ACS Sustainable Resource Management最新文献

Plastic waste is one of the largest contributors to landfill waste globally, with the healthcare industry contributing a large proportion of this. Recycling has been established as a key point of focus to reduce this waste, as addressed in The United Nations Sustainable Development Goals. To this end, this work demonstrates the upcycling of hospital lab waste poly-(propylene) (PP) into a new conductive filament for additive manufacturing, using a zero solvent methodology and incorporating 30 wt % carbon black as a conductive filler. The filament showed excellent low-temperature flexibility, high conductivity, and a low bulk resistance of 61 ± 7 Ω cm^-1. Moreover, the recycled conductive filament produced reproducible electrodes that were electrochemically characterized, showing a heterogeneous electron (charge) transfer rate constant (k ⁰ _obs) of (2.75 ± 0.12) × 10^-3 cm s^-1, improving that of conductive virgin polypropylene electrodes (2.05 ± 0.05) × 10^-3 cm s^-1. These electrodes were utilized in two electroanalytical setups developed for applications in clinical settings. First, the simultaneous electrochemical detection of acetaminophen (ACE) and phenylephrine (PHE) was investigated by using an external counter and reference electrode configuration. These analytes are commonly coformulated in over-the-counter cold and flu medications, highlighting the importance of their concurrent quantification for pharmaceutical quality control and clinical analysis. Second, the sensing of uric acid (UA) using printed electrodes for the working, counter, and reference electrodes, achieving a limit of detection of 0.03 μM and achieving a recovery of 97.6% in urine, sensing of uric acid in urine is important as it is a biomarker for illnesses, for example, gout. This work highlights how waste PP from high use sectors can be upcycled to added-value products, with excellent performance, while contributing toward a circular economy electrochemistry.

Nordic countries are widely recognized for their leadership in sustainability initiatives and have implemented numerous projects to improve plastic waste recycling and utilization. However, the plastic consumption and waste management in these countries remain insufficiently understood due to the lack of dynamic, high-resolution plastic cycle maps that span the entire lifecycle. Here, we devised a polymer-level dynamic material flow analysis model by integrating data from disparate sources to simulate the historical cycle of 14 groups of polymers (1978-2020) and their recycling potentials by 2050 in five Nordic countries (Denmark, Finland, Norway, Sweden, and Iceland). The results show that the average per capita stock in Nordic countries in 2020 reached the saturation level (1100 kg per capita), which is the highest global value. Imported polymers far exceeded the domestic production. Most of the plastic waste was incinerated or landfilled, with the average recycling rate falling below 6%. Enhanced mechanical recycling could contribute to 27% of the regional demand, requiring 6.7 times the expansion of the current recycling capacity by 2050. The additional implementation of chemical recycling could potentially provide 22% of the regional demand, but the potential contribution of chemical recycling is compromised by the lack of industrial production in the region, implying the need for international collaborations. The results contribute to addressing key issues under discussion in the ongoing negotiations of the Intergovernmental Negotiating Committee for the Global Plastic Treaty.

Nowadays, soil is deteriorating at an alarming rate, endangering both land fertility and productivity and thus the world's food supply. Using bulk available spent coffee ground (SCG) solid wastes to enrich and amend the deteriorating soil might be revolutionary because it would assist with its correct disposal and lessen the problems related to environmental contamination and human health. The blend of traditional practices and modern technologies can manage SCG's waste economically, efficiently, and sustainably. The current review article focuses on the potential uses of wasted coffee grounds to improve soil fertility, water-holding capacity, residue management, seed germination, crop growth, and yields. The ability of SCG to amend soil depends upon the nature of SCG (fresh, compost, vermicompost, biochar, etc.), mode of application (extract, mixing, and top dressing), and application rate. The traditional practice of composting using microbes and earthworms to convert phytotoxic SCG into non-phytotoxic compost to enhance crop productivity and soil fertility is quite impressive and has been applied extensively. However, other modern technologies, like SCG-derived biochar, hydrochar, alkaline-treated SCG, SCG-derived nano fulvic-like acid fertilizers, and NPK-organic fertilizers, could be an excellent choice to replace the existing ones. This paper details the recent advancements and effects of various fertilizers on the physicochemical characteristics of soil, compost nutrient composition, plant growth, nutrient uptake by plants, and soil's ability to store water.

In this study, we investigated the reinforcement effects of biochar on a bio-based thermoplastic polyurethane (bio-TPU). The particle size of the biochar was reduced and controlled by using a planetary ball milling process under varying milling conditions. The structure and morphology of ball-milled biochar (BBC) were thoroughly characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, and Brunauer-Emmett-Teller (BET) analysis. Bio-TPU/BBC composites were fabricated via melt compounding. The BBC was found to be preferentially localized within the soft segment (SS) phase of the TPU, as indicated by enhanced crystallization of the SS and a shift in its glass transition temperature (T _g) to higher values. Two-dimensional small-angle X-ray scattering (2D SAXS) analysis revealed an increase in interdomain spacing from 11.22 to 12.09 nm with increasing BBC content, further supporting the preferential localization of BBC within the soft segments. This preferential reinforcement of the SS by BBC led to simultaneous improvements in both ultimate tensile strength (up to 35 MPa) and elongation-at-break (up to 780%) at a filler loading of 2.5 wt %. However, further increasing the BBC content to 10 wt % resulted in a decrease in elongation-at-break and toughness. Notably, the preferential embedment of BBC also contributed to a plateau stress of 8 MPa, addressing a known limitation in TPU design. Additionally, a 512% increase in Young's modulus (YM) and a 26 °C improvement in the temperature corresponding to a 50% mass loss have been observed at 10 wt % BBC-filled bio-TPU composite, demonstrating a significant enhancement in the YM and thermal stability.

