High-value Resources Research Articles

Ball milling of pyrolytic residue from oil sands with MnO2 and reuse as PMS activator: Measurement of ROS exposure and mechanism insights

Pyrolysis is an important process to recover petroleum from oil sands, while the pyrolytic residue of oil sands (PROS) is commonly treated as solid waste. In this study, PROS was treated by ball milling with manganese dioxide and converted into Mn-loaded carbon sand (MnBMCS), which was reused as a peroxymonosulfate (PMS) activator to degrade aniline (AN) in wastewater. The AN (100 mg/L) was almost completely removed by 2 g/L MnBMCS and 1 g/L PMS. Electron paramagnetic resonance tests confirmed the existence of three reactive oxygen species (ROS) including sulfate radical (SO4∙−), hydroxyl radical (∙OH) and singlet oxygen (O21) in MnBMCS/PMS system. A probe-based kinetics model was constructed to measure the ROS exposure. The O21 exposure was 6.73 and 22.95 times of SO4∙− and ∙OH exposure, respectively. But the contribution of SO4∙− to AN degradation was much greater than that of O21 due to its higher oxidation capacity. Characterization analysis showed that Mn(Ⅳ)/Mn(Ⅲ) redox electrons could activate PMS to produce SO4∙− and ∙OH, CO activated PMS to produce O21, and π-π* was also beneficial to generate SO4∙− and ∙OH. This study proposes an innovative integrated process to promote the governance mode of PROS from harmless disposal to high-value resource utilization.

The Effectiveness of National Innovation and Startup Policy (NISP) in Cultivating Entrepreneurial Ecosystems within Management Institutions in Pune

This study investigates the effectiveness of the National Innovation and Startup Policy (NISP) in cultivating entrepreneurial ecosystems within management institutions in Pune. A mixed-method approach involving surveys and interviews with students, faculty, and NISP coordinators across 15 HEIs was employed. The findings reveal that NISP has fostered a supportive environment by promoting awareness, offering mentorship, and establishing infrastructure. However, challenges remain, including limited funding, lack of industry partnerships, and insufficient resources for startups. Analysis of student responses indicates a positive influence on entrepreneurial interest and confidence. However, concerns exist around access to funding, infrastructure, and specialized equipment. Additionally, diversifying engagement activities is crucial to reach a wider student base. Based on these results, recommendations are provided to enhance NISP's effectiveness. These include increased funding, fostering industry collaborations, expanding awareness campaigns, and providing high-value resources like seed funding and investor networks. Additionally, dedicated faculty mentors and standardized resource allocation across institutions are recommended. Finally, establishing data-driven evaluation mechanisms with student feedback loops is crucial for continuous improvement. By implementing these recommendations, NISP can be strengthened to cultivate robust entrepreneurial ecosystems within management institutions, fostering innovation and contributing to India's emergence as a global hub for entrepreneurship.

Reutilization recovered nutrients from wastewater by synthesizing eco-friendly slow-release hydrogel fertilizer for sustainable vegetable production

Recovering and reusing resources from waste is a practical necessity for realizing sustainable development, while the lack of arable land and speedy release of fertilizer is also an urgent issue required to improve soil water and fertilizer conditions. Here, an eco-friendly biodegradable hydrogel was fabricated to serve as a slow-release carrier for nutrients that recovered from wastewater and investigated the potential role of it on vegetable growth. The hydrogel owned excellent water swelling and retention capacity, while degraded by more than 50 % within 11 weeks. Electrostatic interactions, hydrogen bonding, and ion exchange dominate the binding between nutrients and hydrogel, thus contributing to the maximum release period and efficiency for nitrogen, phosphorus, and potassium was 74.28 % in 21 days, 88.28 % in 28 days and 72.52 % in 7 days, respectively. Kinetic model fitting and molecular dynamics simulations indicated that the Fickian diffusion controls the release of fertilizers. Vegetable yields and root elongation were significantly improved by applying the slow-release hydrogel fertilizer, with yield increases up to more than two-fold at the second round of cultivation. Overall, this work provides novel insights into the reutilization of high-value resources from wastewater and agriculture sources to support a stable food supply.

