Circular Economy

Chem Asian J. 2026 Sep;21(17):e70970. doi: 10.1002/asia.70970.

ABSTRACT

Novel Cu/Cu₂O-nanoparticles have been synthesized by the most economical electrochemical method utilizing metallic waste. 4-NP is a toxic pollutant affecting both animal and plant kingdom, necessitating its elimination from environment. This study demonstrates that the prepared nano-catalysts efficiently catalyse the reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) at room temperature under light condition. Further, the reduction process generates amine derivatives, which are intermediates in many industrial processes. This manuscript adheres to the principles of the circular economy by generating nanoparticles through the repurposing of metallic waste discarded by both industry and domestic users. Using scrapped copper from discarded air conditioner (AC) copper tubes as electrodes, we employed an electrochemical technique to develop Cu/Cu₂O nanoparticles. The synthesized nanoparticles were characterized using field emission scanning electron microscopy (FE-SEM), transmission electron (TEM), EDX spectroscopy, powder x-ray diffraction (P-XRD), Fourier transformation infrared (FTIR) spectroscopy, x-ray photoelectron spectroscopy (XPS), Raman spectroscopy, cyclic voltammetry (CV), and Brunauer-Emmett-Teller (BET) analysis. Our study confirms 99% conversion of harmful 4-NP to 4-AP in a rapid reaction time of 5 min. Synthesized nanoparticles can be reused up to four times without losing catalytic activity. UV-vis spectroscopy demonstrated that reduction follows pseudo-second-order kinetics and adsorption follows Freundlich isotherm model.

PMID:42668400 | DOI:10.1002/asia.70970

Sci Adv. 2026 Aug 28;12(35):eaeg8495. doi: 10.1126/sciadv.aeg8495. Epub 2026 Aug 28.

ABSTRACT

Polyvinylidene fluoride (PVDF), a widely used recalcitrant per- and polyfluoroalkyl substance (PFAS) polymer, poses environmental challenges in its defluorination because conventional thermal methods release toxic volatile fluorinated compounds (VFCs). Here, we report an electrochemical water-mediated strategy for efficient, VFC-free PVDF defluorination under ambient conditions. The method achieves a high fluorine-to-fluoride conversion (93%) and is validated with an industrially relevant capacity of 8.5 kg·m^-3·day^-1 on real wasted battery electrodes containing PVDF as the binder. The high efficiency originates from the spatial confinement of electrochemically generated hydroxide ions near the cathode surface. Mechanistically, isotopic labeling and kinetic Monte Carlo simulations reveal water's unprecedented dual role as both a reactant and a catalyst, driving an ionic pathway that fundamentally suppresses VFCs. This offers a scalable, sustainable, and nontoxic alternative for the critical challenge of C─F breaking and PFAS defluorination.

PMID:42664343 | PMC:PMC13524013 | DOI:10.1126/sciadv.aeg8495

Waste Manag. 2026 Aug 28;226:115835. doi: 10.1016/j.wasman.2026.115835. Online ahead of print.

ABSTRACT

Thermochemical conversion of food waste into biochar offers a compelling circular economy pathway for soil amendment, yet comprehensive safety assessments remain limited. This study assessed the stability, contaminant fate, nutrient leaching, and microbial compatibility of bone and mixed vegetable biochars pyrolyzed at 300-600 °C. Feedstock identity dominated variance in yield, ash, and carbon (η² = 0.73-0.91), whereas temperature governed the volatile heteroatoms H, O and N (η² = 0.44-0.74; all p < 0.001). At 600 °C, bone retained higher yield (60.3 ± 0.7 % vs 34.4 ± 0.7 %) and appreciable porosity (118.0 m²/g), whereas vegetable biochar showed negligible surface area (≤1.0 m²/g) yet preserved a carbon-rich matrix (59.5 ± 0.5 % vs 11.5 ± 1.3 % C). Vegetable biochar attained thermal stability (H/C < 0.7) by 400 °C, while bone did not cross this threshold. Bone was nutrient-dense (Ca 145,285 ± 25,963; P 73,321 ± 18,435 mg/kg), but its ions remained matrix-bound, raising leachate pH/EC only to 8.5 ± 0.18 and 235.7 ± 7.9 µS/cm versus 10.3 ± 0.08 and 1,202.5 ± 6.4 µS/cm for K-rich (25,325 ± 5,060 mg/kg) vegetable biochar, releasing far more labile ions (Na 96.4 % vs 44.8 %; p < 0.001). Mild pyrolysis (300 °C) eliminated key agrochemical and pharmaceutical contaminants (carbamazepine, pyrimethanil, o-hydroxybiphenyl) without generating EPA-priority polycyclic aromatic hydrocarbons; industrial plasticizers persisted at 600 °C, highlighting the need for upstream feedstock screening. Pyrolysis reduced dissolved organic carbon to < 10 mg/L, lowering colony counts to control levels, unlike raw bone (59-fold higher, p = 0.001). Bone biochar thus functions as a slow-release mineral scaffold, while vegetable biochar confers liming potential for acidic soils, manageable by pre-washing. Pyrolysis severity and feedstock selection are jointly critical to biochar safety.

