Nanofiltration (NF) is a key water treatment technology crucial for addressing the global water resource crisis. The precise control over the inner microstructure of the membrane presents a critical issue that must be addressed to achieve superior separation performance. Herein, vertical NiAl-layered double hydroxide (LDH) nanoarrays were synthesized and employed as an intermediate layer during interfacial polymerization (IP) to fabricate LDH/polyamide (PA) composite membranes. The vertical LDH arrays can bidirectionally regulate the internal microstructure of the PA layer. At a lower PIP concentration (0.1 w/v%), the hydroxyl groups on LDH delay the diffusion of PIP via hydrogen bonding, resulting in a 24 nm active PA layer with the looser structure (compared with pristine PA (0.1%)). The membrane displayed a permeance value of 65 L m-2 h-1 bar-1 with the methyl blue (MB) rejection of 98.5%, and enabled precise separation of MB and methyl orange (MO). At a higher PIP concentration (1 w/v%), the LDH arrays can effectively store and rapidly release PIP to obtain a complete initial polymer membrane. Subsequently, the confined cross-linking within the initial membrane leads to a denser PA layer (compared with pristine PA (1%)) that exhibits permeance up to 19.86 L m-2 h-1 bar-1 with a 98.2% rejection of Na2SO4. This work first reports a strategy for the bidirectional regulation of the PA active layer toward looser or denser morphological evolution, and highlights the considerable promise of the LDH/PA composite membrane for versatile separation tasks in water treatment.

Humic substances (HSs) and/or iron can drive reactive oxygen species (ROS) generation in various environments; however, most reported systems involve light irradiation or rely on the reduced status of HSs and/or iron. Here, we identify an overlooked abiotic, nonphotochemical pathway for ROS generation and pollutant degradation via thermally induced activation of original HSs and Fe3+ in both bulk solutions and microdroplets at environmentally relevant temperatures. The HO• generation increased by 5.7-18.1-fold with elevated temperatures (20-70 °C) and rising concentrations of HSs and Fe3+. Mechanistic studies involving Fe2+ quantification, ROS scavenging assays, and functional group identification revealed that reductive moieties (e.g., HS(Ar-OH)) within HSs simultaneously facilitated H2O2 and Fe2+ generation. In this process, O2 and Fe3+ functioned as single or dual electron acceptors, with semiquinone radicals (HS(Ar-O•)) acting as key intermediates and HO• and quinone species (HS(Ar═O)) as terminal oxidation products. Remarkably, HS-Fe3+ in microdroplets exhibited ROS production up to 2 orders of magnitude higher than in bulk solution due to interfacial enhanced reactivity, resulting in accelerated micropollutant degradation. A microfluidic device was further developed for in situ visualization, confirming the temperature dependence of ROS generation in HS-Fe3+ microdroplets. This study highlights a thermally driven oxidative pathway with implications for contaminant decomposition in high-temperature or microdroplet-rich environments.

Rising global food demand urges the development of sustainable alternative protein sources. Single-cell protein (SCP), derived from microbial biomass such as bacteria, offers a promising solution due to its efficient production and minimal resource requirements. Recent advances in biotechnology have enabled the conversion of various biowastes into SCP through controlled fermentation processes. However, large-scale application faces challenges related to feedstock sustainability, safety, scalability, and consumer acceptance. Economically viable production requires nutrient-rich, low-cost substrates, such as agricultural residues, food waste, and industrial byproducts. This review highlights the critical role of feedstock in determining the economic and environmental feasibility of bacterial SCP production, and explores scaling-up strategies for industrial application. Future development should prioritize a feedstock-first approach that aligns microbial metabolism with locally available resources and integrates techno-economic and life-cycle analyses, thereby preparing bacterial SCP as a key component of a circular bioeconomy that contributes to global food security.

Nitrate in groundwater should be treated as a nitrogen source rather than a contaminant. Biohybrid technologies coupling microbial selectivity with renewable electro(photo)chemical energy offer opportunities to convert nitrate to value-added ammonium, although challenges remain in scalability, microbial stability, material-microbe integration, process engineering, regulatory compliance, and economic feasibility.

