY ON THE ELEMENTAL CHLORINE FREE BLEACHING OF BAMBOO KRAFT PULP

1INTRODUCTIONChina is a country using the most variety of non-wood fiber raw material and is the largest country producing non-wood fiber pulp and paper in the world[1]. Bamboo is one kind of the main non-wood species for papermaking in China. Although the structure of raw materials for papermaking has being adjusted through increasing the proportion of wood pulp and by effectively utilizing waste paper source, non-wood species will still remain an important fiber resource[1,2].At present…     

中浓纸浆清洁漂白技术的理论与实践

纸浆传统低浓含氯漂白方法(如CEH)存在对环境污染、水耗和能耗大、不可能适应大产能的要求等问题,需要用中浓氧脱木素、中浓二氧化氯漂白、中浓过氧化氢漂白及它们的组合等清洁漂白技术来取代.文中结合各类清洁漂白技术的特点,研究适用于各浆种的中浓氧脱木素、中浓过氧化氢等漂白技术,结合工程实践,提出适合我国国情的中浓纸浆少污染漂白技术及全无氯漂白技术,从而满足日益严格的环保要求,实现清洁漂白生产.     

XYLANASE PREBLEACHING ON NaOH-AQ WHEAT STRAW PULP

INTRODUCTIONChina is a kingdom of straw pulps and wheat strawhas a dominant proportion in non-wood fiberresource. Wheat straw is inexhaustible annual plant.When it is used to make pulp and paper, there is noproblem of affecting afforestation and energyconsumption. In order to make full use of existedresource and make products of good quality witheffluent of low pollution loading, the study of wheatstraw pulp has realistic meaning. On the other hand,application of biotechnology has penetra…     

活化剂在麦草硫酸盐浆中无氯和少氯漂白中的应用

在麦草ＫＰ浆的无氯和少氯漂白程序中使用活化剂,可促进脱木素作用并提高浆的白度。在氧脱木素前用ＮＯ２,硫酸和过氧酸进行预处理比较,以ＮＯ２效果最佳。ＮＯ２用量２％,处理后浆的卡伯值比未处理降低了６％,白度提高４％,粘度只下降１．６％。在Ｄ／ＣＥＤＤ漂白程序中,漂前用对有效氯用量８％的Ｓ１２预处理,白度提高２．３％ＩＳＤ,粘度基本无变化;活化剂ＴＡ用于ＮＯＰ三段漂的Ｐ段,用量４％（对浆）,可提高白度４．３％ＩＳＯ,粘度也有明显提高。本试验采用ＧＯＰＡＰＴＡ无氯漂白程序,可使麦草ｋｐ浆漂后白度达８０％ＩＳＯ,但粘度下降较大     

微波技术在竹浆漂白中的应用

用正交实验法探讨了在微波辐射下次氯酸钠漂白硫酸盐竹浆的工艺条件,结果表明,微波辐射用于硫酸盐竹浆次氯酸盐单段漂白的最佳工艺条件为:微波辐射功率480W,辐射时间2min,用氯量4.29%,氢氧化钠用量1%,浆料浓度12%.在此条件下,纸浆白度可达72.9%IS0;而在相同条件下达到此白度,传统水浴加热则需要90min的时间。因此,微波辐射竹浆次氟酸钠单段漂白能节约能源和提高生产效率.     

STUDY OF COORDINATED PRETREATMENT OF XYLANASE AND LACCASE ON SODA-AQ WHEAT STRAW PULP BEFORE CEH BLEACHING

INTRODUCTIONXylanase pretreatment can produce many small holes on pulp surfaces and cross section by removing part xylose that may be sucked back or exists in style of LCC. Thus penetrability of following chemicals. Olsen [1] observed coordinated pretreatment of xylanase and lignin enzyme (compound of lignin peroxide enzyme and manganese peroxide enzyme) had better delignification than sole xylanase and sole laccase lignin enzyme. So we can forecast that coordinated pretreatment of xylan…     

低纤维素酶活木聚糖酶对麦草浆的辅助漂白作用

利用低纤维素酶活木聚糖酶对麦草浆进行预处理,研究木聚糖酶在氯、碱、次氯酸盐(CEH)三段漂白中对氯气用量的减少以及对漂白过程中纸浆木质纤维组分变化的影响。结果表明:经过木聚糖酶预处理,在保证纸浆漂后白度的同时,氯气用量可以减少50%;木聚糖酶预处理对纸浆中的木素有脱除作用,且能促进木素在碱抽提过程中的溶出,但木聚糖酶对戊聚糖和纤维素也有不同程度的降解作用;酶处理浆漂后的木素和半纤维素的含量略低于未经处理的对照浆,纤维素含量则略高于对照浆。     

THE EVOLUTION OF FIBERLINE TECHNOLOGY IN AN ENVIRONMENTAL LIGHT

With the environment in focus three different fiberlines ranging over a 20-year-period are compared. It is concluded that the environmental operation has significantly been boosted over the years. Today's challenges in the R&D activities relating to fiberline technology include e.g. improved pulp yields and prevention of yellowing of fully bleached pulp. A method for determination of mill pulp yield is presented, and the latest modified cooking concept briefly discussed in relation to the higher yields obtained. The topic of yellowing is discussed and hot chlorine dioxide bleaching is presented as a tool to reduce the yellowing tendency.     

