全棉秆BCTMP脱果胶预处理工艺研究

针对棉秆皮部果胶质含量高，全棉秆浆可漂性差的特点，分别考察了NaOH和Na2C2O4对棉秆原料的脱果胶效果，并将BCTMP工艺的原料预处理方法由汽蒸或热水浸泡改为添加脱果胶试剂的预处理过程，有效减轻了皮部果胶组分对成浆可漂性的不良影响，在温度90℃、草酸钠用量1．5％的预处理条件下，以3．5％NaOH、4％Na2SO3和3％H2O2制得ISO白度达64．5％的全棉秆BCTMP浆．     

SO2-Na2SO3气液反应动力学研究

研究了温度、SO2浓度、SO2流量和Na2SO3初始浓度对Na2SO3和SO2反应过程的影响,并得到了该反应的反应级数和宏观动力学方程.实验表明,Na2SO3和SO2反应过程是由气体传质过程控制的,传质速率随温度的升高而降低,反应速率与Na2SO3初始浓度无关,与SO2浓度的1.02次方成正比.     

响应面法优化核桃雄花穗护绿工艺研究

以核桃雄花穗为原料,研究各单因素Zn(CH3COO)2浓度、Vc浓度、pH值、Na2SO3浓度、烫漂温度、烫漂时间对核桃雄花穗护绿效果的影响,在单因素的基础上再通过响应面试验,确定核桃雄花穗护绿的最佳工艺配方.试验结果表明,各单因素影响核桃雄花穗护绿的程度由大到小的顺序依次为Zn(CH3COO)2浓度、Vc浓度、pH值、Na2SO3浓度;通过响就面试验确定了核桃雄花穗护绿的最佳工艺配方为Zn(CH3COO)2浓度254mg/kg、Vc浓度0.048%、Na2SO3浓度0.498%、pH值8.91、烫漂温度为100℃、烫漂时间20s.     

三种提取剂对凤丹根际土壤重金属提取效率的影响

土壤重金属有效态含量更适合表征土壤重金属对环境的影响能力。采用人工外源添加方式配制Cu、Pb、Cd单一污染土壤,并选用3种提取剂[乙二胺四乙酸二钠(EDTA-2Na)、二乙基三胺五乙酸(DTPA)和(HCl)]进行单独提取,以研究不同提取剂对凤丹根际土壤中重金属的提取效率,为铜陵尾矿区土壤重金属污染修复治理提供科学依据。结果表明:3种提取剂对重金属Cu、Pb和Cd提取量和提取率由大到小依次为EDTA-2Na、HCl、DTPA;就3种提取剂下凤丹根际土壤不同重金属的提取效率而言,EDTA-2Na适合对Pb的提取;HCl和DTPA适合对Cd的提取,EDTA次之;DTPA较适合对Cu的提取。     

成核剂对储热材料Na_2HPO_4·12H_2O过冷性能的影响

用步冷曲线法研究室温冷却环境下成核剂-Na2HPO4·12H2O复合体系的过冷性能,分析成核剂的添加量和晶体结构对过冷度的影响.结果表明:Na2SiO3·9H2O、NaF、CH3COONa·3H2O和Na2B4O7·10H2O这4种成核剂对Na2HPO4·12H2O的过冷现象有不同程度的改善.为有效改善过冷,成核剂的添加量有一个合适的范围.在10g的Na2HPO4·12H2O中,分别添加0.30g的Na2SiO3·9H2O、0.15g的CH3COONa·3H2O、0.05g的NaF和0.05g的Na2B4O7·10H2O时,抑制过冷的效果最好.同时发现,与Na2HPO4·12H2O晶体结构不同的成核剂Na2SiO3·9H2O改善过冷的效果最显著;与Na2HPO4·12H2O晶体结构相同的成核剂中,Na2B4O7·10H2O改善过冷的效果优于CH3COONa·3H2O.     

Na_2SO_3和低浓度SO_2对Fe~Ⅱ EDTA溶液吸收脱硫烟气中NO的增强作用(英文)

NO排放能够形成酸雨、光化学烟雾并引发人类呼吸系统的疾病.采用FeⅡEDTA湿法吸收NO是一种行之有效的方法,它能够满足严格的大气污染排放标准.实验表明,NO吸收效率随着温度的升高而减小,平衡常数在303,313和323 K时分别为1.69×106,1.38×106和1.20×106.吸收液pH值显著影响吸收效果,弱碱性条件有利于NO吸收.根据缓冲溶液理论计算可知,FeⅡEDTA吸收NO的最大允许pH值为10.5.添加Na2SO3到吸收液中,Na2SO3充当还原剂的同时,还能有效地提高吸收液的缓冲容量.通入低浓度0.01%SO2到吸收液中,可以显著地延长吸收时间(1.57倍吸收效率高于60%),在495 min吸收时间内增加吸收容量35.39%.SO2转化为SO32-离子补偿了Na2SO3的消耗,表明低浓度SO2的存在改善了Na2SO3性能,提高了FeⅡEDTA吸收NO的效果.     

