The Promotive Effect of <i>Cyanobacteria</i> and <i>Chlorella</i> sp. Foliar Biofertilization on Growth and Metabolic Activities of Willow (<i>Salix</i> <i>viminalis</i> L.) Plants as Feedstock Production, Solid Biofuel and Biochar as C Carrier for Fertilizers via Torrefaction Process

• Main Authors: Zdzislawa Romanowska-Duda, Szymon Szufa, Mieczysław Grzesik, Krzysztof Piotrowski, Regina Janas
• Format: Article
• Language: English
• Published: MDPI AG 2021-08-01
• Series: Energies
• Subjects: <i>Salix</i> <i>viminalis</i> L.; <i>Cyanobacteria</i>; <i>Chlorella</i> sp.; physiological activity; growth; torrefaction
• Online Access: https://www.mdpi.com/1996-1073/14/17/5262

The effect of foliar application of <i>Cyanobacteria</i> and <i>Chlorella</i> sp. monocultures on physiological activity, element composition, development and biomass weight of basket willow (<i>Salix viminalis</i> L.) and the possibility to prepare biofuel from it in the fortification process was studied. Triple foliar plant spraying with non-sonicated monocultures of <i>Cyanobacteria</i> (<i>Anabaena</i> sp. PCC 7120, <i>Microcystis aeruginosa</i> MKR 0105) and <i>Chlorella</i> 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 <i>Microcystis aeruginosa</i> MKR 0105 was a little more effective than treatment with <i>Chlorella</i> sp. and <i>Anabaena</i> sp. or the environmental sample. The research demonstrate that the studied <i>Cyanobacteria</i> and <i>Chlorella</i> sp. monocultures have prospective and useful potential in production of <i>Salix viminalis</i> 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 <i>Salix viminalis</i> 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 <i>Salix viminalis</i> L. biomass fertilized with <i>Cyanobacteria</i> and <i>Chlorella</i> sp. is relatively low. At the end, a SEM-EDS analysis of ash from torrefied <i>Salix viminalis</i> L. after carbonization process was conducted.