摘要:

This review covers cyclic separation methods used for adsorption, ion exchange, and chromatographic separation processes where the cyclic parameter is a thermodynamic variable which changes the equilibrium distribution coefficients of the solutes. The cyclic methods reviewed include heatless or pressure-swing adsorption, parametric pumping, and cycling zone adsorption. These cyclic techniques have been studied as a possible preparative chromatographic separation method or for continuous production from adsorption or ion exchange columns.

ISSN:0037-2366    

DOI:10.1080/00372367408056067

出版商:Taylor & Francis Group    

年代:1974

数据来源: Taylor

摘要:

The resolution of a zone electrophoretic system or a chromatographic column is customarily defined in terms of the separation of two pure (homogeneous) species. For such separation the resolution increases indefinitely with time for analytic fractionation, or indefinitely with column length for elution separation. It is shown that microheterogeneity of either or both species imposes an upper limit on resolution. This may have a marked effect on conditions for optimal resolution, and on measurements of the apparent diffusion coefficient.

ISSN:0037-2366    

DOI:10.1080/00372367408056068

出版商:Taylor & Francis Group    

年代:1974

数据来源: Taylor

摘要:

Foam separation techniques are evaluated to determine if they would be feasible for removing lead(II) and cadmium(II) from highly contaminated waste water. Variables such as pH, ionic strength, collector concentration, and interfering ions were studied to determine their effects on ion flotation. Increased ionic strength, calcium(II), and phosphate interference made ion flotation impractical. Precipitate flotation of lead sulfide and cadmium sulfide left approximately 0.20 ppm lead(II) and 0.08 ppm cadmium(II) in the bulk solution under optimum conditions—somewhat above the levels considered safe to release into the environment. Adsorbing colloid flotation gave excellent results; lead sulfide and cadmium sulfide were adsorbed to ferrous sulfide which was then removed by foaming with hexadecyltrimethylam-monium bromide. Lead(II) levels were reduced from 0.80 to 0.025 ppm in 34 min foaming with 15 ppm iron(III) added. Cadmium(II) levels were reduced from 1.0 to 0.008 ppm in 45 min foaming with 25 ppm iron(III) added.

ISSN:0037-2366    

DOI:10.1080/00372367408056069

出版商:Taylor & Francis Group    

年代:1974

数据来源: Taylor

摘要:

The isotopic exchange reaction between NO and HNO3was used to prepare14N highly depleted15N. This required an efficient reflux system of low holdup to convert oxides of nitrogen to nitric acid by reaction with oxygen and water. A study of the characteristics of the one constructed showed that less than 1 part in 32,000 of the nitric acid was lost from the refluxer as oxides of nitrogen.14N with an atom fraction of less than 0.00004 of15N was prepared at the rate of 46.0 g/day. The application of the refluxer to a system for producing15N is discussed.

ISSN:0037-2366    

DOI:10.1080/00372367408056070

出版商:Taylor & Francis Group    

年代:1974

数据来源: Taylor

摘要:

This is a scanned image of the original Editorial Board page(s) for this issue.

ISSN:0037-2366    

DOI:10.1080/00372367408056066

出版商:Taylor & Francis Group    

年代:1974

数据来源: Taylor