Removal of Nickel from Aqueous Solutions by Natural Bentonites from Slovakia.

In this study, the removal of nickel (Ni(II)) by adsorption from synthetically prepared solutions using natural bentonites (Lieskovec (L), Hliník nad Hronom (S), Jelšový Potok (JP), and Stará Kremnička (SK)) was investigated. All experiments were carried out under batch processing conditions, with the concentration of Ni(II), temperature, and time as the variables. The adsorption process was fast, approaching equilibrium within 30 min.

Determination of water content in raw perlites: Combination of NIR spectroscopy and thermoanalytical methods.

A new approach to determination of water content in raw perlites, an industrially important material, and obsidian was proposed, utilizing diffuse reflectance spectroscopy in the near-IR region. The phase composition of the perlite of the perlite samples was over 94% rhyolitic volcanic glass, with only small admixture of other components. The observed volatile species contents detected from both thermogravimetric analysis (TG) and the loss of ignition method (LOI) varied from 3 to 7%.