Facile fabrication of robust and tight PIMs-based TFC hollow fiber membranes with a semi-interpenetrating polymer network via liquid phase cross-linking for organic solvent nanofiltration

Resource recovery and reuse are essential for sustainable development, particularly for high-value resources such as homogeneous (photo)catalysts, active pharmaceutical ingredients, and high-value natural compounds, which can offer economic benefits. Recently, organic solvent nanofiltration (OSN) for resource recovery has gained significant attention owing to its advantages including low energy consumption and seamless integration with other processes. Polymers of intrinsic microporosity (PIMs) have great potential as membrane materials for OSN, owing to their excellent pore properties and solution processability. However, swelling and dissolution of PIMs in organic solvents can impede the filtration performance of PIMs-based OSN membranes. In this study, we fabricated thin-film composite hollow fiber membranes for OSN based on PIMs with improved organic solvent stability using a semi-interpenetrating polymer network (semi-IPN) formed by cross-linking Matrimid with 1,6-hexanediamine within the PIMs through the liquid phase cross-linking method. Semi-IPNs mitigate swelling and tighten the pores of PIMs-based membranes, enabling excellent filtration and molecular separation performance. Furthermore, the fabricated PIMs with a semi-IPN membrane exhibited excellent rejection performance (>96 %) for homogeneous photocatalysts, allowing successful concentration and recovery via OSN. Therefore, PIMs-based membranes with a semi-IPN hold great promise as OSN membranes for the recovery of valuable resources.

Complexation of Olive Protein with Soluble Dietary Fibers: A Way to Improve the Functional Properties of Proteins and Efficiently Utilize Olives.

High-value resources beyond oil extraction for the olive industry need to be developed due to increased olive production. Soluble dietary fibers (SDFs) and olive proteins (OPIs) are important components of olives. However, the commercial production process partially damages OPIs' emulsifying and foaming properties. Thus, the preparation of SDF-OPI complexes would help protect and even improve the emulsifying and foaming properties. The effects of pH and thermal-ultrasonic treatment on the complexation were explored, which showed that the SDF-OPI complexes prepared at pH 5 exhibited superior solubility (p < 0.05). SDF addition noticeably improved OPI thermal stability, emulsifying properties, and foaming properties. Moreover, the complexes prepared by thermal-ultrasonic treatment exhibited higher emulsion stability and lower emulsification activity than those prepared without thermal-ultrasonic treatment. In the acidic system, the electrostatic interaction was considered the main driving factor, assisted by the hydrophobic interaction. Additionally, after thermal-ultrasonic treatment, the covalent binding was observed by infrared spectroscopy. These results revealed the interaction mechanism between SDF and OPI, and the complexes significantly enhanced the functional properties of OPI. This study provides a reference for the high-value utilization of olives, thus broadening their potential uses in the food sector and beyond.

ABA and MeJA Induced Catechin and Epicatechin Biosynthesis and Accumulation in Camellia oleifera Fruit Shells.

Camellia oleifera Abel, one of the most valuable woody oil plants, has been widely cultivated for extracting edible oil. The shell of C. oleifera is a by-product generated in the processing of edible oil extraction. However, there is still limited research on the maturity and high-value resource utilization of shell by-products. We found that the C. oleifera 'Huashuo' (HS) fruit shells contained a high content of catechins. Abscisic acid (ABA) and methyl jasmonate (MeJA) enhanced the accumulation of catechins in C. oleifera fruit shells, providing a basis for production and application of the catechins in fruit shells of C. oleifera. We further found that 500 μM ABA and 900 μM MeJA significantly promoted the accumulation of catechin (C) and epicatechin (EC) in fruit shells. Following treatment with 900 μM MeJA, the expressions of CoPAL1, CoC4H1, CoC4H2, CoC4H3, Co4CL1, Co4CL2, CoF3'H1, CoLAR1, CoLAR2, CoLAR3, CoANR2, and CoANRL2 were significantly upregulated, while after 500 μM ABA treatment the expressions of CoPAL3, CoCHS1, CoCHS4, CoF3'H1, CoDFR, CoLAR1, CoLAR2, CoLAR3, CoANS1, CoANR1, and CoANR2 increased dramatically. These results indicate that appropriate concentrations of ABA and MeJA activate C and EC biosynthesis and promote their accumulation in fruit shells. Our results provide new ideas and guidance for promoting the resource utilization of C. oleifera fruit shells.