Integrating water splitting with gas-fixing microorganisms offers a promising route for the sustainable production of chemicals, fuels, and food using renewable electricity. However, challenges such as insufficient gas utilization and undesirable side reactions hinder the scalability of these systems. To overcome these limitations, we proposed and investigated a universal hydrogel-coated electrode strategy to significantly enhance single-cell protein (SCP) production from CO2 and electricity. The hydrogel coating facilitated the formation of hydrogel-sheared microbubbles of H2 and O2, alongside added CO2, improving gas availability for Cupriavidus necator H16 growth. Additionally, this strategy significantly reduced metal ion release (33.73%-89.32%) and restricted the diffusion of reactive oxygen species (ROS, 87.94%-100%) from the electrodes, both of which previously inhibited bacterial growth and SCP yield. This dual-function coating enhanced both performance and protection across a wide voltage range, leading to a 20.56% increase in biomass production and a 55.96%-166.26% increase in essential amino acid content. With a biomass concentration of 0.96 g/L in a 500 mL bioreactor, this approach demonstrates high scalability and potential for application in various biohybrid electrochemical systems, enabling efficient production of value-added products.

To solve the problems of preparation process,flexibility,and flexibility of friction electric fibers,super-elastic triboelectric fibers were prepared by using an extrusion-filling method.The liquid metal EGaIn and thermoplastic elastomer material were used as the conductive electrode and the fiber sleeve,respectively.The fiber could sustain strains up to 2200%and exhibited high electrical outputs.By using a 5 cm long fiber as the medium,the fiber can provide an unsaturated average open circuit voltage of 7 V when in contact with paper;and the instantaneous power density of 1.6 μW/m was obtained with an external load resistance of 200 MΩ.Weaning the fiber into an 8 cm×8 cm textile,the max electrical outputs were 120 V,280 nA,28 nC.Results show that the extrusion-filling technology is an effective way to develop stretchable triboelectric fibers.The super-elastic fibers in this work have the potential for multi-functional wearable smart textiles applications.

Gas fermentation offers a promising approach for converting waste and greenhouse gases into valuable products. Hydrogen-oxidizing microbes like Cupriavidus necator can fix CO2 into single-cell protein (SCP) using H2 under aerobic conditions, but low gas solubility in aqueous media limits productivity. To address this, a hollow fiber membrane bioreactor (HFMB) was integrated with Cupriavidus necator H16 for SCP production via aerobic CO2 bioconversion. Compared to bubble column (BCB) and microbubble column bioreactors (MCB), the HFMB's high gas permeability significantly improved gas dissolution, enhancing bacterial growth (3.15-6.83 folds) and amino acid production (up to 281.11 %). Optimal conditions, including higher gas flow rates (187.5 mL/h) and temperature (40 °C), further increased SCP yields by over twofold in the HFMB. Additionally, HFMB demonstrated the ability to operate continuously with stable SCP production and less membrane fouling. This study underscores the promise of membrane technology for advancing SCP production via gas fermentation.

Aerobic hydrogen-oxidizing bacteria (Cupriavidus necator H16) demonstrate efficient non-phototrophic CO2 assimilation for single-cell protein (SCP) production using H-2 as an energy source. However, achieving high productivity in remote or resource-limited regions is often hindered by challenges in continuous gas supply, utilization, and control. In this study, we proposed a simplified proof-of-concept SCP production line that integrates green energy with a custom-designed fermenter. Utilizing a novel passive gas-feeding strategy driven by concentration differentials between gas and liquid phases, the single-chamber fermenter achieved biomass productivity of 58 mg L-1 h(-1) with minimum waste gas generation. Furthermore, we found that low dissolved O-2 (<1 mg L-1) and ammonium concentrations (<2 g L-1) were crucial factors limiting SCP production in biomass (<50%) when bacterial OD600 reached around 5. To further address safety risks associated with H-2-O-2 mixtures, a dual-chamber fermenter was designed to separate the passive flow of H-2/CO2 and O-2 derived from ambient air. This innovative system facilitates efficient gas utilization and nutrient exchange without gas loss, enabling safe and effective small-scale applications under atmospheric pressure. These results provide a promising approach for enhancing continuous gas fermentation efficiency and addressing safety concerns in SCP production in resource-limited communities.

