Search Results (771)

The prospects for long-distance space flights are becoming increasingly realistic, and one of the key factors for their implementation is the creation of sustainable systems for producing food on site. Therefore, the aim of our work is to assess the prospects for using millet in biological life support systems and to create predictive models of yield components for automating plant cultivation control. The study found that stress from hypergravity (800 g, 1200 g, 2000 g, and 3000 g) in the early stages of millet germination does not affect seedlings or yield. In a closed system, millet yield reached 0.31 kg/m², the weight of 1000 seeds was 8.61 g, and the yield index was 0.06. The paper describes 40 quantitative traits, including six leaf and trichome traits and nine grain traits from the lower, middle and upper parts of the inflorescence. The compiled predictive regression equations allow predicting the accumulation of biomass in seedlings on the 10th and 20th days of cultivation, as well as the weight of 1000 seeds, the number of productive inflorescences, the total above-ground mass, and the number and weight of grains per plant. These equations open up opportunities for the development of computer vision and high-speed plant phenotyping programs that will allow automatic correction of the plant cultivation process and modeling of the required yield. Predicting biomass yield will also be useful in assessing the load on the waste-free processing system for plant waste at planetary stations. Full article

Waste activated sludge (WAS), a byproduct of livestock wastewater treatment, poses significant disposal challenges due to its low biodegradability and potential environmental impact. Anaerobic digestion (AD) offers a sustainable approach for methane recovery and sludge stabilization. This study evaluates the biomethane potential (BMP) of WAS and its co-digestion with swine slurry (SS), water lily (Nymphaea spp.), and lotus (Nelumbo nucifera) shoot biomass to enhance methane yield. Batch BMP assays were conducted at substrate-to-inoculum (S/I) ratios of 1.0 and 0.5, with methane production kinetics analyzed using the modified Gompertz model. Mono-digestion of WAS yielded 259.35–460.88 NmL CH₄/g VS_added, while co-digestion with SS, water lily, and lotus increased yields by 14.89%, 10.97%, and 16.89%, respectively, surpassing 500 NmL CH₄/g VS_added. All co-digestion combinations exhibited synergistic effects (α > 1), enhancing methane production beyond individual substrate contributions. Lower S/I ratios improved methane yields and biodegradability, highlighting the role of inoculum availability. Co-digestion reduced the lag phase limitations of WAS and plant biomass, improving process efficiency. These findings demonstrate that co-digesting WAS with nutrient-rich co-substrates optimizes biogas production, supporting sustainable sludge management and renewable energy recovery in livestock wastewater treatment systems. Full article

Using waste biomass as a raw material for the combined production of electricity and heat offers corresponding energy, economic, environmental and resource efficiency benefits. The study examines both the performance of a system for combined energy production based on the Organic Rankine Cycle (ORC) utilizing wood biomass and the market interest in its deployment within Bulgaria. Its objective is to propose a technically and economically viable solution for the recovery of waste biomass through the combined production of electricity and heat while simultaneously assessing the readiness of industrial and municipal sectors to adopt such systems. The cogeneration plant incorporates an ORC module enhanced with three additional economizers that capture residual heat from flue gases. Operating on 2 t/h of biomass, the system delivers 1156 kW of electric power and 3660 kW of thermal energy, recovering an additional 2664 kW of heat. The overall energy efficiency reaches 85%, with projected annual revenues exceeding EUR 600,000 and a reduction in carbon dioxide emissions of over 5800 t/yr. These indicators can be achieved through optimal installation and operation. When operating at a reduced load, however, the specific fuel consumption increases and the overall efficiency of the installation decreases. The marketing survey results indicate that 75% of respondents express interest in adopting such technologies, contingent upon the availability of financial incentives. The strongest demand is observed for systems with capacities up to 1000 kW. However, significant barriers remain, including high initial investment costs and uneven access to raw materials. The findings confirm that the developed system offers a technologically robust, environmentally efficient and market-relevant solution, aligned with the goals of energy independence, sustainability and the transition to a low-carbon economy. Full article