碱抽提强化的麦草浆二氧化氯漂白及ECF漂白流程研究

摘要：采用四种不同的碱抽提方式对麦草浆二氧化氯漂白(D0)进行强化,考查了不同碱抽提方式的强化效果,并对不同ECF漂白流程进行了对比研究。结果表明：在D0ED1漂白流程中,不同碱抽提方式对D0木素的修饰效果不同,就后续D1漂段而言,四种不同碱抽提模式下纸浆的可漂性顺序为：D0EOP>D0EP>D0EO>D0E。在D0ED1漂白流程中,D1段ClO2对白度的提升是有限的,达到白度极限后再增加ClO2用量对白度提高不明显。本实验条件下D1段ClO2用量以1.0%~1.2%为佳。从D0ED1与D0EP各漂白流程的对比来看,在终段漂白中以P取代D1效果要好,表明H2O2用于终段漂白其效果要好于ClO2。从其它ECF漂白流程的对比来看,D0EPP和D0EOPP流程漂白效果优于其它流程。本实验条件下采用D0EPP和D0EOPP漂白流程,麦草浆漂后白度可分别达到83.8%和85.7%。     

碱抽提强化的麦草浆ClO_2漂白及ECF漂白流程

采用常规碱抽提(E)、氧加强的碱抽提(EO)、H2O2强化的碱抽提(EP)、氧和H2O2强化的碱抽提(EOP)对ClO2脱木素(D0)麦草浆进行改性,考查不同碱抽提方式的改性效果在后续漂段(D1)的体现,并就不同无元素氯(ECF)漂白流程(D0ED1、D0P、D0A/QP、D0EP、D0EPD1、D0EPP)进行对比.结果表明:不同碱抽提方式对D0浆木素的改性效果不同,就对后续漂段D1的影响而言,4种不同碱抽提方式下纸浆的可漂性顺序为D0EOPD0EPD0EOD0E;在4种碱抽提方式所对应的D0ED1漂白流程中,D1段ClO2用量的增加对白度的提升是有限的,以0.8%~1.0%为佳;D0EPD1和D0EPP流程漂白效果优于其它流程,采用D0EPD1和D0EPP流程漂后白度可分别达到82.3%ISO和83.8%ISO,均适用于麦草浆短序ECF漂白.     

漂白废水的厌氧与好氧生物降解动力学

对厌氧好氧联合处理工艺处理纸浆漂白废水的动力学模型进行了探讨。结果表明：废水对厌氧过程微生物呈现出明显的抑制作用，经厌氧处理后废水对好氧反应微生物几乎没有抑制作用，并求得了相应的动力学模型和动力学参数。     

改良木聚糖酶辅助漂白芦苇浆的工艺研究

采用分子改良后的木聚糖酶对芦苇浆进行生物预处理,考察了改良木聚糖酶辅助漂白的效果。结果表明,酶预处理可以降低CEH三段漂白中氯化C段的氯气用量60%。改良木聚糖酶预处理辅助漂白芦苇纸浆最佳条件为:pH为7.0,温度60℃,浆浓(质量分数)5%,酶用量12μmol/(min.g),预处理时间60 min。在此条件下C段氯用量降至对照的40%时,酶处理漂后样品白度可达到84.0%(ISO),高出对照样的白度3.7%(ISO)。改良木聚糖酶预处理还能够改善纸浆漂后样的物理性能。     

EXAMINATION OF POLYCHLORINATED DIBENZO-P-DIOXINS AND POLYCHLORINATED DIBENZOFURANS INTO PROCESS WATER OF KRAFT PULP BLEACHING MILL FROM ASPECT OF ENVIRONMENTAL WATER QUALITY

INTRODUCTIONDuring the 1980s, the fact that chlorine used for pulp bleaching is connected to the release of dioxins1 and chloroform2 into the environment was proven in Canada and other countries. Since that time, each papermaking company has also been implementing a variety of policies designed to reduce dioxins generation. However, the Law Concerning Special Measures against Dioxins took effect in Japan on 15th January 2000. According to the new law, "kraft pulp and sulfite pulp bleac…     

