TITLE:
Comparison of Nine Membrane Pairs for Electrodialytic Removal of Nitrate Ions
AUTHORS:
López-García Ulises, Antaño-López René, Orozco German, Torres-González Julieta, Castañeda Federico
KEYWORDS:
Electrodialysis, Ion Exchange Membranes, Nitrate Removal, Nitric Acid, Sodium Hy-droxide
JOURNAL NAME:
Journal of Water Resource and Protection,
Vol.3 No.6,
June
30,
2011
ABSTRACT: Electrodialysis (ED) of NaNO3 solutions was performed to stress the role of the membrane pair as a unit i.e. the behavior as a whole of Anion Exchange Membrane (AEM) and Cation Exchange Membrane (CEM), in the process at room temperature. The membrane pair was also tested in the reclamation of nitric acid and sodium hydroxide. It was found that the membrane pair ranking in Limiting Current Density does not agree with that of ions leakage and both rankings are not the same as for Current Efficiency or Specific Power Consumption, each parameter for a specific membrane pair depends on the associated membrane and at a lesser degree on the flow rate. Results show that one cannot select a membrane or a membrane pair only by its limiting current density i.e. it is necessary to evaluate several parameters of the process by characterizing the whole membrane pair and to decide the parameter of interest, i.e. denitrification speed, ions leakage, proton back migration, current efficiency or specific power consumption.