ACS Sustainable Resource Management最新文献

This study introduces a straightforward, sustainable, and eco-friendly approach to fabricating nanohybrids of TiO₂ integrated with carbon nanotubes (CNTs) derived from Persea americana leaves at ambient temperature, thus obviating the requirement for harmful chemicals. The Persea americana leaf extracts serve as both reducing and capping agents, and the reaction at room temperature enables precise control over the nucleation and growth of anisotropic TiO₂ particles within the nanohybrid structure. Surface morphology analysis reveals a mitochondria-like morphology with distorted spherical tips for the TiO₂ particles, while the CNTs act as connecting bridges. TEM analysis confirms that the CNTs are multiwalled, and TiO₂ exhibits a crystallite size of around 12.1 nm. X-ray diffraction analysis revealed that the synthesized TiO₂ exhibits the anatase phase. Assessment of the photocatalytic performance using methylene blue (MB) as a model contaminant demonstrates remarkable results, with the nanohybrid achieving 99.80% degradation of the dye and over 98.3% degradation within an hour under both UV and visible light, respectively. Furthermore, the TiO₂/CNT nanohybrid exhibits excellent recyclability even after numerous cycles, consistently achieving dye removal exceeding 99.99%. Overall, the TiO₂/CNT nanohybrid demonstrates the rapid and efficient removal of hazardous dyes from industrial water waste while maintaining its degradation efficiency over multiple uses. Additionally, its sustainable and straightforward synthesis methods make it a promising advanced material for water remediation applications.

Caragana korshinskii (Ck) is a typical tillering deciduous shrub whose branches have certain medicinal value. In this work, a magnetic iron niobate (FeNb₂O₆) nanosphere was prepared and used for the catalytic hydrolysis of Ck to valuable bio-oils. FeNb₂O₆ has good >C–O- cracking activity and hydrothermal stability. Under optimal conditions (Ck/FeNb₂O₆ = 5/1, 1 MPa H₂, 300 °C, and 60 min), the bio-oil yield is as high as 40.6 wt %. Structural features of Ck, derived residue (R_CH), and bio-oil (SP_EA) were further evaluated. Solid-state ¹³C NMR, XPS, TG/DTG, and FTIR analyses show that C_aliphatic moieties dominate Ck with abundant >C–O- groups. Core units of most aromatic clusters are polysubstituted benzene rings. FeNb₂O₆ promotes the cleavage of −COO-, >C–O-, and >N-X bridged bonds in Ck. Resulting SP_EA is rich in aliphatic and >C═O/>C–O- moieties, while R_CH is characterized by lignin. GC/MS and ¹H NMR analyses further show that >C_alOH, >C_ar-O-, and >C═O are 3 core classes in SP_EA, and alkanols, cyclanols, arenols, alkoxy-substituted phenols, and ketones dominate. Aromatics are mostly ortho-para substituted and mainly attributed to the release of inherent guaiacyl/syringyl units. On this basis, the structure information with higher accuracy, including four basic units, bridged bonds, and aromatic fragments, was obtained by GC/MS and 2D NMR matching. Bridged bonds involve β-O-4, α,β-diaryl ethers, β-5, β–β, and carbohydrates, while aromatic fragments refer to guaiacyl/syringyl, ferulate, p-hydroxybenzoate, and p-coumarate units as well as the cinnamyl alcohol end-group.

Given the significant industrial applications of rare earth elements (REEs), supply chain constraints, and negative environmental impacts associated with their extraction, finding alternative sources has become a critical challenge. Previously, we highlighted the potential of living Ulva sp. in the removal and pre-concentration of Y from a solution obtained by sequential acid leaching of spent fluorescent lamps (SFLs). Here, we extended that study to other REEs extracted from SFLs and evaluated the effect of pH (4.5–9.0), light exposure (absence, natural and supplemented with artificial light), and Hg (presence and absence). The results showed small differences in the removal of Y (23–30%) and other REEs at the different pH values, opening the scope of the methodology. However, Ulva sp. relative growth rate (RGR) was negatively affected in the higher acidity condition, without any visible signs of decay. In the absence of light, the RGR also decreased, which was accompanied by a halving of the removal efficiency compared to that with artificial light supplementation (40% for Y). Although Hg had minimal influence on the removal and concentration of REEs by Ulva sp., its presence in the enriched biomass is undesirable. Therefore, this contaminant was selectively removed from the solution using Fe₃O₄@SiO₂/SiDTC nanoparticles before contact with the macroalgae (70% removal in 30 min; 99% in 72 h). In addition to easy solubilization, macroalgae enriched with REEs have a simpler composition compared to SFLs. Calcination of the biomass allowed the REEs to be further concentrated, with concentrations (130 mg/g for Y) up to 240 times higher than in typical apatite ore. This highlights enriched biomass as a sustainable alternative to traditional mining for obtaining these critical raw materials.

