Search Results (356)

Nature-Based Solutions (NBS) are recognized as urban strategies to face environmental degradation and climate change vulnerability to address social challenges. However, NBS are context-dependent and must be based on evidence. Thus, this document details the NBS implementation in a global south city such as Tijuana, a semiarid city at the Mexico–USA border, which has rapidly grown under poor urban planning, widespread irregular settlements, increase in air and water pollution, and limited green spaces. In response, six hectares of a severely eroded slope have been transformed by El Colef into Ecoparque, an Urban Resilience Laboratory. This academic initiative aims to enhance residents’ quality of life by analyzing environmental problems, raising awareness, and engaging the community, in addition to identifying opportunities for implementing NBS. This paper presents the 32 years’ experience of implementing NBS at Ecoparque, such as a constructed wetland as part of a wastewater treatment, reforestation with native plants grown in an in situ nursery, soil restoration using its own-produced compost, and urban ecosystem rehabilitation. Moreover, main challenges and upscaling opportunities are identified to adopt NBS in a Global South city. Results showed that the most relevant problems have been insufficient human and financial resources, as well as the lack of a proper legal framework. This study provides an analytical significance that could be useful to apply under similar contexts. Full article

Livestock manure is a major source of environmental pollution and greenhouse gas emissions if improperly managed. Aerobic composting represents a sustainable approach to manure recycling that can stabilize organic matter, mitigate carbon loss, and recover nutrients for agricultural use. In this study, sheep manure was mixed with sawdust to optimize the carbon-to-nitrogen (C/N) ratio and enhance aeration, and the mixture was subjected to aerobic composting with a cellulose-degrading microbial inoculant. To rigorously evaluate the biological effects, a control treated with sterilized inoculant was included to eliminate nutrient inputs from the carrier matrix. The inoculant significantly improved composting performance by extending the thermophilic phase by five days and reducing the C/N ratio to 19.8 on day 32, thereby shortening the composting cycle. Moreover, microbial inoculation enhanced nutrient retention, resulting in a 20.14% increase in total nutrient content, while the germination index (GI) reached 89.75%, indicating high compost maturity and reduced phytotoxicity. Microbial community analysis revealed that cellulose-degrading inoculants significantly altered microbial richness and diversity and accelerated community succession. Redundancy analysis (RDA) and hierarchical partitioning analysis showed that total organic carbon (TOC) and GI were the main environmental drivers of bacterial community dynamics, whereas pH and GI primarily regulated fungal community succession. These findings suggest a strong link between compost maturity and microbial community restructuring. This study demonstrates that cellulose-degrading microbial inoculation accelerates the composting of sheep manure, enhances organic matter degradation, and improves fertilizer efficiency while reducing the phytotoxicity of the final product. Full article

Italian inner areas face population decline, limited access to services and fragile infrastructure; however, the micro-mechanisms through which community practices generate tangible improvements often remain unclear. Still, local communitarian initiatives, such as those represented by ecovillages, can be an effective response to the ongoing process of marginalisation, becoming true living labs for place-based transitions. Through the analysis of the Torri Superiore Ecovillage (Imperia, Italy), a recognised and well-known good practice in the national and international ecovillage circuit, we want to find answers to three research questions: (RQ1) To what extent can an ecovillage act as a living lab for social innovation and ecological transition in inner areas? (RQ2) Which demographic and governance conditions enable territorial resilience and which ones block it? (RQ3) Which environmental practices generate locally significant improvements and with what limitations? Based on qualitative and interpretative evidence (2016–2025)—field observations, internal documents and testimonies—and on essential demographic indicators (ISTAT/SNAI), this study examines the Torri Superiore Ecovillage as a small-scale living lab. Torri Superiore and the surrounding municipalities are ageing and have reduced demographic bases; however selective immigration and heterogeneity of skills act as partial buffers. The governance of the Torri Superiore Ecovillage combines clear rules, participatory routines and coordination mechanisms, promoting problem solving while remaining sensitive to leadership burdens. The “bridging” between multiple actors enables terrace maintenance, local water resource management, agroecological practices, renewable energy adoption, waste prevention/composting and light mobility to achieve tangible environmental improvements on a small scale. We frame transferability as analytical (not statistical), specify the enabling conditions (sufficient active participants, stable routines, territorial management) and outline the relevant policy implications for SNAI classes and a lightweight longitudinal observatory. Full article

