草甘膦母液减量方法研究

在10%草甘膦水剂停止生产后,草甘膦母液的处理问题成为了制约草甘膦生产的关键性因素,处理不当最终会导致生产停滞。探寻草甘膦生产过程中减少母液量的方法,从而降低草甘膦母液处理成本,使草甘膦生产中的母液产出和处理达到平衡。     

草甘膦母液膜处理技术研究的探讨

阐述了草甘膦母液中的主要杂质成分及杂质的量平衡,并结合当前膜法母液处理工艺流程,剖析了该工艺存在的突出问题和必须突破的技术难点,探讨了草甘膦母液处理的研究方向.     

草甘膦废水处理

草甘膦生产母液含大量甲醛和CODCr,难处理排放。本文主要讨论了纳滤浓缩回收母液中大部分的草甘膦,然后以生石灰处理纳滤透过液、浓缩液的草甘膦母液处理方法。采用(纳滤回收草甘膦+生石灰)处理废液的工艺可以得到较好的处理效果和草甘膦回收率。     

1158号公告对草甘膦水剂生产的影响及对策

分析了农业部、工业和信息化部第1158号公告对草甘膦生产企业的影响,介绍了草甘膦母液处理利用的技术,为草甘膦企业提供参考。     

草甘膦原粉母液处理的探讨

用过氧化氢氧化还原双甘膦制备草甘膦后,提取草甘膦原粉,对剩余草甘膦母液的处理条件进行摸索,进而提高草甘膦的生产收率,增加草甘膦母液的利用途径。     

草甘膦专利信息

膜技术分离提浓草甘膦母液中草甘膦的方法 本发明公开了一种膜技术分离提浓草甘膦母液中草甘膦的方法,它是先对母液进行过滤处理,除去其中的固体成分,再根据母液中需要分离提浓的草甘膦等组分的分子结构、分子质量、微粒大小和电荷性,从大到小,选择合适的超滤膜、纳滤膜和反渗透膜进行逐级分离,及至提浓有效成分草甘膦.     

草甘膦母液湿式催化氧化处理技术

介绍了草甘膦母液的主要化学成分,分析了湿式催化氧化母液处理技术的难点(催化剂的研发,设备及管道堵塞,设备腐蚀,氯化钠的出路),提出了解决方案。     

草甘膦制造时母液产排节点及治理技术研究

采用甘氨酸法制备草甘膦时会产生大量的母液,这些母液中含有多种难降解的有机物、盐、总磷、COD等,由于母液在处理过程中产生废盐的危险物属性缺失,导致对其管理极为混乱,对母液的综合利用和排放都存在着较大的风险。因此对草甘膦生产过程中的母液产排节点进行了分析,综合建议从生产工艺上进行优化,减少母液排放,并对母液进行综合利用处理,从而减少草甘膦生产过程中的污染。     

草甘膦母液深度处理新工艺获鉴定

<正>日前由浙江悦瑞环保工程有限公司等单位研发的"草甘膦母液催化湿式氧化深度处理新工艺"在北京通过中国石油和化学工业联合会组织的成果鉴定。该新工艺对草甘膦母液经过催化湿式氧化低温结晶分离滤液膜浓缩MVR浓缩蒸发等将母液转化为无机磷、氨氮、二氧化碳和水并回收磷酸盐、氯化钠、硫酸铵等实现草甘膦母液深度处理和资源化在催化剂研     

草甘膦母液深度处理新工艺获鉴定

<正>日前,由浙江悦瑞环保工程有限公司等单位研发的"草甘膦母液催化湿式氧化深度处理新工艺"在北京通过中国石油和化学工业联合会组织的成果鉴定。该新工艺对草甘膦母液经过催化湿式氧化,低温结晶分离,滤液膜浓缩,MVR浓缩蒸发等,将母液转化为无机磷、氨氮、二氧化碳和水,并回收磷酸盐、氯化钠、硫酸铵等,实现草甘膦母液深     

