摘要:

Zinc extraction from perchlorate medium, with 1, 10-bis[ 1-phenyl-3-methyl-5-hydroxy-4-pyrazolyl]-1,10-decanedione (HL-8-LH) and its mixtures with tri-n-octylphoaphine oxide (TOPO) in chloroform has been investigated and compared with the corresponding extraction systems with 1-phenyl-3-methyl-4-benzoyl-pyrazol-5-ol (HL*). The extraction processes are: Zn2+ + 2 HL-8-LH 3* 2 H+ + Zn(L-8-LH) (K )

ISSN:0736-6299    

DOI:10.1080/07366299008917984

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

It is shown that the distribution of homologous series of nor-α-aminoacids in liquid two-phase three-component systems formed by salting-out of low aliphatic alcohols from their aqueous solutions by sodium chloride can be described by the following relation: 6nZ)=a + blnφ, where:Dis the distribution coefficient expressed as the ratio of concentration of aminoacid in the upper and lower phases, respectively; φ is the ratio of alcohol concentration expressed in molar percent in the same phases; a and b are constants related to activity coefficients and salting-out constants of aminoacid and alcohol by sodium chloride.

ISSN:0736-6299    

DOI:10.1080/07366299008917985

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

The extraction behavior of Eu(III) from nitric and hydrochloric acid By solutions of CMPO with and without TBP has been studied using mesitylene and dodecane as diluents. Compared to CMPO alone, the CMPO-TBP mixture shows a slight enhancement in the extraction of Eu(III) from nitric acid above 2M and lower DEu’ s from low acidity. The distribution ratios measured for Eu(III) between HN03 and CMPO-TBP in dodecane are higher than the corresponding values in mesitylene.Extractant dependency studies in the presence and absence of TBP show that at low HN03 concentrations, the extractant dependency curve obtained in the presence of TBP lies below the curve obtained in the absence of TBP. At high acidity, the opposite is observed. The extraction of Eu(III) from hydrochloric acid by CMPO-TBP in dodecane is much lower than from nitric acid. A comparison between CMPO and D2EHPA for Eu(III) extraction has been carried out.

ISSN:0736-6299    

DOI:10.1080/07366299008917986

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

The separation of uranium from synthetic Hanford site groundwater by liquid-liquid extraction and by supported liquid membranes (SLM) was atudied. Bis(2,4,4-trimethylpentyl) phosphinic acid, H[DTMPeP], contained in the commercial extractant Cysnex 272, was selected for the membrane carrier because of its selectivity for uranium over calcium and magnesium. n-Dodecane was used as diluent and polypropylene membranea were used as the support. A water soluble complexing agent, 1-hydroxyethane-1,1-diphoaphonic acid, HEDPA, was used as atrlpping agent.

ISSN:0736-6299    

DOI:10.1080/07366299008917987

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

A mathematical model of the shell progressive mechanism with changing bulk solution concentration and exchanger volume in ion exchange is presented and its conformity with experimental results is demonstrated.

ISSN:0736-6299    

DOI:10.1080/07366299008917988

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

A chromatograph with on-line gamma-detector compatible with corrosive eluants is described. The interplay among chromatographic resolution, speed of analysis, and precision of a radio-activity detector is reviewed. The precision of the peak area measurement of a radio-chromatographic peak can be improved by incorporating a multiscaler in the counting circuit. The void volume and cation exchange capacity of a column packed with experimental monodisperse 9.8 μm, highly (>40%) crosslinked porous resin particles have been measured by different methods. Measured cation exchange capacity by isotopic exchange between (23Na)r+ (22Na)sand the titration method are identical. The variation of overall height equivalent to a theoretical plate for the isotopic exchange with flow rate is reported. The extrapolated value of plate height at zero flow rate is about 3.2 times particle diameter.

ISSN:0736-6299    

DOI:10.1080/07366299008917989

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

Improved column efficiencies and decreased tailing of Eu3+and Lu3+elution peaks with 2-hydroxy isobutyric acid, HIBA, were obtained by partial sulfonation of experimental monodisperse 5 and 10 μm, highly (>40%) crosslinked porous beads. Blocking of micropores of such highly crosslinked porous gels with n-dodecane before sulfonation further reduces the extent of sulfonation and improves column efficiency. Simultaneous choice of a smaller particle size and less sulfonation improves the column performance. The normalized performance of a monodisperse 10 μm, highly crosslinked porous resin of 0.058 meq/ml capacity was similar to that of a monodisperse 15 μm, 10% crosslinked surface sulfonated gel type resin of 0.031 meq/ml capacity for Lu3+/HIBA.

ISSN:0736-6299    

DOI:10.1080/07366299008917990

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

Elution of Eu with 2—hydroxy isobutyric acid, HIBA, from experimental 10 μm, highly (>40%) crosslinked porous resins (XP-11, XP-3016) gives tailed elution peaks. Elution volume of the peaks decreases and column efficiency increases when the flow rate of the mobile phase increases. The increased tailing and height equivalent to a theoretical plate observed for Lu/HIBA (and Eu/HIBA) compared to Ln-isotopic exchange for XP-3016 resin is due to the slow release of the LnL4−complex ion from the micropores. On the other hand, a mono-disperse 10 μm, 5% cross-linked cation-exchanger (XP-7) has high column efficiency and a 3 cm column separated the Yb-Lu pair, but it is unsuitable in an HPLC system where the ionic strength of mobile phase changes.

ISSN:0736-6299    

DOI:10.1080/07366299008917991

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

The adsorption properties of cobalt(II) ions have been studied on layered dihydrogen tetratitanate hydrate fibers, H2Ti4O9,•nH2O, in the temperature range from 298 to 523 K. The distribution coefficients of the adsorption of cobalt (II) ions were increased with increasing temperatures up to 367 K, but were decreased in the temperature range between 367 and 523 K. The X-ray powder diffraction patterns of the fibers indicate that the fibers hold layer structure up to 367 K, but change to low crystalline anatase or its precursor above that temperature. It is notable that the material has the capability of cobalt (II) adsorption even at 523 K, although the maximum is present at 367 K.

ISSN:0736-6299    

DOI:10.1080/07366299008917992

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

The thermodynamics of alkali and alkaline earth metal ion exchange on a layered zirconium sulphophosphonate having the general composition Zr(O3PC6H4SO3H)×(HPO4)2−×yH2O have been investigated. Enthalpy and entropy changes accompanying the M2+- H+exchange (M = Na+, Cs+, Mg2+and Ba2+)were determined by the temperature variation method. For the monovalent ions, Na+and Cs+, the enthalpy terms favor exchange whereas the entropy terms are unfavorable. In contrast, for the divalent ions, Mg2+and Ba2+, the exchange is due to highly favorable entropy terms.

ISSN:0736-6299    

DOI:10.1080/07366299008917993

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor