摘要 : The biofilm sequencing batch reactor (BSBR) technique has been deployed in the laboratory to enrich phosphorus from simulated wastewater, but it is still not clear what its performance will be when real world sewage is used. In this work, the effluent from the multi-stage anoxic-oxic (AO) activated sludge process at a sewage plant was used as the feed water for a BSBR pilot system, which had three reactors operating at different levels of dissolved oxygen (DO). The phosphorus adsorption and release, the biofilm growth, and the extracellular polymeric substances (EPS) components and contents were examined. The microbial communities and the signaling molecules N -acyl- l -homoserine lactones (AHLs) were also analyzed. Gratifyingly, the BSBR process successfully processed the treated sewage, and the biofilm developed phosphorus accumulation capability within 40 days. After entering stable operation, the system concentrated phosphate from 2.59 ± 0.77 mg/L in the influent to as much as 81.64 mg/L in the recovery liquid. Sludge discharge had profound impacts on all aspects of BSBR, and it was carried out successfully when the phosphorus absorption capacity of the biofilm alone was comparable to that of the reactor containing the activated sludge. Shortly after the sludge discharge, the phosphate concentration of the recovery liquid surged from 50 to 140 mg/L, the biofilm thickness grew from 20.56 to 67.32 μm, and the diversity of the microbial population plunged. Sludge discharge stimulated Candidatus competibacter to produce a large amount of AHLs, which was key in culturing the biofilm. Among the AHLs, both C10-HSL and 3OC12-HSL were significantly positively correlated with EPS and the abundance of Candidatus competibacter . The current results demonstrated BSBR as a viable option to enrich phosphorus from real world sewage with low phosphorus content and fluctuating chemistry. The mechanistic explorations also provided theoretical guidance for cultivating phosphorus-accumulating biofilms.

摘要 : Transition metal selenides (TMSs) stand out as a promising anode material for sodium-ion batteries (SIBs) owing to their natural resources and exceptional sodium storage capacity. Despite these advantages, their practical application faces challenges, such as poor electronic conductivity, sluggish reaction kinetics and severe agglomeration during electrochemical reactions, hindering their effective utilization. Herein, the dual-carbon-confined CoSe 2 /FeSe 2 @NC@C nanocubes with heterogeneous structure are synthesized using ZIF-67 as the template by ion exchange, resorcin-formaldehyde (RF) coating, and subsequent in situ carbonization and selenidation. The N -doped porous carbon promotes rapid electrolyte penetration and minimizes the agglomeration of active materials during charging and discharging, while the RF-derived carbon framework reduces the cycling stress and keeps the integrity of the material structure. More importantly, the built-in electric field at the heterogeneous boundary layer drives electron redistribution, optimizing the electronic structure and enhancing the reaction kinetics of the anode material. Based on this, the nanocubes of CoSe 2 /FeSe 2 @NC@C exhibits superb sodium storage performance, delivering a high discharge capacity of 512.6 mA h g −1 at 0.5 A g −1 after 150 cycles and giving a discharge capacity of 298.2 mA h g −1 at 10 A g −1 with a CE close to 100.0 % even after 1000 cycles. This study proposes a viable method to synthesize advanced anodes for SIBs by a synergy effect of heterogeneous interfacial engineering and a carbon confinement strategy.

摘要 : As a convenient photothermal material, polydopamine (PDA) has been widely utilized in wood-based evaporators. However, the loading conditions of polydopamine on biomass bulk materials have not been systematically studied. In this paper, the suitable reaction conditions of polydopamine were studied with rattan as the substrate, and a reference for the improvement of the loading conditions was proposed. The polydopamine-loaded rattan-based evaporator (PDA-R) prepared on this basis exhibits excellent working stability due to the unique large-scale hierarchical porous structure of rattan. In addition to excellent salt resistance and cycle performance (evaporation rate decays by 5.1% after 30 cycles), the larger-aperture channel (200–450 μm) also brings better adaptability to salinity changes than polydopamine-loaded basswood-based evaporator (PDA-BW) (the attenuation coefficient of PDA-R is 6.2%, while the attenuation coefficient of PDA-BW is 16.3%). All of these indicate the broad prospects of polydopamine-loaded rattan-based evaporator as a multi-effect treatment scheme of brine.

