Search Results (417)

A controlled composting biodegradation system was implemented to evaluate a wood–plastic composite (WPC) composed of wood fibers and recycled HDPE (rHDPE), in accordance with ASTM D5338, by measuring CO₂ capture over 45 days. This evaluation was complemented with mechanical and physicochemical characterization, including stereomicroscopy/SEM, mass loss, water absorption, contact angle, tensile strength, FTIR, TGA, and DSC. The results showed 6.12% biodegradation, classifying the material as neither biodegradable nor compostable. SEM analysis revealed increased surface roughness, cracks, and microbial-like structures, together with a 10% decrease in contact angle. The mechanical properties declined by 33% (tensile strength), despite only 1.26% mass loss, which was attributed to weakening of the matrix–fiber interfacial adhesion due to water absorption. TGA, DSC, and FTIR supported the interpretation that degradation occurred preferentially in the wood fibers. Full article

The main sources of biodegradable waste come from agriculture and municipal waste, with animal manure and food waste (FW) being the most representative respectively. Most of this waste remains still unexploited, while there is skepticism regarding the environmental footprint of various methods of their utilization. This work provides a reliable comparative environmental evaluation using life cycle assessment (LCA). In the present work, LCA applied to compare two alternative scenarios regarding the management of (a) sheep and goat manure and (b) FW. Alternative scenarios for sheep and goat manure include composting for fertilizer and energy production via anaerobic digestion (AD), while FW scenarios include incineration and energy production through AD. In both case studies, the AD scenario generates environmental benefits (expressed as negative damage) across all three damage categories namely resource scarcity, human health and ecosystem quality. Regarding sheep and goat manure, the most significant effect of AD is on human health (−0.016 Pt) while in the scenarios of FW the superior performance of AD is particularly evident in the ecosystem quality (−0.21 Pt). Both case studies reached the same conclusion pointing out that the use of sustainable technologies for managing agricultural and municipal waste mitigates the environmental impacts. Full article

Environmental concerns with petroleum-based polymers have accelerated the development of biodegradable alternatives, making poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) a promising candidate for sustainable packaging. However, its functional performance necessitates modification through blending. In this study, blends containing 65–85 wt.% polylactide (PLA) were investigated to establish structure–property relationships relevant to compostable packaging. The results reveal partial miscibility of the blends and pronouncedcomposition-dependent changes in morphology and thermal behavior, characterized by an increase in glass transition temperature and a decrease in PLA melting temperature. Increasing PLA content (≥80 wt.%) enhanced thermal stability, increasing the degradation temperature to 288.0 °C. In contrast, higher PHBV content (≥25 wt.%) significantly improved barrier properties of PLA, reducing oxygen and water vapor transmission rates to 74.47 cm³ m⁻² day⁻¹ and 29.11 g m⁻² day⁻¹, respectively. Biodegradation behavior revealed complete degradation of PHBV after 56 days, whereas PLA showed only 1.29% mass loss under identical conditions. In the blends, biodegradation proceeded preferentially through the PHBV phase, resulting in composition-dependent mass loss. Among the investigated compositions, PLA65/PHBV provided the most balanced combination of barrier performance, mechanical behavior, and biodegradation response. Overall, these findings demonstrate that tailoring composition enables the design of polymer systems for sustainable packaging applications. Full article

Microbial biodegradation represents a promising approach to addressing global plastic pollution, yet the metabolic pathways and environmental origins of polymer-degrading microorganisms remain incompletely characterized. This review synthesizes current knowledge on biodegradation mechanisms across major polymer classes and identifies key environmental reservoirs harboring native plastic-degrading microbiota. Biodegradation pathways differ fundamentally according to polymer chemistry. Polyesters such as PET undergo hydrolytic cleavage by PETases and MHETases, releasing terephthalic acid and ethylene glycol for assimilation via the β-ketoadipate pathway and the TCA cycle. Biodegradable polyesters (PLA, PBAT, PHAs, PCL) are similarly hydrolyzed by cutinases, lipases, and depolymerases. In contrast, polyolefins (PE, PP) and polystyrene lack hydrolyzable bonds and require oxidative attack by laccases, peroxidases, and alkane monooxygenases, followed by β-oxidation to acetyl-CoA. Three principal environmental reservoirs supply plastic-degrading microorganisms: contaminated ecosystems including landfills and the plastisphere; soil microbiota contributing ligninolytic fungi and actinomycetes; and compost environments yielding thermostable enzymes such as leaf-branch compost cutinase. Across all environments, microbial consortia demonstrate superior degradation efficiency compared to single-species cultures, reflecting the enzymatic complexity required for complete polymer mineralization. Understanding these pathways and their environmental origins provides a foundation for biological plastic waste management strategies. Full article

