The sorption of contaminant ions existing in residual aqueous solutions onto nano-structured calcium silicate has been studied. The sorbent was prepared by chemical reaction between a soluble solution of sodium silicate and calcium hydroxide. X-ray diffraction analysis showed the amorphous character of the obtained calcium silicate, although patterns associated to wollastonite, CaSiO 3 , and larnyta-syn, Ca 2 SiO 4 were detected. The particle mean size was approximate 0.5 to 1.0 µm having an average BET surface area of 333.0 m 2 /g and a mean pore diameter variable between 15.8-23.6 nm. The nano-structured calcium silicates were contacted with industrial residual aqueous solutions containing, among others, Cu(II), Zn(II), Cd(II) and the anions PO 4 3-, SO 4 = and CrO 4 = , being copper (II) and phosphate the ions that were most easily and quantitatively adsorbed. The results of equilibrium experiments showed that the Redlich-Peterson adsorption isotherm model explained the experimental results for some metal ions.The experimental kinetics followed a pseudo-second-order kinetics model for Cu(II) and Zn(II) sorption.

Zn(II) sorption from aqueous solutions was studied on polymeric hydrophobic microcapsules (MCs) containing 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester as the extractant (PC-88A). The microcapsules were synthesised by adding this extractant during in situ radical polymerisation using styrene and ethylene glycol dimethacrylate (EGDMA) as starting monomers and benzoyl peroxide as the polymerisation initiator. SEM analysis of the microcapsules indicated that they had a spherical shape and a rough surface. A set of experiments was designed to study Zn(II) sorption behaviour onto MCs using aqueous solutions containing 100 mg/L of Zn(II) with an initial pH of 4.0. A Langmuir isotherm model fitted the experimentally observed equilibrium sorption data well. Results of kinetics experiments conducted between 293 and 323 K were well explained by a pseudo-second order kinetic model with an activation energy of 43.27 kJ mol -1 .Calculated thermodynamic parameters revealed that the chemisorption process was spontaneous and exothermic. The observed negative entropy change indicated that the metal bound to the extractant on the surface of MCs would generate a moderately ordered structure.

La parálisis periódica hipopotasémica tirotóxica (PPHT) es una manifestación poco frecuente del hipertiroidismo caracterizada por dolor y debilidad muscular asociada a hipopotasemia, pudiendo conducir a la muerte del paciente. Presentamos el caso de una mujer de 38 años que consulta por debilidad generalizada, astenia y mialgias de 24 horas que en el examen físico muestra paraparesia severa y taquicardia. El laboratorio muestra hipopotasemia severa, TSH disminuida y T4 libre elevada. En el electrocardiograma se observa taquicardia sinusal y T aplanadas. Se realiza diagnóstico de PPHT. Se realiza reposición de potasio y tratamiento con metimazol y propranolol con evolución favorable clínica y analítica.