Photolysis-induced generation of reactive oxygen species (ROS) is a crucial aspect of environmental processes, yet the photoactivity of natural clay minerals (CMs) and the carbon cycle involved remain unclear. Here, we discovered the light wavelength-dependent photoactivity of CMs in ROS generation and deeply elaborated the transformation of DOM on the CM’s surface. Our results reveal that CMs exhibit varying adsorption capabilities and a preference for highly unsaturated phenolic and aliphatic compounds within DOM, possibly related to their physical properties e.g., surface area. The formed CM-DOM aggregates result in photolysis ROS redistribution and DOM transformation at the CM-DOM interface, leading to the generation of saturated and oxidized smaller molecules. Moreover, we uncovered the previously overlooked release of transformed DOM from the CM-DOM interface. These findings unveil new environmental ROS generation and distribution through the photolysis of CMs and DOM, shedding light on previously neglected carbon cycling at the CM-DOM interface.

Naturally occurring reactive oxygen species (ROS) are widely involved in many environmental processes. Here we investigated the ROS generation associated with the interaction between complexed natural clay minerals (CMs) and dissolved organic matter (DOM). Our results showed that among the nine chemical-reduced CMs (CR-CMs), the light brown CR-CM (CR-CM 7) generated the highest ROS via oxygenation, relying on the reactive structural Fe(II) (Fe species that can transfer electrons to oxygen) instead of total structural Fe(II) as previously reported. Moreover, DOM affected the oxygenation of CR-CMs differently. The tight interaction between DOM and CR-CM 7 formed DOM-complexed Fe, while the weak interaction between DOM and the dark gold CR-CM (CR-CM 1) and the black CR-CM (CR-CM 5) exhibited decreased efficiencies. Mechanism studies revealed that ROS were generated through three pathways but all followed a similar one-electron transfer process in the presence of DOM. We further developed a three-layer geobattery model system and demonstrated that long electron transfer driven by CR-CMs/DOM could extend ROS generation to several centimetres across the oxic-anoxic interface, even without redox switching. These findings offer new insights into CMs-involved ROS generation and associated organic matter transformation in natural environments.

Clay minerals (CMs) and pyrogenic carbons (PCs) often co-exist in the environment and participate in the redox cycling of pollutants. This study unveiled the dual role of PCs in CM-dominated chromium transformation in both aqueous and agar solidification media. The findings showed that CMs and PCs adsorbed minimal Cr(VI), while reduced CMs and PCs displayed a substantial difference by directly reducing Cr(VI) to solid/dissolved Cr(III) through reactive structural Fe(II) and functional groups, respectively. Moreover, dissolved PCs were found to mediate electron transfer from reduced CMs to Cr(VI) in aqueous and solid media. Interestingly, the effect of solid PCs on Cr(VI) reduction by reduced CMs was concentration-dependent. At lower concentrations, solid PCs dispersed reduced CMs, acting as electron mediators and facilitating both direct and indirect Cr(VI) reduction, resulting in solid Cr(III) rather than dissolved Cr(III). Conversely, at higher concentrations, solid PCs served as redox buffers, storing electrons transferred from reduced CMs to Cr(VI). In either case, the transformed chromium was primarily immobilized on the surface of CMs rather than PCs. These findings offer valuable insights into pollutant transformations associated with CMs and PCs, deepening our understanding of their geochemical processes.

Flexible and wearable textile -based triboelectric nanogenerators (TENGs) have attracted extensive attention in wearable electronics owing to their ability to convert waste mechanical energy from human motion into electrical energy. However, the performances of TENGs are lower than those of planar/film configurations due to the complex fiber fabrications and limited mechanical freedom. In this work, we demonstrate an extrusion method combined with thermal drawing (ETD method) for continuous and scalable triboelectric fiber fabrication, providing longitudinal uniform fibers for hundreds of kilometers. Based on the ETD method, super -elastic microstructured triboelectric fibers (SMTFs) were fabricated, consisting of hollow elastomeric and liquid metal cores (EGaIn). The SMTFs showed excellent superelasticity with clear and uniform microstructures. The fibers could withstand strain up to 1800% and exhibited excellent electrical output performance. Utilizing a single fiber as the medium for triboelectric energy collection, the average open circuit voltage and instantaneous power density are respectively up to 210 V/m and 21 mu W/m with a 40 M omega external load resistance. The SMTFs could also be woven into deformable textiles with high electrical outputs up to 160 V, 10 mu A, and 50 nC. In addition, the SMTFs-based textiles were further demonstrated as completely soft and stretchable components for self -powered sensing in smart home applications.

