共查询到19条相似文献，搜索用时 46 毫秒
1.
采用正交试验方法对竹浆Co-salen型仿酶系统催化漂白竹浆最优工艺条件及影响因素进行了研究。用白度、硬度、黏度和选择性这四个指标评价仿酶预处理的效果,并通过计算确定了各因子的影响程度及最佳因子组合。结果表明,竹浆Co-salen仿酶催化预处理较适宜的条件为:NaOH用量3.0%,H2O2用量1.0%,Co-salen用量0.03%,吡啶用量0.007%,温度90℃,时间5 h,氧压0.2 MPa,浆浓5%。 相似文献
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用对甲苯磺酸(p-TsOH)对未漂硫酸盐竹浆进行了处理,将处理后的竹浆进行抄纸,并对成纸性能做了相关分析.发现在p-TsOH浓度25％～50％、温度70℃、时间30～60 min的温和反应条件下,木质素脱除率可达60％,竹浆纤维的得率超过87％,得到的纤维形态基本完整,纤维平均长度未发生明显变化,官能团种类未发生改变.... 相似文献
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蔗渣硫酸盐浆次氯酸盐漂白中有害物质的研究 总被引：1，自引：0，他引：1
本文对蔗渣硫酸盐浆次氨酸盐漂白中有机氯及三氯甲烷的形成情况进行了研究，结果表明：这些有害物质的生成量与漂白用氟量、漂白浓度、温度和时间等条件有关；在次氨酸盐漂白时加入少量H2O2,可以有效地减少三氯甲烷的生成量，通过GC及ESR分析阐明H2O2能减少废液中三氯甲烷含量的机理。 相似文献
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桉木硫酸盐浆DMD漂白工艺条件的研究 总被引：1，自引：0，他引：1
使用新漂剂二甲基二环氧乙烷（Dimethyldioxirane,简称DMD）漂白桉木硫酸盐浆时,应严格控制反应的pH值为7．0~7．5;过氧硫酸盐和丙酮用量增加,二甲基二环氧乙烷的漂白能力随之增强;5％用量的DMD漂浆经碱抽提后脱木素能力与氧脱水素相当,但前者漂浆得率高,脱木素选择性好。 相似文献
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漆酶和聚木糖酶协同漂白蔗渣硫酸盐浆的研究 总被引：11，自引：1，他引：11
进行了蔗渣硫酸盐浆漆酶 /介体 (LMS)生物漂白的研究 ,分析了漆酶 /介体体系和聚木糖酶在漂白流程中作为前后漂段或在同一段中同时使用对漂白效果的影响。漆酶 /介体体系与聚木糖酶同时或前后处理蔗渣硫酸盐浆 ,在一定程度上提高了纸浆的漂终白度和强度 ,说明生物漂白改善了漂白选择性 相似文献
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本文针对二氧化氯漂白系统的介质条件,检测与验证了四种耐蚀树脂,得出了国产乙烯基酯树脂可满足试验条件的结论。 相似文献
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本文研究了半纤维素酶E—An—76对桦木硫酸盐浆无氯漂白流程的影响．研究结果表明：在桦木硫酸盐浆OEDP漂白过程中插入E－An－76组成的OXEDP流程与原漂程比较，可节省大量化学漂剂的用量而保持白度和得率。 相似文献
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二氧化氯的漂白及制备方法 总被引：1，自引：0，他引：1
我国大多数造纸厂生产漂白纸浆均采用含氯漂白技术,应用这些漂白剂漂白后的纸浆废液中含有很多的有毒甚至剧毒的有机氯化合物。本文介绍的二氧化氯是一种新的对环境污染少、对纸张漂白效果好、不影响纸张质量的漂白剂。阐述二氧化氯用于纸浆漂白原理及其优势,介绍二氧化氯的几种常见制备方法。 相似文献
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高战备 《中国洗涤用品工业》2011,(3):63-64
采用Color Quest XE色度测量仪,分别分析了过氧化硫酸盐对红色棉布的彩漂性能和对白色棉布的漂白性能。经过多次洗涤后检测表明,过氧化硫酸盐的彩漂功能明显。 相似文献
11.
Yi Liu Baojuan Deng Jiarui Liang Jiao Li Baojie Liu Fei Wang Chengrong Qin Shuangquan Yao 《International journal of molecular sciences》2022,23(21)
Chlorine dioxide is widely used for pulp bleaching because of its high delignification selectivity. However, efficient and clean chlorine dioxide bleaching is limited by the complexity of the lignin structure. Herein, the oxidation reactions of phenolic (vanillyl alcohol) and non-phenolic (veratryl alcohol) lignin model species were modulated using chlorine dioxide. The effects of chlorine dioxide concentration, reaction temperature, and reaction time on the consumption rate of the model species were also investigated. The optimal consumption rate for the phenolic species was obtained at a chlorine dioxide concentration of 30 mmol·L−1, a reaction temperature of 40 °C, and a reaction time of 10 min, resulting in the consumption of 96.3% of vanillyl alcohol. Its consumption remained essentially unchanged compared with that of traditional chlorine dioxide oxidation. However, the consumption rate of veratryl alcohol was significantly reduced from 78.0% to 17.3%. Additionally, the production of chlorobenzene via the chlorine dioxide oxidation of veratryl alcohol was inhibited. The structural changes in lignin before and after different treatments were analyzed. The overall structure of lignin remained stable during the optimization of the chlorine dioxide oxidation treatment. The signal intensities of several phenolic units were reduced. The effects of the selective oxidation of lignin by chlorine dioxide on the pulp properties were analyzed. Pulp viscosity significantly increased owing to the preferential oxidation of phenolic lignin by chlorine dioxide. The pollution load of bleached effluent was considerably reduced at similar pulp brightness levels. This study provides a new approach to chlorine dioxide bleaching. An efficient and clean bleaching process of the pulp was developed. 相似文献
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Nazar Almeida Valrie Meyer Auphlia Burnet Jeremy Boucher David Talens-Perales Susana Pereira Petri Ihalainen Thomas Leve Julio Polaina Michel Petit-Conil Susana Camarero Paula Pinto 《International journal of molecular sciences》2022,23(21)
Xylanases can boost pulp bleachability in Elemental Chlorine Free (ECF) processes, but their industrial implementation for producing bleached kraft pulps is not straightforward. It requires enzymes to be active and stable at the extreme conditions of alkalinity and high temperature typical of this industrial process; most commercial enzymes are unable to withstand these conditions. In this work, a novel highly thermo and alkaline-tolerant xylanase from Pseudothermotoga thermarum was overproduced in E. coli and tested as a bleaching booster of hardwood kraft pulps to save chlorine dioxide (ClO2) during ECF bleaching. The extremozyme-stage (EXZ) was carried out at 90 °C and pH 10.5 and optimised at lab scale on an industrial oxygen-delignified eucalyptus pulp, enabling us to save 15% ClO2 to reach the mill brightness, and with no detrimental effect on paper properties. Then, the EXZ-assisted bleaching sequence was validated at pilot scale under industrial conditions, achieving 25% ClO2 savings and reducing the generation of organochlorinated compounds (AOX) by 18%, while maintaining pulp quality and papermaking properties. Technology reproducibility was confirmed with another industrial kraft pulp from a mix of hardwoods. The new enzymatic technology constitutes a realistic step towards environmentally friendly production of kraft pulps through industrial integration of biotechnology. 相似文献