PMID:42664606 | DOI:10.1016/j.wasman.2026.115835

J Environ Qual. 2026 Sep-Oct;55(5):e70250. doi: 10.1002/jeq2.70250.

ABSTRACT

Microplastic pollution is an emerging global concern, with fibrous microplastics (FMPs) representing a dominant class that poses a particular danger due to their persistence and high aspect ratios. FMPs originate from both industrial and consumer activities, with wastewater treatment plants acting as a major transmission pathway. Despite extensive research on microplastics, a morphology-focused understanding of FMP sources, transport pathways, environmental fate, and biological impacts has remained limited. The present study integrates a systematic literature synthesis with a bibliometric analysis using VOSviewer to identify global research hotspots and trends on FMPs. Bibliometric analysis shows that 80% of publications have been led by China, the United States, and European countries in the past 5 years. Thematic clustering reveals textiles, polyester fibers, and wastewater systems as dominant research nodes. Global studies reported a 6.3-fold increase in the production of synthetic microfibers between 1980 and 2015, with the laundering of textiles projected to release over 22 million tonnes of microplastic fibers between 2015 and 2050. Across both industrial and municipal wastewater treatment systems, FMPs consistently emerge as the dominant morphology, accounting for 50%-92% of detected microplastics in treated effluents. This review also identifies a conserved tri-modal impact pattern of FMP exposure, mechanical disruption, oxidative inflammatory activation, and chemical vectoring, highlighting fiber morphology as a critical determinant of ecological and physiological vulnerability across biodiversity. In conclusion, this comprehensive review aims to contribute to the existing scholarship of FMPs and urges the development of strategies, sustainable textile innovations, and targeted research on FMPs and advanced removal technologies to limit their environmental footprint.

PMID:42665786 | PMC:PMC13525083 | DOI:10.1002/jeq2.70250

iScience. 2026 Aug 19;29(9):117248. doi: 10.1016/j.isci.2026.117248. eCollection 2026 Sep 18.

ABSTRACT

Biochar with low cost, green, and renewable characteristics is an important research direction for porous carbon electrode materials at present. Herein, nitrogen-doped hierarchical porous carbon was prepared from Weigela japonica waste biomass through the hydrothermal-KOH activation-N doping collaborative strategy. By tuning the melamine dosage, the pore structure and electrochemical performance were systematically regulated. The optimized NWJPC-2 exhibited a specific surface of 2,916 m² g^-1 and delivered 318.8 F g^-1 at 1 A g^-1. A symmetric supercapacitor retained 99.8% of its capacitance after 10,000 cycles. When assembled into a zinc-ion hybrid capacitor, NWJPC-2 achieved 109.5 mAh g^-1 at 0.5 A g^-1 and an energy density of 44.7 Wh kg^-1 at 225.0 W kg^-1, with 99.9% capacity retention after 10,000 cycles. This research confirms that waste offering a straightforward and efficient approach to developing sustainable electrode materials for energy storage and enabling the high-value conversion of waste biomass resources.

PMID:42662864 | PMC:PMC13521071 | DOI:10.1016/j.isci.2026.117248

F1000Res. 2026 Mar 26;15:439. doi: 10.12688/f1000research.172412.1. eCollection 2026.

ABSTRACT

PURPOSE: Achieving Sustainable Development Goal 9 (SDG 9)-which promotes resilient infrastructure, inclusive and sustainable industrialization, and innovation-is central to global economic, social, and environmental progress. This study investigates the implementation of SDG 9 across 120 countries using an integrative Theory-Context-Characteristics-Methodology (TCCM) framework.