The increasing challenges posed by climate change demand holistic approaches to mitigate ecosystem degradation. In Mediterranean-type regions—biodiversity hotspots facing intensified droughts, fires, and biological invasions—such strategies are particularly relevant. Among invasive species, Acacia longifolia produces substantial woody and leafy biomass when removed, offering an opportunity for reuse as soil-improving material after adequate processing. This study aimed to evaluate the potential of invasive A. longifolia Green-waste compost (Gwc) as a soil amendment to promote soil recovery and native plant establishment after fire. A field experiment was carried out in a Mediterranean ecosystem using Arbutus unedo, Pinus pinea, and Quercus suber planted in control and soils treated with Gwc. Rhizospheric soils were sampled one year after plantation, in Spring and Autumn, to assess physicochemical parameters and microbial community composition (using composite samples) through Next-Generation Sequencing. Our study showed that Gwc-treated soils exhibited higher moisture content and nutrient availability, which translated into improved plant growth and increased microbial richness and diversity when compared with control soils. Together, these results demonstrate that A. longifolia Gwc enhances soil quality, supports increased plant fitness, and promotes a more diverse microbiome, ultimately contributing to faster ecosystem recovery. Transforming invasive biomass into a valuable resource could offer a sustainable, win–win solution for ecological rehabilitation in fire-affected Mediterranean environments, enhancing soil and ecosystem functioning. Full article

Inefficient chromium (III)–collagen cross-linking during leather tanning generates solid waste and effluents containing residual chromium, raising environmental and health concerns. Biological strategies are increasingly popular for tannery waste treatment, but the microbial communities involved in leather degradation remain poorly understood. This study did not seek to evaluate leather disintegration according to standardised compostability criteria, but to establish a thermophilic composting system suitable for characterising leather-associated microbial communities, biofilm formation on leather and isolating cultivable strains. Composting assays were carried out at two scales, in which wet blue leather was mixed with organic compost under self-heating thermophilic conditions. Temperature was monitored, and mass loss and changes in leather structure were determined by gravimetry and scanning electron microscopy. Bacterial and fungal communities in compost with and without leather were analysed using high-throughput amplicon sequencing. Thermophilic consortia dominated by Firmicutes, Actinobacteria and Ascomycota were established, and several bacterial isolates and a filamentous fungus were recovered. Together, these results provide a first basis for understanding the communities and strains associated with chromium-tanned leather during thermophilic composting, supporting future searches for microorganisms and enzymes of interest for biological strategies to manage chromium-tanned leather waste. Full article

Humus is the core product and key indicator of compost maturity. How to improve the humus content and accelerate its formation in composting is critical for the improvement of compost quality. This study investigated the effects of adding compost derived from different stages including thermophilic, cooling, and maturation phases on compost initiation and efficiency in terms of humus formation and microbial community dynamics. The results reveal that adding compost from the cooling stage markedly outperforms the thermophilic and maturation phases, achieving a germination index of 107.22%, a carbon-to-nitrogen ratio of 15.95, a humus content of 91.12 g/kg, a humic acid concentration of 71.49 g/kg, and a polymerization degree of 3.64. EEMs indicated that the cooling-phase additive increased humic-like fluorescence (Region V) at day 35. The abundance and diversity of humifying bacteria were significantly enriched, and the succession of microbial community was accelerated as confirmed by redundancy analysis. This approach also improved compost quality and reduced the overall composting duration, thus suggesting that using compost from the cooling phase as an additive is an effective way to increase the humus content and accelerate the humification, providing a green solution for organic waste recycling and sustainable agricultural development and production. 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