摘要 : Global daily oil consumption reaches nearly 100 million barrels, a figure which consequently leads to the generation of substantial volumes of oily wastewater during the processes of oil production and transportation. Existing advanced materials exhibit remarkable properties for emulsions stabilized by specific surfactants. However, these materials face limitations in practical application due to the intricate composition of surfactants present in real-world oily wastewater. In this paper, we aim to tackle this issue by presenting a solution that involves the utilization of surface-engineered graphene-based multi-level filter materials (GMFMs). These specially prepared GMFMs incorporate positively charged, negatively charged, and uncharged graphene sheets, which synergistically combine to form a porous structure with unique wettability. This innovative design allows the filter material to exhibit exceptional separation capabilities for complex emulsions. The surface-engineered GMFMs exhibited exceptional efficiency in the separation of mixed surfactant-stabilized emulsions and industrial wastewater. Operating at a high throughput of approximately 5000 L m −2 h −1, these GMFMs achieved an impressive oil removal efficiency of 99.8 % or higher after just one-step separation. The combined efficiency, reusability, and broad applicability of GMFMs facilitate efficient separation of oil-in-water emulsions on a large scale, promising a sustainable solution to the pressing issue of oily wastewater treatment.

摘要 : The research of high-speed photodetector and high-speed optical receiver garners significant attention due to their indispensable properties in many fields including high-temperature event monitoring, security, and ad hoc network wireless communication. Inorganic perovskite oxides LaCoO 3 films showcase an extensive prospect in this area owing to their remarkable photoconductive effect. Up to present, however, LaCoO 3 films are mostly grown on rigid instead of flexible substrates, greatly limiting their applications to wearable optoelectronic sensors. In this work, we fabricated some flexible LaCoO 3 thin films to study their photoresponse. By inserting SrTiO 3 and BaTiO 3 as buffer layers, we find that LaCoO 3 thin films could epitaxially grow on the fluorphlogopite surface and show a stable photoresponse to visible-light. Nevertheless, we also found that the epitaxial strain and the content of surface-adsorbed oxygen could impact the photoconductivity. The mechanical strain generated by bending the fluorphlogopite substrate has been confirmed to has a tunable effect on the photoresponse. Moreover, with the fatigue tests of 10 5 bending cycles, the flexible LaCoO 3 thin films maintain a good photoresponse without any essentially weakening, proving a superior mechanical durability and stability. This work not only indicates the feasibility of the LaCoO 3 films applied for flexible photodetectors but also opens a path for other perovskite films applications for flexible substrate.

摘要 : Indoor formaldehyde poses a significant carcinogenic risk to human health, making its removal imperative. Electro-Fenton degradation has emerged as a promising technology for addressing this concern. In the electro-Fenton system, ·OH is identified as the primary active species responsible for formaldehyde removal. Hence, its generation and utilization are pivotal for the system's effectiveness and economy. Experimental and quantum chemical methods were employed to investigate the effects and mechanisms of nitrogen doping on various aspects influencing ·OH generation and utilization. Results indicate that nitrogen doping synergistically enhances the generation and utilization of ·OH, leading to an improved formaldehyde removal efficiency in nitrogen-doped cathodic systems. The dominant nitrogen type influencing ·OH generation and utilization varies across different stages. Pyridinic nitrogen facilitates H 2 O 2 adsorption through hydrogen bonding, while pyrrolic and graphitic nitrogen contribute to formaldehyde adsorption and catalyze the conversion of H 2 O 2 to ·OH. Both pyridinic nitrogen and pyrrolic nitrogen boost the degradation of formaldehyde by ·OH. In comparison to the unmodified system, the modified system with NAC-GF/700C as cathode exhibits remarkable improvements. The formaldehyde removal efficiency has increased twofold, and energy consumption reduced by 73.45%. Furthermore, the system demonstrates excellent cyclic stability. These advancements can be attributed to the activation temperature, which leads to the appropriate types and high content of nitrogen elements in NAC-GF/700C. The research represents an important step towards more economical and efficient electro-Fenton technology for indoor formaldehyde removal.

摘要 : Dealuminated Beta zeolite has a large amount of silanol defects on its interface, which provides an ideal place for embedding metal species and creating metal active sites in a confined microenvironment. The confined metal sites as well as their surroundings are closely related to the reactant activation and transient state achievement. Hence, unraveling the confined metal sites is of great significance for the catalytic reaction process. Herein, niobium species were incorporated into the silanol defects over dealuminated Beta zeolite with a facile dry impregnation method, co-grinding the niobium precursor with dealuminated Beta zeolite support. The successful incorporation of niobium into the silanol defects for 30Nb-Beta zeolite was verified by DRIFT, 1 H MAS NMR, UV–Vis and UV-Raman characterizations. XAS characterization and DFT calculations further disclosed that the confined Nb species existed as (SiO) 2 Nb(OH)(=O), containing two Si−O−Nb bonds, one Nb=O bond as well as one Nb−OH bond. The synthesized 30Nb-Beta zeolite catalyst displayed a superior cyclohexene conversion of 51.1%, cyclohexene oxide selectivity of 83.1% as well as TOF value of 188.2 h −1 ascribed to the inherent electrophilicity of Nb(V) for confined (SiO) 2 Nb(OH)(=O) species as well as the low oxygen transfer energy barrier for Nb V −OOH species. Furthermore, the prepared 30Nb-Beta zeolite can be effectively employed to other cyclic alkene epoxidation reactions.