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     

钝化预处理对316L不锈钢在漂液中电化学腐蚀性能的影响

采用电化学测试、SEM分析等方法,研究了316 L不锈钢在质量分数为30%的浓硝酸溶液及98%硫酸+20 g/L硝酸钾混合液两种钝化剂预处理后的特性,以及在ClO2漂液中的电化学抗腐蚀性能。结果表明,316 L不锈钢在25℃、30%硝酸介质中处理30 min时抗点蚀能力ΔE可达到773 mV,钝化效果较好。EIS图谱表明:316 L不锈钢在ClO2漂液中具有双容抗弧特征,钝化处理容抗弧半径较未钝化的增大,处理后的316 L不锈钢在60℃出现了Warburg阻抗;钝化膜的外层电阻和内层电阻均比未钝化的大。经钝化处理后的316 L不锈钢在ClO2漂液中的受腐蚀速率较未钝化的降低近一半,与钛材相比耐蚀性较差,但能在一定条件下起到减缓腐蚀的作用。     

混凝-水解-接触氧化处理造纸漂白废水的研究

本文研究了混凝,厌氧酸化,生物接触氧化一体化反应器处理造纸制浆含氯漂白废水,在水力停留时间为15h时,整个系数CODcr总去除率达88．1％,BOD5去除率达81％,AOX去除率达98．4％,毒性值去除了92％,絮凝单元去除的主要是大分子氯代有机物,厌氧单元通过还原脱氯及酸性水解,氯代有机物得到了基本的去除;好氧单元对COD有较高的去除率,红外光谱的分析结果表明：废水中既有木素又有纤维素和半纤维素,虽然漂白废水厌氧处理效果不如好氧处理,但厌氧,好氧联合处理可有效地提高其处理效果。     

残氯对于造纸漂白废水毒性测试的影响

通过利用发光细菌法测试蔗渣浆CEH漂白废水毒性的研究,对比了在有残氯和无残氯的两种情况下,漂白废水毒性的变化,发现废水中残氯含量越高,对废水毒性的贡献越大,得出了残氯对于测试生物毒性有着比较重要的影响,在研究纸浆漂白废水中主要有机物的毒性时要注意废水中残氯的消除.     

ON THE BLACK LIQUOR AND RECYCLE COOKING OF AS-AQ STRAW PULP

1.INTRODUCTIONAs a kind of agriculture residues, straw occupies an important status in the non-wood papermaking material in China. Straw is herbaceous plant yearly, and composed with successive and organized cell groups that is similar with others plants. The construction of straw fiber has three obvious layers and the sequence is lamella, primary wall and second wall. Because the organization is loosen andporous, the lignin content is lower and the cooking liquor is easer to penetrate so…     

COMPARISON OF ECF-LIGHT,TCF AND CEH BLEACHING OF NON-NOOD FIBERS

A comparative evaluation of DQP, OQP and CEH bleaching of non-wood fibres has revealed that wheat straw, reed, bagasse and bamboo pulps can be bleached to brightness levels of just above 80% ISO,when applying an OQP bleaching sequence and to brightness levels of about 85% ISO when applying the DQP sequence using 10 - 15 kg/tp of ClO2 (aC1.),15 - 20 kg/tp of H2O2 together with 1 - 2 kg/tp of EDTA. The P.C. numbers of the DQP and OQP bleached pulps are much lower and the viscosity much higher than those of the CEH bleached pulps.Compared with CEH pulps, both the DQP and OQP pulps had better strength properties, particularly Tear Index. In spite of their higher final brightness levels,the DQP pulps show similar or better strength properties than the OQP pulps. A comparison of the CEH and DQP effluents showed that the DQP bleaching could reduce the pollution load (CODCDBOD5, SS) by 35 to 60% without the need for recirculation of any effluent streams. The AOX levels could be reduced by 87 to 93%.     

纸浆的酶生物漂白及其机理

应用白腐菌（Ｗｈｉｔｅｒｏｔｂａｓｉｄｉｏｍｙｃｅｔｅｆｕｎｇｕｓ）产生的降解木素的三种酶类木素过氧化物酶［（Ｌｉｇｎｉｎｐｅｒｏｘｉｄａｓｅ，Ｌｉｐ）（ＥＣ．１．１１．１．１４）］、锰过氧化物酶［（Ｍｎ－ｐｅｒｏｘｉｄａｓｅ，ＭｎＰ）（ＥＣ．１．１１．１．１３）］和漆酶［（Ｌａｃｃａｓｅ，Ｌａｃ）（ＥＣ．１．１０．３．２）］及黑曲霉（Ａ．ｎｉｇｅｒ）产生降解半纤维素的聚木糖酶［（Ｘｙｌａｎａｓｅ）（ＥＣ．３．２．１．４）］和桉木（Ｅｕｃａｌｙｐｔｕｓ）硫酸盐浆作用，结果显示，酶处理能降低纸浆的卡伯值（Ｋａｐｐａｖａｌｕｅ），提高白度，而对粘度降低较少．ＧＣ和ＦＴＩＲ分析表明，经酶处理后，纸浆中的发色基团和助色基因减少，阿拉伯糖和木糖含量降低，按木ＫＰ浆木素－碳水化合物复合物（ＬＣＣ）的木素－阿拉伯糖基及木素－木糖基结合键断裂，并活化木素分子的芳香环结构，促进木素的溶出，提高了纸浆的白度和可漂性．生物漂白废液的污染负荷降低了．