Search Results (474)

In an effort to reduce global dependence on fossil-based polymers and advance toward a more sustainable materials industry, research over recent decades has increasingly focused on the development of bio-based polymers and broadening their potential applications. Within this context, the present study investigates nanocomposites based on poly(butylene succinate-co-butylene adipate) (PBSA), reinforced with two types of nanofillers: silicon dioxide nanoparticles (SiO₂ NPs) and cellulose nanofibrils (CNFs). The main objective of this work is to examine how the morphology, geometry, and chemical nature of the nanofillers influence the thermal, mechanical, and barrier properties of PBSA, as well as its biodegradability. For each nanofiller, three formulations were prepared, containing 1, 2, and 5 wt% of filler, respectively. Scanning electron microscopy (SEM) analysis confirmed good dispersion and minimal aggregation in the SiO₂-based systems, whereas marked aggregation was observed in the CNF-based samples. Thermal analysis indicated that the intrinsic thermal properties of neat PBSA were largely preserved. Mechanical testing revealed improvements in both the elastic modulus and elongation at break for most nanocomposite samples. In particular, CNFs provided the most consistent reinforcing effect, with enhancements of approximately 40% in the elastic modulus (495.4 vs. 356.4 GPa in neat PBSA) and 52% in elongation at the break (185.1 vs. 122.0% in neat PBSA) with 5 wt% loading. Additionally, the incorporation of nanofillers did not alter the surface hydrophilicity, but it did improve the oxygen barrier performance and enhanced disintegration under composting conditions. Overall, these findings demonstrate the promising potential of PBSA-based nanocomposites for sustainable rigid packaging applications. Full article

Composting represents a sustainable and effective strategy for converting organic waste into nutrient-rich soil amendments, providing a safer alternative to raw manure, which poses significant risks of soil, crop, and water contamination through pathogenic microorganisms. This study, conducted under semi-arid Moroccan conditions, investigated the efficiency of co-composting green garden waste with sheep manure in an open window system, with the objective of assessing pathogen inactivation and evaluating compost quality. The process, conducted over 120 days, maintained thermophilic temperatures exceeding 55 °C, effectively reducing key pathogens including Escherichia coli, total coliforms, Staphylococcus aureus, and sulfite-reducing Clostridia (SRC), while Salmonella was not detected throughout the composting period. Pathogen reductions exceeded 3.52-log despite moderate temperature fluctuations, indicating that additional sanitization mechanisms beyond heat contributed to inactivation. Compost quality, assessed using the CQI, classified Heap 2 (fallen leaves + sheep manure) as good quality (4.06) and Heap 1 (green waste + sheep manure) as moderate quality (2.47), corresponding to differences in microbial dynamics and compost stability. These findings demonstrate that open windrow co-composting is a practical, low-cost, and effective method for safe organic waste management. It supports sustainable agriculture by improving soil health, minimizing environmental and public health risks, and providing guidance for optimizing composting protocols to meet regulatory safety standards. Full article

With the growing demand for eco-friendly food packaging, poly(butylene adipate-co-terephthalate) (PBAT)/polylactic acid (PLA) composite films have emerged as promising biodegradable alternatives, but their inherent limitations (e.g., poor antioxidant capacity, weak UV stability, and insufficient antimicrobial activity) hinder practical applications. This study aimed to address these drawbacks by incorporating Rosmarinus officinalis L. extract (RM) as a natural multifunctional additive. PBAT/PLA/RM blend films with RM concentrations of 0.1%, 0.3%, 0.5%, and 1% were fabricated via melt extrusion and blown film processing. Key characterizations were conducted to evaluate thermal stability, mechanical properties, morphology, antioxidant activity, UV-shielding performance, antimicrobial efficacy, and biodegradability. The results showed that RM significantly enhanced the antioxidant capacity of the films, with the highest DPPH radical scavenging activity achieved at 0.3% RM. UV-blocking performance improved incrementally with increasing RM concentration, and films containing ≥0.5% RM filtered over 90% of UVA and UVB radiation. All composite films met biodegradability standards, with over 90% degradation observed after 240 days of composting, though RM prolonged the initial degradation stage by inhibiting early microbial activity. However, the antimicrobial effect of RM was limited, and concentrations exceeding 1% caused film stickiness, impeding processing. This work demonstrates that RM is a viable natural additive for functionalizing PBAT/PLA films, offering enhanced antioxidant and UV-shielding properties while maintaining biodegradability, thus providing a promising solution for sustainable food packaging. Full article

