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Recycling Composite Food Packaging: Recovering and Valorization of Individual Components

2026-06-12T10:04:48Z

Title: Recycling Composite Food Packaging: Recovering and Valorization of Individual Components Authors: Mourão, Paulo; Coelho, David; Marques, Carolina; Assis, Carolina; Panizio, Roberta; Nobre, Catarina; Brito, Paulo Editors: Sérgio Brito, Paulo; Sanches Galvão, João; Almeida, Henrique; Rosa Ferreira, Liliana; Flores de Oliveira Gala, Pedro Abstract: Paper composite packaging, increasingly used in various sectors including food, offers benefits like enhanced product preservation. However, its recycling poses challenges due to the difficulty in separating its components, leading to waste accumulation in landfills or incineration. This work aims to develop a sustainable recycling strategy to address this environmental issue. The methodology was designed to investigate and assess the materials present in composite packaging, their compatibility with various solvents, and the feasibility of recovering packaging components such as paper, synthetic polymers, metals, and others. Additionally, the study aimed to recover solvents used in the process and determine the calorific value of the recycled samples. Using Hansen Solubility Parameters, we identified the most effective solvents for dissolving the composite food packages under analysis. Following solubilization, two samples (SL1’ and SH1’) were selected for further investigation, both dissolved using p-Cymene. These samples underwent FTIR-ATR and NMR analysis, that enabled the identification of specific polymers, including PE (Polyethylene), LDPE (Low-density polyethylene), HDPE (High-density polyethylene), PP (Polypropylene), and PC (Polycarbonate), present on those composite packaging. Furthermore, both samples were incinerated, and their calorific values were measured, ranging from 18.19 to 18.76 MJkg−1, demonstrating that they have potential for being valorized via energy recovery.

Taguchi Robust Design of Phase Transfer Catalytic Hydrolysis of Polyethylene Terephthalate (PET) Waste in Mild Conditions: Application for the Preparation of Metal–Organic Frameworks

2026-06-12T10:04:37Z

Title: Taguchi Robust Design of Phase Transfer Catalytic Hydrolysis of Polyethylene Terephthalate (PET) Waste in Mild Conditions: Application for the Preparation of Metal–Organic Frameworks Authors: Asma Nouira, Asma Nouira; Imene Bekri-Abbes, Imene Bekri-Abbes; Cansado, Isabel; Mourão, Paulo Editors: Semsarilar, Mona; Ladmiral, Vincent Abstract: With the rapid increase in polyethylene terephthalate (PET) usage in recent years, recycling has become indispensable in mitigating environmental damage and safeguarding natural resources. In this context, this study presents a methodology for valorizing PET waste through phase transfer catalytic hydrolysis conducted at a low temperature (80 °C) and atmospheric pressure, with the goal of recovering the terephthalic acid (TPA) monomer. The recovered TPA monomer was subsequently utilized as a precursor for the synthesis of metal–organic frameworks (MOFs). Tributylhexadecyl phosphonium bromide (3Bu6DPB) was selected as the phase transfer catalyst due to its efficiency and sustainability. The process parameters, including the concentration of NaOH, the wt.% of catalyst to PET, and the concentration of PET in the solution, were varied to optimize the hydrolysis reaction. The Taguchi design methodology with an L9 (3^3) orthogonal array was employed to analyze the influence of these factors on the depolymerization time. The analysis of variance (ANOVA) results revealed that the concentration of NaOH was the most significant factor, contributing to 93.3% of the process efficiency, followed by the wt.% of the catalyst to PET (6.5%). The findings also demonstrated that the concentration of NaOH had the greatest impact (Δ = 4.27, rank = 1), while the concentration of PET had the smallest effect (Δ = 0.16, rank = 3). The optimal conditions for PET depolymerization were achieved in 75 min with 20 g/100 mL of NaOH, 12 wt.% of catalyst to PET, and 5 g/100 mL of PET. The recovered TPA monomer was further employed as an organic ligand to synthesize Fe(III)-TPA MOFs under mild conditions (80 °C for 24 h). The X-ray diffraction (XRD) analysis revealed the simultaneous formation of MOF-235(Fe) and MIL-101(Fe), two multifunctional materials with diverse properties and applications. This study highlights an efficient approach for producing low-cost MOFs while promoting urban waste recycling, contributing to an integrated strategy for PET recycling and resource valorization.

