Determination of smectite clay sorption capacity | Smektītu mālu sorbcijas kapacitātes noteikšana
2009
Sarcevica, I., University of Latvia, Riga (Latvia) | Actins, A., University of Latvia, Riga (Latvia)
On the course of comparative analysis of data processing methods for methylene blue sorption results a lower deviation was shown to be reached when methylene blue equilibrium concentration was analyzed as a function of amount of methylene blue added; meanwhile, a higher deviation appears when analyzing sorption dependence on the equilibrium concentration. Langmuir isotherms are characterized by the greatest deviations. The data obtained may be explained by the increase in number of approximate values obtained in the course of the indirect measurements. The equilibrium constant of sorption as a parameter to be optimized has an insignificant influence both on the values of sorption capacity and deviations. As a result, the equilibrium constant values gained during optimization have a greater dispersion. In order to ensure more precise equilibrium constant values, the number of measurements should be increased. This statement refers to the inward bend area of graph displaying methylene blue equilibrium concentration versus the amount of methylene blue added. Methodology for the determination of methylene blue sorption parameters applying X-ray spectrometry has been developed. The offered methodology is based on determination of sulphur and chlorine content in clay samples before and after sorption. The data obtained by the X-ray spectrometry are correlated closely with the data obtained by photometric measurements. Clay chemical treatment methods focused on clay enrichment, i.e. increase of smectite proportion, modify surface of smectite layers in the space between layers. Furthermore, the geometric location of methylene blue molecules is changed.
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