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1.
生物机械制浆废水特征及处理研究 总被引:2,自引:0,他引:2
研究表明,生物机械制浆废水的污染负荷只有其它高得率浆(CMP,CTMP)废水污染负荷的1/3-1/2。用活性尼法处理Bio-MP废水,只要较短的水力停留时间(3-4h)即可去除79%的COD和98%的BOD。紫外分光光度研究表明,处理后的Bio-MP废水废水的木质素素含量降至处理前的36%。Bio-MP废水污染负荷低,毒性小且具有良好的可生物处理性。 相似文献
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本文介绍了杨木的纤维特性、化学成份和利用杨木生产高得率纸浆的适应性,以及杨木为原料的漂白化学热磨机械浆(BCTMP)和碱性过氧化氢化学机械浆(APMP)。APMP是90年代研制成功的高得率制浆新方法,其特点是纸浆得率高、白度高和强度好。该法适用于针阔叶木,特别是杨木。杨木APMP可代替部分长纤维针叶木浆,配抄低定量胶印新闻纸和涂布纸等。 相似文献
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21世纪的木材硫酸盐制浆新技术 总被引:1,自引:0,他引:1
本文论述了21世纪的木材硫酸盐制浆技术。其中,在蒸煮方面介绍了间歇蒸煮的快速置换、药液全置换技术与连续蒸煮的改良、深度脱木素改良技术;漂白方面介绍了氧漂白、臭氧漂白、过氧化物漂白、生物漂白、无元素氯漂白、完全无氧漂白技术。通过改进蒸煮技术,采用氧脱木素、高温洗涤和无氯漂白,可以解决硫酸盐制浆漂白废水污染问题,满足环保的要求。 相似文献
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研究了颤杨机械浆和高得率浆在回用过程中性质的变化,并对照研究了黑云杉热磨机械浆的回用性能。结果表明,纸浆了明显的变化,发生在第一次加用后。用于研究的所有浆的保水值下降,游离度增加,并伴随着结合的能力的降低,而纤维本身折强度并没有明显变化。云极TMP对回用的反应与颤杨TMP不同;经磺化处理的颤杨CMP与未磺人的颤有区别。显然,机械浆和高得率浆的回用性能与树种和制浆条件有关。 相似文献
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本文论述了21世纪的木材硫酸盐制浆技术。其中,在蒸煮方面介绍了间歇蒸煮的快速置换、药液全置换技术与连续蒸煮的改良、深度脱木素改良技术;漂白方面介绍了氧漂白、臭氧漂白、过氧化物漂白、生物漂白、无元素氯漂白、完全无氧漂白技术。通过改进蒸煮技术,采用氧脱木素、高温洗涤和无氯漂白,可以解决硫酸盐制浆漂白废水污染问题,满足环保的要求。 相似文献
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被子植物亚门 ANGIOSPERMAE双子叶植物纲 DICOTYLEDONEAE 玉蕊科 LECYTHIDACEAE玉蕊(Barringtoniaracemosa(Linn.)Spreng);H(15),D(35)。文昌(头宛)。本岛东北部海滩或海岸。 野牡丹科 MELASTOMATACEAE※海南谷木(MemecylonhainanenseMerr.etChun);吊罗。小乔木,本岛南半部常见。谷木(M.LigustrifoliumChamp.etBenth.),角木(琼);H(20)… 相似文献
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青冈常绿阔叶林死地被层和土壤性质特征的研究 总被引:10,自引:0,他引:10
1990年至今对浙江建德青冈常绿阔叶林生态系统的养分循环进行了研究。报道了死地被层现存量,死地被层(包括L、F、H三亚层)和土壤(包括A、E、B三层)中C和8种养分元素的分布,以及植物对养分元素的累积特征。结果表明:死地被层现存量为14.141t/hm2,其中H>F>L.死地被物中9种元素含量和贮量大小依次为C>N>Ca>Mn>K>Mg>P>Zn>Cu,而土壤中为C>N(K)>K(N)>Mg>Mn>Ca>P>Zn>Cu。与其它地区相比,本区土壤中Mn和N的含量较高而P和Ca较低.不同元素具有不同的层次分布和季节变化特征。自表层至深层,C、N、Ca、Mn的含量呈下降趋势;而K、Mg的含量均在表层较低,并在深层有较高的含量;而P、Cu和Zn则以H与A层的含量为最高.植物对元素的累积特征因元素和层次(种类)而异。各元素中以Ca的富集系数最高,N次之,Cu和Zn最低;一般而言,藤本、草本和下木层植物对元素的累积程度比乔木层和亚乔木层要高。 相似文献
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V. Masura 《Wood Science and Technology》1999,33(5):381-389
Summary A new mathematical model for checking and controlling the kraft pulping process has been derived. The model is based on the
modified relationship between the lignin content and the alkali concentration of a cooking liquor expressed as the ratio of
lignin/active alkali vs. concentration of the active alkali in a cooking liquor. The derived model characterizes the variation
of the lignin content of the partially delignified wood or pulp with the concentration of the residual alkali in a cooking
liquor during an entire pulping cycle, i.e. during the initial, transition, bulk and residual phases of the kraft delignification.
The relationship between the lignin content of the partially delignified wood ships or pulp and the concentration of the residual
alkali in a cooking liquor is expressed by the logarithmic straight line equation or its power form. The slope and intercept
constants of the derived equation for the individual phase of delignification have different values.