Toward Climate-Smart Rewilding: An integrated framework for biodiversity, climate change, and society

2026-06-12T10:01:18Z

Title: Toward Climate-Smart Rewilding: An integrated framework for biodiversity, climate change, and society Authors: Stark, Gavin; Weissgerber, Magali; Quintero-Uribe, Laura C.; Giergiczny, Marek; Poulsen, Rauff; Villar, Nacho; Mols, Bjorn; Bakker, Elisabeth S.; Alagador, Diogo; Pereira, Henrique M. Abstract: The Kunming-Montreal Global Biodiversity Framework calls for restoring at least 30% of degraded ecosystems by 2030, while the IPCC and IPBES emphasize restoration as central to addressing climate change and biodiversity loss. Rewilding, defined as the promotion of self-sustaining, complex ecosystems through minimal human intervention, has emerged as a prominent restoration strategy, yet its climate change mitigation potential is often underexplored. Here, we propose a climate-smart rewilding framework that explicitly integrates biodiversity recovery with climate mitigation, climate adaptation, and socio-economic considerations. Using Europe as a case study, we map potential synergies and trade-offs among carbon sequestration, ecosystem resilience to climate change, wildlife-based tourism opportunities, and the risk of livestock predator conflict. We argue that this integrative framework provides a practical basis for identifying and assessing restoration strategies that deliver multiple benefits across regional and continental scales.

Feedstock and pyrolysis conditions of biochars: influence on soil phytotoxicity and water ecotoxicity

2026-06-12T10:01:07Z

Title: Feedstock and pyrolysis conditions of biochars: influence on soil phytotoxicity and water ecotoxicity Authors: Coelho, Luisa; Canedo, João; Custódio, Mariana; Flores, Deolinda; Mourão, Paulo; Palma, Patrícia; Prats, Sérgio Abstract: The use of biochar for soil restoration requires understanding ecological trade-offs, particularly how feedstock selection, dose, and production methods influence soil and aquatic ecotoxicity. The ecotoxicological effects of nine biochars derived from vineyard residues, Acacia wood, and olive pomace were evaluated after mixing them at rates of 1.5–5 % into two agricultural soils. Additionally, specific details of the biochar production method were assessed: blending ratios (vine pruning:stalks), pyrolysis temperature, (for Acacia wood) and hydrothermal activation method (for olive pomace). Physicochemical characterization—pH, electrical conductivity, organic matter, carbon and nitrogen content, polycyclic aromatic hydrocarbons (PAHs), FTIR spectroscopy and inertinite content—was combined with ecotoxicological assessment (Lactuca sativa L. phytotoxicity test and aquatic lethal and sub-lethal bioassays with Daphnia magna and Thamnocephalus platyurus). Vineyard pruning and shredded Acacia biochars, which had higher OM contents and lower EC and PAH concentrations, showed the lowest toxicity in soils and aqueous extracts. Soil mixed with biochar at 3–5 % blends optimally restored acidic soils through pH neutralization and moisture retention, which favoured seed growth. The aquatic assays showed stimulatory effects on D. magna feeding rates, increasing by 20–90 % at 5 % biochar concentration. Finally, production assessment revealed that both blending ratios and pyrolysis temperature caused minimal variability in organisms’ responses. Hydrothermal activation reduced PAH content (<0.08 mg kg􀀀 1) but failed to reduce salinity-driven ecotoxicity. These results suggest that 3–5 % wood-derived biochars are suitable to restore soils without risk to aquatic ecosystems. Olive pomace and vine stalk alternatives need a pre-application screening to detect PAHs and salinity conditions, essential factors affecting physicochemical properties of agricultural soils and environmental safety.