Accelerated screening of active sites on biochar for catalysis and adsorption via multidimensional fingerprint factor descriptors

Highly active biochar has great application potential in heterogeneous catalysis and adsorptive processes. The complexity of carbonization process makes it difficult to construct target active sites. This work put forward a reactive descriptor based on pyrolysis parameters and intrinsic composition of biomass. Results show that the model showed better predictive performance for C-C/C=C (R2 = 0.85), C=O (R2 = 0.85) and defect (R2 = 0.91) sites. The SHapley Additive exPlanation analysis shows that the pyrolysis parameters and the higher heating values are equally important for the active sites. The predictive performance and guiding role of the descriptor were validated by experiments. The descriptors proposed in this study integrated significant advantages of simplicity and easy accessibility, which would break the bottleneck of accurate construction of active sites and provide a theoretical basis for high-value resource utilization of biomass.

A new strategy for utilization of gasification ash: Manganese oxides-modified activated carbon for efficient copper citrate removal

To address the challenges posed by solid waste generated from coal gasification ash, a pyrolysis self-activation method was employed to prepare activated carbon by gasification ash, followed by the modification with manganese oxide to enhance its adsorption performance. Subsequently, the removal efficiency and mechanism for copper citrate were investigated. The results demonstrated the successful preparation of manganese oxides modified gasification ash-derived activated carbon (GAC-MnOx), exhibiting a specific surface area of 158.3 m2/g and a pore volume of 0.1948 cm³/g. The kinetic process could be described by the pseudo-second-order kinetic model (R2 = 0.958). High removal efficiency and low concentration of dissolved Mn were observed within the pH range of 3–10, where the adsorption capacity of GAC-MnOx for copper citrate exhibited an inverse relationship with pH. Notably, the fitting results of the Langmuir model demonstrated that the maximum adsorption capacity of GAC-MnOx for copper citrate is determined to be 7.196 mg/g at pH 3. The adsorption capacity of GAC-MnOx was found to be significantly reduced to 0.26 mg/g as the pH decreased below 2, potentially attributed to the dissolution of Mn. The findings of the Dual-Mode model demonstrated that the copper citrate removal mechanism by GAC-MnOx involved both surface adsorption and precipitation processes as follows: the porous structure of activated carbon enables physical adsorption of copper citrate, the MnOx or oxygen-containing functional groups establish chemical bonds with copper citrate and subsequently precipitate onto the surface of the adsorbent. The physical adsorption remains predominant in the removal of copper citrate, despite a gradual decrease in its proportion with increasing pH and equilibrium concentrations. Moreover, the X-ray photoelectron spectroscopy results indicated that copper citrate might be oxidized by MnOx to release copper ions and be retained on the surface of the adsorbent, meaning the adsorption efficiency of Cu(II)-Cit by GAC was enhanced through MnOx oxidation. This study could provide a new strategy for the high-value resource utilization of gasification ash.

Synthesis of Low-Silicon X-Type Zeolite from Lithium Slag and Its Fast Exchange Performance of Calcium and Magnesium Ions.

Without the addition of silicon and aluminum sources, a pure-phase KNaLSX zeolite was successfully synthesized from the residue (lithium slag), which was produced from spodumene in the production process of lithium carbonate. The KNaLSX samples were characterized by an X-ray Diffractometer (XRD), Scanning Electron Microscope (SEM), X-ray Fluorescence Spectrometer (XRF), Thermogravimetric Differential Thermal Analysis (TG-DTA), Fourier Transform Infrared Spectrometer (FT-IR), and N2 adsorption measurement. The ion exchange capacity and the ion exchange rate of calcium and magnesium ions were measured as used for a detergent builder, and the results were compared with the standard zeolites (KNaLSX and 4A). The experimental results show that the pure-phase KNaLSX synthSynthesis and characterization of co-crystalline zeolite composite of LSX/esized from lithium slag has a SiO2/Al2O3 ratio of 2.01 with a grain size of 3~4 μm, which is close to the commercial KNaLSX sample of a SiO2/Al2O3 ratio of 2.0. The BET-specific surface area of KNaLSX is 715 m2/g, which is larger than the low-silicon X-type zeolite (LSX) synthesized from waste residue reported in the literature. The ion exchange rate constant of calcium and magnesium ions in KNaLSX is 5 times and 3 times that of 4A zeolite, respectively. KNaLSX also has a high ion exchange capacity for magnesium ion of 191 mgMgCO3/g, which is 2 times than that of 4A zeolite, and a high ion exchange capacity for calcium ion of 302 mgCaCO3/g, which meets the first-grade standard of zeolite for detergent builders in China. The work provides the basis for high-value resource utilization of lithium slag and the development of a detergent builder for rapid washing.