The increasing amounts of discarded textiles represent a potentially valuable resource that could be reclaimed, for example, by chemical techniques. This work underscores the significance of utilizing chemical recycling techniques for multicomponent fabrics under mild reaction conditions to investigate the reusability of recovered components. We present a method for recovery of cotton, elastane, and nylon from polyester blends through mild alkaline hydrolysis supported with a phase-transfer catalyst. To juxtapose the impact of these various fibers on the depolymerization of the polyester component into terephthalic acid (TPA), consistent reaction conditions were maintained. The average TPA yield (by mass) was 93.9 ± 2.8% for pre-consumer materials and 89.5 ± 3.1% for post-consumer materials. This comparative analysis provides insights into factors contributing to the observed decrease in the TPA yield. Inimitable to this study, an analysis of the reuse potential of recovered cotton via tensile strength was performed. The average cotton recovery (by mass) was 95.9 ± 0.8%. Comprehensive material characterization of all recovered components was performed. This research paves the way for a deeper understanding of the potential contamination of TPA, the quality of recollected fibers, and what components of a mixed textile stream act as potential "disruptors" to recyclability.

[This corrects the article DOI: 10.1021/acssusresmgt.4c00258.].

Membrane distillation crystallization (MDCr) is gaining recognition as a sustainable and cost-effective method for treating hypersaline brine. The current study explores magnesium sulfate (MgSO₄) crystallization by using MDCr from synthetic nanofiltration (NF) brine. The study evaluates three feed temperature conditions (41.8 °C, 54.9 °C, and 64.5 °C), along with the corresponding permeate temperatures (19.9 °C, 23.2 °C, and 26.2 °C) and flow rates (1.3 and 0.7 L/min). The tested conditions revealed that temperature impacts the MDCr performance and MgSO₄ crystallization more effectively than the flow rate. The presence of other ions (Na⁺, K⁺, and Cl^‑) decreases the solubility of MgSO₄ (compared with the theoretical solubility at the tested temperature) and increases the tendency of co-crystallization with NaCl, which poses a significant challenge in the final separation stage. The examined process conditions (feed temperature 64.5 ± 0.5 and flow rate 1.3 L/min) successfully delay the crystallization of MgSO₄, toward a higher water recovery factor (65.98 %), owing to the higher solubility of MgSO₄ at higher temperatures, which minimizes the extent of co-crystallization. The recovered crystals (a mixture of NaCl and MgSO₄) are then separated by selectively dissolving NaCl in a saturated solution of MgSO₄. No compromise with the permeate purity (<5 μm/cm) was observed under all tested conditions.

MoCo/γ-Al₂O₃ catalysts used in petroleum refining are commonly recycled to recover Mo and V; however, the contained Ni and Co are not typically recovered as purified products. The goal of this study was to evaluate the environmental impacts of recycling a spent catalyst and recovering all of the valuable metals: Mo as MoO₃, V as V₂O₅, Ni as Ni(OH)₂, and Co as Co(OH)₂. Process simulation was used to study the inputs and outputs of the system, and the gathered process data inventory was used to perform life cycle assessment to determine the environmental impacts. The results show that when the content of Mo, V, Ni, and Co in the spent catalyst is high enough, the potential environmental impacts of the recycling system are lower than those of the primary production of equivalent products. For example, the global warming of the recycling systems decreases from 250% of the primary impacts (with 6 wt % metal content) to 53% (with 29 wt % metal content). The process hotspots in the recycling process were found to be mainly in the production of the chemicals and utilities consumed by the process. Particularly NH₃, electricity, HCl, NaOH, and H₂SO₄ increased the environmental impacts. In addition, in the recycling process direct gaseous emissions were generated, which contributed substantially to global warming and acidification.

The environmental impacts of MoCo/γ-Al₂O₃ catalyst recycling are evaluated using process simulation-based life cycle assessment with several uncertainty and sensitivity analysis methods to determine the influence of simulation parameter uncertainty.

Biocarbon (BC) has been widely employed as a support to disperse nanoscale zerovalent iron (nZVI) particles to prevent their aggregation and rapid oxygen passivation. Here, we compare the chemical stability of nanozerovalent iron composites (nZVI@BC) made by liquid-phase reduction (LPR) versus carbothermal reduction (CTR). In the LPR route, Fe³⁺ was impregnated onto demineralized bamboo-BC formed at 600 °C, followed by NaBH₄ reduction under N_2. The CTR method employed aqueous FeCl₂-impregnated bamboo-BC, which was dried and carbonized from 50 to 1000 °C under N₂. nZVI@BC’s chemical stabilities were compared in air, water, and soil. Both routes produced Fe⁰, confirmed by the XRD peak at 2θ = 44.6°. Fresh LPR-nZVI@BC vs. CTR-nZVI@BC exhibited efficient Cu²⁺uptakes of 32 mg/g (212 mg/g Fe⁰) and 40 mg/g (266 mg/g Fe⁰) in 30 min, respectively, via Fe⁰ reduction of Cu²⁺to Cu⁰. Exposing LPR-nZVI@BC samples to water for 4 h led to the complete disappearance of the Fe⁰ XRD peak and the appearance of the Fe₃O₄ peak at 2θ = 35.0°, reducing Cu²⁺ uptake by 98%. In contrast, CTR-nZVI@BC only experienced a 51% drop in capacity due to the presence of a layered graphene sheet shell, preventing Fe⁰ from rapid oxidation. No Fe₃O₄ XRD peaks were observed in CTR-nZVI@BC after 7 days of air and soil exposure, unlike in LPR samples. Resistance to passivation in air, water, and soil makes the CTR a promising synthetic route to nZVI@BC.