The aim of the research was to investigate the effect of biogas plant waste on the physiological activity, growth, and yield of Jerusalem artichoke and the energetic usefulness of the biomass obtained in this way after the torrefaction process. The use of waste from corn grain biodigestion to methane as a biofertilizer, used alone or supplemented with Apol-humus and Stymjod, caused increased the physiological activity, growth, and yield of Jerusalem artichoke plants and can limit the application of chemical fertilizers, whose production and use in agriculture is harmful for the environment. The experiment, using different equipment, exhibited the high potential of Jerusalem artichoke fertilized by the methods elaborated as a carbonized solid biofuel after the torrefaction process. The use of a special design of the batch reactor using nitrogen, Thermogravimetric analysis, Differential thermal analysis, and Fourier-transform infrared spectroscopy and combustion of Jerusalem artichoke using TG-MS showed a thermo-chemical conversion mass loss on a level of 30% with energy loss (torgas) on a level of 10%. Compared to research results on other energy crops and straw biomass, the isothermal temperature of 245 °C during torrefaction for the carbonized solid biofuel of Jerusalem artichoke biomass fertilized with biogas plant waste is relativlely low. An SEM-EDS analysis of ash from carbonized Jerusalem artichoke after torrefaction was performed after its combustion.

The effect of foliar application of Cyanobacteria and Chlorella sp. monocultures on physiological activity, element composition, development and biomass weight of basket willow (Salix viminalis L.) and the possibility to prepare biofuel from it in the fortification process was studied. Triple foliar plant spraying with non-sonicated monocultures of Cyanobacteria (Anabaena sp. PCC 7120, Microcystis aeruginosa MKR 0105) and Chlorella sp. exhibited a considerably progressive impact on metabolic activity and development of plants. This biofertilization increased cytomembrane impermeability, the amount of chlorophyll in plants, photosynthesis productivity and transpiration, as well as degree of stomatal opening associated with a decreased concentration of intercellular CO₂, in comparison to control (treatments with water, Bio-Algeen S90 or with environmental sample). The applied strains markedly increased the element content (N, P, K) in shoots and the productivity of crucial growth enzymes: alkaline or acid phosphorylase, total dehydrogenases, RNase and nitrate reductase. Treatments did not affect energy properties of the burnt plants. These physiological events were associated with the improved growth of willow plants, namely height, length and amount of all shoots and their freshly harvested dry mass, which were increased by over 25% compared to the controls. The effectiveness of these treatments depended on applied monoculture. The plant spraying with Microcystis aeruginosa MKR 0105 was a little more effective than treatment with Chlorella sp. and Anabaena sp. or the environmental sample. The research demonstrate that the studied Cyanobacteria and Chlorella sp. monocultures have prospective and useful potential in production of Salix viminalis L., which is the basic energy plant around the word. In this work, a special batch reactor was used to produce torrefaction material in an inert atmosphere: nitrogen, thermogravimetric analysis and DTA analysis, like Fourier-transform infrared spectroscopy. The combustion process of Salix viminalis L. with TG-MS analysis was conducted as well as study on a willow torrefaction process, obtaining 30% mass reduction with energy loss close to 10%. Comparing our research results to other types of biomasses, the isothermal temperature of 245 °C during thermo-chemical conversion of willow for the carbonized solid biofuel production from Salix viminalis L. biomass fertilized with Cyanobacteria and Chlorella sp. is relatively low. At the end, a SEM-EDS analysis of ash from torrefied Salix viminalis L. after carbonization process was conducted.

An innovative approach to the management of waste in the form of ash obtained during biomass combustion is justified due to its specific properties, including the presence of macro- and microelements. The aim of the current study was to determine the concentration of ash obtained from Sorghum combustion regarding its fertilizer value and its effect on the cytological structures, physiological parameters, growth and development of Lemnaceae plants, thereby demonstrating the possibility of using this waste to supplement culture media. The analyses showed that the use of ash in the in vitro cultivation of Lemnaceae aquatic plants had a dose-dependent effect. The addition of 2% ash favorably affected the condition of plant roots, i.e., meristem elongation and an increase in nucleoli sizes as well as improving the chlorophyll content index, gas exchange parameters, chemical oxygen demand (COD) and plant vigor via PSII, which was confirmed by a chlorophyll fluorescence measurement. On the other hand, too high of a concentration, i.e., 10% ash, adversely affected the plant development and parameters studied. Concluding, the use of ash at a low concentration favorably affected the yielding of Spirodela polyrrhiza, whose biomass can be used for energy purposes in the production of bioethanol, plant biogas or the phytoremediation of industrial waters and leachate.