The depletion of natural resources has emerged as a major global concern, accelerating the transition from petroleum-based to renewable materials. The development of biobased ‘active’ materials is emerging especially in food packaging to ensure safety and functionality. Such packaging systems containing bioactive ingredients provide effective antioxidant, antimicrobial, and UV-protective features extending food shelf life. In this context, plant-derived secondary metabolites have gained substantial interest as functional reinforcements. These compounds not only provide food protection but also contribute to environmental safety owing to their inherent biocompatibility, biodegradability, and compostability. However, their high production costs remain a major challenge to large-scale applications. Therefore, the valorization of agro-food byproducts/wastes has been increasingly promoted. This review aims to discuss the combined use of plant secondary metabolites and biopolymers for the development of innovative packaging solutions, highlighting recent advances and functional performance. Furthermore, key challenges limiting their real-world applicability are addressed. In particular, the intrinsic hydrophilicity of many biobased materials compromises their moisture barrier and mechanical stability. To overcome this limitation, the use of biobased hydrophobic ingredients including natural waxes has emerged as a sustainable and effective approach to enhance water resistance while preserving the bioactive functionality of the packaging materials. Full article

Inadequate management of urban organic waste generates significant environmental impacts, including the accumulation of biodegradable residues and greenhouse gas emissions. Composting represents a key biotechnological strategy for the valorization of organic waste; however, its efficiency may be limited by long stabilization periods. This study evaluated the effect of a microbial consortium composed of Klebsiella oxytoca, Sphingomonas paucimobilis, and Pantoea spp. on the composting of organic waste generated at a higher education institution in Colombia using the Earthgreen SAC-2250 Autonomous Composting System. Four treatments based on different proportions of organic waste (OW) and sawdust (DM) were evaluated, and the best-performing formulation was subsequently inoculated with the microbial consortium and compared with a non-inoculated control pile. The 3:1 ratio (OW:DM) showed the best performance, reaching compost stabilization within 45 days. Inoculation with the microbial consortium reduced the stabilization time by approximately 20 days compared with the control treatment. These results demonstrate that microbial bioaugmentation using selected environmental isolates can significantly accelerate organic matter degradation and improve the efficiency of composting systems, providing a promising strategy for sustainable organic waste management in institutional environments. Full article

The use of bio-based and biodegradable plastic products (BBpPs) ensures the mitigation of environmental effects of fossil-based plastics, especially in humanitarian crises where waste management is challenging. Polyhydroxyalkanoates (PHAs) are promising biodegradable biopolymers that are biocompatible and do not cause microplastic pollution. However, experimental assessment of PHA biodegradation is challenged by its time- and resource-intensiveness. In this study, a comprehensive computational Quantitative Structure–Activity Relationship (QSAR)-based approach was developed to predict biodegradability of short chain length (scl)-PHA-based formulations consisting of various additives and building blocks. A novel curated dataset for the (scl)-PHA poly(-3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), with literature-reported environmental and biodegradation parameters from lab-scale experiments in soil, marine, freshwater and compost systems, was constructed and used to develop and validate the introduced approach. Random forest (RF) and Extreme Gradient Boosting (XGBoost) machine learning (ML) models were optimized and validated with cross-validation and test set predictions. The optimal models reported high accuracy values of the coefficient of determination R², indicating excellent relationships between structure and biodegradation metrics. Further analysis of descriptor variable importance confirmed that biopolymer biodegradability was favorably affected by biodegradation time, while mechanisms, environmental conditions, and additives contributed secondary yet physically consistent effects. The proposed QSAR framework demonstrated a robust and interpretable web-based tool for predicting the environmental fate of PHBV in natural environments and supported the sustainable safe-by-design (SSbD) approach of next-generation biodegradable polymers. Full article

Microplastics (MPs), defined as plastic particles ranging in size from 0.1 μm to 5 mm, have gained significant scientific attention worldwide due to their widespread occurrence and potential risks for human health and the environment. MPs can accumulate in water and soil, affecting organisms across multiple trophic levels and negatively impacting agricultural productivity and animal husbandry. Agricultural practices, such as plastic mulching, compost, and sewage sludge application, contribute to environmental plastic contamination, while irrigation and wastewater reuse facilitate their transport and deposition across ecosystems. Given the limited efficiency and high costs of physicochemical remediation methods, microbial biodegradation has attracted growing attention as a potentially sustainable strategy. This review focuses primarily on the metabolic potential of bacteria and fungi and the mechanisms underlying MP degradation. In the context of environmental safety, such studies are of particular importance. Under optimal laboratory conditions, reported microbial degradation efficiencies varied with microplastic type, microbial strain(s), and experimental conditions, ranging from 4% to >97%. Moreover, the literature review identifies key barriers to practical application, including environmental variability and the limited transferability of laboratory findings to field settings. Future research should therefore prioritize testable, application-oriented approaches. Addressing these gaps is essential to developing effective microbial degradation strategies for mitigating microplastic pollution. Full article

