Search Results (601)

Circular agriculture reclaims nutrients from waste streams to reduce fertilizer imports, mitigate environmental impacts, and close material loops. This review evaluates the agronomic performance of nitrogen, phosphorus, and potassium products recovered from wastewater, crop residues, and manure compared with conventional fertilizers. A structured literature survey identified 85 pot and field trials published between 2010 and 2024, covering ammonium salts, struvite, ashes, compost, digestate, biochar, hydrochar, and biostimulants. Ammonium sulfate and nitrate consistently matched synthetic yields (95–105%) due to their solubility and immediate N availability, while aqueous ammonia showed variable results depending on application timing and soil pH. Struvite and phosphorus-rich ashes performed best (90–100%) in neutral to slightly acidic soils, whereas organo-mineral phosphate fertilizers (85–95%) were less effective in alkaline soils. Potassium-rich ashes and waste mica were effective (80–95%) in soils with moderate cation exchange, though mica underperformed (60–75%) in coarse soils. Biochars and hydrochars improved soil water retention and nutrient exchange, yielding 90–110% of synthetic performance, while biostimulants increased yields by 8–20%. Recovered products demonstrate agronomic equivalence while offering co-benefits for soil health, waste management, and circular economy goals. Future work should prioritize long-term field validation, techno-economic analysis, and regulatory integration to enable large-scale adoption. Full article

Incineration is a widely adopted method for the disposal of waste energetic materials (SP). Nevertheless, this approach is associated with considerable thermal energy loss and significant environmental pollution. To address these limitations, this study proposes a co-pyrolysis process incorporating pine sawdust (SD) with SP. This technique utilizes the exothermic decomposition of energetic substances and the endothermic pyrolysis of biomass. Through this synergistic thermal interaction, the process enables efficient energy recovery and facilitates the resource valorization of SP. The pyrolysis kinetics and thermodynamics of SP, SD, and their blends were investigated. Synchronous thermal analysis examined the co-pyrolysis reaction heat at varying blend ratios, while the temperature’s effects on the gas–liquid–solid product distribution were explored. The results indicate that the apparent activation energy (E_a) required for co-pyrolysis of the SP and SD exhibits an initial increase followed by a decrease in both Stage 1 and Stage 2. Furthermore, the mean apparent activation energy (E_avg) during Stage 1 (FWO: 101.87 kJ/mol; KAS: 94.02 kJ/mol) is lower than that in Stage 2 (FWO: 110.44 kJ/mol; KAS: 100.86 kJ/mol). Co-pyrolysis reaction heat calculations indicated that SD addition significantly mitigates the exothermic intensity, shifts decomposition to higher temperatures (the primary exothermic zone shifted from 180–245 °C to 265–400 °C), and moderates heat release. Elevated temperatures increase the gas yield (CO and H₂ are dominant). High temperatures promote aromatic bond cleavage and organic component release; the char’s calorific value correlates positively with the carbon content. Higher co-pyrolysis temperatures increase the nitrogenous compounds in the oil, while the aldehyde content peaks then declines. This work proposes a resource recovery pathway for SP, providing fundamental data for co-pyrolysis valorization or the development of catalytic conversion precursors. Full article

The transformation of organic by-products derived from waste into value-added resources represents a promising strategy to advance circular economy principles and bolster environmental and agricultural sustainability, especially in soilless cultivation. This study evaluates the viability of three organic by-products—wood fiber (WF), coffee silverskin (CS), and brewer’s spent grains (BSGs)—as partial peat replacements in horticultural substrates. Ten growing media formulations were assessed, incorporating increased doses (0–40% v/v as peat replacement-PR) of each alternative by-product. The effects on physical and hydraulic substrate properties, along with plant growth traits, were examined using two ornamental Salvia genotypes, ‘Victoria’ and ‘Amistad’. To synthesize the multivariate growth data into a single, biologically meaningful metric, based on the first principal component, a Growth Index (GI), a PC1-derived index, was calculated, providing a powerful, unified metric to rank substrate efficacy. WF-based substrates exhibited increased porosity and diminished water retention, whereas media enriched with CS and BSG enhanced moisture availability, particularly at 20–40 PR. The bulk density was highest at PR40 for both WF and BSG treatments, and at PR20 in CS-based substrates. Electrical conductivity increased in CS and BSG treatments with rising PR levels. The results on the vegetative growth of ornamental sages have highlighted that differential PR rates are required depending on the specific organic by-product and plant genotype. In ‘Victoria’, GI indicates that a 20% replacement of peat with BSG provided the optimal conditions for holistic plant development; the lowest GI for WF substrates across nearly all peat replacement levels indicated that it was the most detrimental alternative for this cultivar. In ‘Amistad’, the analysis of the GI scores revealed that the CS20 and BSG20 of peat replacement yielded the highest overall growth, with GI scores significantly greater than those of the peat control. CS10 and BSG40 also showed high GI scores in ‘Amistad’. WF10 had GI scores similar to those of the peat control. In general, the GI-based approach confirms that moderate inclusion of brewer’s spent grain (BSG20) is a highly effective peat replacement for both genotypes. At the same time, coffee silverskin (CS) is particularly effective for the ‘Amistad’ genotype. This analysis underscores that optimal substrate formulation is not only dependent on the amendment type and rate but also critically on the plant genotype. Full article

