共查询到17条相似文献,搜索用时 109 毫秒
1.
2.
研究了NH4Cl在以多孔聚丙烯平板膜(Celgard 2400)为支撑体、磷酸二(2-乙基己基)酯(D2EHPA)为膜液载体和煤油为膜溶剂的支撑液膜体系中的分离过程,采用交流阻抗法动态监测支撑液膜的膜液流失过程,这种方法的优点是可以连续实时监测支撑液膜的膜液流失.通过IM6电化学工作站测出了不同时间下的膜电阻来监测支撑液膜膜液流失的各个阶段,同时考察了影响膜液流失的一些因素.结果表明,膜电阻能够实时反映出膜液流失情况,原料相初始浓度降低和载体浓度增加均使液膜流失加快. 相似文献
3.
支撑液膜分离技术的研究进展 总被引:10,自引:2,他引:8
介绍了支撑液膜分离技术的最新研究进展,特别是欧洲的研究现状.叙述了近年来使用支撑液膜进行金属离子的选择分离,光学异构体的分离,生物活性物质的分离及气体分离的基本原理和研究进展.列举了不同金属离子和有机酸选择分离的载体.同时报道了支撑液膜作为分析检测的辅助手段用于微量成份,环境中污染药物,人体体液中的药物的分离富集分析检测的研究.并对支撑液膜稳定性的研究进展,包括支撑液膜不稳定性的机理,改进支撑液膜稳定性的方法作了介绍. 相似文献
4.
《膜科学与技术》2017,(5)
以界面聚合法在聚偏氟乙烯(PVDF)疏水膜支撑体表面分别制备了含有载体的活性复合支撑液膜和普通复合支撑液膜,研究了两种复合膜的基本性质、传质性能以及稳定性.结果显示,复合层中载体的加入改变了涂层的表面形态和孔径等,从而影响了聚酰胺层的基本性质,使其亲水性增强,荷负电性增强.液膜萃取N(Ⅱ)的实验结果显示,活性复合膜的初始通量比普通复合膜提高了66.0mg/(m~2·h),5h萃取率提升了8.5%,反萃率提升了7.3%,通量衰减率降低了20.6%.载体在复合层中的加入促进了Ni(Ⅱ)的传质效率,同时增进了支撑液膜萃取过程的稳定性.相比普通复合支撑液膜,活性复合支撑液膜在传质效率和运行稳定性方面更具优势. 相似文献
5.
三正辛胺—二甲苯支撑液膜萃取Cd(Ⅱ)的研究 总被引:3,自引:1,他引:2
研究了Cd(Ⅱ)在三正辛胺-二甲苯支撑液膜体系中的迁移规律.结果表明,载体三正辛胺浓度显著影响Cd(Ⅱ)的渗透系数P.料液中H+浓度、Cd(Ⅱ)浓度和膜溶剂对Cd(Ⅱ)的迁移有影响.在此液膜体系中反萃剂醋酸铵比氢氧化钠好,温度升高能提高Cd(Ⅱ)的迁移速率. 相似文献
6.
以聚丙烯(PP)中空纤维膜为支撑体,二(2-乙基己基)磷酸(简称D2EHPA)为载体,煤油为膜溶剂,探讨D2EHPA-煤油-H2SO4中空纤维支撑液膜(SLM)体系对水中氨氮的传质行为.以去除率为指标,考察了料液初始氨氮浓度及pH值、载体浓度、反萃剂浓度对传质效果的影响;并通过对比实验分析了导致传质速率降低的主要原因.结果表明:在反萃剂H2SO4浓度为2 mol/L,料液相pH值在8~13范围内,提高料液pH值、增大膜相中载体浓度,均能提高氨氮的去除率.D2EHPA-煤油-H2SO4体系对氨氮的传质能力随氨氮浓度降低而下降.料液中氨氮浓度下降和pH值降低是导致氨氮传质速率降低的主要原因,调节料液pH值可调控和提高氨氮的去除与传质效果. 相似文献
7.
8.