The mobilization of complex microbial communities from natural resources can be a valuable alternative to the use of single-species biofertilizers when it comes to the decomposition of plant residues. However, the functioning and interaction of microorganisms within these communities remain largely unexplored. Our task was to investigate the cellulose-degrading community using the biofertilizer BAGS (peat-based compost with straw) as an example and define its active component. For this, we monitored the succession of the biofertilizer’s taxonomic composition during two consecutive rounds of its six-month composting process, varying in the applied mineral fertilization. The amount of added nitrogen significantly affected the performance of the biofertilizer, contributing to its high cellulolytic activity. Based on the network analysis, the biofertilizer’s mature phase was determined, and its characteristic ASVs (amplicon sequence variants) were described. Metagenomic analysis of this phase revealed MAGs (metagenome-assembled genomes) corresponding to these ASVs, which contained genes for cellulose and aromatics degradation, as well as genes for nitrogen and sulfur pathways, including anaerobic nitrate reduction and thiosulfate oxidation. Thus, we propose that the cellulose-decomposing bacterial component of BAGS, associated with the mature phase, occupied different trophic niches, not limited to cellulose degradation, which should be considered when designing natural or artificial microbial systems for the decomposition of plant residues. Full article

This study presents an observational analysis of the chemical and microbial dynamics of cattle manure compost during maturation in a system inoculated with Lactobacillus acidophilus. Composting samples were collected at D15 and D60 to assess changes in key nutrient parameters and microbial community shifts from the early stage to the composting phase. At D60 in this inoculated composting system, ammonium nitrogen (NH₄⁺-N), potassium (K), phosphorus (P), calcium (Ca), magnesium (Mg), and total nitrogen (T-N) levels were higher than at D15, with NH₄⁺-N measuring 813.01 and 1714.24 mg/kg at D15 and D60, respectively (p < 0.001). Microbial analysis based on 16S rRNA gene sequencing showed that alpha diversity was slightly lower at D60 than at D15, although this difference was not statistically significant; in contrast, the community composition shifted toward a higher relative abundance of Firmicutes and lower relative abundances of Bacteroidetes and Proteobacteria. Mantel correlation analyses indicated strong associations between specific bacterial phyla and manure chemical properties, particularly between Firmicutes and levels of NH₄⁺-N, chloride, and sodium. PICRUSt2-based functional prediction further suggested that mature compost samples had a higher predicted representation of genes associated with nitrogen- and energy-related pathways, including arginine and polyamine biosynthesis and butanoate fermentation. This observational study outlines how nutrient profiles, microbial communities, and PICRUSt2-predicted functional potentials change over time in a composting system amended with L. acidophilus. By documenting these characteristic patterns, our results provide a useful reference for focusing future research on specific nutrient–microbe–function linkages in lactic acid bacteria-amended composting systems, and for interpreting compost maturation in such systems within the context of sustainable agricultural practice. Full article

Island ecosystems, are characterized by isolation, limited land, and tourism-driven economies, face persistent waste management challenges. Spatial constraints and inadequate infrastructure often limit the development of waste recovery and recycling systems, leading to practices such as open dumping or burning that pose serious environmental and health risks. This paper examines how circular economy (CE) principles, reduce, reuse, recycle, can transform waste into a resource and enhance local resilience. A refined definition of “small islands” is introduced, combining UN criteria with a tourism-intensity filter to capture the strong link between visitor flows and solid waste generation. Barriers to CE adoption are classified into institutional, technical, geographical, financial, and social dimensions, and connected to enabling practices in four thematic areas: multi-stakeholder partnerships, recycling and composting innovations, policy and regulatory tools, and community engagement. Comparative case studies from Europe, Asia, Africa, and the Pacific reveal that integrated approaches are more durable than isolated efforts. Successful initiatives blend technology with governance, education, financial mechanisms, and community participation. The analysis highlights that no single model fits all islands; strategies must be locally adapted to be effective and transferable. Overall, the study shows that circular transitions are both feasible and necessary, offering environmental gains, economic value, and alignment with the EU Green Deal and global sustainability goals. Full article

