Search Results (1,296)

Recirculating aquaculture systems (RASs) improve water-use efficiency in fish production but generate nutrient-rich effluents requiring management. Integrating aquatic biomass cultivation into RASs offers a promising approach to nutrient recovery, CO₂ utilization, and biomass production. This study evaluates the technical and economic feasibility of integrating Wolffia globosa cultivation with RASs through process simulation and techno-economic analysis (TEA). A pilot-scale system in Thailand was modeled using SuperPro Designer, comparing static and suspended aeration cultivation. The suspended configuration required only ~10–12 m² for 28.80 m³, whereas static cultivation required 131 m² for 32.80 m³, corresponding to about a 12-fold reduction in land area. The suspended system achieved higher annual biomass production (1056 kg dry weight (DW) yr⁻¹) than the static system (690 kg DW yr⁻¹), corresponding to CO₂ fixation of ~1.50 and ~0.98 t CO₂ yr⁻¹, respectively. The static system achieved higher nutrient removal efficiencies (97% N and 99.66% P), while the suspended system showed lower removal (64% N and 65.30% P) but higher productivity. Economic analysis confirmed feasibility, with the suspended system achieving higher return on investment (17.56% vs. 12.89%) and a shorter payback period (5.70 vs. 7.76 years). These results demonstrate the potential of RAS–Wolffia integration as a circular approach for resource recovery and sustainable aquaculture. Full article

Municipal wastewater represents an underutilized secondary biomass resource rich in organic carbon and nutrients that can be valorized through biotechnological conversion. In this study, we developed an integrated multi-microbial biorefinery platform to transform municipal wastewater into value-added biofuel via sequential bacterial treatment, microalgal biomass generation, and fungal-assisted harvesting. Wastewater was first pretreated with Bacillus subtilis to enzymatically hydrolyze complex organic substrates and enrich the medium with bioactive metabolites, including auxins and gibberellins. The conditioned wastewater was subsequently used to cultivate Chlorella vulgaris, followed by biomass recovery using Trichoderma viride pellets as a sustainable bioflocculant. The integrated consortium significantly enhanced nutrient removal efficiency and promoted algal biomass accumulation, lipid enrichment, and biodiesel productivity compared to monoculture controls. Elevated hydrolytic enzyme activities (cellulase, protease, and amylases) facilitated organic matter conversion into bioavailable substrates, while increased phytohormone levels stimulated algal growth and lipid biosynthesis. Additionally, fungal bioflocculation substantially improved biomass recovery efficiency, reducing the need for energy-intensive harvesting technologies. This work highlights the potential of a biotechnology-driven approach for integrating wastewater remediation with biofuel production. By integrating microbial metabolism, enzymatic transformation, and sustainable separation processes, the proposed biorefinery system suggests a potentially low-carbon approach for simultaneous environmental remediation and biomass valorization, although further life cycle and energy balance analyses are required to validate this aspect. Full article

Starvation is a fundamental physiological stressor that triggers conserved adaptive responses across species, however, its effects are shaped by both developmental stage and prior nutritional history. This study aimed to investigate the effects of acute nutrient deprivation in Artemia franciscana, comparing newly hatched nauplii and adult individuals previously exposed to reduced caloric intake during development. Organisms were subjected to starvation for 24, 48, and 72 h, and mortality, morphometric parameters, and locomotor activity were assessed, complemented by in silico analysis of starvation-related pathways. Starvation induced distinct responses between groups, with markedly higher mortality in adults compared to nauplii. While these differences reflect developmental stage-associated responses, they are also influenced by prior nutritional history. Body length was significantly reduced under starvation in both developmental stages, while antennal length remained largely unchanged. Locomotor activity, including distance travelled and swimming velocity, was consistently decreased, indicating energy-conserving behavioral adaptation. Partial recovery of locomotor performance and antennal length was observed following restoration of feeding. Bioinformatic analysis suggested the presence of conserved autophagy-related genes and enrichment of pathways associated with autophagy and TOR signaling. However, these findings should be interpreted as hypothesis-generating, given the reliance on a proxy species for pathway inference. These findings indicate that starvation responses in A. franciscana are shaped by an interaction between developmental stage and prior nutritional history, supported by conserved stress–response pathways, highlighting the potential of this model for studying metabolic stress responses. Full article