钴离子在P507—CCl4液膜体系中的活性迁移 总被引:1,自引:1,他引:0
研究了在P507-CCl4大块液膜体系中,载体P507浓度、反萃液硫酸的浓度、料液pH、醋酸根浓度等因素对Co2+的活性迁移的影响.实验结果表明,载体浓度增加,Co2+的迁移通量增加.反萃液硫酸浓度增加,料液pH及醋酸根浓度适度增加均有利于Co2+的迁移.实验中观察到Co2+在膜迁移中的滞留现象,并在支撑液膜实验中测定了较大的P507浓度时Co2+的渗透系数P. 相似文献
9.
以往通过萃取精馏法实现苯/环己烷的体系分离,没有考虑膜液的流失问题,损失量及物料循环量均较高,耗能较大.提出基于离子液体支撑液膜的苯/环己烷体系分离方法,使用离子液体"充填型"支撑液膜,进行苯/环己烷的体系分离实验,分析了不同离子液体、不同操作温度、不同孔状结构的聚偏二氟乙烯超滤膜和原料侧苯蒸汽压等对分离性能的影响.结果显示,对聚偏氟乙烯支撑液膜离子液体填充后,渗透通量明显提高,分离因子也成倍增长.实验结果可以有效说明,离子液体支撑液膜的分离过程可以作为苯/环己烷体系分离的高效方法. 相似文献
10.
11.
12.
钇离子在P507作载体的支撑液膜中的传输 总被引:1,自引:1,他引:0
本文研究了转速、pH、P_(507)浓度,I—表面活性剂对P_(507)为载体的支撑液膜提取钇(Y~(3+))的影响,计算了P_(507)浓度增加时的各种膜阻力。 相似文献
13.
14.
Facilitated transport of uranyl ion from nitric acid feed solutions was investigated across PTFE supported liquid membranes using N,N,N',N'-tetra-2-ethylhexyl-3-pentane-diamide (T2EHDGA) in n-dodecane as the carrier extractant containing 30% iso-decanol as the phase modifier. Solvent extraction studies indicated extraction of species of the type, UO(2)(NO(3))(2)·T2EHDGA. The distribution coefficients increased in the presence of NaNO(3) as compared to equivalent concentration of HNO(3) which was exactly the opposite of what was reported for Am(III)-TODGA extraction system. Supported liquid membrane studies indicated about 11h were required for quantitative transport of U(VI) from a feed of 3M HNO(3) using 0.2M T2EHDGA in n-dodecane containing 30% iso-decanol as the carrier extractant. Effect of various parameters such as feed acidity, T2EHDGA concentration, and nature of the strippant on the transport rate was investigated. The transport was found to be diffusion controlled in the membrane phase and the permeability coefficient was calculated to be (3.20 ± 0.13)× 10(-4)cm/s for the feed composition of 3M HNO(3), receiver phase composition of 0.01 M HNO(3) and membrane carrier phase of 0.2M T2EHDGA in n-dodecane containing 30% iso-decanol. The present results may be useful for the separation of U from lean solutions or radioactive wastes considered hazardous due to the presence of alpha-particle emitting radionuclides. 相似文献
15.
The emulsion liquid membrane technique was used for the extraction of hexavalent chromium ions from aqueous solution of waste sodium dichromate recovered from the pharmaceutical industry wastewater. The liquid membrane used was composed of kerosene oil as the solvent, Span-80 as the surfactant and potassium hydroxide as internal reagent. Trioctyl amine and Aliquat-336 were used as carriers. The emulsion stability was carried out at different surfactant concentration, agitation speed and emulsification time. Statistical experimental design was applied for the optimization of process parameters for the extraction of chromium by emulsion liquid membrane. The effects of process parameters namely, agitation speed, membrane to emulsion (M/E) ratio and carrier concentration on the extraction of chromium were optimized using a response surface method. The optimum conditions for the extraction of chromium (VI) using response surface methodology for Trioctyl amine were: agitation speed – 201.369 rpm, M/E ratio – 0.5887% (v/v) and carrier concentration – 4.0932% (v/v) and for Aliquat-336: agitation speed – 202.097 rpm, M/E ratio – 0.5873% (v/v) and carrier concentration – 3.9211% (v/v). At the optimized condition the maximum chromium extraction was found to be 89.2% and 96.15% using Trioctyl amine and Aliquat-336, respectively. 相似文献
16.