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对麦草浆二氧化氯与氧气脱木素效率及相应的漂白流程进行了对比研究。结果表明,ClO2脱木素(D0)对木素的修饰和改性效果好于氧脱木素(O),在脱木素率低于及接近氧脱木素率的条件下,D0浆的可漂性均大于O浆。在D0段和O段脱木素率相同的条件下,采用D0A/QP、D0EP漂白流程漂后纸浆白度分别比OA/QP漂白流程高11.2和10.3个百分点。D0段废液和相应D0A/QP漂白流程三段混合废水的CODCr负荷均比O段和OA/QP漂白流程混合废水的CODCr负荷轻。D0段和O段废液的紫外光谱都呈现出木素苯环的特征吸收。纸浆的FT-IR谱图分析表明,D0浆和O浆中的羟基和羰基数量增多,随着漂白的进行,羰基等主要发色基团逐渐消除,纸浆白度得到提高。纸浆纤维形态的SEM分析显示,D0段和相应的D0A/QP漂白流程对纤维表面的破坏和损伤较O段和相应的OA/QP漂白流程轻。 相似文献
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Isabel M. C. L. Sêco Carlos Pascoal Neto Armando J. D. Silvestre 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2008,83(3):218-226
BACKGROUND: Brightness stability is a key property of bleached chemical pulps and is primarily determined by wood species and bleaching process conditions. Eucalyptus globulus is becoming a very important raw material for hardwood pulp production. In spite of this importance, there is a relative lack of systematic studies in the literature dealing with the subject. This research aims to study the effect of some of the foremost bleaching parameters of a DEDD bleaching sequence as well as the effect of a final P stage (DEDP instead of DEDD) in the brightness stability of bleached E. globulus kraft pulps. RESULTS: The increase of the D0 stage temperature from 55 °C to 90 °C caused an increase in brightness stability. Increasing the ClO2 charges from 2.8% to 3.2% also improved significantly the brightness stability. A high H2SO4 charge in the D0 stage (10 kg tonne?1 pulp) diminished the brightness stability. The combination of H2O2 addition to the E stage and ClO2 reduction in the two final D stages does not affect brightness reversion. Raising the D2 stage temperature from 65 °C to 82 °C decreased the brightness reversion, while an increase was obtained when the temperature rose above 82 °C. Substitution of the last ClO2 stage in the DEDD sequence by a H2O2 stage (DEDP) significantly reduced the brightness reversion. CONCLUSION: For an existing pulp mill in which the implementation of new technologies to improve brightness reversion is considered, the results obtained showed that brightness stability can be improved without any significant capital investment. Copyright © 2007 Society of Chemical Industry 相似文献
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二氯化氯作为一种新型杀菌漂白剂,在欧美等发达国家已得到了广泛的应用,目前国内的应用正处于发展阶段.文章介绍了二氧化氯的特性、生产方法及多种用途,并对其开发前景进行了分析. 相似文献
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The reaction of chlorine dioxide with hydrogen peroxide was studied in a well stirred batch reactor in a pH range of 3.60 to 5.07, which is of interest for commercial chlorine dioxide bleaching of chemical pulp. The reaction rate was determined by following the consumption of chlorine dioxide and hydrogen peroxide and the formation of chlorite. The rate equation was established. It was found that the concentration dependencies of chlorine dioxide, hydrogen peroxide and hydroxide ion were all first-order. A reaction mechanism compatible with the rate equation was proposed. Since it was found in previous work that chlorite in chlorine dioxide solution by the addition of small amount of hydrogen peroxide potentially led to a decrease in the formation of organically bound chlorine during chlorine dioxide bleaching, two methods were suggested to implement this technique in a bleach plant. 相似文献
18.
二氧化氯(ClO_2)的制备方法及其应用 总被引：3，自引：0，他引：3
介绍了ClO2 的主要生产制备方法和ClO2 作为漂白剂、消毒杀菌剂、水处理剂等在多种行业中的应用 ,进一步分析展望了ClO2 的生产和应用前景。 相似文献
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模糊控制技术在纸浆漂白过程中的应用 总被引：3，自引：3，他引：0
针对漂白过程干扰因素多、大滞后的特点 ,采用模糊控制技术研究并开发了氯气流量模糊控制器来修正氯气流量设定值 ;应用该控制器不仅使白度提高了 2 .2 % ,而且使得每吨浆可以节约氯气 2 .3 9kg 相似文献