Improving the anaerobic digestion (AD) of swine manure is crucial for sustainable waste-to-energy systems, given its high organic load and process instability risks. This study examined the combined effects of substrate-to-inoculum ratio (SIR, 0.1–3.2) and magnetite-mediated direct interspecies electron transfer on biogas production, effluent quality, and microbial community dynamics. The highest methane yield (262 ± 10 mL CH₄/g COD) was obtained at SIR 0.1, while efficiency declined at higher SIRs due to acid and ammonia accumulation. Magnetite supplementation significantly improved methane yield (up to a 54.1% increase at SIR 0.2) and reduced the lag phase, particularly under moderate SIRs. Effluent characterization revealed that low SIRs induced elevated soluble COD (SCOD) levels, attributed to microbial autolysis and extracellular polymeric substance release. Furthermore, magnetite addition mitigated SCOD accumulation and shifted molecular weight distributions toward higher fractions (>15 kDa), indicating enhanced microbial activity and structural polymer formation. Microbial analysis revealed that magnetite-enriched Syntrophobacterium and Methanothrix promoted syntrophic cooperation and acetoclastic methanogenesis. Diversity indices and PCoA further showed that both SIR and magnetite significantly shaped microbial structure and function. Overall, an optimal SIR range of 0.2–0.4 under magnetite addition provided a balanced strategy for enhancing methane recovery, effluent quality, and microbial stability in swine manure AD. Full article

This study examines the adoption of real-time visibility (RTV) technologies in the Australian meat cold supply chain, a sector where sustainability challenges such as food spoilage, energy inefficiency, and waste are acute. RTV technologies offer promising solutions by enhancing traceability, operational efficiency, and decision-making across supply chain stages. However, adoption remains uneven due to a range of contextual, organisational, and perceptual factors. Through a nationally distributed quantitative survey targeting stakeholders across inventory, logistics, and retail operations, we identify key drivers and barriers influencing RTV adoption. We explore how demographic factors (e.g., age, role), perceived usefulness and ease of use, and supply chain characteristics interact to shape adoption outcomes. Importantly, the study investigates how horizontal collaboration and data-sharing practices moderate these relationships, especially within the transport and logistics stages where cold chain vulnerabilities are highest. Spearman and partial correlation analyses, alongside binary logistic regression, reveal that perceived ease of use and usefulness are significant predictors of adoption, while barriers such as cost and technical complexity impede it. However, strong collaboration and data-sharing networks can mitigate these barriers and enhance adoption likelihood. Our findings suggest that targeted digital infrastructure investment, workforce training, and policy support for cross-organisational collaboration are essential for advancing sustainability in meat cold chains. This research contributes to a growing body of knowledge that connects technological innovation with food system resilience and waste minimisation. Full article

