## 3 Results  
With regard to plant biomass, Lavandula angustifolia and Miscanthus sinensis were tested for absorptivity depending on the granulometric composition. The achieved values of absorptivity are shown in Figures 5 and 6. Figure 4: Apparatus for the free-fall drop test: (**a**) Scheme; (**b**) Photo; 1—Burette containing the liquid, 2—Analysed material, 3—Cock, 4—Balloon. Figure 5: Wetting of biomass consisting of Lavandula angustifolia at granulometric compositions: (a) Under 0.5 mm; (b) 0.5-1 mm; (c) 1-2 mm. Figure 6: Wetting of biomass consisting of Miscanthus sinensis at granulometric compositions: (a) Under 0.5 mm; (b) 0.5-1 mm; (c) 1-2 mm. The highest absorptivity of Lavandula angustifolia was observed at a fraction of 0.5-1 mm (24 mm) with the use of tensile. The lowest absorptivity was exhibited at a fraction of 1-2 mm, with the highest value amounting to only 9 mm when tensile was used. With other wetting media, absorptivity values were low and they exhibited very similar curves. The other three liquids had very similar courses of effects on wetting Lavandula angustifolia, at all three fractions. The lowest wettability, at fractions below 0.5 mm and of 0.5-1 mm, was observed when cold water was used; this indicated a correlation between the effect of the liquid on the surface tension, the value of which decreased as the temperature increased [10]. The aforementioned facts indicate that at all fractions the best results were achieved when industrial tensile was used; however, it must be noted that the ability of lavender to absorb liquids is very low. Wettability of Miscanthus sinensis grass may be regarded as very good. In this case, the best results were achieved at a fraction below 0.5 mm. A comparison of the results showed that, at various granulometric compositions, the absorptivity values were different and this was also confirmed by the relevant graph curves. The research indicates that different media have different effects on absorptivity. The best absorptivity was observed with both analysed types of plant biomass, at the granulometric composition in the category of below 0.5 mm and from 0.5 to 1 mm. From the granulometry point of view, the lowest absorptivity was observed in both cases with the grain size category of 1-2 mm. In this case, however, the influence of the used type of liquid was evident--there was a 3-fold difference between soapy water and tensile. With lavender, the highest value of capillary water absorption (24 mm) was achieved when tensile was used. Nevertheless, in general the absorptivity of lavender biomass was not as \"dynamic\" as that of Miscanthus sinensis. Wetting was very slow and gradual, in some cases millimetre by millimetre, regardless of the used medium. In the initial stage, the wetting process was fast, but gradually it became slower and slower, and eventually the process stopped completely. In the case of granulometry below 0.5 mm and with the use of cold water, the wetting speed was very low from the beginning. In this grain size category, the highest absorptivity values were observed at the level of 14 to 15 mm, and the effects of soapy water and tensile were almost identical. In general, it may be concluded that out of all grain size categories, the category of 1-2 mm exhibited the lowest absorptivity values. The same effect was also demonstrated in the wetting of Miscanthus--at the granulometry of 1-2 mm, the highest absorptivity value was 15 mm with the use of industrial tensile. The effect of industrial tensile was very strong as the highest achieved absorptivity value was 34 mm (at a granulometric fraction below 0.5 mm). There was an interesting finding that the use of tensile resulted in a fast onset of wetting of Miscanthus sinensis. This tendency continued during the entire test, whereas with lavender the onset was fast, but then the process slowed down significantly. This phenomenon was observed in all grain size categories.