This study evaluated the effects of applying fecal sludge-based co-compost (CC) integrated with chemical fertilizers on soil nutrient status, organic carbon (OC) storage, and economic returns in paddy soils. Ten integrated nutrient management (INM) treatments were tested, i.e., BRRI recommended dose of fertilizer (RDF), CC 5.0 t ha⁻¹, RDF + CC 2.0 t ha⁻¹, RDF + CC 1.5 t ha⁻¹, RDF + CC 1.0 t ha⁻¹, RDF + CC 0.5 t ha⁻¹, 75% RDF + CC 2.0 t ha⁻¹, 75% RDF + CC 1.5 t ha⁻¹, 75% RDF + CC 1.0 t ha⁻¹, and 75% RDF + CC 0.5 t ha⁻¹. Two rice varieties were cultivated over two consecutive seasons—winter rice (boro) and monsoon rice (aman)—in the experimental field. Soil samples (0–15 cm) were collected before and after the seasons and fractionated into labile particulate organic matter (>53 µm) and stable mineral-associated organic matter (<53 µm). Bulk soils and CC were analyzed for OC, nitrogen (N), phosphorus (P), potassium (K), sulfur (S), and heavy metals, while the fractions were analyzed for OC and N. Across both seasons, 75% RDF combined with 2.0 t ha⁻¹ or 1.5 t ha⁻¹ of CC consistently showed the highest OC, total N, and soil C stock, with moderate P, K, and S levels. Sole RDF produced the lowest OC and N. Among fractions, stable OC was the highest in the 75% RDF + 2.0 t ha⁻¹ CC treatment, statistically similar to 75% RDF + 1.5 t ha⁻¹ CC, and the lowest under RDF alone. Economically, sole RDF yielded the highest profit, while full RDF + CC achieved competitive returns. Reduced RDF + CC treatments (75% RDF + 1.5 or 2.0 t ha⁻¹ CC) offered slightly lower returns but improved soil sustainability indicators. Overall, applying 75% RDF + 1.5 t ha⁻¹ CC provided the most cost-effective balance of nutrient enrichment, soil C stock, and profitability. This CC-based INM approach reduces chemical fertilizer dependency, enhances soil health, and promotes sustainable waste management, supporting environmentally resilient rice production. Full article

This study investigated the effects of different Effective Microorganism (EM) inoculation concentrations (0%, 0.5%, 2%, 5%, 10%, 15%) on the co-composting of Auricularia heimuer residue with chicken manure and the subsequent growth of maize. The aim was to enhance composting efficiency and promote maize productivity. Results showed that EM addition, particularly at medium concentrations, significantly accelerated the composting process by shortening the heating phase and prolonging the thermophilic period, with the 10% treatment reaching >50 °C by day 2. The 5–10% EM treatments markedly promoted the degradation of cellulose and hemicellulose, and enhanced key enzyme activities (e.g., cellulase and hemicellulase) during composting and maize growth stages. Regarding soil nutrients, the 5% EM treatment led to the most balanced increases in total nitrogen (TN), total phosphorus (TP), and total potassium (TK) contents, with rises of 58.7%, 47.8%, and 130.4%, respectively, during the seedling stage. For maize yield, this treatment enhanced total grain weight, hundred-grain weight, and root activity by 25.7%, 30.9%, and 53.2%, respectively, while also increasing dry matter and root weight. Redundancy and correlation analyses indicated strong positive relationships among root activity, soil TN, cellulase activity, and final yield. In conclusion, EM inoculation at 5–10% optimizes the composting process, improves substrate quality and nutrient supply, and promotes maize root development and yield, with 5% EM offering the most comprehensive benefits. This study provides a practical approach for agricultural waste recycling and sustainable maize cultivation. Full article