Digital pollution, encompassing energy consumption, e-waste, and the environmental impact of digital technologies, poses a significant and increasingly pressing environmental challenge that has received insufficient research attention. This study explores public perceptions, attitudes, and behaviors related to digital pollution, focusing on both individuals’ willingness to pay for environmentally friendly digital solutions and their actions to reduce digital environmental impact. Through a comprehensive survey of 300 UK participants, we examined the associations between demographic factors, knowledge levels, perceptions, and environmental actions. While traditional demographic factors such as age and income showed no significant correlation with willingness to pay, we found strong positive correlations with the frequency of environmental consideration (r = 0.47), willingness to act (r = 0.42), and perceived importance of digital pollution (r = 0.40). Notably, knowledge of digital pollution was not correlated with willingness to pay, while self-assessed tech-savviness and environmental knowledge had positive correlations with both willingness to pay and actions taken. Based on a robust cluster analysis, we identified four distinct participant groups: ’Engaged Eco-Tech Enthusiasts’ (youngest, most tech-savvy, and with the highest willingness to act), ‘Knowledgeable Traditionalists’ (oldest, highest knowledge scores, and moderate action), ‘Unengaged Pragmatists’ (lowest engagement), and ‘Affluent Moderates’ (wealthiest and with moderate engagement). These findings provide valuable insights for developing targeted interventions and communication strategies to address this emerging environmental challenge. Full article

This study investigates the fracture behavior of recycled aggregate concrete by integrating fractal theory and empirical modeling to quantify how recycled coarse aggregates (RCAs) and recycled fine aggregates (RFAs) influence crack complexity and maximum crack width under varying content and loads. The results reveal distinct scale-dependent behaviors between RCA and RFA. For RCA, moderate dosages enhance fractal complexity (a measure of surface roughness) by promoting micro-crack proliferation, while excessive RCA reduces complexity due to matrix homogenization. In contrast, RFA significantly increases both fractal complexity and crack width under equivalent loads, reflecting its susceptibility to micro-scale interfacial transition zone (ITZ) degradation. Non-linear thresholds are identified: RCA’s fractal complexity plateaus at high loads as cracks coalesce into fewer dominant paths, while RFA’s crack width growth decelerates at extreme dosages due to balancing effects like particle packing. Empirical models link aggregate dosage and load to fractal dimension and crack width with high predictive accuracy (R² > 0.85), capturing interaction effects such as RCA’s load-induced complexity reduction and RFA’s load-driven crack width amplification. Secondary analyses further demonstrate that fractal dimension correlates with crack width through non-linear relationships, emphasizing the coupled nature of micro- and macro-scale damage. These findings challenge conventional design assumptions by differentiating the impacts of RCA (macro-crack coalescence) and RFA (micro-crack proliferation), providing actionable thresholds for optimizing mix designs. The study also advances sustainable material design by offering a scientific basis for updating standards to accommodate higher recycled aggregate percentages, supporting circular economy goals through reduced carbon emissions and waste diversion, and laying the groundwork for resilient, low-carbon infrastructure. Full article

The integration of recycled materials into cementitious systems presents a sustainable path to reducing environmental impact in construction. This study investigates the mechanical and durability performance of self-compacting mortars (SCMs) incorporating finely ground mortar waste powder (MWP) as a partial cement substitute, reinforced with aluminum oxide (Al₂O₃) and iron oxide (Fe₂O₃). Eleven mixes were designed with MWP replacing cement at 0–50% by volume. Fresh-state tests showed that slump flow decreased moderately (from 259 mm to 240 mm), while V-funnel times improved (from 10.51 s to 7.01 s), indicating acceptable flowability. The optimum performance was observed in SCM2 (5% MWP + oxides), which achieved 75.62 MPa compressive and 13.74 MPa flexural strength at 28 days, outperforming the control mix. Durability under high temperature and freeze–thaw cycling revealed that oxide-reinforced mixes exhibited superior strength retention, with SCM2 maintaining over 87 MPa after 300 °C exposure and minimal degradation after 100 freeze–thaw cycles. Porosity remained low (16.1%) at optimal replacement levels but increased significantly beyond 25% MWP. The results confirm that low-level MWP replacement, when reinforced with reactive oxides, provides a viable strategy for producing durable, high-performance, and eco-efficient SCMs. Full article

