Development of a Layer Made of Natural Fibers to Improve the Ecological Performance of the Face Mask Type II.

The aim of this study was to develop a natural nonwoven layer made of cottonized bleached flax and cotton fibers which is suitable to replace one of the three polypropylene layers of face mask type II in order to reduce non-biodegradable waste production and limit the negative impact of used masks on the environment. The work focused on the design of a nonwoven structure based on properly blending cotton and flax fibers as well as ensuring the cover factor, which can support the mask's barrier properties against air dust particles and does not make breathing difficult. Additionally, a biodegradable film was developed to connect the nonwoven layer with the other polypropylene filtering layers. The effectiveness of the biodeterioration of the flax/cotton nonwoven was evaluated based on a test of the susceptibility of materials to the action of soil microorganisms. The flax/cotton nonwoven layer was tested in terms of mechanical, physical, and biophysical properties, and an analysis of the covering of the nonwoven surface with fibers was conducted as well. The results confirmed that the structure of flax/cotton nonwovens is suitable to replace the nondegradable polypropylene layer of the face mask type II to improve its environmental performance.

Polish Varieties of Industrial Hemp and Their Utilisation in the Efficient Production of Lignocellulosic Ethanol.

Nowadays, more and more attention is paid to the development and the intensification of the use of renewable energy sources. Hemp might be an alternative plant for bioenergy production. In this paper, four varieties of Polish industrial hemp (Bialobrzeskie, Tygra, Henola, and Rajan) were investigated in order to determine which of them are the most advantageous raw materials for the effective production of bioethanol. At the beginning, physical and chemical pretreatment of hemp biomass was carried out. It was found that the most effective is the alkaline treatment with 2% NaOH, and the biomasses of the two varieties were selected for next stages of research: Tygra and Rajan. Hemp biomass before and after pretreatment was analyzed by FTIR and SEM, which confirmed the effectiveness of the pretreatment. Next, an enzymatic hydrolysis process was carried out on the previously selected parameters using the response surface methodology. Subsequently, the two approaches were analyzed: separated hydrolysis and fermentation (SHF) and a simultaneous saccharification and fermentation (SSF) process. For Tygra biomass in the SHF process, the ethanol concentration was 10.5 g∙L-1 (3.04 m3·ha-1), and for Rajan biomass at the SSF process, the ethanol concentration was 7.5 g∙L-1 (2.23 m3·ha-1). In conclusion, the biomass of Polish varieties of hemp, i.e., Tygra and Rajan, was found to be an interesting and promising raw material for bioethanol production.

Effective Utilisation of Halophyte Biomass from Saline Soils for Biorefinering Processes.

The salinity of European soil is increasing every year, causing severe economic damage (estimated 1-3 million hectares in the enlarged EU). This study uses the biomass of halophytes-tall fescue (grass) and hemp of the Bialobrzeskie variety from saline soils-for bioenergy, second generation biofuels and designing new materials-fillers for polymer composites. In the bioethanol obtaining process, in the first stage, the grass and hemp biomass were pretreated with 1.5% NaOH. Before and after the treatment, the chemical composition was determined and the FTIR spectra and SEM pictures were taken. Then, the process of simultaneous saccharification and fermentation (SSF) was carried out. The concentration of ethanol for both the grass and hemp biomass was approx. 7 g·L-1 (14 g·100 g-1 of raw material). In addition, trials of obtaining green composites with halophyte biomass using polymers (PP) and biopolymers (PLA) as a matrix were performed. The mechanical properties of the composites (tensile and flexural tests) were determined. It was found that the addition of a compatibilizer improved the adhesion at the interface of PP composites with a hemp filler. In conclusion, the grass and hemp biomass were found to be an interesting and promising source to be used for bioethanol and biocomposites production. The use of annually renewable plant biomass from saline soils for biorefinering processes opens up opportunities for the development of a new value chains and new approaches to sustainable agriculture.