Background: Municipal solid waste management is a relevant component of climate and air quality policy, yet published life cycle assessments report inconsistent conclusions on whether sanitary landfilling, waste-to-energy incineration, composting, or anaerobic digestion yields the lowest greenhouse gas and co-pollutant impacts because results depend strongly on methodological choices and local context. Objective: To synthesize and critically evaluate how key life cycle assessment assumptions and boundary decisions influence reported emissions across major waste management pathways, with primary emphasis on the United States and selected comparison to European Union policy frameworks. Methods: Peer-reviewed life cycle assessment studies and supporting technical and regulatory sources were reviewed and compared, focusing on functional unit definition, system boundaries, time horizon, energy substitution and crediting methods, and treatment of methane, nitrous oxide, and air pollutant controls; drivers of variability were identified through structured cross study comparison and sensitivity-focused interpretation. Results: Reported pathway rankings vary primarily with landfill gas collection and utilization assumptions, the carbon intensity of displaced electricity or heat for waste-to-energy systems, and the representation of biological process emissions across active and curing stages; harmonized comparisons reduce variability but do not yield a single consistently superior pathway across all plausible settings. Conclusions: Comparative conclusions are context-dependent and policy-relevant interpretation requires transparent reporting and sensitivity analysis for capturing efficiency, substitution factors, and biological emission controls, along with clear alignment between modeled scenarios and real-world operating conditions. Full article

Peppers are of substantial economic importance and hold a prominent position among vegetables rich in health-promoting compounds, which drives continuous efforts to develop improved cultivation strategies. The study aimed to determine the effects of substrate type and depolymerized chitosan on the physiological parameters, the chemical composition of leaves and fruits, and the yield of two bell pepper cultivars: ‘Marta Polka’ and ‘Oda’. The plants were grown in a 100% peat substrate and in a mixture of peat, wood fiber (Pinus sylvestris), and green compost (2:1:1 v/v/v), with or without drenching with a solution of depolymerized chitosan. Results indicated that the growing medium, chitosan application, cultivar type, and their interactions altered several physiological, morphological, and biochemical traits. The highest total fruit weight fresh (471.23 g plant⁻¹) was obtained for the ‘Marta Polka’ cultivar grown in peat drenched with chitosan, whereas the lowest (192.02 g plant⁻¹) was recorded for ‘Oda’ grown in a substrate mix without the biostimulant. Net CO₂ assimilation rate, stomatal conductance, fresh weight of fruit, and antioxidant activity (ABTS and FRAP assays) were improved in the ‘Oda’ cultivar grown in the substrate mix and treated with depolymerized chitosan compared with plants grown in 100% peat without chitosan. The ‘Marta Polka’ plants grown in the substrate mix and treated with chitosan had a higher net CO₂ assimilation rate, photosynthetic water-use efficiency, total free amino acid content, and antioxidant activity (FRAP assay) than those grown in peat alone and not treated with the biostimulant. The results demonstrate that both substrate composition and the response to depolymerized chitosan are cultivar-specific, and that wood fiber and compost can serve as ecological alternatives to peat, enhancing overall pepper fruit quality. Full article