废钢在底吹反应器中运动熔化及混匀的水模型实验

通过水模型实验,使用饱和氯化钾溶液制作的冰样模拟重型废钢,研究其在底吹气体搅拌反应器中的运动、融化及溶质的混匀规律。探究了单孔吹气模式下的液面高度、双孔吹气方式下的气体流量等因素对其的影响。结果表明,单孔吹气时,液面高度较低时(液面高度与直径比为0.42),气柱发展不充分,容器内环流较弱,盐球在气柱上下往复运动,融化较为缓慢。随着液面高度增加(液面高度与直径比为1.04),盐球随着环流运动,融化过程加快,按照98%标准得到的KCl的混匀时间甚至低于融化时间。双孔吹气时,A孔气体流量0.8 m3/h不变,B孔气体流量为0.5和1.0 m3/h时,盐球从吹气孔A上方加入后,在容器底部停留一段时间,在60~70 s之后才运动到顶部,沿着环流运动;B孔流量增加至1.5 m3/h时,盐球不会在底部停留,随气柱运动到吹气流量大的一侧的羽流区,其融化过程较快。在双孔吹气方案中,也发现了KCl的混匀时间低于融化时间的规律,这和融化末期盐球质量较小,释放的盐分较少有关。在本研究中,双孔吹气对盐球融化的促进作用不如单孔吹气且流量较大的方案。     

Effect of the sol fraction and hydrostatic deformation on the viscoelastic behavior of prestrained highly filled elastomers

This study focuses on the relations between the microstructure and the viscoelastic behavior of an industrial solid propellant belonging to the class of highly filled elastomers. Precisely, the study aims at determining the impact on the viscoelastic behavior of the presence of the sol fraction inside the polymer network. The sol fraction is the part of the binder that a good solvent can extract. The solid propellant is swollen to various extents by solutions of plasticizer and polymer molecules. This swelling leads to a hydrostatic deformation of the polymer network, corresponding to an extension or contraction loading for each specimen. Prestrained dynamic mechanical analysis tests, superimposing a small oscillating strain on a prestrain, characterize the viscoelastic behavior. The degree of swelling of the network and the effective filler fraction drive the viscoelastic response. In addition, the mechanical behavior does not depend on the chemical nature of the introduced sol fraction. Moreover, a nonlinear behavior, i.e., an increase in both storage and loss moduli with increasing prestrain, is initiated at low prestrain. This nonlinearity depends on the contraction or extension of the network and could result from particles aligning with prestrain, which is expected in such highly filled materials. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Lipid soil removal from cotton fabric after mercerization and carboxymethylation finishing

Soiling and soil removal from cotton fabrics that had been chemically modified by mercerization and carboxymethylation were studied using electron microscopy and radiotracer techniques. The distribution of lard soil in specimens before and after laudering was determined by means of chemical tagging with osmium tetroxide. Both the chemical and physical changes of the cotton resulted in differences in soiling and soil removal of lipid soil. Mercerization and carboxymethylation of cotton swell the cotton fiber, decrease the crenulation and the lumen, and smooth the fiber surface. These finishes also increase the pore volume and thus the chemical accessibility of the fibrillar structure. In addition, carboxymethylation causes changes in the chemistry of the fiber by increasing the carboxyl group content. These structural changes reduce the amount of soil deposited in the lumen of the fiber, particularly for the carboxymethylated cotton. They also increase soil removal from the crenulation and the interfiber spaces in the yarn bundle. Soil removal from fiber surfaces and from within the fiber—both lumen and secondary wall—was highest for the carboxymethylated cotton, and mercerization also enhanced lipid soil removal. The results of this experiment indicate that chemical accessibility and hydrophilicity of the fiber structure influence both soil deposition and soil removal of lipid soils. Soil removal of these modified cottons is enhanced by multiple mechanisms: (i) the decrease in small crevices and the crenulation or small capillary along the fiber, (ii) the increase in pore volume that enhances chemical accessibility and thus detergency within the fiber structure, (iii) the increase in hydrophilicity that enhances soil removal from the surface by the roll-up mechanism, (iv) the increase of mechanical action due to enhanced swelling of the carboxymethylated cotton, and (v) the reduction of soil redeposition on carboxymethylated surfaces.     