DESIGN/METHODOLOGY/APPROACH: The TCCM framework synthesizes sustainable development theory, innovation diffusion models, infrastructure resilience concepts, and industrial ecology principles to examine interdependencies among infrastructure quality, technological innovation, and institutional capacity. A mixed-methods design combines panel regression and difference-in-differences analyses with qualitative interviews involving policymakers and industry leaders from high-, medium-, and low-performing countries.

FINDINGS: Quantitative analysis demonstrates that governance quality, research and development investment, and digital connectivity significantly influence infrastructure and innovation outcomes. Qualitative insights highlight institutional capacity as a key moderating factor shaping policy effectiveness and resource allocation. Results reveal reciprocal feedback loops: improved infrastructure enhances innovation diffusion, while technological progress reinforces system resilience. Sectoral and regional comparisons show that high-income economies display mature infrastructure-innovation linkages, whereas low-income countries struggle with governance and financing constraints. Energy and manufacturing sectors lead in eco-efficiency through circular economy adoption, while transport systems lag in rural connectivity.

ORIGINALITY/VALUE: This study contributes a comprehensive analytical model that integrates theoretical and empirical perspectives on sustainable industrialization. The TCCM framework unifies diverse literature streams and offers a practical tool for assessing SDG 9 progress.

PRACTICAL IMPLICATIONS: Policy recommendations include the establishment of resilient infrastructure standards, promotion of digital inclusion, strengthening of public-private partnerships, and enhancement of institutional capacity. The framework provides a replicable approach for policymakers, industry practitioners, and researchers seeking to accelerate sustainable industrialization and innovation aligned with the 2030 Agenda.

PMID:42661595 | PMC:PMC13507844 | DOI:10.12688/f1000research.172412.1

ACS Omega. 2026 Aug 14;11(33):49280-49298. doi: 10.1021/acsomega.6c02141. eCollection 2026 Aug 25.

ABSTRACT

Inadequate waste-management practices have led to significant environmental impacts, requiring the development of sustainable valorization alternatives. The exponential growth of plastic waste represents a major challenge that must be addressed through coordinated global strategies. Among polymers, polyethylene terephthalate (PET) is one of the most produced and used worldwide, mainly for food and beverage packaging. It offers significant opportunities for the implementation of circular economy practices due to its inherent properties. Chemical processes can effectively return PET to its original components by molecular transformation, facilitating its reintegration into the production cycle. This study established a sustainability assessment for the chemical valorization of PET waste, incorporating technological, economic, environmental, and social dimensions with their corresponding indicators, all based on data compiled from a comprehensive literature review. The technological dimension was defined to allow the decision-maker to compare the technological readiness level (TRL) of each pathway. A Sustainability Index (SI), using selected indicators, was developed and applied to evaluate seven chemical valorization pathways. The sustainability assessment identified the top three alternatives in a base case: glycolysis as the most sustainable pathway (SI = 0.20), followed by basic hydrolysis (∼0.22) and microbiological degradation (∼0.25). Additionally, a sensitivity analysis was conducted by varying the level of importance of the dimensions, revealing the most influential factors for each valorization pathway. These findings underscore the potential of these alternatives to address the complex challenge of PET waste management, offering more sustainable solutions compared to conventional practices such as landfilling or incineration.

PMID:42662234 | PMC:PMC13519995 | DOI:10.1021/acsomega.6c02141

ACS Omega. 2026 Aug 11;11(33):50517-50530. doi: 10.1021/acsomega.6c07059. eCollection 2026 Aug 25.

ABSTRACT

The valorization of agro-industrial waste for producing sustainable and functional packaging is a key strategy within the circular economy and green chemistry. This study developed active antioxidant edible films by incorporating a phenolic-rich extract from yellow passion fruit seeds into two composite polysaccharide matrices: β-glucan/carboxymethyl cellulose (BG/CMC) and β-glucan/citrus pectin (BG/PEC). The phenolic extract, obtained through a sequential ultrasound-assisted extraction from defatted yellow passion fruit seeds, was incorporated into the film-forming solutions at different concentrations (0, 57, 114, and 190 μg GAE/mL), which were subsequently cast and dried. The films were thoroughly characterized. Both film series exhibited excellent UV light barrier properties and homogeneous morphology. The BG/CMC films were fully water-soluble and showed the highest antioxidant activity (up to 19.42 μmol TE/g by TEAC assay) at the highest extract concentration. In contrast, BG/PEC films demonstrated superior and enhanced mechanical properties when loaded with the highest extract amount, achieving a balanced combination of tensile strength (3.64 MPa) and elongation at break (20.84%). Structural analyses (FTIR, XRD, and TGA) confirmed the successful incorporation of the extract and revealed an amorphous structure with good thermal stability. The BG/PEC films showed visible enhancement on thermal stability with the incorporation of the phenolic extract, in any concentration, with a final mass loss near 30%. All films showed good synergy within the matrices ingredients, corroborated by the FTIR spectra where the main bands were still present. The results demonstrate that the choice of the polysaccharide matrix (CMC vs pectin) dictates the final functional profile of the active film. This work successfully transforms passion fruit processing waste into tailorable, antioxidant edible films, providing sustainable alternatives for active food packaging applications.