Garden waste is a solid waste produced by plant littering or pruning. Improper disposal can easily pollute the environment. The addition of bulking agents (BAs) can improve the efficiency of organic waste composting. In this study, garden waste and dairy manure were used as raw materials, and easily available and recyclable branches were used as bulking agents to realize the synergistic resource utilization of the two. Three treatments were set up in the experiment, and 10% crushed branches, 1 cm branches, and 3 cm branches were added to the raw materials, respectively. The results showed that compared with the control group (adding crushed branches), the addition of 1 cm branches and 3 cm branches increased the cellulose degradation rate by 13.16–13.33% and the hemicellulose degradation rate by 18.24–23.86%. The monitoring results of CO₂ release showed that the cumulative CO₂ release of the treatment groups with 1 cm and 3 cm branches was 78.56 L and 102.17 L, respectively, which was significantly higher than that of the crushed branches (67.24 L), indicating that the addition of 1 cm and 3 cm branches increased microbial activity and degradation efficiency. Microbial diversity analysis further showed that in the treatment group with 1 cm branches, the number of nodes in the co-occurrence network increased by 24.11% and 2.84%, respectively, compared with the crushed branches and 3 cm branches, and the number of edges increased by 44.25% and 19.72%, forming the most abundant and complex microbial community, which verified its promotion effect on the composting process from the microbial level. In summary, this study recommends the use of branches with a particle size of 1 cm as BAs for garden waste composting. Full article

Annually, up to 15 million tons of coffee production waste are produced worldwide. Among them are spent coffee grounds (SCG), which have the potential to be recycled and used as organic fertilizers. However, their direct application to soil is limited due to the presence of ecotoxic compounds (phenols, tannins, and caffeine). Composting is a promising approach; however, the highly variable properties of the raw coffee materials require the selection of optimal production and application modes. In this study, we performed two composting methods for SCG, i.e., vermicomposting and microbial composting, in mixtures with co-composting substrate at five SCG/substrate ratios (0, 25, 50, 75, and 100% SCG). First, the acute toxicity of raw SGC and its mixtures to earthworm Eisenia andrei was evaluated. After 30 days of composting, chemical and microbiological properties, including pH, RedOx potential (Eh), organic carbon (C_org), lignin content, bacteria count, diversity, and potential metabolic activity, were determined in the end products. As composting went on, the pH increased from 5.6–6.2 to 6.0–7.3 and 7.4–7.7 under microbial composting and vermicomposting, respectively. RedOx potential levels achieved 142–166 mV for microbial composting and 73–113 mV for vermicomposting. Organic matter (OM) content reached 86–94%, with an increasing proportion of lignin, demonstrating the decomposition of more readily accessible organic matter. Vermicomposting and microbial composting produced chemically safe and microbiologically highly active composts. An initial SCG content of 25–50% of the compost mixture’s weight yielded the most favorable properties for the resulting compost (high organic matter content and optimal pH levels). Due to the high biological activity of both composting methods, the resultant composts are likely to have a positive effect on plant growth and development and soil health when used as organic nutrient resources. Full article

Objective. To determine how bamboo loadings (2.5–5 wt%) and compatibilization with PBAT-g-MAH (BP-1, 10 wt%) affect melt flow and early-time mineralization of PLA biocomposites under near-ambient soil–compost conditions (ASTM D5988), while using PBAT-g-GMA (BP-2) only as a melt-flow screening reference. Methods. Melt flow index (MFI, ASTM D1238, 2.16 kg; 190/210/230 °C) was first measured for neat PLA and PLA/BP-1/BP-2 blends to select a printable matrix. PLA/10BP-1 composites containing 2.5–5 wt% bamboo were then compounded, extruded as bars for biodegradation tests, and validated by FFF printing. Biodegradation was quantified from titrimetric CO₂ evolution in soil–compost reactors at 21 ± 2 °C and pH ≈ 7 (triplicate specimens plus triplicate blanks; mean ± SD and endpoint statistics). ATR-FTIR was used to support mechanistic interpretation. Results. BP-1 markedly increased MFI relative to neat PLA, whereas BP-2 remained close to the neat matrix, consistent with epoxy-driven coupling that can raise viscosity. Under ambient burial, all materials exhibited very low mineralization over 0–23 days; PLA/10BP-1/2.5B and PLA/10BP-1/5B showed a slight increase in net CO₂ evolution compared with neat PLA, but the differences remained modest and within the experimental uncertainty, reflecting a balance between bamboo’s pro-hydrolytic effect and the sealing action of PBAT-g-MAH compatibilization. Significance. The data delineate a printing–degradation window in which PLA/10BP-1 with 2.5–5 wt% bamboo combines easy processing and short-term durability while preserving industrial compostability at end-of-life. Full article