摘要 : Herein, a dual-emitting fluoroprobe was pioneered for the sensitive and selective detection of hydroquinone (HQ) in environmental waters, which was based on integration of a tailor-made fluorescent ionic liquid ([TBAOH][NA]) with Eu 3+ (([TBAOH][NA]/Eu 3+ ). HQ could substantially enhance the 365-nm fluorescence intensity (FI 365 ) of [TBAOH][NA]/Eu 3+, whereas no prominent variation ocurred in FI 615 . After HQ binding with [TBAOH][NA], the electronic structure of S1 was completely pi-pi, and the orbital overlap of the latter was much higher, thereby promoting photon transitions. After some key factors were optimized using a central-composite-design (CCD) approach, this fluroprobe provided a linear response from 0.5 to 100 μM and detection limit of 0.15 μM for HQ assay, which was comparable to analytical performance by conventional HPLC-DAD analysis. Overall, the prominent advantages of as-developed fluoroprobe lie in two aspects: (1) Employing the ratio of two well-resolved emission and significantly differential responses to HQ greatly enhance sensitivity and accuracy through a self-calibration system; and (2) [TBAOH][NA] has not only the superiority of "green solvent" like conventional ionic liquids, but also possesses strong luminescence signal owing to introducing 1-naphathoic acid as an anion into tetrapropylammonium hydroxide. Consequently, this dual-emitting fluoroprobe is endowed with great potential in on-site and outdoor HQ monitoring.

摘要 : Lithium-sulfur batteries (LSBs) have emerged as a promising energy storage system, but their practical application is hindered by the polysulfide shuttle effect and sluggish redox kinetics. To address these challenges, we have developed CoO/MoO 3 @nitrogen-doped carbon (CoO/MoO 3 @NC) hollow heterostructures based on porous ZIF-67 as separators in LSBs. CoO has a strong anchoring effect on polysulfides. The heterostructure formed after the introduction of MoO 3 increases the adsorption of polysulfides. The carbon coating outside the heterostructure improves the ion transmission efficiency of the battery, leading to enhanced electrochemical performance. The modified LSB demonstrates a low-capacity decay rate of 0.092% over 500 cycles at 0.5C, with a high discharge capacity of 613 mAh g −1 at 1C. This work presents a novel approach for the preparation of hollow heterostructure materials, aiming for high-performance LSBs.

摘要 : Vegetation restoration exerts transformative effects on nutrient cycling, microbial communities, and ecosystem functions. While extensive research has been conducted on the significance of mangroves and their restoration efforts, the effectiveness of mangrove restoration in enhancing soil multifunctionality in degraded coastal wetlands remains unclear. Herein, we carried out a field experiment to explore the impacts of mangrove restoration and its chronosequence on soil microbial communities, keystone species, and soil multifunctionality, using unrestored aquaculture ponds as controls. The results revealed that mangrove restoration enhanced soil multifunctionality, with these positive effects progressively amplifying over the restoration chronosequence. Furthermore, mangrove restoration led to a substantial increase in microbial diversity and a reshaping of microbial community composition, increasing the relative abundance of dominant phyla such as Nitrospirae, Deferribacteres, and Fusobacteria. Soil multifunctionality exhibited positive correlations with microbial diversity, suggesting a link between variations in microbial diversity and soil multifunctionality. Metagenomic screening demonstrated that mangrove restoration resulted in a simultaneous increase in the abundance of nitrogen (N) related genes, such as N fixation ( nirD / H / K ), nitrification ( pmoA-amoA / B / C ), and denitrification ( nirK, norB / C, narG / H, napA / B ), as well as phosphorus (P)-related genes, including organic P mineralization ( phnX / W, phoA / D / G, phnJ / N / P ), inorganic P solubilization ( gcd, ppx-gppA ), and transporters ( phnC / D / E, pstA / B / C / S )). The relationship between the abundance of keystone species (such as phnC / D / E ) and restoration-induced changes in soil multifunctionality indicates that mangrove restoration enhances soil multifunctionality through an increase in the abundance of keystone species associated with N and P cycles. Additionally, it was observed that changes in microbial community and multifunctionality were largely associated with shifts in soil salinity. These findings demonstrate that mangrove restoration positively influences soil multifunctionality and shapes nutrient dynamics, microbial communities, and overall ecosystem resilience. As global efforts continue to focus on ecosystem restoration, understanding the complexity of mangrove-soil interactions is critical for effective nutrient management and mangrove conservation.