提高马尾松KP浆过氧化氢漂白效率的研究

探讨了改善Ｈ＿２Ｏ＿２漂白化学浆效率的途径。结果表明，高温漂白和漂前预处理可明显改善Ｈ＿２Ｏ＿２的漂白效率。当漂白温度由６０℃提高到９０℃时，白度增加６％ＩＳＯ。预处理效果的大小顺序为：木素活化剂＞螯合剂＞木聚糖酶＞硫酸。活化剂－螯合剂复合处理不仅可进一步提高白度，而且明显抑制了纤维素的降解。     

Biorefinery process water effluent treatments by salt coagulation

Acid pretreatment is one of the critical pretreatments for the biorefinery. However, little information is available on water effluent that results from this acidic pretreatment compared to alkaline pretreatment. In this study, the wastewaters from an integrated modern magnesium bisulphite pulp mill (acidic) were utilized as models for the acid pretreatment effluents of a modern biorefinery. The coagulation technique, using high valency electrolytes, was applied for the treatment of treated and untreated process water from the pulp mill. The effectiveness of some electrolytes and the selectivity of the coagulation process were compared by measuring the removal extent of critical contaminants such as organics, phosphorus and colour. The salt coagulation process was found to be selective for colour and total phosphorus removal from the wastewater, achieving more than 90% removal of contaminants.     

Post-harvest pod storage: A method for pulp preconditioning to impair strong nib acidification during cocoa fermentation in Malaysia

In Malaysia, pulp preconditioning by post-harvest storage of cocoa pods leads to the reduction of nib acidification during subsequent fermentation, reduction of the acid note and an increase in cocoa flavour in the resulting raw cocoa. Data from several shallow-box fermentations, with material from unstored and stored pods, are compared and interpreted, obtained in the years 1984 to 1987 in a cooperational investigation of the Malaysian Agricultural Research and Development Institute (MARDI), Malaysia, and the Botanical Institute, Technical University of Braunschweig (TUBS), FRG. Prior to and during fermentation, pulp volume and pulp sugars; pH value, acetic acid and lactic acid content in the pulp and nibs; and oxygen concentration and temperature in the mass were determined. Some flavour assessments from selected samples are given. The great reduction in pulp volume per seed rather than the decrease of pulp sugars per seed during pod storage was found to be of the most importance. Pulp-volume reduction enhances mass aeration and increases the ratio of respiration to ethanol fermentation and its subsequent oxidation to acetic acid. As a consequence, the acidification of the seeds during the formative stages of flavour precursors (after the death of the seeds) is strongly reduced. With effectively dry stored pods (pulp volume per gram of seed ≤0·6 ml) the anaerobic phase during the initial stages of fermentation which is common with unstored pods is suppressed. Under these conditions the nib pH value does not fall below 5·0 and no drastic acid (and flavour) degradation at the end of fermentation is necessary to reduce the acidity in the seeds.     

Electrochemical degradation of pulp and paper industry waste‐water

BACKGROUND: Conventional biological waste‐water treatment techniques are insufficient to degrade large quantities of dissolved lignin discharged by small‐scale paper mills. The current investigation is aimed at comparing the overall performance of basic electrochemical reactor configurations such as batch, batch recirculation, recycle and single pass systems, in removing the organic part of waste‐water from a small‐scale, agro‐based paper industry. The effect of current density, supporting electrolyte concentration, duration of electrolysis, specific electrode surface and fluid flow rate on the removal of pollutants and energy consumption are critically evaluated. The improvement in biodegradability of the effluent during treatment is also noticed. RESULTS: The batch recirculation mode of operation was found to be superior in comparison with a batch system using the same specific electrode surface for both COD removal (73.3 vs. 64%) and capacity utilization (rate constant 1.112 × 10^?3 vs. 1.049 × 10^?3 cm s^?1). The pollutant removal performance of the batch recirculation system improved considerably with increase in the circulation flow rate. At the best operating point in the recycle system, 59% of COD was removed, corresponding to a current efficiency of 68.9% and specific energy consumption of 18.46 kWh kg^?1. The biodegradability index of the waste‐water was improved from 0.18 ± 0.01 to 0.36 ± 0.01. CONCLUSION: A recycle reactor was the best configuration, because of its flexibility of operation. Circulation flow rate and withdrawal flow rate enable the control of transfer coefficients and treatment duration respectively. Electrochemical treatment not only removes the bulk of the organic matter, but also makes the remaining pollutants more easily biodegradable. Copyright © 2009 Society of Chemical Industry     

制浆造纸业实现跨越式发展需要新思维和缜密操作(续)