Experimental investigation on high-temperature co-gasification and melting behavior of petrochemical sludge and bituminous coal in CO2 atmosphere

High-temperature co-gasification of petrochemical sludge (PS) and bituminous coal (BC) can melt heavy metals and fly ash in hazardous waste, decompose dioxins, and generate syngas, which can achieve clean disposal and high value resource utilization of wastes. In this investigation, the high-temperature co-gasification and ash melting experiments of PS mixed with BC were carried out in a high-temperature tube furnace under CO2 atmosphere. The effects of gasification temperature and blending ratios (PS:BC) on co-gasification characteristics and ash melting behavior were investigated. The synergistic effect of co-gasification of PS-BC was examined. The results show that the yield of syngas (CO + H2) was proportional to the temperature and the proportion of BC. As the temperature increased from 1100 °C to 1400 °C, the yield of syngas increased from 1.42 m3/kg to 1.54 m3/kg. At 1300 °C, as the blending ratio of PS:BC shifted from 1:0 to 0:1, the yield of syngas increased significantly from 0.49 m3/kg to 1.88 m3/kg. The most significant synergistic effect of PS-BC co-gasification was the enhanced CO yield. At a blending ratio of 1:1, the synergistic coefficient of CO yield reached a maximum of 1.31. As for the residues, with the increase of temperature and the proportion of BC, the ash melting got promoted. The leaching toxicity of heavy metals in the residues can meet the release standard (GB5805.3–2007), being safe for disposal.

A Comprehensive Review on Reductive Recycling of Cathode Materials of Spent Lithium-Ion Batteries.

The prosperity of the lithium-ion battery market is inevitably accompanied by the depletion of corresponding resources and the accumulation of spent batteries in a dialectical manner. Spent lithium-ion batteries are harboring the characteristics of hazardous waste and high-value resources, so efficient recycling is of great significance. The cathode material is considered as an interesting target for repurposing. Despite some important reviews give commendable emphasis to recycling technologies, there is still a dearth of exploration of recycling mechanisms. This deficiency of awareness highlights the need for further research and development in this area. This review aims to systematically review and thoroughly discuss the reduction reaction mechanism of each method regarding different cathode materials. And systematically digest the selection of reducing agent and the effect of reduction reaction on material regeneration are systematically digested, as well as the impact of the reduction reaction on the regeneration of materials. This review emphasizes the importance of balancing efficiency, economic and environmental benefits in reuse technologies. Finally, the review proposes an outlook on the opportunities and challenges facing the reuse of key materials for next-generation spent batteries aimed at promoting the green and sustainable development of lithium-ion batteries, circular economy and ecological balance.

Study on Pyrolysis Characteristics of Phosphate Tailings under H2O Atmosphere.

The pyrolysis separation of calcium and magnesium from phosphate tailings is an important process due to its high-value resource utilization. In this paper, aiming to address the problems of high energy consumption, a slow decomposition rate and the low activity of decomposition products in the high-temperature pyrolysis of phosphate tailings, the medium-temperature pyrolysis of phosphate tailings under a H2O atmosphere was carried out, and the phase reconstruction and activation of pyrolysis process were discussed. The results showed that compared with N2, air and CO2 atmospheres, the pyrolysis process of phosphate tailings in a H2O atmosphere was changed from two stages to one stage, the starting decomposition temperature was reduced to 500 °C and the decomposition time was shortened to 30 min. The order of the influence of each factor on the pyrolysis of phosphate tailings was temperature > H2O pressure > holding time. Under the optimized pyrolysis conditions, the yield of CaMg(CO3)2 decomposition of phosphate tailings into MgO and CaO was 97.3% and 98.1%, respectively, and the reactivity of MgO was 31.6%. The distribution of Ca and Mg elements in the phosphate tailings after pyrolysis showed a negative correlation, and both of them no longer formed associated compounds; Ca mainly existed in the form of Ca(OH)2, Ca5(PO4)3F, CaSiO3 and CaF2, and Mg mainly existed in the form of MgO, MgF2 and Mg(OH)2.

