ACS Sustainable Resource Management最新文献

Harvesting nutrients from waste presents a promising initiative to advance and deliver the circular economy in the water sector while mitigating local shortages of mineral fertilizers worldwide. Urine, a small fraction of municipal wastewater, holds substantial amounts of nitrogen, orthophosphate (PO₄–P), and chemical oxygen demand (COD). Separating urine aids targeted nutrient recovery, emissions reduction, and releasing capacity in wastewater treatment plants and taps into overlooked vital nutrients like magnesium (Mg²⁺) and potassium (K⁺), essential for plant growth. The ability of selected microorganisms (Brevibacterium antiquum, Bacillus pumilus, Halobacterium salinarum, Idiomarina loihiensis, and Myxococcus xanthus) to remove and recover nutrients from fresh urine through bio-mineral formation of struvite was investigated. The selected microorganisms outcompeted native microbes in open-culture fresh urine, and intact cell counts were 1.3 to 2.3 times larger than in noninoculated controls. PO₄–P removal reached 50% after 4 days of incubation and 96% when urine was supplemented with Mg²⁺. Additionally, soluble COD was reduced by 60%; urea hydrolysis was only < 3% in controls, but it reached 35% in inoculated urine after 10 days. The dominant morphology of recovered precipitates was euhedral and prismatic, identified using energy dispersive spectroscopy and X-ray diffraction as struvite (i.e., bio-struvite), but K⁺ was also present at 5%. Up to 1 g bio-struvite/L urine was recovered. These results demonstrate the ability of bio-mineral producing microorganisms to successfully grow in urine and recover nutrients such as bio-struvite, that could potentially be used as sustainable fertilizers or chemicals.

Urine, rich in N and P water pollutants, served as a substrate for microorganisms to recover nutrients via bio-mineral formation recovering resources sustainably.

Resource utilization of bulk industrial solid wastes and byproducts has been recognized as a feasible strategy for coping with a sustainable resource supply in the future. Herein, the iron red composite pigments with a yellowish-red color were fabricated by twin screw extrusion mechanochemical technology followed by the calcining process based on oil shale semicoke (OSSC) waste and ferrous sulfate byproduct, which were derived from the retorting of oil shale and the production of titanium white pigment, respectively. The mechanochemical effect during the extrusion process promoted the complex reaction between the active groups of residual organic matter in OSSC and the involved Fe ions and contributed to the shaping formation of the precursor. The thermally diffused Al species derived from OSSC induced the formation of α-Fe₂O₃ nanoparticles on the silicate surface via Al–O–Fe chemical bond and endowed the pigment particles with excellent dispersion and environmental stability. In addition, the doping of the diffused Al species changed the band gap energy of α-Fe₂O₃ crystals, and the composite pigments presented a bright yellowish-red color (L^* = 32.05, a^* = 33.22, b^* = 37.89, C^* = 50.39), while the tinting strength, oil absorption, and hiding power of composite pigments were slightly inferior to those of the commercial iron red pigments due to the lower content of chromogenic iron species and the particle size difference. Based on the synergistic effect of each component in composite pigments, the composite pigments exhibited good application prospects in the high-temperature overglaze ceramic, coloring, and reinforcing of polypropylene and anticorrosion coating.

This study focuses on copyrolyzing pretreated sawdust and polystyrene utilizing microwave-assisted pyrolysis (MAP) with equal mixing to synthesize and characterize biochar. Graphite was used as a susceptor to facilitate precise pyrolysis temperature control. Potassium hydroxide (KOH) powder serves as a catalyst, influencing the char yields and properties. Torrefied raw sawdust at various temperatures (125–175 °C) enhances biochar yields (24–29 wt %). The feedstocks sawdust and polystyrene are characterized by elemental, proximate, and TGA examinations. Furthermore, comprehensive surface, crystallographic, FTIR, and SEM-EDX analyses are performed on microwave copyrolyzed biochar. The developments in BET surface area during copyrolysis show changes concerning pretreatment temperatures: 125 °C (5.6 m²/g) < 150 °C (6.8 m²/g) < 175 °C (8.6 m²/g). Functional groups connected to the alcohols’ O–H bend and C–O stretching vibrations are detected in the biochar samples through FTIR analysis. Sharp peaks with 2θ values between 33.2° and 36.2° appear in the XRD scan of biochar, indicating the presence of crystalline components in the sample. The EDX results demonstrated that the components of biochar included Mg, C, O, and Ca, indicating that it could have plenty of advantageous applications. The study highlights the obstruction of sawdust char’s porous structures by polystyrene, hindering volatile emissions and leading to increased heating rates. These findings underscore the unique contributions of this method to biochar production.