PMID:42662381 | PMC:PMC13520549 | DOI:10.1021/acsomega.6c07059

Food Chem X. 2026 Aug 15;38:104310. doi: 10.1016/j.fochx.2026.104310. eCollection 2026 Aug.

ABSTRACT

Pomelo processing by-products, traditionally regarded as agricultural waste, are underutilized bioactive-rich candidate feedstocks for circular economy. This study optimized isolation protocol (differential centrifugation with PEG precipitation) for Pomelo Peel Exosome-Like Nanoparticles (PPELNs), uniform nanovesicles (195.8 ± 78.6 nm) with gastrointestinal stability. Proteomic analysis identified 1145 proteins enriched in carbohydrate, energy, amino-acid metabolism and stimulus response. In vitro human fecal fermentation model demonstrated PPELNs intervention altered gut microbiota, increased beneficial taxa (Bifidobacterium, Blautia, Phascolarctobacterium) and suppressed Escherichia-Shigella, suggesting potential prebiotic effects. Metabolomic profiling revealed elevated bioactive compounds (naringenin 7-rhamnoglucoside, auraptenol). PPELNs fermentation enhances short-chain fatty acids (SCFAs), including acetic, propionic, butanoic and valeric. Further analysis showed microbiota-metabolite correlations. Propionic, butyric and auraptenol positively correlated with Blautia but negatively with Escherichia-Shigella; naringenin 7-rhamnoglucoside positively correlated with Phascolarctobacterium and Ruminococcus. These findings upcycle pomelo peel into a high-value functional ingredient, provide the first evidence establishing specific metabolite-microbe correlations.

PMID:42662859 | PMC:PMC13521061 | DOI:10.1016/j.fochx.2026.104310

Environ Sci Pollut Res Int. 2026 Aug 28. doi: 10.1007/s11356-026-38174-0. Online ahead of print.

ABSTRACT

This study presents a comprehensive experimental research study to investigate the feasibility of utilizing mechanically activated ferrochrome slag (FCS) as a supplementary cementitious material (SCM) for manufacturing eco-friendly mortar, aiming to address the pressing need to reduce the energy-intensive production of ordinary Portland cement (OPC). Two types of slag, air-cooled (AC-FCS) and water-cooled (WC-FCS), were used to partially replace ordinary Portland cement (OPC) at substitution levels of 5% to 35% (in 5% increments) to determine the effect of the cooling process of FCS on the mortar performance. The examination includes key parameters such as flowability, fresh and hardened density, porosity, compressive strength, flexural strength, ultrasonic pulse velocity (UPV), microstructural study of the blended mortar, rapid chloride permeability and mechanical performance at elevated temperatures. Chemical composition, crystallinity and amorphousness of the FCS samples were determined using X-ray fluorescence (XRF) and X-ray diffraction (XRD) tests. The research is filling the gap of comparative evaluation of mechanically activated AC-FCS and WC-FCS as supplementary cementitious materials in the cement mortar. The analysis confirmed that FCS exhibits pozzolanic characteristics similar to Class F fly ash. Mortars containing up to 15% WC-FCS had comparable or higher 28-day compressive strength than the control mix. The optimum performance was observed at 10% WC-FCS, where compressive strength rose by 16% along with better chloride resistance and thermal performance. The findings highlight WC-FCS as an effective SCM, fostering circular economy goals in the construction sector.

PMID:42665743 | DOI:10.1007/s11356-026-38174-0

Curr Biol. 2026 Aug 28:S0960-9822(26)00933-4. doi: 10.1016/j.cub.2026.07.034. Online ahead of print.