桉木硫酸盐浆TCF漂白的研究

研究桉木硫酸盐浆H2O2强化的氧脱木素效果;研究KMnO4和螯合物对桉木硫酸盐氧漂浆H2O2漂白的改善效果,并对其最佳工艺条件及各种因素对漂白效果的影响进行探讨。结果表明：在氧脱木素过程中加入少量的H2O2,就能起到很好的强化效果;氧漂浆在KMnO4的预处理、DTPA处理后再经过H2O2漂白,可使KP法桉木浆白度达80％以上。     

298K时四元体系Na~+,K~+/Cl~-,HCO_3~--H_2O和Na~+,K~+/SO_4~(2-),HCO_3~--H_2O溶解度预测

基于盐的溶解平衡条件及稳定共饱点的判别原理 ,用 Pitzer模型的 HW公式对四元体系 Na+ ,K+ /Cl- ,HCO-3-H2 O和 Na+ ,K+ /SO2 -4,HCO-3-H2 O在 2 98K的溶解度进行了预测 ,并绘出了这两个体系的相图 :前者有两个共饱点 ,Na Cl,Na HCO3,KCl和 KHCO3四个相区 ;后者有三个共饱点 ,Na2 SO4 · 1 0 H2 O,K3Na(SO4 ) 2 ,K2 SO4 ,Na HCO3和 KHCO3五个相区     

不同浸提剂对干旱区黄土Cu、Zn的浸提

为了研究不同提取剂对干旱区黄土重金属的提取效果,选取了5种提取剂在不同平衡时间提取干旱区不同粒径黄土中重金属Cu、Zn,比较它们的提取效果.结果表明:不同提取剂对黄土中Cu、Zn的提取量和提取率有明显差异,5种提取剂对黄土中Cu的提取量大小为DTPAEDTA-2NaMgCl_2CaCl_2HAc-NaAc;对Zn的提取量大小为EDTA-2NaDTPACaCl_2MgCl_2HAc-NaAc.在试验设定的提取时间范围内,当振荡时间达到60 min时,5种浸提剂对供试土壤中重金属Cu、Zn的浸提均达到平衡.黄土粒径对重金属Cu的浸提量无明显影响,但粒径减小会增加CaCl_2、DTPA、EDTA-2Na对Zn的浸出量.通过对比5种浸提剂对黄土中Cu、Zn的浸提量可知,DTPA是提取黄土中有效态Cu最适宜的浸提剂,而EDTA-2Na更适宜提取黄土中有效态Zn.     

SO2衍生物对大鼠血压的影响

为了进一步研究SO2衍生物(亚硫酸根离子和亚硫酸氢根离子的摩尔比为3∶1,pH值为7.2)对大鼠血压的影响,采用对雄性Wistar大鼠腹腔注射的方法,用RBR-Ⅰ型大鼠血压计测量给药期间大鼠每天的血压变化.结果表明,低剂量的SO2衍生物(Na2SO345.36 mg/kg与NaHSO312.48 mg/kg)对大鼠血压影响不显著;中剂量的SO2衍生物(Na2SO368.04 mg/kg与NaHSO318.32 mg/kg)引起大鼠血压降低;高剂量SO2衍生物(Na2SO390.72 mg/kg与NaHSO324.96 mg/kg)引起大鼠血压的显著降低.另外,Na2SO4对大鼠的血压没有影响.从而得到,二氧化硫衍生物可引起大鼠血压剂量依赖性降低.设想SO/SO2可能是一种新型的细胞气体信号分子.     

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。     

ENZYMATIC DEINKING OF OLD NEWSPRINT WITH CELLULASES AND XYLANASE

The enzymatic deinking and fiber modification of old newsprint (ONP) with several cellulases and xylanase were investigated and the suitable enzyme candidates were selected for ONP deinking in this paper. The results demonstrated that the cellulases and hemicellulases could significantly improve the deinking efficiency and fiber modification.Moreover, the synergistic effects of Novozym342 and xylanase (HC) can further enhance the deinking performance, reduce the dirt count and improve the brightness of resulting pulp. Additionally, compared to deinked pulps, obtained from conventional chemical materials, enzymatically deinked pulps had better bleachability, and the brightness of the bleached pulp reached 59.1% ISO, 9% ISO higher than the unbleached pulp.     

