# The Experimental Study of Innovative Methods Regarding the Removal of Sm(III)
## 2 Materials and methods
### Solvent Sublation  
Solvent sublimation is a method of surface separation combining the flotation of ions or molecules and a method of liquid extraction. The organic phase (in-out case that is isocotyl alcohol) was above the aqueous phase [17]. The process was implemented with small gas consumption. The method was used for wastewater treatment from organic impurities and for quantitative determination of trace metals and surfactants [23; 24; 25].  
The feature of solvent sublimation regarding the possibility of the concentration of multiple metal ions in a small volume of organic solvent shows the potential of this method for wastewater treatment containing metal ions for their subsequent recovery. It should be noted that currently available data regarding the organic phase nature, which are very limited [26; 27], indicate that the organic phase (\"trap\") should have some polarity and should comply with basic requirements for an organic phase in solvent sublimation including: being less dense than water; minimum water solubility; and maximum capacity of sulphate accumulation. Nowadays, many authors of conducted studies showed that during solvent sublimation, the substance distribution is determined by its ability to adsorb on bubble walls, passing through the solution, and it does not depend on the phase volume relationship. Thereby, the sulphate adsorption process is the determining factor of the process.  
Figure 2: A diagram of the B-\(\Phi\)/I137 flotation machine.  
Compared to the foam separation method, the process of solvent sublimation is poorly studied. Originally, solvent sublimation was proposed for ion removal by the surfactant and afterwards the process was realized for dissolved substance removal based on their surface activity and sediment flotation [19; 28; 29].  
Additionally, there is a carrier agent for the colligand in solvent sublimation surfactants. An important property of this method is its high selectivity. In the flotation method, most dissolved impurities go into the froth, while in solvent sublimation, one can achieve such a separation, at which the substance partially goes into the organic phase and partially returns. It should be noted that with foam separation, water is also removed from the solution together with the isolated substance. First, this reduces the concentration ratio of the substance. Second, in the foam separation method, water removal results in rapid floating solution consumption and in the end, prevents from making a total curve during the experiment with one initial solution. In solvent sublimation, this is not the case, as water always returns to the aqueous phase. Despite all advantages, the solvent sublimation method has disadvantages: (1) it is not always possible to select a solvent that could dissolve the formed sublate and (2) both the formation of aqueous emulsion in the organic phase is possible and the contamination of this organic phase by undesirable ingredients from the aqueous solution is possible [1].  
In the solvent sublimation process, a glass column was used [1]. In total, 100 mL of Sm(NO3)3 (chemically pure grade samarium nitrate hexahydrate) and 5 mL of 2-octanol were added into the column. Nitrogen was fed through the glass filter at the base of the column. The process time was 2 h.