5强调现代物流与传统产业链节发展全过程的关联，推动现代物流工作使之成为现代制浆造纸企业运作的关键战术之一，并且提到战略高度认识。动现物流议题的提出，某些读者也许会感到唐突。物流这个概念在我国的历史不长，英文是Logistics，过去翻译成中文意思多为后勤（保障）等。其实物流的内容以及变化和我们的浆纸厂生产密切相关，传统意义上我们也往往理解为后勤保障，或者仓储运输等。随着时代的演变，物流的内容极大的丰富，其中服务性的成分不断充实，已经形成一个相当完整的体系。人们之所以研究和探讨物流问题，完全因为处理好物流…     

Enhancement of anaerobic batch digestion of sisal pulp waste by mesophilic aerobic pre-treatment

Pre-treatment of sisal pulp prior to its anaerobic digestion was investigated using an activated sludge mixed culture under aerobic conditions in batch bioreactors at 37 degrees C. The progression of aerobic pre-treatment of the residue in relation to the activities of some extracellular hydrolytic enzymes in the slurry was monitored. The highest activity of hydrolytic enzymes was obtained at 9 h of pre-treatment. Filter paper cellulase had a maximum activity of 0.90 IU/ml, while carboxymethyl cellulase, amylase and xylanase were produced to a maximum of about 0.40 IU/ml. The methane yield obtained after anaerobic digestion of the pre-treated pulp ranged between 0.12 and 0.24 m3 CH4/kg VS added. The highest and lowest values were obtained for 9 and 72 h of pre-treatment, respectively. Nine hours of pre-treatment of sisal pulp prior to anaerobic digestion demonstrated a 26% higher methane yield when compared to the sisal pulp without pre-treatment. The consortia of microorganisms in activated sludge demonstrated a useful potential in the production of hydrolases acting on major macromolecules of sisal pulp. The fact that a correlation was observed between high enzyme activity and high methane yield at 9 h of aerobic pre-treatment suggests that such a short pre-treatment period could be an alternative option for increasing solubilization of sisal pulp and promoting methane productivity.     

梅岭玉地质特征及成因探讨

介绍江苏省梅岭玉（软玉）矿床的地特征,通过野外调查,室内镜下观察、化学分析、光谱分析、电镜分析、Ｘ射红衍射分析,电子探针定量分析等综合研究后认为：梅岭玉是透闪石族的软玉,有白玉、青白玉、青玉等不同的品种。矿床是多成因形成的;其中以透闪石矿物为主物的梅岭白玉是接触交代变质作用形成的,以钠透闪石矿物为主的青玉形成较虹,是由“玉浆”贯入后,在低压高温下的迅速冷凝形成的。     

Self-tuning control of a chip refiner motor load

On a chip refiner the gain of the transfer function between the refiner motor load and the plate gap is subject to a slow drift due to plate wear and to sudden changes in sign due to collapse of the pulp pad. A self-tuning regulator was designed to control motor load by manipulating the plate gap. It uses a recursive least-squares estimator with a variable forgetting factor in conjunction with a Dahlin regulator. Results of plant trials on an industrial thermomechanical pulp production unit show that this regulator is capable of tracking the slow gain drift and of taking proper action in case a pulp pad collapse occurs.     

Chemical kinetics of alkaline peroxide brightening of mechanical pulps

A new mechanism is proposed for the heterogeneous alkaline peroxide brightening reactions of mechanical pulps. The mechanism consists of four key kinetic steps: adsorption of hydrogen peroxide and hydroxide to the pulp fiber walls; chromophore-removing chemical reaction on the fiber wall; desorption of “light” organic products formed from the fiber wall; and oxidation chain reduction of the cleaved organic substances. The most important step here is the surface reaction, rather than reactions occurring in the liquid phase. In general, the removal of the cleaved organic substances from the fiber wall is not anticipated to occur completely during the brightening reaction operation stage. The failure of the “light” organic products to completely dissociate from the fiber wall is more pronounced at high consistencies and when agitation is weak. The pulp brightness is measured after washing the pulp and thus removing the “light” organic products. The overall brightness enhancement or chromophore-removal rate is thus limited by the reaction occurring on the fiber wall. A kinetic model has thus been developed based on the proposed mechanism. An apparent second-order reaction in terms of the chromophore concentration, first orders in terms of the adsorbed hydrogen peroxide and adsorbed hydroxyl concentrations are observed from the kinetic model. The derived kinetic model can explain the existing experimental data from various sources quite well.     

全自动纸浆模塑机组干燥过程工艺参数的优化

随着纸质快餐具的广泛应用,纸浆模塑机组的效率和节能显得越来越重要。本研究在生产实用设备的实验基础上,利用“正交回归”实验分析方法对该设备的干燥过程进行了优化设计,求出优化结果,为同类设备设计和生产调试提供了参考依据。