Extraction chromatography of common anions in liquid-liquid anion exchange systems. Part II. Sulphuric and phosphoric acid or their sodium salts as eluants

1978 ◽  
Vol 11 (2) ◽  
pp. 96-98 ◽  
Author(s):  
R. Kocjan ◽  
S. Przeszlakowski
Keyword(s):  
Phosphoric Acid ◽  
Anion Exchange ◽  
Extraction Chromatography ◽  
Sodium Salts

scholarly journals Chronopotentiometric study of the transport of phosphoric acid anions through an anion-exchange membrane under different pH values

2020 ◽  
Vol 238 ◽  
pp. 116421 ◽  
Author(s):  
C. Gally ◽  
M. García-Gabaldón ◽  
E.M. Ortega ◽  
A.M. Bernardes ◽  
V. Pérez-Herranz
Keyword(s):  
Phosphoric Acid ◽  
Anion Exchange ◽  
Anion Exchange Membrane ◽  
Ph Values ◽  
Exchange Membrane

scholarly journals Partial Fluxes of Phosphoric Acid Anions through Anion-Exchange Membranes in the Course of NaH2PO4 Solution Electrodialysis

2019 ◽  
Vol 20 (14) ◽  
pp. 3593 ◽  
Author(s):  
Olesya Rybalkina ◽  
Kseniya Tsygurina ◽  
Ekaterina Melnikova ◽  
Semyon Mareev ◽  
Ilya Moroz ◽  
...  
Keyword(s):  
Phosphoric Acid ◽  
Anion Exchange ◽  
Diffusion Layer ◽  
Current Density ◽  
Membrane Surface ◽  
Feed Solution ◽  
Potential Difference ◽  
Limiting Current ◽  
Mineral Fertilizers ◽  
Partial Currents

Electrodialysis (ED) with ion-exchange membranes is a promising method for the extraction of phosphates from municipal and other wastewater in order to obtain cheap mineral fertilizers. Phosphorus is transported through an anion-exchange membrane (AEM) by anions of phosphoric acid. However, which phosphoric acid anions carry the phosphorus in the membrane and the boundary solution, that is, the mechanism of phosphorus transport, is not yet clear. Some authors report an unexpectedly low current efficiency of this process and high energy consumption. In this paper, we report the partial currents of H2PO4−, HPO42−, and PO43− through Neosepta AMX and Fujifilm AEM Type X membranes, as well as the partial currents of H2PO4− and H+ ions through a depleted diffusion layer of a 0.02 M NaH2PO4 feed solution measured as functions of the applied potential difference across the membrane under study. It was shown that the fraction of the current transported by anions through AEMs depend on the total current density/potential difference. This was due to the fact that the pH of the internal solution in the membrane increases with the growing current due to the increasing concentration polarization (a lower electrolyte concentration at the membrane surface leads to higher pH shift in the membrane). The HPO42− ions contributed to the charge transfer even when a low current passed through the membrane; with an increasing current, the contribution of the HPO42− ions grew, and when the current was about 2.5 ilimLev (ilimLev was the theoretical limiting current density), the PO43− ions started to carry the charge through the membrane. However, in the feed solution, the pH was 4.6 and only H2PO4− ions were present. When H2PO4− ions entered the membrane, a part of them transformed into doubly and triply charged anions; the H+ ions were released in this transformation and returned to the depleted diffusion layer. Thus, the phosphorus total flux, jP (equal to the sum of the fluxes of all phosphorus-bearing species) was limited by the H2PO4− transport from the bulk of feed solution to the membrane surface. The value of jP was close to ilimLev/F (F is the Faraday constant). A slight excess of jP over ilimLev/F was observed, which is due to the electroconvection and exaltation effects. The visualization showed that electroconvection in the studied systems was essentially weaker than in systems with strong electrolytes, such as NaCl.

Anion Exchange Equilibrations in Phosphoric Acid Solutions

1959 ◽  
Vol 31 (3) ◽  
pp. 330-331 ◽  
Author(s):  
E. C. Freiling ◽  
Juan. Pascual ◽  
A. A. Delucchi
Keyword(s):  
Phosphoric Acid ◽  
Anion Exchange ◽  
Acid Solutions

Evaluation of the separation and purification of 227 Th from its decay progeny by anion exchange and extraction chromatography

2017 ◽  
Vol 124 ◽  
pp. 100-105 ◽  
Author(s):  
P.I. Ivanov ◽  
S.M. Collins ◽  
E.M. van Es ◽  
M. García-Miranda ◽  
S.M. Jerome ◽  
...  
Keyword(s):  
Anion Exchange ◽  
Extraction Chromatography ◽  
Separation And Purification
Sign in / Sign up

Export Citation Format

Share Document