ChemInform Abstract: HEATS OF MIXING AQUEOUS ELECTROLYTES PART 11, THE CHARGE-ASYMMETRIC LIMITING LAW AT LOW CONCENTRATIONS, BARIUM CHLORIDE WITH SODIUM CHLORIDE AND SODIUM SULFATE WITH SODIUM CHLORIDE

1974 ◽  
Vol 5 (46) ◽  
pp. no-no
Author(s):  
R. B. CASSEL ◽  
R. H. WOOD
Keyword(s):  
Sodium Chloride ◽  
Sodium Sulfate ◽  
Barium Chloride ◽  
Aqueous Electrolytes ◽  
Heats Of Mixing ◽  
Low Concentrations

Ion exchange process in the presence of high sulphate concentration: resin regeneration and spent brine reuse

2006 ◽  
Vol 6 (3) ◽  
pp. 35-41 ◽  
Author(s):  
R. Baciocchi ◽  
A. Chiavola
Keyword(s):  
Sodium Chloride ◽  
Ion Exchange ◽  
Exchange Process ◽  
Chloride Concentration ◽  
Barium Chloride ◽  
Ion Exchange Resin ◽  
Mass Action ◽  
Sulphate Concentration ◽  
Ion Exchange Process ◽  
Resin Regeneration

This paper provides new insights on the regeneration step of an ion exchange process for the treatment of surface and ground water characterized by high sulphate concentration. Repeated regeneration of ion exchange resin with a sodium chloride solution (brine) did not alter the resin performances with respect to the fresh one. Besides, neither the sodium chloride concentration of the brine, which was varied between 1 and 3 M, nor the presence of sulphates at concentrations up to 20 g/L in the brine, did notably affect the regeneration efficiency. The brine was effectively treated by adding calcium or barium chloride, in order to remove the sulphates and re-establish the original chloride concentration. Calcium chloride was allowed to obtain up to 70% sulphate precipitation, whereas an almost 100% precipitation efficiency was obtained when barium chloride was used. The precipitation step was described by a model based on the mass action, coupled to the Bromley model for the description of the non-ideal behaviour of the electrolytic solution. This model was shown to give correct, or at least conservative, estimates of the equilibrium sulphate concentration when either calcium or barium chloride was used as precipitating agent.

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