The present status of operational biorefineries confronts an array of technological and economic hurdles, encompassing challenges related to product diversification, environmental impacts, and efficient waste management. In this study, a highly streamlined and techno-economically viable material-driven phase III lignocellulosic feedstock biorefinery system is delineated, aiming to sequentially extract non-structural and structural components from diverse lignocellulosic biomass and pretreatment chemicals such as nitrogen-, potassium-, and phosphorus- (NPK) containing materials. To construct the biorefinery system, a thermo-pressurized sequential phosphoric acid-potassium hydroxide pretreatment method was employed on extractives-free lignocellulosic biomass, effectively fractionating numerous non-wood and hardwood samples into their structural components. Applying the pretreatment process, the primary structural components, i.e., hemicellulose (77 to 98%), cellulose/pulp (77 to 93%), and lignin (75 to 85%), were separated. The pretreatment chemicals were also recovered (around 100%) as valuable NPK fertilizers in crystalline and liquid forms from the spent liquors by using ammonium hydroxide. A techno-economic analysis was performed on the biorefinery system (small-scale plant; lignocellulosic biomass used: 7300 t/y; production capacity: 19,568 t/y; estimated capital cost: 31.00 million USD; operating cost: 23.48 million USD) by developing a deterministic model that showed a payback period of 6.69 years. Local sensitivity and uncertainty analyses were also performed using the deterministic model, and changes in the return on investment were evaluated. Additionally, a superstructure was developed for the biorefinery, showing potential downstream operations. Overall studies, including cradle-to-gate lifecycle assessment, demonstrated that the biorefinery is a green and sustainable technology for the conversion of lignocellulosic biomass with greater than 95% atom economy.

This study presents a comparative analysis of Ni-Co rich oxalate (rMOx) and oxide (rMO), developed from process leach liquor of spent lithium-ion batteries (LIBs) following an economic and environmentally friendly strategy, as an electroactive material for supercapacitor and the oxygen evolution reaction (OER) applications in alkaline media. Utilizing a tandem approach, rMOx and rMO were recovered from spent LIBs leach liquor, achieving >90% recovery of transition metal ions. rMOx shows a discharge specific capacitance of 220 Fg^–1 at 1 Ag^–1, surpassing the rMO of 156.5 Fg^–1. An asymmetric supercapacitor device fabricated to analyze the practical applicability using rMOx and MXene achieved a discharge specific capacitance of 46 Fg^–1 at 0.8 mA cm^–2 with energy and power densities of 6.43 Wh kg^–1 and 303.03 W kg^–1, respectively. In the case of OER, rMOx exhibited an overpotential of 176 mV at 10 mA cm^–2 and a Tafel slope of 81 mV dec^–1, outperforming rMO and benchmark electrocatalyst IrO₂. The superior performance of rMOx can be attributed to its higher electrochemical active center formation due to metal-oxalate to metal-oxy-hydroxide conversion during electrode-electrolyte interaction. Thus, this study presents a novel approach for establishing electrochemical bifunctionality and energy sustainability.

To resolve the trade-off between permanent cross-linking and recycling, the integration of dynamic metal-ligand coordination bonds into elastomer systems is a burning topic of current research. This approach could provide recyclable elastomeric materials that are otherwise not possible with conventionally cross-linked elastomers. Therefore, proper utilization of such a dynamic bond could significantly contribute to sustainability as well as promote the principles of a circular economy. In this work, we utilized a heterocyclic imidazole base (1,2-dimethyl imidazole, DMI) to achieve controlled cross-linking of carboxylated nitrile butadiene rubber (XNBR) via ferric-carboxylate interaction. This was investigated and confirmed by X-ray photoelectron and infrared spectroscopy. This is further supported by swelling and rheological studies. The resulting composites show multistep recyclability without any further deterioration of mechanical performance. Even after the third recycling, the DMI containing composites XNBR-DMI₁-Fe_1.5 and XNBR-DMI₄-Fe_1.5 demonstrate recycling efficiencies as high as 84 % and 90 %, respectively. This is well-supported in the creep study, where the deformation recovery for those composites at 130 °C was found to be 53.4 % and 65.2 %, respectively. The development of such an excellent recyclable and ecofriendly elastomer material becomes possible via the dynamic coordination network of the ferric ion complex throughout the XNBR matrix. Furthermore, the formation of clusters, as evidenced by the small-angle X-ray scattering study, is believed to enhance the mechanical properties. A plausible mechanism is proposed that shows the critical role of DMI in the cross-linking process.