Rising industrial demand for carbon monoxide (CO) motivates the development of sustainable pathways for its production. Composting has recently emerged as a potential biogenic CO source, yet the role of biowaste moisture in CO production has remained unquantified. In this study, the moisture dependence of CO generation during composting was assessed to address this knowledge gap. Laboratory-scale biowaste composting was conducted under mesophilic conditions (45 °C) with passive aeration for the initial 14-day phase, using three initial moisture levels: 31.6% (variant M100), 21.6% (M90), and 12.6% (M80), and periodic H₂O addition in M100 and M90. Monitoring of CO, CO₂, and O₂ concentrations, complemented by scanning electron microscopy of composts, revealed a non-monotonic moisture effect on CO formation. The intermediate-moisture treatment (M90; ~41–50%) was associated with the highest CO production, reaching a maximum of 681 ppm and 18.2 mg CO∙kg wet mass⁻¹, whereas high moisture (M100; ~51–64%) with lower CO levels (max. 276 ppm, 4.4 mg CO∙kg wet mass⁻¹), matrix compaction, elevated CO₂ and lower O₂ concentrations. The driest treatment produced trace CO (<20 ppm, max. 0.4 mg CO∙kg wet mass⁻¹) and retained a rigid, porous microstructure consistent with limited biodegradation. The results showed rapid but transient CO pulses after H₂O addition, implicating moisture-driven shifts in biological activity and/or abiotic formation. These findings identify an optimal moisture window for reproducible CO generation. Full article

In municipal wastewater treatment plants (WWTPs), anaerobic digestion of municipal mixed sludge (MMS) often yields low energy recovery and operational instability due to imbalances between primary and secondary sludges. Anaerobic co-digestion (AcoD) with readily biodegradable wastes, such as fruit and vegetable waste (FVW), can enhance process stability and biogas production. Life cycle assessment (LCA) methodology is used in this study to evaluate the environmental performance of implementing AcoD of MMS and FVW in a municipal WWTP, compared with a business-as-usual scenario combining mono-digestion of MMS and incineration of FVW. The LCA was modelled in openLCA 2.5 using the ecoinvent 3.9.1 database (cut-off allocation approach), and impacts were assessed with the ReCiPe 2016 Midpoint (H) method, focusing on climate change, terrestrial acidification, fossil fuel depletion, and marine eutrophication. Results indicate that AcoD reduces impacts across all environmental categories, mainly due to higher biogas yields that increase on-site electricity generation and decrease reliance on grid electricity. Improved total solids removal also lowers digestate production and composting-related burdens. Electricity consumption remains the main hotspot in both scenarios, highlighting the importance of energy efficiency and electricity mix. Sensitivity analysis on methane content (61–65% v/v) confirms the robustness of AcoD’s environmental benefits. Full article

Polyhydroxyalkanoates (PHAs) emerge as promising biodegradable polymers for sustainable applications, yet predicting their biodegradation behavior under different environmental conditions remains challenging. In this study, we propose a novel data-driven computational framework for predicting biodegradation-induced weight/mass loss in PHA-based materials. A comprehensive database of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV)-based formulations was manually curated by systematically collecting and harmonizing material descriptors, environmental parameters, and experimental biodegradation outcomes from laboratory- and large-scale studies conducted in soil, marine, freshwater, and compost environments. Multiple regression-based quantitative structure–activity relationship (QSAR) models were developed and rigorously validated, demonstrating high predictive performance and strong correlations between polymer structure, environmental conditions and degradation behavior. “Exposure time”, “degradation environment” and “hydroxybutyrate (HB) ratio” were identified as the most important features for weight loss. Finally, the predictive model was integrated into the Jaqpot computational platform, enabling open access and facilitating data-driven assessment and design of biodegradable polymer systems. Full article

