Some types of biomass require great inputs to guarantee high conversion rates to methane. The complex structure of lignocellulose impedes its penetration by cellulolytic enzymes, as a result of which a longer retention time is necessary to increase the availability of nutrients. To use the full biogas potential of lignocellulosic substrates, a substrate pretreatment is necessary before the proper methane fermentation. This article discusses the impact of the pretreatment of maize silage with a pulsed electric field on biogas productivity. The experiment showed a slight decrease in cellulose, hemicellulose and lignin content in the substrate following pretreatment with a pulsed electric field, which resulted in a higher carbohydrate content in the liquid substrate fraction. The highest biogas production output was obtained for the pretreated sample at the retention time of 180 s for 751.97 mL/g volatile solids (VS), which was approximately 14% higher than for the control sample. The methane production rate for the control sample was 401.83 mL CH₄/g VS, and for the sample following disintegration it was 465.62 mL CH₄/g VS. The study found that pretreatment of maize silage with a pulsed electric field increased the biogas potential.

Due to the high availability of lignocellulosic biomass, which can be obtained from terrestrial plants, agricultural waste biomass, and the agro-food, paper or wood industries, its use for energy production by methane fermentation is economically and environmentally justified. However, due to their complex structures, lignocellulosic substrates have a low conversion factor to biogas. Therefore, scientists are still working on the development of new methods of the pre-treatment of lignocellulosic materials that will increase the biogas productivity from lignocellulosic biomass. The presented research focuses on the use of a pulsed electric field (PEF) to disintegrate rapeseed straw prior to the methane fermentation process. Scanning electron microscopy observation showed that, in the disintegrated sample, the extent of damage to the plant tissue was more severe than in the control sample. In the sample disintegrated for 7 min, the chemical oxygen demand increased from 4146 ± 75 mg/L to 4920 ± 60 mg/L. The best result was achieved with a 5-min PEF pre-treatment. The methane production reached 290.8 ± 12.1 NmL CH₄/g VS, and the biogas production was 478.0 ± 27.5 NmL/g VS; it was 14% and 15% higher, respectively, compared to the control sample.

This study used chicken manure classified as lignocellulosic biomass due to its high straw content. This paper compares the possibility of using pulsed electric field (PEF) pretreatment of lignocellulosic substrates with ultrasonic disintegration (UP) to increase methane production. As for ultrasonic treatment, the BMP increased from 210.42 ± 7.92 mL/g VS to 250.06 ± 8.68 mL/g VS, whereas with PEF disintegration, the BMP ratio increased from 210.42 ± 7.92 mL/g VS to 248.90 ± 9.29 mL/g VS. The use of PEF and UP pretreatment increased methane production from 307.29 ± 13.65 mL/g VS to 366.99 ± 14.18 mL/g VS and from 307.29 ± 13.65 mL/g VS to 365.07 ± 11.71 mL/g VS, respectively. This study showed that both ultrasonic treatment and PEF contribute to the biochemical potential of methane (BMP) from chicken manure.

Wastewater rich in organic carbon, nitrogen and phosphorus may serve as a convenient source of carbon and nutrients for a year-long microalgae production. Scientific reports indicate that some single-cell microalgae such as Chlorella and Scenedesmus, are highly tolerant to wastewater environments and efficiently remove biogenic compounds. The aim of this study was to determine the possibility of using the effluent produced in the process of anaerobic degradation of whey as a culture medium for the multiplication of Chlorella vulgaris algae biomass and to characterise their growth efficiency and rate. The content of nitrogen and phosphorus in wastewater was sufficient for conducting an effective culture of algae. The efficiency of nitrogen removal in the flow system was 15.61 ± 1.38 mg N/dm³/day.

The global market shows high demand for products of natural origin to reduce the use of synthetic substances in the food, pharmaceutical and cosmetics industries. One of the opportunities for acquiring natural compounds of industrial value is the use of cyanobacteria biomass. In terms of biomass composition, cyanobacteria of the species Arthrospira platensis deserve particular attention. They are characterised by high contents of protein, γ-linolenic acid, polysaccharides, β-carotene, chlorophyll and phycocyanin. Phycocyanin is a pigment-protein complex widely used in the food and cosmetics industry. It is also used as fluorescent probes in histochemistry, fluorescence microscopy, flow cytometry and fluorescence immunoassay. Due to the extensive use of phycocyanin in various industries, a high demand for this pigment is generated, which determines the search for methods of intensifying phycocyanin production by the cells of A. platensis. The aim of the study was to determine the effect of light of different wavelengths on phycocyanin productivity by cyanobacteria of the species Arthrospira platensis. The highest biomass concentration and phycocyanin concentration were obtained in a culture using Red LED lighting.

Lignocellulosic biomass is included in the group of renewable energy sources. Its calorific value is high, owing to which it can be successfully used in the production of second-generation fuels, e.g., biogas. However, its complex structure makes it necessary to apply a pretreatment in order to increase the biogas output. This study presents the usability of a pulsed electric field in grass silage pretreatment in methane fermentation and compares it with microwave-induced disintegration. The experiment shows that substrate disintegration with a pulsed electric field (PEF) results in an increase in methane output. The productivity of methane from PEF pretreatment silage increased by 20.1% compared to the untreated control. The application of microwave disintegration, with the assumption that the same energy is used for the pretreatment, resulted in a methane output increase of 6% compared to the control. The highest biogas production output in PEF-pretreated samples was 535.57 NL/kg VS, while the highest biogas output from substrates pretreated with microwaves was 487.18 NL/kg VS.