The plant-based oil industry contributes significantly to food waste/by-products in the form of underutilized biomass, including oil pomace, cake/meal, seeds, peels, wastewater, etc. These waste/by-products contain a significant quantity of nutritious and bioactive compounds (phenolics, lignans, flavonoids, dietary fiber, proteins, and essential minerals) with proven health-promoting effects. The utilization of them as natural, cost-effective, and food-grade functional ingredients in novel food formulations holds considerable potential. This review highlights the potential of waste/by-products generated during plant-based oil processing as a promising source of bioactive compounds and covers systematic research, including recent studies focusing on innovative extraction and processing techniques. It also sheds light on their promising potential for valorization as food ingredients, with a focus on specific examples of food fortification. Furthermore, the potential for value creation in the food industry is emphasized, taking into account associated challenges and limitations, as well as future perspectives. Overall, the current information suggests that the valorization of plant-based oil industry waste and by-products for use in the food industry could substantially reduce malnutrition and poverty, generate favorable health outcomes, mitigate environmental concerns, and enhance economic profit in a sustainable way by developing health-promoting, environmentally sustainable food systems. Full article

Background/Objectives: Hermetia illucens larvae can efficiently convert agri-food residues into high-protein biomass for animal feed and nutrient-rich frass for soil amendment. However, the potential spread of carbapenem resistance genes (CRGs), which confer resistance to last-resort carbapenem antibiotics, and Enterobacteriaceae, common carriers of these genes and opportunistic pathogens, raises important safety concerns. This study aimed to assess the influence of different agri-food-based diets on Enterobacteriaceae loads and the CRG occurrence during the bioconversion process. Methods: Four experimental diets were formulated from agri-food residues and anaerobic digestate: Diet 1 (peas and chickpea waste), Diet 2 (peas and wheat waste), Diet 3 (onion and wheat waste), and Diet 4 (wheat waste and digestate). Enterobacteriaceae were quantified by viable counts, while five CRGs (bla_KPC, bla_NDM, bla_OXA-48, bla_VIM, and bla_GES) were detected and quantified using quantitative PCRs (qPCRs). Analyses were performed on individual substrates, formulated diets, larvae (before and after bioconversion), and frass. Results: Plant-based diets sustained moderate Enterobacteriaceae loads. In contrast, the digestate-based diet led to a significant increase in Enterobacteriaceae in both the frass and mature larvae. CRGs were detected only in legume-based diets: bla_VIM and bla_GES were found in both mature larvae and frass, while bla_OXA-48 and bla_KPC were found exclusively in either larvae or frass. No CRGs were detected in onion- or digestate-based diets nor in young larvae or diet inputs. Conclusions: The findings suggest that the diet composition may influence the proliferation of Enterobacteriaceae and the persistence of CRGs. Careful substrate selection and process monitoring are essential to minimize antimicrobial resistance risks in insect-based bioconversion systems. Full article

The demand for biomass has been growing in recent years for several reasons, related to environmental, economic, and social trends. In the context of global climate changes and the depletion of natural resources, the recycling of plant biomass waste is a promising strategy for sustainable development that contributes to minimizing waste, improving resource efficiency, and achieving the goal of creating a circular economy. One of the highly demanded products of agricultural waste recycling is glucose. Glucose is an important organic substrate that allows a number of value-added products to be obtained. In this review, we focused on the commercially significant products of glucose oxidation: gluconic and glucaric acids. This review summarized the latest available data on the scope of the application of each product as well as the methods of their production. The capabilities and limitations of currently used methods of synthesis were highlighted. Full article

Biofloc technology (BFT), traditionally centered on feed supplementation and water purification in aquaculture, harbors untapped multifunctional potential as a sustainable resource management platform. This review systematically explores beyond conventional applications. BFT leverages microbial consortia to drive resource recovery, yielding bioactive compounds with antibacterial/antioxidant properties, microbial proteins for efficient feed production, and algae biomass for nutrient recycling and bioenergy. In environmental remediation, its porous microbial aggregates remove microplastics and heavy metals through integrated physical, chemical, and biological mechanisms, addressing critical aquatic pollution challenges. Agri-aquatic integration systems create symbiotic loops where nutrient-rich aquaculture effluents fertilize plant cultures, while plants act as natural filters to stabilize water quality, reducing freshwater dependence and enhancing resource efficiency. Emerging applications, including pigment extraction for ornamental fish and the anaerobic fermentation of biofloc waste into organic amendments, further demonstrate its alignment with circular economy principles. While technical advancements highlight its capacity to balance productivity and ecological stewardship, challenges in large-scale optimization, long-term system stability, and economic viability necessitate interdisciplinary research. By shifting focus to its underexplored functionalities, this review positions BFT as a transformative technology capable of addressing interconnected global challenges in food security, pollution mitigation, and sustainable resource use, offering a scalable framework for the future of aquaculture and beyond. Full article

