Decolorization of reactive brilliant red X-3B by heterogeneous photo-Fenton reaction using an Fe–Ce bimetal catalyst

Decolorization of reactive brilliant red X-3B was studied by using an Fe–Ce oxide hydrate as the heterogeneous catalyst in the presence of H₂O₂ and UV. The decolorization rate was in the order of UV–Fe–Ce–H₂O₂ > UV–Fe³⁺–H₂O₂ > UV–H₂O₂ > UV–Fe–Ce ≥ Fe–Ce–H₂O₂ > Fe–Ce. Under the conditions of 34 mg l⁻¹ H₂O₂, 0.500 g l⁻¹ Fe–Ce, 36 W UV and pH 3.0, 100 mg l⁻¹ X-3B could be decolorized at efficiency of more than 99% within 30 min. The maximum dissolved Fe during the reaction was 1 mg l⁻¹. From the fact that the decolorization rate of the UV–Fe–Ce–H₂O₂ system was significantly higher than that of the UV–Fe³⁺–H₂O₂ system at Fe³⁺ = 1 mg l⁻¹, it is clear that the Fe–Ce functioned mainly as an efficient heterogeneous catalyst. UV–vis, its second derivative spectra, and ion chromatography (IC) were employed to investigate the degradation pathway. Fast degradation after adsorption of X-3B is the dominant mechanism in the heterogeneous catalytic oxidation system. The first degradation step is the breaking down of azo and CN bonds, resulting in the formation of the aniline- and phenol-like compounds. Then, the breaking down of the triazine structure occurred together with the transformation of naphthalene rings to multi-substituted benzene, and the cutting off of sulphonic groups from the naphthalene rings. The last step includes further decomposition of the aniline structure and partial mineralization of X-3B.     

Effect of solution properties on nanofibrous structure of electrospun poly(lactic‐co‐glycolic acid)

Electrospinning of poly(lactic‐co‐glycolic acid) (PLGA) in chloroform or 1,1,1,3,3,3‐hexafluoro‐2‐propanol (HFIP) was investigated, focusing on its solution parameters, to develop nonwoven biodegradable nanofibrous structures for tissue engineering. PLGA nanofibers were obtained by electrospinning of 15 wt % PLGA solution and the resulting average fiber diameters were varied with the range of 270–760 nm, depending on solution property. When small amounts of benzyl triethylammonium chloride (BTEAC) was added to the PLGA/chloroform solution, the average diameter was decreased from 760 to 450 nm and the fibers were densely amounted in a straight shape. In addition, the average fiber diameter (270 nm) of nanofibers electrospun from polar HFIP solvent was much smaller than that (760 nm) of nanofibers electrospun from nonpolar chloroform solvent. Therefore, it could be concluded that conductivity or dielectric constant of the PLGA solution was a major parameter affecting the morphology and diameter of the electrospun PLGA fibers. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 1214–1221, 2006     

聚合硅酸铝铁絮凝剂的研究动态

概要评述了国内外聚合硅酸铝铁盐类混凝剂的研究动态。分析了各种制法的特点，对今后的研究工作提出了一些建议。     

青岗钾肥厂试车小结

为满足农业生产上对硫酸钾的需求，化工部上海化工研究院复肥所着重开发了硫铵转化法的生产工艺，并在推广过程中，针对操作工艺和设备上所存在的问题，继续探索，取得了新的结果。该技术已用于青岗钾肥厂万吨级硫酸钾生产装置。本文着重介绍了该装置在试车过程中所发生的问题及处理方法。     

溴化十六烷基三甲基铵胶束高效液相色谱的研究和应用

研究了苯、苯胺、苯酚和甲苯在以溴化十六烷基三甲基铵(CTAB)水溶液为移动相,YWG-NH_2为固定相时的保留行为。当柱温为45℃、移动相组成为5%正丙醇(或9%乙醇)的0.03mol/L CTAB 时,苯、苯胺、苯酚和甲苯分离最佳。还计算了溶质传质过程的焓值及其在水、胶束、固定相间的分配系数。     

甲醇合成化学平衡常数的测定与推算

以低压法(5MPa)甲醇合成为背景,建立了气相法甲醇合成化学平衡常数的实验测定系统,测定了不同温度和压力下,CO、CO_2同时加H_2合成CH_3OH反应的平衡组成及化学平衡常数K_p,同时以实验结果为依据,对K_p的理论推算进行了探讨,其中对文献中计算以逸度表示的平衡常数K_f的各种方程进行了比较。结果表明,基于Cherednichenko的K_(f,Ⅰ)和Bissett的K_(f,Ⅱ),采用修正的SRK方程,对K_p的推算取得了满意的结果。     

甜菊糖甙超滤的应用研究

本文主要描述不同分子量的ＰＡＮ和ＣＡ膜净化甜菊糖甙，超滤后的甜菊糖甙较好地解决了生产中所出现的沉淀和起泡问题，并对新旧工艺进行对比和评价。     

沥青混凝土心墙坝渗漏检测及防渗体系修复综述

针对部分沥青混凝土心墙坝出现渗漏情况,为判定沥青混凝土心墙坝渗漏的部位及通道,需采用多种检测方法对坝体渗漏情况进行综合分析和判定。列举了多个工程应用实例,对沥青混凝土心墙坝渗漏检测方法如水下声纳检测、孔内彩电观测、示踪连通试验、坝体内水位分析和物探检测,以及混凝土防渗墙和控制灌浆修复坝体防渗体系方案及其影响因素进行了综述,以期为类似工程提供借鉴。     

JS118的杀虫活性与作用方式研究

室内生物测定研究了JS118的触杀、胃毒、拒食、内吸活性。结果表明(1)JS118对棉铃虫有明显的触杀活性和胃毒活性,对棉铃虫6龄幼虫的触杀毒力、胃毒毒力和综合毒力分别为2.486 mg/pest、0.606 mg/pest和0.4856 mg/pest。(2)JS118对试虫无明显的驱避效果。24 h内对试虫的取食影响不明显,但在24 h后,抑制试虫进食。(3)JS118无明显的根内吸活性。     

Structural and electrochemical characterization of mechanochemically synthesized calcium zincate as rechargeable anodic materials

Hydrated calcium zincate was synthesized by mechanical ball milling of ZnO and Ca(OH)₂ in water at room temperature. The structural and electrochemical properties of this material used as rechargeable anodic material were examined by microelectrode voltammetry, charge–discharge measurements and structural analysis. The results showed that during mechanical milling, ZnO, Ca(OH)₂ and H₂O reacted rapidly to form Ca[Zn(OH)₃]₂ · 2H₂O which was subsequently transformed to a stable structure CaZn₂(OH)₆ · 2H₂O. Since this composite oxide has lower solubility in KOH solution (<35 wt %) and better electrochemical reversibility than ZnO-based negative materials, the zinc anodes using this material can overcome the problems of shape changes and dendritc formation, and therefore exhibit improved cycling life.