Mercury Removal from Aqueous Solution Using ETS-4 in the Presence of Cations of Distinct Sizes

Simão P. Cardoso; Tiago L. Faria; Eduarda Pereira; Inês Portugal; Cláudia B. Lopes; Carlos M. Silva

doi:10.3390/ma14010011

Mercury Removal from Aqueous Solution Using ETS-4 in the Presence of Cations of Distinct Sizes

Materials ◽

10.3390/ma14010011 ◽

2020 ◽

Vol 14 (1) ◽

pp. 11

Author(s):

Simão P. Cardoso ◽

Tiago L. Faria ◽

Eduarda Pereira ◽

Inês Portugal ◽

Cláudia B. Lopes ◽

...

Keyword(s):

Kinetic Data ◽

Fluid Phase ◽

Mass Action ◽

Mercury Removal ◽

Batch Experiments ◽

Average Deviation ◽

Counter Ions ◽

Competition Effects ◽

Mass Action Law ◽

Sodium Form

The removal of the hazardous Hg2+ from aqueous solutions was studied by ion exchange using titanosilicate in sodium form (Na-ETS-4). Isothermal batch experiments at fixed pH were performed to measure equilibrium and kinetic data, considering two very distinct situations to assess the influence of competition effects: (i) the counter ions initially in solution are Na+ and Hg2+ (both are exchangeable); (ii) the initial counter ions in solution are tetrapropylammonium (TPA+) and Hg2+ (only Hg2+ is exchangeable, since TPA+ is larger than the ETS-4 micropores). The results confirmed that ETS-4 is highly selective for Hg2+, with more than 90% of the mercury being exchanged from the fluid phase. The final equilibrium attained under the presence of TPA+ or Na+ in solution was very similar, however, the Hg2+/Na+/ETS-4 system in the presence of Na+ required more 100 h to reach equilibrium than in the presence of TPA+. The Hg2+/Na+/ETS-4 system was modelled and analyzed in terms of equilibrium (mass action law) and mass transfer (Maxwell–Stefan (MS) formalism). Concerning equilibrium, no major deviations from ideality were found in the range of studied concentrations. On the other hand, the MS based model described successfully (average deviation of 5.81%) all kinetic curves of mercury removal.

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Studies on Activator Formation in Human Plasma with Streptokinase

Thrombosis and Haemostasis ◽

10.1055/s-0038-1649088 ◽

1973 ◽

Vol 30 (02) ◽

pp. 381-392

Author(s):

M Martin ◽

Keyword(s):

Human Plasma ◽

Plasminogen Activator ◽

Mass Action ◽

Activator Concentration ◽

Kinetic Effect ◽

Mass Action Law

SummaryThe plasminogen-streptokinase complex called “activator” was present in diluted plasma in the form of a largely dissociated mixture. More than ⅞ of the streptokinase and plasminogen molecules were available for further activator formation.The activator is probably a dissociated complex of the formulaStreptokinase + Plasminogen ⇄ Activator.The fact that an increase in activator concentration by x times is obtained by multiplying either the streptokinase content by the factor y or the plasminogen concentration by the same factor y would point to a kinetic effect along the lines of the mass action law.

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