An increasing number of soils, including those in EU countries, are affected by organic matter deficiency and the deterioration of nutrients, and using mineral fertilizers is often associated with negative environmental impacts. One of the basic recommendations for sustainable agriculture is to increase the proportion of organic fertilizers in crop production and preserve soil biodiversity. An increasingly common organic fertilizer is biogas plant digestate, the physical and chemical properties of which depend primarily on the waste material used in biogas production. However, the fertilizer value of this additive and its effects on the soil environment, including beneficial organisms, remain insufficiently studied. Soil macrofauna, particularly earthworms, play a crucial role in soil ecosystems, because they significantly impact the presence of plant nutrients, actively participate in forming soil structures, and strongly influence organic matter dynamics. The present study was undertaken to determine the effects of fertilizing a silt loam soil with the solid fraction of digestate in monoculture crop production on earthworm community characteristics and the resulting changes in selected soil physicochemical properties. The research was conducted at a single site, so the original soil characteristics across the experimental plots were identical. Plots were treated annually (for 3 years; 2021–2023) with different levels of digestate: DG100 (100% of the recommended rate; 30 t ha⁻¹), DG75 (75% of the recommended rate; 22.5 t ha⁻¹), DG50 (15 t ha⁻¹), DG25 (7.5 t ha⁻¹), and CL (a control plot without fertilizer). An electrical method was used to extract earthworms. Those found at the study site belonged to seven species representing three ecological groups: Dendrodrilus rubidus (Sav.), Lumbricus rubellus (Hoff.), and Dendrobaena octaedra (Sav.) (epigeics); Aporrectodea caliginosa (Sav.), Aporrectodea rosea (Sav.), and Octolasion lacteum (Örley) (endogeics); and Lumbricus terrestris (L.) (anecics). Significant differences in the abundance and biomass of earthworms were found between the higher level treatments (DG100, DG75, and DG50), and the lowest level of fertilization and the control plot (DG25 and CL). The DG25 and CL plots showed an average of 24.7% lower earthworm abundance and 22.8% lower biomass than the other plots. There were no significant differences in the earthworm metrics between the plots within each of the two groups (DG100, DG75, and DG50; and DG25 and CL). The most significant influence on the average abundance and average biomass of Lumbricidae was probably exerted by soil moisture and the annual dosage of digestate. A significant increase in the abundance and biomass of Lumbricidae was shown at plots DG100, DG75, and DG50 in the three successive years of the experiment. The different fertilizer treatments were found to have different effects on selected soil parameters. No significant differences were found among the values of the analyzed soil traits within each plot in the successive years of the study. Full article

Conventional ammonia production uses fossil-based hydrogen, resulting in high greenhouse gas emissions. Given the growing demand for sustainable solutions, it is essential to replace fossil hydrogen with renewable alternatives. This study assessed the technical, economic, and environmental viability of renewable ammonia production in Minas Gerais. To this end, an optimization model based on mixed integer linear programming (MILP) was developed and implemented in LINGO 20^® software. The model incorporated investment costs; raw materials; transportation; emissions; and indicators such as NPV, payback, and minimum sale price. Hydrogen production routes integrated into the Haber–Bosch process were analyzed: biomass gasification (GS_WGS), anaerobic digestion of vinasse (Vinasse_BD_SMR), ethanol reforming (Ethanol_ESR), and electrolysis (PEM_electrolysis). Vinasse_BD_SMR showed the lowest costs and the greatest economic viability, with a payback of just 2 years, due to the use of vinasse waste as a raw material. In contrast, the electrolysis-based route had the longest payback time (8 years), mainly due to the high cost of the electrolyzers. The substitution of conventional hydrogen made it possible to avoid 580,000 t CO₂ eq/year for a plant capacity of 200,000 t NH₃/year, which represents 13% of the Brazilian emissions from the nitrogenated fertilizer sector. It can be concluded that the viability of renewable ammonia depends on the choice of hydrogen source and logistical optimization and is essential for reducing emissions at large scale. Full article