Phosphorus is an essential and finite resource critical for global food production, yet its inefficient use and discharge from wastewater systems contribute to eutrophication and resource depletion. The transition from conventional wastewater treatment plants to water resource recovery facilities has intensified interest in technologies that enable phosphorus recovery within a circular economy framework. This review provides a critical and up-to-date synthesis of phosphorus recovery strategies from wastewater, with primary emphasis on struvite (MgNH₄PO₄·6H₂O) crystallization as one of the most mature and practically implemented recovery routes. The occurrence and chemical forms of phosphorus in wastewater streams are discussed alongside conventional approaches, such as enhanced biological phosphorus removal and chemical precipitation, in order to position struvite recovery within the broader phosphorus management landscape. In addition to struvite crystallization, selected competing and complementary recovery pathways, including electrochemical systems, biochar-assisted processes, and sludge ash recovery, are discussed to compare technological maturity, recovery potential, and practical applicability. Particular attention is given to reactor configurations, full-scale applications, and commercial technologies to assess operational reliability, recovery performance, and fertilizer product quality. Life-cycle assessment results and regulatory developments are also discussed to contextualize sustainability claims, technology selection, and market integration. The review identifies key technical and economic challenges, particularly regarding magnesium supply, competing ions, wastewater matrix effects, and the feasibility of mainstream application. Overall, controlled sidestream struvite crystallization appears to offer the most favorable balance between recovery efficiency, operational reliability, and fertilizer product quality under suitable plant conditions. Full article

Integrated waste management through vermicomposting combined with biochar amendments represents an innovative approach for sustainable resource recovery. This study evaluated the effects of sugarcane bagasse biochar (SBB) at 0%, 5%, and 10% application rates on Eisenia fetida performance and vermicompost quality during preincubation-vermicomposting of sewage sludge and press-mud mixtures. The 10% SBB treatment significantly (p < 0.05) enhanced earthworm biomass (72.3% increase) and cocoon production (24.8 ± 1.8 per earthworm vs. 12.3 ± 1.2 in control). Lignocellulosic degradation improved substantially, achieving 22.6%, 10.7%, and 38.8% degradation for cellulose, hemicellulose, and lignin, respectively. Macronutrient concentrations increased significantly: TN by 38.4%, TP by 15%, and TK by 21.4% compared to initial mixtures. Moreover, total heavy metal concentrations decreased significantly during vermicomposting, with reductions of 8.1–8.7% for Pb, 5.3–7.6% for Cd, and 3.0–4.8% for Cr, with reduced bioavailability factors indicating enhanced metal stabilization. The final vermicompost exhibited optimal maturity indices, including a C:N ratio of 15.4 ± 0.2 and improved electrical conductivity. Results demonstrate that 10% sugarcane bagasse biochar amendment facilitates efficient concurrent management of sewage sludge and sugarcane industrial wastes while producing high-quality organic fertilizer with enhanced nutrient content, reduced heavy metal bioavailability, and accelerated stabilization for sustainable agricultural/horticultural applications. Full article

Water temperature is a key ecological and metabolic factor in rivers and other continental systems, and thermal pollution caused by anthropogenic activities (dams, discharges, urban stormwater, industrial cooling) alters the natural thermal regime of rivers, modifying the structure and functioning of communities (primary producers, macroinvertebrates and fish) and favouring thermophilic and often invasive species. Wastewater treatment plants (WWTPs) generate and discharge excess heat: their effluents are often several degrees above the temperature of the receiving river, which increases the metabolism of communities, favours eutrophication and can intensify the effects of nutrients and toxic pollutants. This excess heat from wastewater is a major renewable energy resource that can be recovered using heat pumps, both in buildings and in the treatment plants themselves, as well as in district heating networks, reducing the demand for fossil fuels and CO₂ emissions. Heat recovery in WWTPs, especially from treated effluent connected to district networks, offers very high technical potential (tens of TWh per year on a national scale in some countries) and can contribute significantly to more sustainable urban energy systems. Heat recovery in WWTPs can minimize the thermal impact of effluents on receiving rivers, reducing the negative effects of discharges on the natural environment. Full article