硫酸盐木浆漂白前木聚糖酶预处理的研究

研究了木聚糖酶用于硫酸盐木浆 H2 O2 漂白前预处理的工艺条件 ,结果表明 ,预处理最佳工艺条件为 :酶用量为每克浆 2 0 IU ,时间 3h,浆浓为 6 %。在相同的 H2 O2 漂白条件下 ,经酶处理后的浆料白度可提高 2 %～ 3% SBD。     

THE TCF BLEACHING OF NS-AQ ASPEN HIGH YIELD CHEMICAL PULP

INTRODUCTIONNowadays, under the pressure of energy crisis, Methods押The pulp was put in the high-density polyethylene plastic bag in the of thermostatic water bath where the pulp was treated with chelated environment pollution and market competition, the pulp industry has being developed in the direction of "Three Highness" and " Three Lowness". "Three Highness" means high yield, high strength and high brightness; on the other hand, " Three Lowness" means low energy consumption, low wa…     

ONP脱墨浆二氧化硫脲漂白研究

实验主要探讨了ONP脱墨浆FAS单段漂白的工艺条件,找出了FAS漂白的最佳工艺条件为:FAS用量0.6%,NaOH用量0.3%,漂白温度65℃,漂白时间30min,浆浓10%,在此条件下漂后浆白度达66.6%ISO。     

HE EFFECT OF TRANSITION METAL IONS-IRON ON HYDROGEN PEROXIDE BLEACHING

Hydrogen peroxide bleaching has been extensively used in high-yield pulp bleaching. Unfortunately,hydrogen peroxide can be decomposed under alkaline condition, especially when transition metal ions exit. Experiments show that the valence of transition metal ion is also responsible for the decomposition of hydrogen peroxide.Iron ions are present in two oxidation states, Fe2+ and Fe3+. They are both catalytically active to hydrogen peroxide decomposition. Because Fe3+ is brown, it can affect the brightness of pulp directly, it can also combine with phenol, forming complexes which not only are stable structures and are difficult to be removed from pulp, but also significantly affect the brightness of pulp because of their color.Sodium silicate and magnesium sulfate, when used together, can greatly decrease hydrogen peroxide decomposition. The optimum dosage of sodium silicate is about 0.1% (on solution) for Fe2+ and 0.25% (on solution) for Fe3+. Adding chelants such as DTPA or EDTA with stabilizers simultaneously can obviously improve pulp brightness. For iron ions, the chelate effect of DTPA is better than that of EDTA.Under acidic conditions, sodium hyposulfite and cellulose can reduce Fe3+ to Fe2+ effectively, and pulp brightness is improved greatly. Adding sodium thiosulfate simultaneously with magnesium sulfate,sodium silicate, and DTPA to alkaline peroxide solution can result in higher brightness of pulp.pH is a key parameter during hydrogen peroxide bleaching, the optimum pH value should be 10.5-12.     

THE EFFECT OF TRANSITION METAL IONS-IRON ON HYDROGEN PEROXIDE BLEACHING

INTRODUCTIONHydrogen peroxide bleaching has been extensively used in high-yield pulp bleaching. IT is well known that hydrogen peroxide can be easily decomposed under alkaline conditions, especially in the presence of transition metal ions due to their catalyzing effect on the decomposition of hydrogen peroxide. Some recent reports show that the valence of transition metal ion can have a drastic effect on the decomposition of hydrogen peroxide.Generally, iron can exist in Fe2+ and Fe3+…     

MODIFIED OPAL:A NOVEL STABILIZER FOR HYDROGEN PEROXIDE BLEACHING OF PULPS

The possibility of modified opal as the stabilizer of hydrogen peroxide bleaching was investigated. The results showed that the modified opal in place of sodium silicate as the stabilizer of hydrogen peroxide bleaching is feasible. At the same dosage, above 3% ISO can be increased for both wheat straw pulp and deinked pulp. The stabilizing ability of the modified opal to hydrogen peroxide bleaching of pulp is improved markedly. It is favorable for bleaching to increase temperature and time within a permissive extent. The suitable process conditions are 10% of pulp consistency, 3% of hydrogen peroxide, 1.5% of sodium hydroxide, 3% of the modified opal, 70℃ and 60 min when the modified opal is used as the stabilizer of hydrogen peroxide bleaching. At these conditions, the brightness gain can reach about 16% ISO for wheat straw pulp. In addition, it is favorable for bleaching to add a little magnesium sulfate when the modified opal is used as the stabilizer of hydrogen peroxide bleaching, the brightness of pulp can increase I%ISO if0.05% of magnesium sulfate is added. The cost analysis indicated that the modified opal is superior to sodium silicate as the stabilizer of hydrogen peroxide bleaching in economical aspect and has further the potential of market development.     

THE EFFECT OF DIFFERENT STABILIZERS ON ALKALINE H2O2 BLEACHING OF NS REED PULP

This paper uses a new stabilizer of H2O2 bleaching and compares the stabilizing effect of the new stabilizer with that of Na2SiO3. The results show that the new stabilizer is better than the conventional Na2SiO3. The optimum conditions of the stable latter process bleaching of H2O2 as follow: NaOH 3%,MgSO4 0.05%, H2O2 3%, stabilizer 3%, temperature 80℃, concentration 12%, time 3h.