聚电解质静电沉积改性制备高性能反渗透膜

利用次氯酸钠溶液对商品反渗透膜表面进行氯化处理,然后将聚阳离子电解质壳聚糖通过静电吸附作用沉积在RO膜的表面,系统地研究了氯化过程的pH、氯化时间、次氯酸钠浓度、壳聚糖浓度及其沉积时间对膜性能的影响,以制备出高通量、高截留率的RO膜。在压力1.55 MPa、原料液温度（298±1）K的条件下,测定RO膜处理2000 μg·g^-1氯化钠溶液的水通量和截留率。结果表明,当pH=9、氯化时间为30 min、次氯酸钠浓度为1000 mg·L^-1时,水通量较原膜提高了约19.89%,截留率略有提高;当壳聚糖浓度为0.1%（质量分数）、沉积时间为30 min时,改性膜的接触角降低到34.88°,亲水性提高,水通量较氯化后的RO膜几乎保持不变,为60.55 L·m^-2·h^-1,截留率达到了99.56%。经过氯化和沉积改性后的RO膜水通量和截留率均得到了提高。     

Calculation of Residual Thermal Stresses in Injection Molded Amorphous Polymers by the Finite Element Method

Abstract

The finite element method (FEM) is used to calculate the distribution of residual internal stresses in an injection molded plate-shaped polystyrene specimen. The first step of the calculating procedure is the determination of the temperature distributions in the plate and its variation with cooling time. The temperature distribution data are then used for the determination of the corresponding stress distribution. Also this latter step is accomplished using the FEM-technique. The residual stress distribution is obtained when the sample has been cooled to the temperature of the mold. The main result of the calculations is the finding that the surface layer of the plate is subject to compressive stresses, while the interior accommodates stresses of tensile type. The calculations relate to a polystyrene specimen. The results are shown to agree well with earlier data concerning internal stresses in injection molded objects. The possible influence of anisotropy and visco-elastic relaxation has been neglected. The method can be applied to other amorphous polymers and, after a slight modification, also to polymers of semicrystalline type.     

Pd-Pb/SiO2催化高浓度乙烯基乙炔加氢合成丁二烯

研究了硅胶负载钯铅双金属催化剂催化高浓度乙烯基乙炔加氢合成丁二烯过程。结果表明,加入适量的铅可起到分隔钯纳米粒子,阻碍钯纳米粒子团聚的作用,从而提高催化剂的催化活性,最佳Pb/Pd摩尔比为0.2。继续提高Pb/Pd摩尔比时,会生成铅钯合金相,造成催化剂活性降低。X射线光电子能谱结果表明,催化剂的催化活性与Pd 3d的电子结合能呈正相关关系。制备催化剂过程中,还原温度对催化剂的结构和催化性能影响显著。在350℃下还原得到的催化剂中金属氧化物还原不彻底,催化剂活性较低;还原温度为450℃时,则会引起钯纳米粒子烧结,造成催化剂的催化活性和对丁二烯的选择性同时降低;催化剂的最佳还原温度为400℃。在40℃催化乙烯基乙炔反应40 h后,积炭造成催化剂的孔道堵塞,催化剂失活。因此,需要进一步开展改善催化剂的抗积炭能力和使用寿命方面的研究。     

Écoulement de Taylor‐Couette en géométrie finie et à surface libre

The reactors of Taylor‐Couette type are relatively recent application in the engineering processes field. The stability and the flow structure in this device are examined under the effect combined of the free surface and the fluid's height in annular space. The exploitation of the flow regimes is carried out according to the number of Taylor for various values of aspect ration Γ. By means of ultrasonic velocimetry (UPV) we determine axial average velocity profile and the axial wavelength. We also carry out the spectral analysis by Fourier's fast transform of the fluctuations associated with the average velocity values in order to analyze the flow structure. We particularly aim for checking the presence or the absence of the azimuth wave according to the filling height and the rotational velocity imposed. We highlight the effects of free surface and aspect ratio on the conditions of appearance of the second instability ( wavy mode). The analysis of the fluctuation shows that the appearance of the azimuth wave regime (Wavy mode) is delayed when the aspect ration decreases. Below a critical value noted Γc = 10, the azimuth wave regime is not observed any more.     