In bioleaching processes, the use of microbial consortia establishes a favourable environment that supports the growth and activity of multiple microorganisms, thereby enhancing their synergistic interactions during leaching. Mineral dissolution efficiency is consistently higher in consortia than in monocultures. Acidithiobacillus thiooxidans and Acidithiobacillus ferrooxidans exhibit metabolic complementarity and synchrony, including interactions with thermophilic microorganisms. Bioleaching is typically conducted under highly acidic conditions (pH 1–2), where microorganisms utilize essential resources such as nutrients and oxygen, while tolerating elevated concentrations of heavy metals. This review aims to examine the characteristics and current applications of microbial consortia, with particular emphasis on their interactions with heavy metals, the behaviour of their exopolysaccharides (EPS) under toxic conditions, their role in bioremediation across diverse environmental systems, and their potential for industrial implementation. Microbial consortia represent a high-value biotechnological tool in both mining and environmental remediation. Their synergistic interactions enable enhanced efficiency in the bioleaching of sulphide minerals, promoting the mobilization of both economically valuable and contaminant metals, and significantly outperforming individual cultures. Consequently, microbial consortia constitute a versatile, resilient, and eco-efficient platform for metal recovery and the mitigation of environmental liabilities. This review focuses on the applications of bacterial consortia in bioleaching processes and highlights their potential for emerging and future use. Full article

The growing importance of renewable energy sources and the implementation of circular economy principles highlight the need for the rational management of biomass combustion by-products. The aim of this study was to assess the chemical composition of ash produced through the combustion of various biomass fractions from four varieties of common hazel (Corylus avellana L.) in the context of its potential for secondary use. The analysis covered the shells, husks, leaves, and shoots of the following varieties: Kataloński, Olbrzymi z Halle, Olga, and Webba Cenny. Combustion was carried out under laboratory conditions at a temperature of 550 °C, and the content of macro- and micro-element oxides (P₂O₅, K₂O, CaO, SO₃, Cl, SiO₂, MnO, Fe₂O₃, NiO, CuO) and potentially toxic elements (ZnO, TiO₂, Cr₂O₃) was determined using the EDXRF method. The results showed significant variation in the chemical composition of the ash depending on the biomass fraction and variety. The highest P₂O₅ content was found in the leaves of the Kataloński variety (5.02), whilst the highest K₂O concentration was found in the husk of the Olga variety (47.33%). The maximum CaO content was found in the leaves of the Webba Cenny variety (32.60). The leaf and husk fractions were characterised by the highest content of nutrients of fertilising importance, whilst the shells exhibited the lowest values for most macronutrients. The content of potentially toxic elements was low. The results obtained indicate that the selective utilisation of specific fractions of hazel biomass can increase the efficiency of mineral recovery whilst maintaining environmental safety, in line with the principles of the circular economy. Full article

Parboiling enhances the nutritional, structural, and economic value of rice, yet its adoption in the United States remains limited despite rising domestic and export demand. This review summarizes key stages of the parboiling process and their effects on milling yield, grain integrity, nutrient retention, and glycemic response. It outlines major industry challenges, including high energy and water use, uneven heating and drying, handling of defective kernels, limited automation in smaller mills, labor shortages, and emerging climate-related risks. Advances such as vacuum soaking, infrared and microwave-assisted drying, smart sensors, and AI-driven control systems show strong potential to improve efficiency and product quality. Circular-economy strategies, including biomass energy recovery, water reuse, and by-product valorization, offer additional sustainability gains. Continued research, modernization, and policy support are critical to strengthen competitiveness and positioning of the U.S. parboiled rice sector for a more resilient and sustainable future. Full article