Composting is a useful way to reduce and recycle agricultural and forestry waste; however, low-temperature environments can inhibit the microbial processes involved in composting. Spent mushroom substrate has a high lignocellulose content, making it particularly difficult to decompose. There is a need to explore methods for effectively promoting microbial activity and enhancing composting efficiency under low-temperature conditions. This study explored the use of C/N ratio adjustments and a microbial inoculum (PLC-8; comprising Proteobacteria, Bacteroidetes, Actinobacteria, Firmicutes, Basidiomycota, Ascomycota, and Cryptomonadales) to improve spent mushroom substrate composting in a low-temperature environment. The temperature, lignocellulose content, pH, and gas emissions were measured during composting, and the microbial community structure was determined to explore associations between biotic and abiotic factors. Compost piles with PLC-8 entered the high-temperature period in 25 days, which was 15 days earlier than the control pile. When the C/N ratio was adjusted to 30:1 and PLC-8 was applied, the cellulose and hemicellulose degradation rates after 60 days were 88.04% and 71.95%, whereas the control group only exhibited degradation rates of 25.39% and 35.64%. Moreover, PLC-8 significantly increased CH₄ and CO₂ emissions and reduced nitrous oxide emissions. Microbial community analysis showed that Proteobacteria and Ascomycota were the dominant phyla in the piles with PLC-8, and these phyla were responsible for lignocellulose decomposition and carbon metabolism. Full article

Antibiotic resistance genes (ARGs) and microbial communities in pig and cow dung from rural China were systematically profiled using high-throughput quantitative PCR arrays and 16S rDNA amplicon sequencing to assess their environmental dissemination and public health risks. The abundance and diversity of ARGs were markedly higher in pig dung than in cow dung. A total of 56 ARGs were enriched in pig dung, including β-lactamase genes (blaCMY, blaCTX-M) and macrolide resistance genes (ermB, ermF), along with several genes related to aminoglycoside and macrolide–lincosamide–streptogramin B resistance. In contrast, only eight ARGs were enriched in cow dung. Microbial community analysis revealed that cow dung was dominated by UCG-005, UCG-010, Methanocorpusculum, and Fibrobacter, taxa typically associated with ruminant digestion. In pig dung, Ignatzschineria, Lactobacillus, Pseudomonas, Streptococcus, Treponema, and conditional pathogens such as Escherichia coli and Leptospira were significantly enriched, indicating higher pathogen-related risks. Functional prediction identified 26 KEGG level-2 and 136 level-3 pathways, showing stronger xenobiotic degradation and amino acid metabolism in pig dung, whereas cow dung was enriched in energy metabolism and chemotaxis pathways. Moreover, the higher abundance of mobile genetic elements (e.g., intI1 and IS613) in pig dung suggests a greater potential for horizontal ARG transfer. Integrating ARG, microbial, and pathogen data reveals that pig dung acts as a composite source of “ARG–pathogen” contamination with enhanced transmission potential. These findings provide localized, data-driven evidence for developing safer livestock waste management practices, such as composting and biogas utilization, and contribute to antibiotic resistance mitigation strategies in rural China. Full article