Wastewater generated in municipal rendering facilities requires multi-step treatment, but it may also serve as a source of nutrients and water and thus may be valorized before or instead of the necessary wastewater treatment operations. In this work, wastewaters from a composting plant were utilized to support the growth of Miscanthus x giganteus, known as both a remediation plant and an energy biomass source. A pot experiment was established to compare the effects of different wastewater doses (0, 50, 100, and 200 mL per pot per week) on the miscanthus biomass yield, phytoextraction of heavy metals, biomass heat of combustion, and plant condition. The increase in the wastewater dose resulted in increases in both biomass yield (from about 44 to 139%) and biomass heat of combustion (from 7 to 17%) when compared to the control sample, with no adverse effects on plant physiological parameters. The highest concentrations of metals were found in miscanthus grown with the highest dose of wastewaters. It was found that higher wastewater dose correlates to both higher phytoextraction and phytorecovery of metals from plant substrate and wastewaters. The highest metal uptake was identified for Fe (431 mg·pot⁻¹), followed by Al, Zn, Mn, Cu, Ni, Cr. The lowest metal uptake was noted for Pb, Co and Cd (0.88, 0.11, and 0.95 mg·pot⁻¹, respectively). The results indicate that miscanthus can be recommended for industrial wastewater treatment. In addition, due to high absorption efficiency of the substrate components, miscanthus can be used as a remediation tool, e.g., for the ecological stabilization of remediation of metal-polluted soils, especially in municipal facilities like rendering plants. This presents a circular perspective for the valorization of post-fermentation wastewaters with subsequent growth of energy crops, with other potential benefits for the environment, such as soil treatment, absorption of CO₂, and air purification. Full article

Composting is an effective biotechnological process for transforming agro-industrial residues into stabilized and nutrient-rich organic amendments. However, the molecular mechanisms underlying organic matter transformation remain poorly resolved. In this study, a mixture of winery by-products and poultry manure was composted under controlled aeration and monitored through high-field ¹H NMR spectroscopy of the water-extractable organic matter (WEOM), followed by interval-based chemometric analysis. The NMR spectra revealed distinct compositional trends, including the rapid depletion of amino acids and carbohydrates, the transient accumulation of low-molecular-weight organic acids, and the gradual enrichment in aromatic and phenolic compounds associated with humification processes. Chemometric modeling using Partial Least Squares (PLS) regression and its interval variants (iPLS and biPLS) enabled accurate prediction of composting time (r ≈ 0.95) and identification of diagnostic spectral intervals corresponding to key metabolites. These findings demonstrate the capability of NMR-based molecular profiling, combined with multivariate modeling, to elucidate the biochemical pathways of composting and to provide quantitative indicators of compost stability and maturity. Full article