The aim of this study was to investigate how delayed fertilization with individual macronutrients (N, P, K, Ca, Mg, and S) affects the growth, yield components, biomass, and spectrophotometric indicators of spring wheat grown under controlled hydroponic conditions. Nutrient deprivation was initiated at BBCH stage 23 and maintained for 21, 28, 35, or 133 days, corresponding to BBCH stages 30, 32, 37, and 99, respectively. In selected treatments, the complete nutrient solution was subsequently restored until harvest to evaluate recovery potential. N, P, and Ca deprivation exerted the strongest negative effects on biomass accumulation across all deprivation durations. Compared to the fully supplied control, biomass was reduced by 60% under N deprivation and by 44.5% under P deprivation after 21 days. After 35 days, calcium deprivation resulted in a 97.7% reduction in biomass. Following 133 days of deprivation, biomass was reduced by 98%, 96.8%, and 95.9% under N, calcium, and P deficiencies, respectively. Root mass followed a similar pattern: after 21 days, it decreased by 52.46% (N) and 36.44% (P); after 28 days—by 57.4% (N) and 52.7% (P); after 35 days—by 90.7% (Ca), 66% (N), and 59.1% (P); and after 133 days—by 95.1–90.1% (Ca, N, P). Magnesium deprivation caused substantial reductions in growth parameters, reflecting its central role in chlorophyll structure and photosynthetic efficiency. Sulfur deprivation resulted in moderate but consistent biomass suppression and spectral divergence, indicating its importance in protein synthesis and redox regulation. Short-term deficiencies allowed partial recovery of growth and productivity, whereas long-term deprivation induced pronounced morphological alterations linked to stress adaptation. These effects were further confirmed through in vivo spectral reflectance measurements compared to healthy control plants. Full article

The rumen simulation technique (RUSITEC^®) is a known model for research in rumen microbiology and fermentation. However, our research group observed inconsistencies in gas production across trials. This study investigated the effects of different gas outlet locations on digestibility, ruminal fermentation, gas production, and microbial protein synthesis. Fifteen fermenters tested three different gas outlet locations within the RUSITEC^® equipment: (1) gas outlet directly on the effluent vessel for output liquid (EV); (2) gas outlet directly on fermenter cap (F); and (3) gas outlet on both effluent vessel and fermenter cap (EVF). Data were analyzed using a completely randomized design in SAS (v. 9.4) with the MIXED procedure, and significance was set at p < 0.10. Results showed that altering the gas outlet location did not affect nutrient digestibility (p > 0.10), microbial protein synthesis (p > 0.10), and volatile fatty acid (VFA) production when expressed on a molar basis (p > 0.10). However, total gas production (p = 0.108) was higher in the EVF group and ammonia nitrogen produced in the fermenter was higher in group F (p = 0.081). Furthermore, methane (CH₄) production was underestimated when the gas outlet location was in just one of the locations when compared to the EVF group (p = 0.006). VFA proportion was also affected, with lower acetate (p = 0.005) and higher butyrate (p = 0.014) for group EV. These results indicate that the location of the gas outlet is an important methodological factor affecting fermentation measurements in the RUSITEC system, with outlets positioned in both the effluent and fermenter vessels enhancing gas recovery. Full article

Swine wastewater is a high-strength agricultural effluent characterized by high organic loading, elevated ammonium nitrogen and phosphorus concentrations, and frequently low C/N ratios, which make simultaneous pollutant removal and resource recovery challenging. Conventional physicochemical, anaerobic, and aerobic treatment technologies are widely used, but they are often constrained by high energy demand, ammonia inhibition, insufficient nitrogen recovery under low C/N conditions, and limited resource valorization. This review comparatively evaluates these conventional technologies alongside microalgal and algal–bacterial symbiotic (ABS) systems for swine wastewater treatment and resource recovery. Particular attention is given to algal–bacterial interactions, oxygen and carbon exchange, nitrogen and phosphorus removal pathways, reactor configurations, key operational parameters, and biomass valorization routes. The reviewed evidence shows that conventional anaerobic–aerobic systems generally achieve stable COD removal (>80%) but often provide limited nitrogen recovery, whereas microalgal systems can remove 80–90% of nitrogen and phosphorus but remain restricted by ammonia toxicity, light attenuation, and biomass harvesting costs. Under optimized conditions, ABS granular systems have achieved >90% COD removal, >80% total nitrogen removal, and 70–95% total phosphorus removal, while also improving biomass settleability and process stability. Overall, ABS systems offer a promising route to shift swine wastewater treatment from discharge-oriented pollution control toward resource-oriented management. Future research should prioritize reactor scale-up, long-term operational stability, biological monitoring, and economically viable biomass valorization. Full article