Lithium-ion batteries (LIBs) require critical resources for cathode active materials production, including elements such as cobalt, nickel, and lithium. Therefore, their recycling from spent LIBs is a priority for European countries. Current recycling technologies mainly consist of hydrometallurgical processes that require large amounts of inorganic acids, reducing agents, and other chemicals for a selective recovery. In the present paper, an innovative and efficient process of Li and Co leaching from LiCoO₂ (LCO) cathode materials, which allows reducing the consumption of chemicals, is proposed. The combination of two bio-based organic acids, namely, citric acid (H₃Cit) and ascorbic acid (AsAc), enables complete recovery of Li and Co in just 1 h through mechanochemical leaching using ball milling. By using a relative molar ratio of H₃Cit:AsAc:LCO (1:0.5:1), this innovative approach offers an optimized leaching process. This method holds promise for significantly reducing the carbon footprint of future lithium-ion battery recycling efforts.

We all are surrounded by millions of bacteria, and antibiotics are the only medicine that exists on the Earth to protect us from the thousands of bacterial infections. However, excess consumption of these antibiotics has accelerated the bacterial resistance process. The resistive bacteria then spread and grew exponentially and created several health problems. So, a system is necessarily required that smartly detects the presence of antibiotics in the contaminated samples. Here in this work, a carbon quantum dots (CQDs) based fluorescence resonance energy transfer (FRET) “Turn-Off” sensor was developed for tetracycline (Tetra) detection in animal-derived food samples. The highly fluorescent CQDs have average particle size of around 1.80 ± 0.435 nm were synthesized using pyrolysis method. Here, CQDs-Tetra form a FRET pair, and the emission intensity of CQDs reduced to 57. 3% in the presence of Tetra due to the transfer of energy from donor (CQDs) to acceptor (Tetra). Further, analyzing the lifetime decay of CQDs, which changed from 9.43 ns to 8.89 ns with addition of Tetra, confirms the FRET quenching mechanism. The sensor show the linear response with Tetra concentration varies as 0.05–100 μM with a limit of detection 10.47 nM. The applicability test of the sensor was carried out with real milk and egg samples spiked with standard concentration of Tetra. The test results proved that the sensor could be used as a food monitoring tool.

To face the growing need for NdFeB permanent magnets in devices in our everyday life, while considering the fluctuating market of rare earth elements such as neodymium (Nd), their recycling is strategic, especially for countries devoid of mines. Here, we report the proof of concept for permanent magnets’ direct recycling through solvothermal chemistry. Compared to existing processes requiring either the use of acids or dihydrogen, this greener approach is only based on the use of a water/ethanol mixture under pressure (250 bar) and temperature (250 °C) treatment. The mechanism consists of the hydrolysis of an intergranular Nd-rich phase, consuming it to form a Nd(OH)₃ powder together with a lattice expansion due to hydrogen insertion (Nd₂Fe₁₄BH_x), leading to the collapse of the ceramic into a Nd₂Fe₁₄B-based powder. This powder can then be directly reused and mixed with a virgin one to make new permanent magnets with interesting magnetic performance.

New carbon structures and allotropes could significantly contribute to material sustainability in an era of existential concerns. Herein, for the first time, a highly crystalline body-centered tetragonal (BCT) carbon structure was synthesized from a nonedible biowaste (coconut rachis) through a low-temperature carbonization process. The formation of BCT carbon was monitored via the crystal structure changes of the biowaste upon variation of the calcination temperature, showing the critical role of microcrystalline cellulose in achieving carbon allotropes with high crystallinity. The electronic properties of the synthesized carbon were also investigated, suggesting potential uses in applications such as photoconversion, photocatalysis, transistors, and sensors. This study opens the path toward the synthesis of new carbon allotropes sustainably for advanced applications.