Research Articles

The aim of this study was to demonstrate the utilization of invasive plant materials a resource for energy production, applying pelletization and pellet pyrolysis, thus integrating plant eradication efforts with renewable energy solutions and valorization of plant biomass. The approach was demonstrated for three invasive plants – Japanese knotweed [Reynoutria japonica (Houtt.)], Jerusalem artichoke [Helianthus tuberosus (L.)], and Canadian goldenrod [Solidago canadensis (L.)] which are abundant in Northern Europe and elsewhere. As binder materials for pellet formation, sapropel and peat extraction residues were selected for their sustainability potential, as both represent organic waste materials that, similarly to invasive plant biomass, face a high likelihood of being disposed of without added value if not valorized. The calorific value of biomass plant pellets is comparable to values common for wood pellets and other plant materials, thus supporting their use for energy production. Pyrolysis provides possibilities to obtain biochar with increased specific surface area and higher caloric content, as well as application potential in agriculture. The studied invasive plant pellets do not contain elevated concentrations of heavy metals or other pollutants, thus supporting their application for the production of bioenergy or as a soil amendment.

Using an electron beam (EB) accelerator, natural cotton fibers were pre-irradiated for grafting with glycidyl methacrylate (GMA). Subsequently, phosphoric acid (phosphoric) was used to functionalize the GMA-grafted fibers (cotton-g-GMA). Various analyses, including scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), thermogravimetric and derivative thermogravimetric (TG-DTG) analysis, and surface charge analysis, were performed to evaluate the morphological and physiochemical attributes of the fibrous adsorbent. The prepared adsorbent was then tested for metformin hydrochloride (MFH) adsorption from an aqueous solution. The MFH’s adsorption on phosphoric-cotton-g-GMA followed a pseudo-2^nd order model. The Langmuir isotherm model was close behind the Redlich-Peterson model, which described the equilibrium data the best, according to the isotherm analysis. At 24.7 mg/g, the maximum adsorption capacity was attained. Meanwhile, the regeneration and recycling of the adsorbent were possible for at least five cycles, with recovery of MFH being nearly 94.65% in the final cycle. According to the findings, it was deduced that the fibrous phosphoric-cotton-g-GMA adsorbent could be used to successfully eliminate MFH at an industrial scale.

Recyclability is an important feature of packaging materials. Although packaging materials made from cellulose fibers such as those found in paper or paperboard can typically be recycled through repulping, the application of coatings, especially polymeric plastic coatings, often impairs their recyclability, leading to increased amounts of rejects and low fiber yields. Herein, the surface properties and repulpability performance of paperboard substrates coated with aqueous dispersion of wood bark-derived suberin, stabilized using synthetic surfactants or bio-based surfactants, were investigated. The results were compared with commercial polyethylene coated material. Surface properties of the materials were investigated through surface imaging, water absorption, and wettability measurements. Repulpability was evaluated based on the amounts of rejects after two screening stages. Fiber analysis was performed for the materials that passed both the screenings. All suberin-coated materials showed hydrophilic surface characteristics and greater water absorbency than the reference material. Repulpability analysis revealed that the suberin coatings resulted in a lower amount of rejects than coated reference material. These results highlight the potential of suberin coatings in developing recyclable and sustainable packaging solutions for cellulose fiber substrates.