This study evaluated the effects of different types and rates of locally produced organic residues on soil organic matter (SOM) and soil health in highly degraded loamy soils of olive orchards in arid southern Tunisia. Three residues were tested: poultry manure, raw date palm waste, and composted date palm waste mixed with manure. A randomised field trial was conducted over three years. Two years after application, soil samples were analysed for physical and chemical properties, basal respiration, nitrogen mineralisation, microbial biomass, enzyme activities (dehydrogenase, phosphomonoesterase, β-glucosidase, urease, arylsulphatase), and community-level physiological profiles. All residues increased SOM and available phosphorus (Pi), with dose-dependent effects sustained over time, though significant increases were only observed at the highest application rates. The most notable improvements occurred in soils amended with composted date palm waste. In contrast, biological and biochemical parameters showed little response, even after remoistening to stimulate microbial activity. This limited response was attributed to the absence of vegetation and, consequently, of root exudates and plant residues. This will be further investigated by assessing changes in the same biological and biochemical properties following the implementation of an intercropping system, which is expected to enhance both SOM content and microbial activity in these soils. Full article

White mulberry (Morus alba L.) is a tree growing up to 15 m in height. It is a plant whose cultivation is historically associated with silk production. Mulberry leaves are the only food source of the mulberry silkworm caterpillars (Bombyx mori L.). The cultivation of this tree has recently gained renewed importance. Due to the content of numerous bioactive substances, mulberry is a valuable raw material for the food, pharmaceutical and herbal industries. This article presents the results of tests on pellets from 1-, 3- and 5-year-old branches, which are waste biomass remaining after pruning mulberry shrubs cultivated to obtain leaves to feed silkworms. Additionally, analyses of pellets from mulberry leaves were also carried out. For the specified mulberry biomass yield, analyses of chemical composition of mulberry biomass (branches and leaves) were carried out, and energy properties (heat of combustion and calorific value) and energy potential were calculated. The heat of combustion of pellet from mulberry branches was, on average, 19,266 MJ∙Mg⁻¹, and the calorific value was 17,726 MJ∙Mg⁻¹. The energy potential, on the other hand, was, on average, 159 GJ∙ha⁻¹ and 44 MWh∙ha⁻¹. The obtained results indicate the possibility of the effective use of mulberry branches after the annual pruning of bushes in plantations for energy purposes. Full article

This study investigates biochar-enriched organic fertilizers made from bagasse, ash, spent wash, and cane tops, assessing their impact on corn growth over 45 days. A randomized complete block design with three replicates was used, testing six formulations with biochar levels at 0%, 10%, and 20%, along with soil-only and commercial fertilizer controls. Treatments T5 (bagasse + ash + spent wash + cane tops), T11 (T5 + 10% biochar), and T17 (T5 + 20% biochar) showed the best results for plant height, leaf development, and biomass production, with T17 performing the best for growth, biomass, and girth. The biochar in T17 had a pH of 9.37 ± 0.16, 18.00 ± 1.25% ash content, and a surface area of 144.58 m²/g. Nutrient analysis of the compost showed 2.85% potassium, 1.12% phosphorus, 1.85% nitrogen, 4.1% calcium, 0.23% magnesium, and 130 mg/kg zinc. The elemental composition was 68.50% carbon, 4.50% hydrogen, 6.00% nitrogen, and 25.30% oxygen, with 85.00% total organic carbon (TOC). This study concludes that T17 is the most effective formulation, offering both environmental and financial benefits, with composting potentially generating $11.16 million in profit, compared to the $19.32 million spent annually on waste management in Sri Lanka’s sugar industry. Full article