黏弹性表面活性剂溶液中颗粒沉降特性研究

黏弹性表面活性剂溶液悬浮颗粒流广泛存在于自然界和工业生产中,黏弹性表面活性剂溶液的非线性流变性质及应力松弛效应对其中颗粒沉降有着显著影响。采用FENE-P和Giesekus黏弹性本构模型对表面活性剂溶液中颗粒沉降特性进行研究,发现两种本构模型不仅表现出剪切稀化,而且出现拉伸硬化。颗粒在沉降初期的不稳定性主要是由溶液自身的弹性效应引起,弹性效应越强,颗粒沉降速度不稳定性越强,而剪切稀化效应会减弱颗粒沉降速度的不稳定。颗粒沉降过程中在其尾部形成一个“负尾迹”,随着剪切稀化和拉伸硬化效应增强,负尾迹区增大,弹性效应增加,负尾迹增强,负尾迹区流体内部反向速度分布导致的表面活性剂溶液中微观胶束的拉伸断裂和重构可能是引起颗粒沉降速度持续波动的原因。     

Selective Sequestration of Pyrrolizidine Alkaloids from Diverse Host Plants by Longitarsus Flea Beetles

In 11 species of the flea beetle genus Longitarsus we investigated whether the insects sequester the pyrrolizidine alkaloids (PAs) present in their host plants of the families Asteraceae and Boraginaceae. In all cases where PAs could be detected in the leaves of the local host plant, they could also be detected in the corresponding beetles. In one host plant, Pulmonaria officinalis, no PAs could be detected in the leaves, yet were present in the beetles collected from them. We suggest this is due to uptake of PAs during the root-feeding larval stage. By comparing the GC-MS pattern of PAs found in the beetles with those of their hosts, we investigated the specificity of this sequestration. Furthermore, we compared the pattern of sequestered PAs across beetle species that had been feeding on the same plant, and across hosts in Longitarsus species that feed on different plants in the field. This allowed us to analyze to what extent the PA pattern in the insects is specific for the beetle species and depends on the local food plant. Our data indicate that the PAs found in the beetles are largely determined by the host plant, e.g., whether alkaloids typical of the Boraginaceae or Asteraceae are present. However, there are some indications for a selective uptake of PAs and apparently the beetles are able to metabolize them.     

Combined electrochemical and surface analysis investigation of degradation processes in polymer electrolyte membrane fuel cells

Fuel cells allow an environmentally friendly and highly efficiently conversion of chemical energy to electricity and heat. Therefore, they have a high potential to become important components of an energy-efficient and sustainable economy. The main challenges in the development of fuel cells are cost reduction and long-term durability. Whereas the cost can be significantly reduced by innovative mass production, the knowledge to enhance the lifetime sufficiently is not available.Surface science analysis methods used for the characterization of the new and used electrodes can be use to determine the alterations in the fuel cell components and in this way to identify the degradation processes, but they do not allow to quantify the influence of the alterations in the electrodes on the electrochemical performance. For this purpose electrochemical methods are necessary; especially the electrochemical impedance spectroscopy (EIS) allows to separate the performance losses individually and to assign them to different components and processes of the cell via a model, whereas the choice of the right model can be problematic.Two important and distinct structural degradation processes were identified by surface analysis of the electrodes before and after fuel cell operation: first, the decomposition of poly tetra-fluoro-ethylene (PTFE) which is used as an organic binder and as a hydrophobic agent in the electrodes and second, a change of the structure of the catalysts. The observed decomposition of the PTFE is associated with a decrease of the hydrophobicity of the electrode. A loss of hydrophobicity influences drastically the required operation conditions and leads to a more critical water management of the fuel cell. In contrast, the alteration of the catalysts structure in the electrodes causes an irreversible decrease of the electrochemical performance. In polymer electrolyte fuel cells (PEFCs) a particle agglomeration of the platinum catalysts at the cathodes is detected.With EIS the effect of two different degradation processes in the membrane-electrode-assembly was quantified. During continuous operation the degradation of the PTFE induces an approximately two times higher performance loss compared with the performance loss related to the agglomeration of the platinum catalyst.