This study addresses this gap by proposing a multilevel fuzzy evaluation model combined with an analytic hierarchy process (AHP) to quantify the greenness of furniture products across their entire lifecycle. Focusing on an office desk as a case study, we developed an indicator system encompassing environmental attributes, resource efficiency, energy consumption, economic costs, and quality performance. Weighting results revealed that environmental attributes (27.2%) and resource efficiency (27.2%) dominated the greenness evaluation, with material recycling rate (33.5%) and solid waste pollution (24.3%) as critical sub-indicators. The prototype achieved a moderate greenness score of 70.38/100, highlighting optimization potential in renewable material adoption (10% current rate) and modular design for disassembly. Mechanically recycled materials could reduce lifecycle emissions by 18–25% in key categories. The model demonstrates scalability for diverse furniture types and informs policy-making by prioritizing high-impact areas such as toxic material reduction and energy-efficient manufacturing, thus amplifying its global and interdisciplinary multiplier effects. Full article

The anaerobic co-digestion of agricultural residues emerges as a promising strategy for energy recovery and nutrient recycling within circular agricultural systems. This study aimed to optimize co-digestion parameters for vinegar residue (VR) and cattle manure (CM) using an orthogonal experimental design. Three key variables were investigated which are the co-substrate ratio (VR to CM), feedstock-to-inoculum (F/I) ratio, and total solids (TS) content. Nine experimental combinations were tested to evaluate methane yield, feedstock degradation, and digestate characteristics. Results showed that the optimal condition for methane yield comprised a 2:3 co-substrate ratio, 1:2 F/I ratio, and 20% TS, achieving the highest methane yield of 267.84 mL/g volatile solids (VS) and a vs. degradation rate of 58.65%. Digestate analysis indicated this condition generated the most nutrient-rich liquid digestate and solid digestate, featuring elevated N, P, and K concentrations, acceptable seed germination indices (GI), and moderate humification levels. While total nutrient content did not meet commercial organic fertilizer standards, the digestate is suitable for direct land application in rural settings. This study underscores the need to balance energy recovery and fertilizer quality in anaerobic co-digestion systems, providing practical guidance for decentralized biogas plants seeking to integrate waste treatment with agricultural productivity. Full article

This study evaluated the feasibility of reusing abandoned copper mine tailings (Cu tailings) as a precursor in the production of fly-ash-based alkali-activated materials (FA-AAMs). Two formulations were developed by combining FA and Cu tailings with a mixture of sodium silicate and sodium hydroxide as alkaline activators at room temperature (20 °C). Formulation G1 consisted of 70% Cu tailings and 30% fly ash (FA), whereas G2 included the same composition with an additional 15% ordinary Portland cement (OPC). The materials were characterized using X-ray fluorescence (XRF), -X-ray diffraction (XRD), field emission scanning electron microscopy with energy-dispersive spectroscopy (FESEM-EDS), and particle size analysis. While FA exhibited a high amorphous content (64.4%), Cu tailings were largely crystalline and acted as inert fillers. After 120 days of curing, average compressive strength reached 24 MPa for G1 and 41 MPa for G2, with the latter showing improved performance due to synergistic effects of geopolymerization and OPC hydration. Porosity measurements revealed a denser microstructure in G2 (35%) compared to G1 (52%). Leaching tests confirmed the immobilization of hazardous elements, with arsenic concentrations decreasing over time and remaining below regulatory limits. Despite extended setting times (24 h for G1 and 18 h for G2) and the appearance of surface efflorescence, both systems demonstrated good chemical stability and long-term performance. The results support the use of Cu tailings in FA-AAMs as a sustainable strategy for waste valorization, enabling their application in non-structural and moderate-load-bearing construction components or waste encapsulation units. This approach contributes to circular economy goals while reducing the environmental footprint associated with traditional cementitious systems. Full article

