[en] In this work, the efficiency of adsorption of the Zn (II) cation was studied through the use of two adsorbent materials: the brown algae Laminaria ochrolecua and the brown algae Bifurcaria bifurcata. To carry out this Project, different variables that affect the adsorption process are examined. On the one hand, the influence of pH is studied, with the aim of knowing the appropriate interval to develop the adsorption process, obtaining a pH around 5 for two algae. On the other hand, kinetic studies are carried out where it is observed that the adsorption process for the two algae occurs at relatively short times, 25 minutes for the algae Laminaria ochrolecua and 50 minutes for the algae Bifurcaria bifurcata. Finally, the effect of adsorbent concentration was examined by two different isotherms studies for each algae, analysed according to the Langmuir model. The first study is carried out in the usual way of analysing an isotherm in the laboratory, varying the concentration of Zn (II) cation solution, and the second study is performed with a fixed concentration solution varying the mass of the adsorbent. Data obtained are much more conclusive for the first study, since in the second, variations in the data are detected at high amounts of mass. However, to small masses of algae, both methods present a good removal of the adsorbate from the medium, so, the algae used are considered good bioadsorbents. The Zn determination has been carried out by a colorimetric method using UV-Vis absorption spectroscopy, it was necessary to use a colorimetric agent (Zincon).

[gl] Neste traballo estudouse a eficacia da adsroción do catión Zn (II) mediante o uso de dous materiales adsorbentes: o alga parda Laminaria ochrolecua e o alga parda Bifurcaria bifurcata. Para levar a cabo este proxecto examínanse diferentes variables que afectan ao proceso de adsorción. Por un lado, estudase a influencia do pH, co obxectivo de coñecer o intervalo de pH adecuado para desenvolver o proceso de adsorción, obtendo un pH ao redor de 5 para as dúas algas. Por outro lado, realízanse estudos cinéticos onde se observa que o proceso de adsorción para as dúas algas ocorre a tempos relativamente curtos, de 25 minutos para o alga Laminaria ochrolecua e de 50 minutos para o alga Bifurcaria bifurcata. Finalmente, examinouse o efecto da concentración do adsorbente mediante dous estudos diferentes de isotermas para cada alga, analizadas segundo o modelo de Langmuir. O primeiro estudo lévase a cabo da maneira habitual de analizar unha isoterma no laboratorio, variando a concentración de Zn (II) das disolucións, e o segundo estudo realízase cunha disolución de concentración fixa e variando a masa do adsorbente. Os datos obtidos son moito más concluínte para o primeiro estudo, xa que no segundo detéctanse variacións nos datos a cantidades elevadas de masa. Non obstante, a masas pequenas de alga ambos métodos presentan unha boa eliminación do adsorbato do medio, polo que, as algas utilizadas considéranse bos bioadsorbentes. A determinación do Zn levouse a cabo mediante un método colorimétrico usando espectroscopia de absorción UV-Vis, foi preciso emplear un axente colorimétrico (Zincón).