Dysphagia and age-related oral processing limitations are rising with population aging and the growing burden of neurological diseases. Texture-modified diets remain the most common non-pharmacological intervention, yet conventional pureeing and thickening often yield meals with low visual appeal, variable textures, and diluted nutrient density, which contribute to reduced intake and malnutrition risk. Extrusion-based three-dimensional food printing, especially when combined with gel-derived edible inks, offers a digital route to standardize geometry, portioning, and texture while enabling individualized nutrition and sensory design. In the past three years, the field has progressed from simple single-ingredient pastes to engineered soft-matter systems including emulsion gels, high-internal-phase emulsion gels, Pickering-stabilized gels, bigels, and multi-material constructs enabled by dual and coaxial printing. These advances are underpinned by improved rheological windowing, microstructure engineering, and post-print gelation strategies such as ionic crosslinking, thermal setting, enzymatic bridging, and pH-triggered network formation. Meanwhile, dysphagia-oriented product development has matured from “shape recovery” demonstrations toward clinically relevant texture targets, leveraging the IDDSI tests to anchor swallowability. This review synthesizes the recent literature across materials science, food engineering, and clinical nutrition to connect gel microstructure to extrusion performance, post-processing stability, and oral processing outcomes that are relevant to older adults and dysphagia patients. We propose design principles for gel network selection, phase structuring, and process control that simultaneously satisfy print fidelity and swallowing safety targets. Full article

Long-term monitoring is essential for understanding how recurring disturbances, such as hurricanes and coral bleaching, affect reef fish communities and ecosystem processes. This study evaluates temporal trends (2013–2025) in fish assemblage composition, functional diversity, and nutrient excretion proxies (C, N, and P) across three reef sites on San Andrés Island in the Colombian Caribbean. Our results reveal significant shifts in community structure following major disturbances in 2020 (Hurricanes Eta, Iota) and 2023 (mass bleaching event). Taxonomic and functional richness (TRich, FRich) fluctuated throughout the study period, whereas functional divergence (FDiv) declined earlier (2016), highlighting site-specific differences. A trait-based nutrient-excretion proxy (NPC composite score) identified key species that maintain nutrient cycling. Despite recent coral bleaching, certain sites exhibited functional resilience, sustained by the persistence of high-performing nutrient providing species. However, the overall disconnect between taxonomic recovery and functional stability suggests that ecosystem-level processes remain vulnerable, even when species richness appears to recover. This highlights the importance of integrating functional traits and nutrient recycling proxies into monitoring programs to better predict long-term variability in San Andrés Island reefs under a changing climate. Our findings provide a framework for prioritizing management efforts in the Seaflower Biosphere Reserve with emphasis on maintaining ecosystem services. Full article

Livestock production systems are considered some of the most environmentally degrading due to greenhouse gas (GHG) emissions and their contribution to poor air, soil and water quality, amongst other impacts. Advanced manure treatment technologies are required in response to intensification of dairy production worldwide, and the considerably greater volumes of manure generated that require collection and management. Similarly, in Australian dairy systems cows spend more time off pasture, with increased collection of larger manure volumes from a range of contained housing facilities. Adoption of advanced treatment is required to capture nutrients at risk of loss, and ideally to valorise manure to support uptake of these technologies. This review describes the generation of manure and the manure sources found in commercial Australian systems, including grazing-based and intensive dairy farms, supporting zero grazing. The review draws on manure data from pasture-based industries elsewhere and summarises their properties for comparison with Australian systems. Manure treatments that recover and retain nutrients, water and energy are reviewed. These include additives, mechanical/chemical/membrane separation, thermochemical and biological treatments which produce organic and inorganic soil amendments, clarified or potable water, gases (N₂, H₂), biofuels and energy. The review describes the technical and operational details of the technologies, and where there are opportunities for the Australian dairy industry. Treatment technologies need to be validated for Australian systems based on the collated data of local manure properties, as differences with international manure data have been observed. The relative costs, technological maturity, and the benefits and challenges associated with adoption are discussed. Many advanced technologies are ready for adoption, but others are experimental or at pilot stage and relative costs range from low to very high. However, to accurately assess feasibility of manure treatments, environmental, and production benefits should be balanced against capital and operating expenses and account for costs associated with current management. For large intensive farms, implementing advanced manure technologies may be required to ensure approval to operate/expand and to meet regulatory compliance. Future research for the Australian industry should investigate nutrient retention and further develop separation treatments incorporating chemical and mechanical technologies. Bioconversion of manure through insect composting as well as investigating co-digestion opportunities to enhance biogas production would support famers currently using these systems. Full article