Background: Preimplantation genetic testing for aneuploidy (PGT-A) is a popular approach in assisted reproductive technology that improves embryo selection and implantation rates. Traditional approaches rely on trophectoderm (TE) biopsy, which is an invasive procedure that might jeopardize embryo integrity and create technical constraints such as mosaicism-related misclassification. Non-invasive preimplantation genetic testing (niPGT) has emerged as a possible alternative, using embryonic cell-free DNA (cfDNA) extracted from wasted culture media or blastocoel fluid to assess chromosomal status without requiring direct embryo manipulation. Methods: This systematic study investigates the molecular mechanisms behind cfDNA release, its biological properties, and the technological concerns that influence its utilization in niPGT. We look at recent advances in next-generation sequencing (NGS), whole-genome amplification (WGA), and bioinformatic techniques that improve cfDNA-based aneuploidy detection. In addition, we compare the sensitivity, specificity, and concordance rates of niPGT to conventional TE biopsy, highlighting the major aspects impacting its diagnostic performance. Results: The release of cfDNA from embryos is influenced by apoptotic and necrotic processes, active DNA shedding, and extracellular vesicle secretion, which results in fragmented chromosomal material of different qualities and quantities. While niPGT has shown promise as a noninvasive screening approach, significant variability in cfDNA yield, maternal DNA contamination, and sequencing biases all have an impact on test accuracy. Studies show that niPGT and TE biopsies have moderate-to-high concordance, although there are still issues in detecting mosaicism, segmental aneuploidies, and DNA degradation artifacts. Conclusions: NiPGT is a safer and less intrusive alternative to TE biopsy, with potential clinical benefits. However, technical advancements are required to improve cfDNA collecting procedures, reduce contamination, and improve sequencing accuracy. Additional large-scale validation studies are needed to create standardized methodologies and ensure that niPGT achieves the diagnostic reliability requirements required for widespread clinical deployment in IVF programs. Full article

This work investigates a ⁴He-detector active interrogation system that leverages neutron spectroscopy to classify nuclear waste streams. MCNP models tested the concept through the simulation of a D-D neutron generator, an array of ⁴He detectors, and various waste compositions. The fast-neutron Differential Die-Away signature was augmented with a neutron-energy discrimination signature. This signature isolates induced fission neutrons, the energy of which is greater than that of the D-D monoenergetic spectrum. With the incorporation of this spectroscopic technique, the measurement time decreased by 3–9% (depending on the degree of neutron moderation and absorption presented by the sample), demonstrating how neutron spectroscopy can enhance active interrogation methods. The reduced measurement times would have significant financial and logistical benefits for facilities with large footprints of low-level waste production. Full article

The EU’s Circular Economy Action Plan promotes the use of organic waste as fertilizer, thus allowing the recycling of nutrients in the agricultural system. Research on the agronomic reuse of composted substrates previously employed for mushroom cultivation remains limited, despite their rich content of plant residues and fungal biomass, which could be repurposed as soil amendments under suitable conditions. This study evaluated the agronomic potential of spent mushroom substrates from Agaricus bisporus and Pleurotus ostreatus, including recomposted A. bisporus residues. A range of analytical procedures was employed to assess their suitability for soil improvement and the formation of humic-like substances, including physical, chemical, microbiological, phytotoxicity, and pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) analyses. The spent Pleurotus substrate exhibited low nutrient content (1.1% N, negligible P, 0.9% K), but high water retention (820 kg water Mg⁻¹) and 48% organic carbon (OC), indicating its potential as a soil amendment or seedling substrate. In contrast, spent and composted Agaricus substrates showed moderate nutrient content (1.8–2.7% N; 0.8–0.7% P and 1.3–1.8% K), appropriate C/N ratios (10–15), and sufficient OC levels (24–30%), supporting their use as fertilizers. However, elevated salinity levels (18–23 dS m⁻¹) may restrict their application for salt-sensitive crops. No significant phytotoxic effects on seed germination were observed, and microbiological analyses confirmed the absence of Salmonella spp. in the three substrates. Py-GC/MS revealed a humic acid-like fraction comprising altered lignin structures enriched with lipid and nitrogen compounds. Overall, the studied materials demonstrate promising agronomic value and the capacity to contribute to long-term soil carbon storage. Full article

In China, the sustainable development of rural areas is of great significance to sustainable development. Especially with the acceleration of rural industrial integration in China, its environmental impact not only affects the resilience of rural areas but also affects the regional environment. According to the multiple and different dimensions of the impact of rural industrial integration on rural ecosystems, this research focuses on prefecture-level cities in China, utilizing regional economic and environmental data from 2014 to 2023. To analyze the impact of rural industrial integration on rural air quality using the entropy method, a rural industrial integration index was constructed, and the fixed effects model was used to analyze the findings. The results showed that a 0.01 increase in the rural industrial integration index will result in a decrease of 1.335% in the AQI index of an entire prefecture-level city, with empirical validation of the moderating effects of greening, rural waste treatment, and the mediating effects of infrastructure development. The study found that rural industrial integration and air quality levels in mainland China’s prefecture-level cities exhibited a steady upward trend. Full article