Different types of polymeric materials are used as footbeds in shoes. Environmental degradation behavior of polymeric footbed materials is an important parameter for understanding materials’ environmental footprint. Most of the previous studies focus on geotextiles, polymeric insulation materials, and exposure behaviors that are not the same due to the nature of applications of geotextiles and insulations being completely different from the footbeds. There is a lack of studies to understand artificial weathering, the influence of physical–chemical factors, and the subsequent behavior of different types of footbeds. In this paper, we have selected three needle-punched nonwoven footbed materials and studied their environmental degradation behavior by subjecting them to artificial weathering using different exposure durations, viz. 120 h, 240 h, and 360 h. The physical–chemical properties of polymeric footbed materials were characterized by Fourier-Transform Infrared Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC), and thermogravimetric analysis (TGA). The selected polymeric footbed materials were made from recycled polyester (RPET), hemp, and shoddy fibers. Furthermore, the RPET footbed was tested for biodegradation in soil and compost conditions for 120 days. The footbed materials were also tested for physical and performance (tensile and abrasion resistance) properties. Hemp footbed materials undergo abiotic degradation after 120 h, but in the case of RPET, it undergoes abiotic degradation after 360 h, resulting in a fragmentation process due to synergistic effects of chemical and hydrolytic degradations. From the DSC results, RPET undergoes a slight thermal transition under abiotic degradation after 360 h, indicating that environmental abiotic factors influence degradation behavior. The tensile and abrasion resistance properties of RPET were the highest, followed by hemp and shoddy materials. The tensile strength range of the materials was between 50.74 and 851.44 N. The weight loss range after abrasion resistance was 0.016–0.014%. From the RPET biodegradation test in soil and compost conditions, the evolved CO₂ was 20% and 59%, respectively, after 110 days. The DSC and TGA results indicate that the hemp footbed materials have a higher rate of abiotic degradation as compared to the RPET and shoddy footbed materials. From the RPET biodegradation test in soil and compost conditions, the CO₂ degradation values were 20% and 59%, respectively. The obtained degradation results indicate that the synergistic effect of abiotic and biotic conditions greatly influences footbed materials’ biodegradation under natural environmental conditions. Full article

Municipal solid waste (MSW) management in Brazil faces significant challenges related to waste segregation, collection efficiency, and environmentally adequate disposal. This study quantifies the carbon emissions associated with organic solid waste management, from 2022 to 2034, in the city of João Pessoa (Northeast Brazil). To this end, the Life Cycle Assessment methodology is applied to two scenarios: Scenario 1 (where all organic fraction is landfilled) and Scenario 2 (progressive implementation of composting for the domestic organic waste, starting in 2023, with increases each year until reaching 50% in 2034, and the remainder being landfilled). The latter is proposed based on the targets established in the Municipal Solid Waste Plan of João Pessoa. Projection for MSW considered a per capita rate of 0.86 kg/inhab.day, combined with a population growth rate of 1.92%/year. The results indicate that Scenario 1 emits 825 Mt CO₂-eq while Scenario 2 emits 704 Mt CO₂-eq for the study period (a reduction of 15%). A sensitivity analysis examined the effects of increasing transport distance (25–45 km) and the organic fraction of MSW (35–45%) on GHG emissions. Although total emissions rose under both conditions, the comparative environmental advantage of composting over landfilling remained stable. These results confirm the robustness of the analysis and reinforce composting as a low-carbon, effective strategy for managing urban waste. Full article

Biodegradable chitosan/poly(vinyl alcohol) (PVA) composite films were reinforced either with nanocrystalline cellulose (CNC) or nano-lignocellulose (NLC) and evaluated across a polyparametric design of five matrix ratios and three filler levels for active food packaging applications. ATR-FTIR, DSC, XRD, and SEM demonstrated that 1–5% nanocellulose loading induced a single relaxation temperature (T_g), homogenized the morphology, and enhanced the crystallinity of blend material, evidencing improved thermodynamic compatibility. SEM confirmed uniform filler dispersion up to 5% loading in PVA-rich matrices, whereas limited aggregation appeared in chitosan-dominant systems. CO₂ barrier property (CO₂ permeability coefficients) was diminished by more than two orders of magnitude and fell below 0.01 Barrer in CNC-filled 25-75 and NLC-filled 75-25 blends, while permeability to O₂ and N₂ remained undetectable under identical conditions. Meanwhile, Young’s modulus increased to 3.9 GPa, and tensile strengths of up to 109 MPa were achieved, without affecting the ductility in specific loading values. These data confirm that tailored selection of the filler/matrix combination, rather than elevated nanocellulose content, can simultaneously optimize barrier performance and mechanical integrity. The study therefore offers a scalable, water-based route for producing optically transparent nanocomposite membranes that satisfy either strict modified atmosphere or/and rigid packaging applications and advance the transition toward compostable/or even edible high-performance food contact materials. Full article