The search for waste management opportunities is crucial for achieving environmentally friendly waste practices and ensuring the country’s energy security. This research aimed to valorize biomass and waste generated in greenhouses and to analyze the potential for electricity production from this waste. The analyses compared the situations in Turkey and Poland, where greenhouse production of vegetables is developing and constitutes an important link in agricultural activities, despite differences in climatic conditions. The cultivation of vegetables and flowers under cover is rapidly expanding in both countries and, with changing climatic conditions, is expected to shape the future of agriculture. In addition to estimating the energy that can be obtained, the study also evaluated the economic benefits of such a solution and the volume of avoided CO₂ emissions from fossil fuels. The issue of utilizing these wastes is significant because current methods of their management do not lead to energy production, so their considerable energy potential is wasted, as highlighted in this study. Moreover, there is a lack of similar studies in the literature. The plant species chosen as materials in this study were tomatoes, peppers, eggplant, watermelon, and melon in the case of Turkey. For Poland, the analysis was conducted for tomatoes and greenhouse cucumbers. These crops represent the largest cultivated areas under cover in the respective countries. Results indicated that the average yearly amount of vegetable residue is approximately 463 thousand Mg in Turkey, and 77 thousand Mg in Poland. The estimated annual electricity potential is 430 GWh in Turkey and 80 GWh in Poland. Considering the efficiency of power generation in a typical power plant, the real amount of electricity to be obtained is 0.46 MWh per Mg of waste in Turkey and 0.52 MWh in Poland. Full article

Coastal regions of Ecuador, particularly Esmeraldas and Manabí, face significant challenges related to energy access, waste management, and sustainable agricultural development. This study evaluates the renewable energy potential of cocoa waste biomass generated by smallholder farms in these provinces. A total of 20 cocoa farms, either certified or in the process of certification under the Rainforest Alliance standard, were surveyed to quantify the volume of agricultural and agro-industrial residues. Residual biomass generation ranged from 50 to 6500 tons per year, depending on farm size, planting density, and management practices. Spatial analysis revealed that Esmeraldas holds the highest concentration of cocoa waste biomass, with some farms reaching a gross energy potential of up to 89.07 TJ/year. Using thermochemical conversion scenarios, effective energy potential was estimated, and 75% of the farms exceeded the viability threshold of 100 MWh/year. The results confirm the feasibility of cocoa biomass as a renewable energy source, mainly when managed collectively at the community level. Incorporating this waste into decentralized energy systems supports circular economy models, enhances energy self-sufficiency, and aligns with sustainable supply chain goals promoted by certification schemes. This study contributes to national efforts in energy diversification and provides a replicable model for integrating renewable energy into rural agricultural systems. Full article

This study examines the establishment of a Hub for Circular Economy and Industrial Symbiosis (HUB-CEIS) centred on a forest biomass waste plant in Fundão, Portugal, presenting an innovative model for rural industrial symbiosis, circular economy governance, and sustainable waste management. Designed as a strategic node within a reverse supply chain, the hub facilitates the conversion of solid waste into renewable energy and high-value co-products, including green hydrogen, tailored for industrial and agricultural applications, with an estimated 120 ktCO₂/year reduction and 60 direct jobs. Aligned with the United Nations (UN) Sustainable Development Goals (SDGs) and the Paris Agreement, this initiative addresses global challenges such as decarbonization, resource efficiency, and the energy transition. Employing a mixed research methodology, this study integrates a comprehensive literature review, in-depth stakeholder interviews, and comparative case study analysis to formulate a governance framework fostering regional partnerships between industry, government, and local communities. The findings highlight Fundão’s potential to become a benchmark for rural industrial symbiosis, offering a replicable model for circularity in non-urban contexts, with a projected investment of USD 60 M. Special emphasis is placed on the green hydrogen value chain, positioning it as a key enabler for regional sustainability. This research underscores the importance of cross-sectoral collaboration in achieving scalable and efficient waste recovery processes. By delivering practical insights and a robust governance structure, the study contributes to the circular economy literature, providing actionable strategies for implementing rural reverse supply chains. Beyond validating waste valorization and renewable energy production, the proposed hub establishes a blueprint for sustainable rural industrial development, promoting long-term industrial symbiosis integration. Full article