The limited existing studies elucidate the significant contribution of open dumpsites to greenhouse gas emissions in Sri Lanka and underscore the necessity of improved waste management practices. Considering this, this study formulates and implements a scenario-based transition framework to assess the potential for reducing greenhouse gas emissions by diverting biodegradable waste in a semi-urban governance setting in Sri Lanka, which is marked by data limitations and operational challenges. This study concludes that the environmental feasibility analysis reinforces the potential benefits of solid waste compost adoption in municipal solid waste management and agriculture. Greenhouse gas emissions (CO₂, CH₄, and N₂O) were analyzed using the IPCC Tier 1 methodology. The findings revealed that the total emissions declined significantly from 163.10 tonne CO₂ eq/month to 99.31 tonne CO₂ eq/month. The results indicate that diverting biodegradable waste to composting can play a crucial role in climate mitigation in semi-urban contexts, while promoting organic farming. These findings represent the first scenario-based GHG quantification in a semi-urban context in Sri Lanka, addressing a governance level that has received negligible attention in the composting and waste management literature. The scenario-based evaluation framework offers indicative guidance for municipalities in similarly constrained developing contexts, although direct applicability is contingent on comparable waste compositions, governance structures, and operational conditions. Full article

The initial carbon-to-nitrogen (C/N) ratio is a fundamental parameter for aerobic composting, with a generally recommended optimal range of 25:1 to 30:1. However, in practical applications, the optimal C/N ratio often deviates from the recommended value. We attribute this discrepancy to the limitations of traditional stoichiometric methods in assessing the bioavailability of carbon and nitrogen sources. This study investigated how carbon bioavailability governs composting efficiency and product quality. Laboratory-scale aerobic composting experiments were conducted using six types of raw crop straws and two physically pretreated straws, representing a biodegradability gradient. Results demonstrated that carbon bioavailability significantly modulated the composting performance. Substrates rich in labile carbon pool (LCP), such as wheat straw and extruded cassava plant residue, demonstrated superior thermogenesis, humification, and seed germination indices compared to those dominated by recalcitrant carbon pool (RCP), such as untreated cassava plant residue. Principal component analysis confirmed a strong positive correlation between LCP content and key quality indicators. Microbiological analysis revealed that carbon source variations shaped bacterial succession: Bacteroidota abundance correlated positively with LCP, driving rapid initial degradation, whereas Pseudomonadota were more abundant in RCP-rich treatments, suggesting a role in complex polymer breakdown. This study confirmed that carbon bioavailability, rather than the bulk C/N ratio alone, is a critical limiting factor. This finding logically extends to the role of nitrogen bioavailability, suggesting that a “biochemical C/N ratio”—accounting for the lability of both carbon and nitrogen—could be a more accurate predictor of aerobic composting performance. Full article

This research focuses on developing bioplastic films using agrifood industrial waste, which included starch from avocado seed, cellulose from cornstalk, carrot and beet peel, and pulp from a food company in México. The films were produced with a matrix of gelatin and glycerol, and different formulations of starch and cellulose. The films were characterized and tested as wrappers of Manchego cheese. The films containing starch are transparent; films with cellulose showed opacity and paper-like structure. Films containing starch–cornstalk cellulose showed the highest hydrophobic properties. In turn, films with carrot cellulose had the highest plastic properties with high elongation capacity and the lowest Young modules; films with starch and other celluloses showed the opposite data. The highest thermal capacity was observed in films containing cellulose from cornstalks and beet waste. In turn, the highest temperatures of transition, crystallization, and melting were registered in films containing starch. Films with starch and cellulose served well as wrappers of Manchego cheese, conserving 92% of the weight of cheese after 21 days of storage at 4 °C. All films were biodegradable in compost after 10 days, and they were degradable by physicochemical factors after 40 days. Full article

Compost-based biostimulants (CBB) have emerged as a promising tool in sustainable agriculture, offering an eco-friendly approach to improving soil health, crop productivity, and environmental resilience. Derived from the controlled biodegradation of organic waste, CBB contains a diverse array of beneficial microorganisms, humic substances, and bioactive compounds that act synergistically to stimulate plant growth and soil biological activity. Mechanistically, CBB enhances nutrient acquisition by increasing plant-available nitrogen and phosphate solubility, promoting root development through phytohormone synthesis, and improving stress tolerance by modulating plant defense pathways and antioxidant activity. Additionally, their application enhances soil structure, microbial diversity, and carbon sequestration, making them integral to climate-smart agriculture. Despite their growing relevance, several challenges impede the widespread adoption of CBB. Variability in compost quality, lack of standardized production protocols, limited field-scale validation, and inconsistent regulatory frameworks hinder reproducibility and commercialization. Addressing these gaps requires interdisciplinary research that integrates microbiology, biochemistry, agronomy, and data science to better understand how microbial metabolites interact and optimize formulation strategies. Future research should prioritize the standardization of composting methods, long-term multi-crop field evaluations, and integration with precision agriculture tools for real-time soil monitoring. Policy harmonization, quality assurance frameworks, and farmer education are also vital for ensuring safe and effective use of CBB. Full article