Research on the Resource Recovery of Medium-Chain Fatty Acids from Municipal Sludge: Current State and Future Prospects.

The production of municipal sludge is steadily increasing in line with the production of sewage. A wealth of organic contaminants, including nutrients and energy, are present in municipal sludge. Anaerobic fermentation can be used to extract useful resources from sludge, producing hydrogen, methane, short-chain fatty acids, and, via further chain elongation, medium-chain fatty acids. By comparing the economic and use values of these retrieved resources, it is concluded that a high-value resource transformation of municipal sludge can be achieved via the production of medium-chain fatty acids using anaerobic fermentation, which is a hotspot for future research. In this study, the selection of the pretreatment method, the method of producing medium-chain fatty acids, the influence of the electron donor, and the technique used to enhance product synthesis in the anaerobic fermentation process are introduced in detail. The study outlines potential future research directions for medium-chain fatty acid production using municipal sludge. These acids could serve as a starting point for investigating other uses for municipal sludge.

Consistency in Verreaux's sifaka home range and core area size despite seasonal variation in resource availability as assessed by Enhanced Vegetation Index (EVI).

Primates are adept at dealing with fluctuating availability of resources and display a range of responses to minimize the effects of food scarcity. An important component of primate conservation is to understand how primates adapt their foraging and ranging patterns in response to fluctuating food resources. Animals optimize resource acquisition within the home range through the selection of resource-bearing patches and choose between contrasting foraging strategies (resource-maximizing vs. area-minimizing). Our study aimed to characterize the foraging strategy of a folivorous primate, Verreaux's sifaka (Propithecus verreauxi), by evaluating whether group home range size varied between peak and lean leaf seasons within a seasonally dry tropical forest in Madagascar. We hypothesized that Verreaux's sifaka used the resource maximization strategy to select high-value resource patches so that during periods of resource depression, the home range area did not significantly change in size. We characterized resource availability (i.e., primary productivity) by season at Kirindy Mitea National Park using remotely-sensed Enhanced Vegetation Index data. We calculated group home ranges using 10 years of focal animal sampling data collected on eight groups using both 95% and 50% kernel density estimation. We used area accumulation curves to ensure each group had an adequate number of locations to reach seasonal home range asymptotes. Neither 95% home ranges nor 50% core areas differed across peak and lean leaf resource seasons, supporting the hypothesis that Verreaux's sifaka use a resource maximization strategy. With a better understanding of animal space use strategies, managers can model anticipated changes under environmental and/or anthropogenic resource depression scenarios. These findings demonstrate the value of long-term data for characterizing and understanding foraging and ranging patterns. We also illustrate the benefits of using satellite data for characterizing food resources for folivorous primates.

Analysis of Microbial Diversity and Community Structure of Rhizosphere Soil of Three Astragalus Species Grown in Special High-Cold Environment of Northwestern Yunnan, China.

Astragalus is a medicinal plant with obvious rhizosphere effects. At present, there are many Astragalus plants with high application value but low recognition and resource reserves in the northwestern area of Yunnan province, China. In this study, metagenomics was used to analyze the microbial diversity and community structure of rhizosphere soil of A. forrestii, A. acaulis, and A. ernestii plants grown in a special high-cold environment of northwestern Yunnan, China, at different altitudes ranging from 3225 to 4353 m. These microbes were taxonomically annotated to obtain 24 phyla and 501 genera for A. forrestii, 30 phyla and 504 genera for A. acaulis, as well as 39 phyla and 533 genera for A. ernestii. Overall, the dominant bacterial phyla included Proteobacteria, Actinobacteria, and Acidobacteria, while the dominant fungal ones were Ascomycota and Basidiomycota. At the genus level, Bradyrhizobium, Afipia, and Paraburkholderia were the most prevalent bacteria, and Hyaloscypha, Pseudogymnoascus, and Russula were the dominant fungal genera. Some of them are considered biocontrol microbes that could sustain the growth and health of host Astragalus plants. Redundancy analysis revealed that pH, TN, and SOM had a significant impact on the microbial community structures (p < 0.05). Finally, triterpene, flavonoid, polysaccharide, and amino acid metabolisms accounted for a high proportion of the enriched KEGG pathways, which possibly contributed to the synthesis of bioactive constituents in the Astragalus plants.

