Application of the pH-stat technique in Donnan dialysis: effect of anion invasion in the CoSO/sub 4//Nafion 117/H/sub 2/SO/sub 4/ system
Cobalt transport during Donnan dialysis in the CoSO/sub 4//Nafion 117/H/sub 2/SO/sub 4/ system was measured with a pH-stat technique. (i.e., the pH in the feed compartment was maintained constant). During the transfer process, Co/sup 2 +/ ions moved from the cobalt reservoir to the sink compartment, while hydrogen ions moved in the opposite direction. A standardized NaOH solution was used to neutralize the H/sup +/ ions entering the reservoir compartment, and in the absence of anion invasion, the cobalt flux was determined as J/sub Co/sup 2+// = 1/2 J/sub H/sup +//. The experimental results indicate that for Donnan dialysis experiments involving the high acid concentrations, the invasion of the membrane by the anions associated with the acid can be significant. Since anion transfer is accompanied by the cotransport of protons, it follows therefore that the anion invasion characteristics must be known before the pH-stat technique can be employed successfully. The transport of bisulfate ion (HSO/sub 4//sup -/) through Nafion 117 was measured with the pH-state technique. An invasion-corrected cobalt flux was obtained by substracting the hydrogen flux due to anion invasion from the cobalt flux determined with the above equation. The invasion-corrected flux was in substantial agreement with the flux obtained via cobalt analysis with atomic absorption spectrophotometry.
- Research Organization:
- Pennsylvania State Univ., University Park (USA)
- OSTI ID:
- 6189918
- Report Number(s):
- CONF-871038-
- Journal Information:
- Sep. Sci. Technol.; (United States), Vol. 23:12,13; Conference: 5. symposium on separation science and technology for energy applications, Knoxville, TN, USA, 26 Oct 1987
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
COBALT
MEMBRANE TRANSPORT
MEMBRANES
EFFICIENCY
ANIONS
DIALYSIS
EXPERIMENTAL DATA
PH VALUE
PREDICTION EQUATIONS
SULFURIC ACID
CHARGED PARTICLES
DATA
ELEMENTS
EQUATIONS
HYDROGEN COMPOUNDS
INFORMATION
INORGANIC ACIDS
IONS
METALS
NUMERICAL DATA
SEPARATION PROCESSES
TRANSITION ELEMENTS
400105* - Separation Procedures