Given the industrial importance of rare earth elements, supply chain constraints, and environmental impacts, exploring alternatives like Ulva sp. for REE recovery from spent fluorescent lamps is promising despite challenges related to pH, light and mercury.

Lead pollution has caused serious environmental concerns because of its wide range of applications. How to remove and recover lead via a low-cost and green approach has posed great challenges. In this work, Pb²⁺ has been recovered via a direct-air-capture technique. Bioresource cellulose was used as a substrate to enrich superlow-concentration CO₂ from air and immobilize the resultant Pb²⁺ salts. Being simply operated at modest conditions, PbCO₃ and Pb₃(CO₃)₂(OH)₂ have been identified and immobilized onto cellulose. Their intimate interfacial interaction, as supported by X-ray diffraction, scanning electron microscopy, and Fourier transform infrared, makes the recovery and storage feasible, rapid, and complete. Entire elimination of Pb²⁺ from water is achieved with an adsorption capacity of 320 mg·g^–1. Simultaneously, CO₂ capture capacity gets to 54.5 mg_CO2·g^–1. Thus, two wastes, Pb²⁺-containing effluent and CO₂, are exploited for resource conservation and recycling. Our treatment strategy also helps to decrease/remedy environmental pollution and benefits carbon negativity.

In the context of the bioeconomy, the transition from fossil-based to bio-based chemicals holds promise in reducing dependence on non-renewable resources and mitigating the impacts of climate change. However, the sustainability performance, encompassing environmental, social, and economic aspects, still needs to be demonstrated for emerging bio-based chemicals. Here, we undertake an integrated life cycle sustainability assessment (LCSA) to evaluate and compare a bio-based solvent with its fossil-based counterpart. Our methodological approach integrates the assessment of all three dimensions of sustainability at the inventory level within the LCSA framework to enhance its operationality. Therefore, this publication compares the environmental and social impacts as well as the costs related to the use of 2-methyltetrahydrofuran from bagasse (2-MeTHF B) and from corncobs (2-MeTHF C) and tetrahydrofuran to solvate the reaction media for producing 1 kg of tramadol, an opioid analgesic medication. The results reveal a complex trade-off. 2-MeTHF demonstrates lower environmental impacts (∼7574 μPts for 2-MeTHF B, ∼8961 μPts for 2-MeTHF C, and ∼21490 μPts for THF) and more particularly less climate change impacts (3.24 kg of CO₂ equiv for 2-MeTHF B, 4.4 kg of CO₂ equiv for 2-MeTHF C, and 14.9 kg of CO₂ equiv for THF). However, it has worse social aspects (∼558 medium-risk hours for 2-MeTHF B, ∼840 medium-risk hours for 2-MeTHF C, and ∼173 medium-risk hours for THF) and costs (10.44 USD for 2-MeTHF B and C and 5.4 USD for THF). Geographical aspects of the value chain drive most of the impacts and risks showcased in this study. Optimizing the value chain would help to mitigate life cycle environmental impacts and socio-economic risks associated with 2-MeTHF. Energy optimization in synthesis processes is identified as a key strategy to reduce potential environmental impacts. The level of implementation of the 10 principles of the Life Cycle Initiative is discussed, revealing complete alignment with 5 of the 10 principles. In contrast, four principles exhibit medium alignment, and one is not implemented. Data availability and confidentiality challenges are recognized as hindrances to transparency and replicability. In conclusion, the study emphasizes the necessity of involving diverse stakeholders in enhancing the relevancy of sustainability assessments. Companies in the bioeconomy are encouraged to implement Environmental Management Systems and Corporate Social Responsibility approaches to infuse sustainability practices within their value chains.