The conversion of agricultural residues into high-value organic amendments is fundamental to sustainable farming systems. Corn cobs represent a widely available lignocellulosic resource; however, their rigid structural properties often hinder efficient biodegradation during composting. This study evaluated whether optimizing corn cob particle size could improve aerobic composting performance by enhancing humification and compost quality. Corn cobs were ground into three particle sizes (6-mesh, 10-mesh, and 20-mesh) and composted with a commercial microbial inoculant for up to 51 days. Physicochemical properties, humic substance fractions (HSC, HAC, FAC), microbial community dynamics (16S rRNA and ITS sequencing), and maturity indicators were monitored. The 10-mesh treatment (M10) exhibited the most favorable composting outcomes, achieving the greatest degree of humification (HA/FA = 2.85; HAC = 48.30 g/kg) and the most pronounced aromatic condensation in humic acids. M10 also supported a more diverse and metabolically specialized microbial consortium, with notable enrichment of lignocellulose-degrading and humus-forming genera (e.g., Streptomyces, Thermobifida). Consequently, M10 produced the most mature compost, reflected by the highest germination index (93.63%) and the lowest heavy-metal accumulation, meeting agricultural safety standards. Structural equation modeling revealed that particle size influenced humification primarily by modulating microbial community structure (path coefficient = 0.86), highlighting particle size as a key environmental selector in composting systems. Overall, 10-mesh particle size created an optimal aeration–moisture balance that stimulated microbial metabolism, accelerated organic matter degradation, and enhanced stable organic matter formation. These findings demonstrate that corn cob particle size significantly governs composting efficiency and final product quality. Selecting a 10-mesh size presents a practical pretreatment strategy to accelerate biomass turnover and produce safe, nutrient-rich compost, providing an effective approach for sustainable bioconversion of agricultural residues. Full article

Over 292 million tons of municipal solid waste (MSW) are generated annually in the United States, with more than half disposed of in landfills. Municipal solid waste landfills (MSWLFs) are stationary sources of air pollution and potential health risks for nearby communities. The Agency for Toxic Substances and Disease Registry (ATSDR) has completed over 300 public health assessments (PHAs) and related investigations at MSWLFs and open dumps since the 1980s. This paper reviews the ATSDR’s evaluations of air pathway concerns at 125 MSWLF sites assessed between 1988 and early 2025, with many being evaluated during the 1990s. Most sites were located in the Midwest and Northeast, and only 25% remained active. The ATSDR found no air-related public health hazard at 86% of sites. At sites where hazards were identified, common issues included elevated outdoor or indoor toxicants (e.g., hydrogen sulfide, benzene, trichloroethylene, and mercury) and unsafe methane accumulations. Contributing factors included older site designs, inadequate gas-collection, subsurface fires, and distance from nearby residences. Corrective actions effectively reduced exposures at the affected sites. Results suggest that well-located and maintained landfills minimize public health hazards, while aging or poorly managed sites pose risks. Continued monitoring and research are warranted as waste management shifts toward reducing, reusing, recycling, composting, and energy-recovery technologies to improve efficiency, advance technologies, and address systemic public health challenges. Full article

The intensification of agricultural practices and the consequent dramatic decrease in soil organic matter has increased the use of organic fertilizer to recover soil fertility and plant productivity. The aim of this study was to compare the effect of three amendments obtained from the recycling of urban and agri-food wastes on rhizosphere microbial community, soil, and plant nutrient status. The experiment was carried out on rhizobox-grown, 1-year-old vines of Sangiovese (Vitis vinifera L.), grafted onto 110 Richter (V. berlandieri × V. rupestris) planted in April 2023. Twenty-four rhizoboxes were filled with soil collected from a field trial in which three types of amendments had been applied since 2019. In detail, the complete randomized experimental design (with four replications) compared the following treatments: (1) municipal organic waste compost (ACM), (2) agri-food organic waste compost (ACF), (3) defecation gypsum (GDD), and (4) a control that received 60 kg of N ha⁻¹ year⁻¹ (CK). The application of the amendments increased the soil concentration of total C, total N, and pH. The application of ACM increases soil K and Zn and the concentration of N and K in plant roots. The application of all the amendments increased leaf N concentration in comparison with CK, but only ACF increased leaf P. ACM was the most effective in promoting microbial biodiversity, increasing phyla like Bacillota, Pseudomonata, and Bacteroidota, including genra like Bacillus, Neobacillus, Paenibacillus, and Pseudomonas. ACF promoted Nitrosospherota and Chitinophaga, and GDD promoted Chloroflexota and Agrobacterium. Full article