ABSTRACT

Reproductive behaviors are critical to the sustainability of wild fish populations and are threatened by the presence of potent endocrine-disrupting chemicals.^1,2,3 Laboratory studies have routinely shown that key behaviors (e.g., nesting and aggression) of male fish are reduced following exposure to hormone mimics,^4,5,6,7 yet the applicability of these findings to nature and consequences for wild populations are unknown. Here, we quantified, in situ, the reproductive behavior of male fathead minnows (Pimephales promelas) before, during, and after (spanning 12 years in total) a 3-year period in which the synthetic estrogen, ethinylestradiol (EE2, ∼5 ng/L) was added to an experimental lake, while also recording fish in nearby unmanipulated reference lakes.^8,9 In contrast to expectations, nesting males showed heightened aggression during the exposure period that was triggered by the unexpected presence of more conspecifics at nest sites. Consequently, paternal care became more fragmented, males spent less time at the nest, and they had fewer eggs in their nests. These altered breeding dynamics, including marked reductions in male secondary sexual characteristics, contributed to a population collapse during EE2 amendments. Our findings underscore that social interactions in natural systems provide a challenging but necessary arena in which to pursue ecotoxicological studies if we are to understand whether risk assessments meaningfully protect wild populations.

PMID:42664962 | DOI:10.1016/j.cub.2026.07.034

Nat Commun. 2026 Aug 27;17(1):9153. doi: 10.1038/s41467-026-76965-8.

ABSTRACT

Carbon is the foundation of life and industrial production, but the current use of fossil-based carbon in a linear economy leads to climate breakdown with global ecological consequences. To mitigate the effects of the climate catastrophe, transitioning from a fossil-based linear economy to a circular carbon economy requires scalable strategies that do not compete with arable land resources. Accordingly, processes for the utilization of waste streams from various sources including CO₂ must be established to enable circularity. Here, we propose synthesis gas (syngas; CO, H₂ and CO₂) as a universal, homogenized hub feedstock that decouples upstream waste heterogeneity from downstream chemical and biotechnological manufacturing. We review established and emerging routes for syngas production from biogenic and fossil-derived wastes and discuss their integration with thermocatalytic upgrading and biological gas fermentation. Advances in aerobic and anaerobic microbial assimilation and hybrid abiotic-biotic systems enable the selective conversion of syngas and syngas-derived intermediates such as methanol, acetate and ethanol into a broad spectrum of fuels, chemicals and materials. We argue that syngas-based value chains provide a flexible, carbon-agnostic platform for closing carbon loops across sectors and geographies. Realizing this vision will require (i) further quantitative exploration to identify optimal waste-to-product strategies; (ii) continued innovation in catalyst and bioprocess engineering, continuous operation concepts; and (iii) supportive policy frameworks that incentivize chemical recycling and gas-based carbon utilization as core pillars of the circular economy.

PMID:42660936 | PMC:PMC13522546 | DOI:10.1038/s41467-026-76965-8

Nat Commun. 2026 Jul 29;17(1):9177. doi: 10.1038/s41467-026-75803-1.

ABSTRACT

Recovery of precious metals from waste has high social and economic value, but in practice, recycling is often inefficient due to limits in technologies and materials. Here we show a group of materials-two-dimensional (2D) metallic 1 T/1 T' phase transition metal dichalcogenides (TMDs, MoS₂, WS₂, TaS₂, and TiS₂)-that allows for efficient, selective, and scalable extraction of valuable gold (Au) from leaching solutions of end-of-life electronics. The materials exhibit rapid kinetics, delivering an impressive 99.99% extraction efficiency of Au³⁺ in merely 0.25 min. Furthermore, they showcase strong selectivity for Au³⁺ adsorption, featuring a distribution coefficient (K_d) 5-6 orders of magnitude higher than that of other competitive cations (Cu²⁺, K⁺, Ni²⁺, Na⁺, Zn²⁺, Ca²⁺, and Mg²⁺). Amongst, TiS₂ exhibits an unprecedented extraction capacity of 9093 mg⋅g^-1 toward Au³⁺, which is approximately 1 order of magnitude higher than most other benchmark adsorbents (silver-organic frameworks). Importantly, through batch production of TiS₂ nanosheets (5 g) and subsequent membranes fabrication for gold extraction, we demonstrated 0.15 g gold (23.8 Karat) recovery by treating 30 discarded central processing units (CPUs). Our work provides a foundation for the efficient and selective recovery of high-value metals from waste, contributing to a sustainable and circular economy.

PMID:42660871 | PMC:PMC13521935 | DOI:10.1038/s41467-026-75803-1