Received 5 June 1996 相似文献
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The importance of eucalypt as a raw material for pulping is steadily growing. Eucalyptus globulus was compared with European hardwood species using two alkaline pulping processes, kraft and alkaline sulfite, anthraquinone
pulping (ASA), which is a recently developed modified alkaline sulfite process. All cooks were performed to similar kappa
numbers. Poplar cooks resulted in the highest yields followed by eucalypt and birch which were on the same level. Yield of
beech pulps was definitely lower. ASA pulps show a moderate higher yield due to the less alkaline pH-profile of the cooking
liquor. This yield advantage was maintained and even enhanced after TCF-bleaching. The bleaching response of all pulps was
excellent. The birch pulps had the highest tensile strength followed by the poplar and beech pulps. Surprisingly eucalypt
pulps had the lowest tensile strength. But this was compensated by the very good tear index of eucalypt pulps. The runnability
factor, as an index for the overall strength potential, was on the same level for all pulps. Due to the higher hemicellulose
content of the ASA pulps their tensile strengths were higher, but tear strengths lower compared to the kraft pulps. The different
morphology of the hardwoods investigated resulted in different volumes and light scattering coefficients of the corresponding
pulps.
Dedicated to Prof. Dr. Dr. h. c. mult.Walter Liese on the occasion of his 80th birthday. 相似文献
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The effects of anthraquinone (AQ) and polysulfide (PS) on the hexenuronic acid (HexA) content of pulp during kraft cooking
were studied using Acacia mearnsii (acacia) and Larix leptolepis (Japanese larch) sapwood. In contrast to the results of cooking Japanese larch at an H-factor of 1200, the HexA contents
of acacia pulp with a kappa number of 20 at an H-factor of 291 did not differ greatly between the kraft, kraft-AQ, and PS-AQ
cooking methods, although the hydroxide ion concentration in the acacia cooking liquor decreased on the addition of AQ or
sulfur. To explain this difference, we studied the behavior of the formation and degradation of HexA during alkaline cooking
of glucuronoxylan from cotton linter, which was cooked with 1.0 and 2.0 mol/l NaOH. The relationship between HexA content
and H-factor during alkaline cooking of glucuronoxylan was clarified. The amount of HexA and its rate of decomposition were
higher in the 2.0 mol/l solution than in the 1.0 mol/l solution. At a low H-factor similar to that for hardwood cooking, HexA
content increased to a maximum level and then started to decrease at high hydroxide ion concentrations such as 2.0 mol/l,
whereas it slowly decreased at low hydroxide concentrations such as 1.0 mol/l. At an H-factor of around 450, the HexA formation/degradation
curve for 1.0 mol/l of hydroxide crossed the decomposition curve for 2.0 mol/l of hydroxide. Therefore, it was shown that
at a low H-factor, a decrease in hydroxide ion concentration during acacia wood cooking had little effect on the HexA content
of pulp. 相似文献
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本文介绍了用杨木生产漂白化学浆,包括硫酸盐法,硫酸盐-蒽醌法,烧碱-蒽醌法和碱性亚硫酸钠-蒽醌法制浆;用杨木生产漂白化学热磨机械浆;用杨木生产碱性过氧化氢机械浆;特别是杨木碱性过氧化氢机械浆是90年代发展研制成功的高得率、高白度和强度性好的新化学机械浆种,它适用于配抄低定量胶印新闻纸、低定量涂布纸等。 相似文献
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António Santos Ofélia Anjos Maria Emília Amaral Nuno Gil Helena Pereira Rogério Sim?es 《Journal of Wood Science》2012,58(6):479-486
Wood density and pulp yield are key parameters in the evaluation of tree productivity and quality for pulping and their relationships are of high practical importance. The influence of wood density on pulp yield and other pulp quality parameters was investigated using Acacia melanoxylon and its natural variability as a case study. Twenty trees were harvested (five trees in each of four sites in Portugal), and wood discs taken at different height levels, from the base to the top of the tree, providing 100 wood samples, covering the natural variability of wood density ranging from 449?kg?m?3 to 649?kg?m?3. Under the same experimental conditions of kraft pulping, screened pulp yield ranged 47.0?C58.2?%, Kappa number 10.9?C18.4, ISO brightness 14.9?C45.6, fibre length 0.660?C0.940?mm and fibre width 16.2?C22.9???m. The pulp yield and Kappa number were not correlated with wood density. Higher pulp yields were associated with lower Kappa numbers and alkali consumption, suggesting the important role of chemical composition of wood on kraft cooking. The results confirm the high pulping potential of Acacia melanoxylon trees grown in Portugal and suggest the possibility of tree selection using both wood density and pulp yield. 相似文献
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Response surface methodology with central composite design was used to investigate the influence of pulping conditions, viz. cooking temperature, time-at-temperature and alkali charge for alkaline pulping of oil palm empty fruit bunch fibres, on the properties of the pulp and paper obtained (screened yield, Kappa number, tensile and tear indices). Quadratic models consisting of the three independent variables were found to accurately describe the pulping of this material with correlation between the actual and predicted values of the response variables having a relatively good degree of R2. The delignification of oil palm empty fruit bunch fibre can be achieved with ease using sodium hydroxide as the sole cooking agent to about 30–45% yield with the process greatly enhanced by an increase in temperature. Although, a relatively low temperature (about 160°C) within the limits of pulping time (60–120 min) and of alkali charge between 20 and 30% is generally sufficient. 相似文献
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G. J. Kubes B. I. Fleming J. M. MacLeod H. I. Bolker 《Wood Science and Technology》1980,14(3):207-228
Summary The technology and chemistry of recent advances in alkaline pulping are reviewed from the standpoint of the authors' work over the past few years. Topics reviewed include soda-amine [particularly soda-ethylenediamine (EDA)], soda-anthraquinone (AQ), kraft-AQ, and soda-AQ/EDA pulping and their effects on pulp strength properties and bleachability. There is evidence to support the concept that the rates of all alkaline delignification reactions, including kraft, are controlled by a reductive step which transfers electrons to the degrading lignin. 相似文献