A Fundamental Study on the Preparation of Sodium Tungstate from Wolframite via the Smelting Process

Tungsten is a high-value resource with a wide range of applications. The tungsten metal is produced via ammonium paratungstate, which is a multi-stage process including leaching, conversion, precipitation, calcination, and reduction. A short process to produce tungsten metal from the electrolysis of molten sodium tungstate has been demonstrated. However, sodium tungstate cannot be directly produced from wolframite in the conventional hydrometallurgical process. There was no information reported in the literature on producing sodium tungstate directly from tungsten concentrates. The present study proposed a simple and low-cost process to produce sodium tungstate by high-temperature processing of wolframite. The mixtures of wolframite, sodium carbonate, and silica were melted in air between 1100 and 1300 °C. High-density sodium tungstate was easily separated from the immiscible slag, which contained all impurities from wolframite, flux, excess sodium oxide, and dissolved tungsten oxide. The slag was further water leached to recover sodium tungstate in the solution. Effects of Na2CO3/Ore and SiO2/Ore ratios, temperature, and reaction time on the recovery of tungstate and the purity of sodium tungstate were systematically studied. Sodium tungstate containing over 78% WO3 was produced in the smelting process, which is suitable for the electrolysis process. The experimental results will provide a theoretical basis for the direct production of sodium tungstate from wolframite. The compositions of the WO3-containing slags and sodium tungstate reported in the present study fill the knowledge gap of the tungsten-containing thermodynamic database. Further studies to use complex and low-grade tungsten concentrates to produce sodium tungstate are underway.

The amnesic shellfish poisoning toxin, domoic acid: The tattoo of the king scallop Pecten maximus

Domoic acid (DA) is a potent neurotoxin produced by diatoms of the genus Pseudo-nitzschia and is responsible for Amnesic Shellfish Poisoning (ASP) in humans. Some fishery resources of high commercial value, such as the king scallop Pecten maximus, are frequently exposed to toxic Pseudo-nitzschia blooms and are capable of accumulating high amounts of DA, retaining it for months or even a few years. This poses a serious threat to public health and a continuous economical risk due to fishing closures of this resource in the affected areas. Recently, it was hypothesized that trapping of DA within autophagosomic-vesicles could be one reason explaining the long retention of the remaining toxin in P. maximus digestive gland. To test this idea, we follow the kinetics of the subcellular localization of DA in the digestive glands of P. maximus during (a) the contamination process — with sequential samplings of scallops reared in the field during 234 days and naturally exposed to blooms of DA-producing Pseudo-nitzschia australis, and (b) the decontamination process — where highly contaminated scallops were collected after a natural bloom of toxic P. australis and subjected to DA-depuration in the laboratory for 60 days. In the digestive gland, DA-depuration rate (0.001 day−1) was much slower than contamination kinetics. The subcellular analyses revealed a direct implication of early autophagy in DA sequestration throughout contamination (r = 0.8, P < 0.05), while the presence of DA-labeled residual bodies (late autophagy) appeared to be strongly and significantly related to slow DA-depuration (r = -0.5) resembling an analogous DA-tattooing in the digestive glands of P. maximus. This work provides new evidence about the potential physiological mechanisms involved in the long retention of DA in P. maximus and represents the baseline to explore procedures to accelerate decontamination in this species.

Two-step pyrolysis of mango branch for the preparation of B/N/O co-doped porous carbon materials

Porous carbon prepared by conventional pyrolysis of forestry waste usually possesses poor specific capacitance as supercapacitor electrodes, which mainly attributes to the shortcomings of its poor microstructure and few chemical functional groups on the surface. It is suggested that the introduction of active groups can enhance the wettability and induce redox reactions, thereby increasing the specific capacitance. In this paper, novel functional carbon materials with high electrochemical activity were effectively prepared from forestry waste by a green and economical B/N/O co-doping synthesis strategy using NH4B5O8 as bi-functional additive. The doped content of heteroatoms, specific surface area, and pore features were controlled by adjusting the NH4B5O8 mixing ratio and pyrolysis temperature. MA3-T700 showcases a specific surface area of 1621 m2/g, preferable B/N/O atoms doped content (0.62%, 1.98%, and 13.82%, respectively), and interconnected micropores/mesopores structure. It exhibits an ultra-high specific capacitance of 322 F/g at 1 A/g and an exceptional rate performance of 77.02% even at 20 A/g. Furthermore, MA3-T700 symmetric supercapacitor was assembled, exhibiting an impressive capacitance retention of 96.11% after 10,000 cycles and achieving an energy density of 8.4 Wh/kg. This work provides technical and theoretical support for the utilization of high-value resources from forestry waste.

Process optimization of osmotic membrane distillation for the extraction of valuable resources from water streams

The rising demand for sustainable wastewater management and high-value resource recovery is pressing industries involved in, e.g., textiles, metals, and food production, to adopt energy-efficient and flexible liquid separation methods. The current techniques often fall short in achieving zero liquid discharge and enhancing socio-economic growth sustainably. Osmotic membrane distillation (OMD) has emerged as a low-temperature separation process designed to concentrate valuable elements and substances in dilute feed streams. The efficacy of OMD hinges on the solvent’s migration from the feed to the draw stream through a hydrophobic membrane, driven by the vapor pressure difference induced by both temperature and concentration gradients. However, the intricate interplay of heat and mass processes steering this mechanism is not yet fully comprehended or accurately modeled. In this research, we conducted a combined theoretical and experimental study to explore the capabilities and thermodynamic limitations of OMD. Under diverse operating conditions, the experimental campaign aimed to corroborate our theoretical assertions. We derived a novel equation to govern water flux based on foundational principles and introduced a streamlined version for more straightforward application. Our findings spotlight complex transport-limiting and self-adjusting mechanisms linked with temperature and concentration polarization phenomena. Compared with traditional methods like membrane distillation and osmotic dilution, which are driven by solely temperature or concentration gradients, OMD may provide improved and flexible performance in target applications. For instance, we show that OMD—if properly optimized—can achieve water vapor fluxes 50% higher than osmotic dilution. Notably, OMD operation at reduced feed temperatures can lead to energy savings ranging between 5 and 95%, owing to the use of highly concentrated draw solutions. This study underscores the potential of OMD in real-world applications, such as concentrating lithium in wastewater streams. By enhancing our fundamental understanding of OMD’s potential and constraints, we aim to broaden its adoption as a pivotal liquid separation tool, with focus on sustainable resource recovery.

Novel process for high value utilization of high-alumina fly ash: valuable metals recovery and mesoporous silica in situ preparation.

Extraction of valuable metals besides silica from high-alumina fly ash is one of the most important high-value utilization pathways. However, it is difficult to realize high-efficiency extraction due to the stable structure e.g. of quartz and mullite. In this paper, mineral phase transformation for valuable metal recovery and mesoporous silica in situ preparation from fly ash by a selective acid leaching method was proposed. The mineral phase transformation, dissolution behavior of each metal, and pore structure of fly ash derived mesoporous silica were systematically investigated. The results show that the co-activation of fly ash by Na2CO3-K2CO3 formed the phases of kalsilite and (Na, K)AlSiO4. During the acid leaching process, Al, Li, and Ga could be leached with the efficiencies of 86.17%, 89%, and 80% in the FK system. In the FN system, the efficiencies of Al, Li, and Ga are 92.38%, 95%, and 83%, respectively. The crystal plane (002) was destroyed for kaliophilite while all the crystal planes were destroyed for nepheline. With the increase of HCl solution concentration, the porous silica exhibited the same change order of pore shape. The pore structure of as-prepared porous silica was type IV and the hysteresis loop was type H3, and the specific surface areas could be 565.54, 448.02, and 746.76 m2 g-1, respectively. Finally, the leaching liquors can be used to produce crystal aluminum chloride, lithium carbonate and gallium. This paper might provide technical support for full recycling of high-value resources from fly ash.