Microplastics (MPs) and Perfluorooctane sulfonate (PFOS) are two hard -biodegradable pollutants widely existing in the waste streams treated by anaerobic digestion. However, their synergistic effect on methanogenic metabolism is still unknown. This study investigated the impact of polyethylene terephthalate (PET) MPs alone and co -existing with PFOS on CO2 conversion to CH4 in a thermophilic biogas upgrading system. The results showed that either PET MPs addition alone or coexisting with PFOS improved the ultimate CH4 percentage and increased CO2 utilization rate. When Fe0 was added into the reactors with PET to enhance the interspecies electron transfer, a potential defluorination was observed with a defluorination rate of 15.88 +/- 1.53%. Exposure of the reactor to PFOS of 300 mu g/L could change the methanogenic pathway, resulting in a newly emerged Methanomassiliicoccus with dominance of 16%. Furthermore, under the exposure of PFOS, the number of predicted genes regulating enzymes in methanogenic steps from CO2 increased. These results suggest that the co -existence of PET MPs and PFOS will not inhibit the activity of hydrotrophic methanogenes, and a portion of PFOS may be biodegraded during the methanogenesis under Fe0 regulation.

In this work, a novel Nd3+-doped silica fiber preform was fabricated by the UV-curable nanocomposite technology combined with the solution doping method. The preform sample had a great homogeneity with a doping concentration of 1.14 wt% Nd3+ ions and 2.51 wt% Al3+ ions. The obtained Nd3+-doped core glass provided a relatively large emission cross section (-0.84 pm2) and a long lifetime (373 mu s) of 916 emission. On this basis, by using an 808 nm laser diode as the pump source, lasing at 916 nm was achieved from a 4 cm long fabricated Nd3+-doped silica fiber, with the corresponding slope efficiency of -13.6 %. Notably, only 2 cm-short created fiber alone was enabled for 916 nm lasing generation. Our results indicated that the created Nd3+ doped fiber by the novel approach has unique advantages and potential for compact short-cavity 0.9 mu m laser applications.

The photo-Fenton process provides a sustainable and cost-effective strategy for removing refractory organic contaminants in wastewater. Herein, a high-efficient Fe-doped g-C3N4 photocatalyst (Fe@CN10) with a unique 3D porous mesh structure was prepared by one-pot thermal polymerization for ultrafast degradation of azo dyes, antibiotics, and phenolic acids in heterogeneous photo-Fenton systems under visible light irradiation. Fe@CN10 exhibited a synergy between adsorption-degradation processes due to the co-existence of Fe3C and Fe3N active sites. Specifically, Fe3C acted as an adsorption site for pollutant and H2O2 molecules, while Fe3N acted as a photocatalytic active site for the high-efficient degradation of MO. Resultingly, Fe@CN10 showed a photocatalytic degradation rate of MO up to 140.32 mg/L min-1. The dominant ROS contributed to the removal of MO in the photo-Fenton pathway was hydroxyl radical (•OH). Surprisingly, as the key reactive species, singlet oxygen (1O2) generated from superoxide radical (•O2-) also efficiently attacked MO in a photo-self-Fenton pathway. Additionally, sponge/Fe@CN10 was prepared and filled in the continuous flow reactors for nearly 100% degradation of MO over 150 h when treating artificial organic wastewater. This work provided a facile route to prepare highly-active Fe-doped photocatalysts and develop a green photocatalytic system for wastewater treatment in the future.

Hollow-core anti-resonant fibers (HC-ARFs) are widely used for high-power laser transmission owing to their low nonlinearity and high damage threshold. However, most existing structural designs are suitable for single-mode guidance but are inadequate for efficient transmission of few- or multi-mode lasers with high output power. In this study, we fabricated a low-loss multi-mode 8-tube nested hollow-core anti-resonant fiber (Nested HC-ARF) with a minimum loss of 3.27 dB/km at 1 mu m wavelength, which enabled the efficient transmission of at least five mode groups. Accordingly, we demonstrated the transmission of a record 3 kW few-mode (M-2 similar to 1.38) continuous-wave laser with a maximum transmission efficiency of 95.2% using a 10 m multi-mode Nested HC-ARF and an optimized transmission system. The experimental verification of the beam quality and spectrum indicated distortion-free transmission, which paves the way to power delivery on the scale of tens of kilowatts.

Vivianite recovery from wastewater driven by Geobacter is one of the promising approaches to address the challenges of phosphorus (P) resource shortage and eutrophication. However, the interfere of heavy metals which are prevalent in many actual wastewater with this process is rarely reported. In this study, we investigated the impact of heavy metals (i.e., Cu and Zn ions) on microbial activity, Fe reduction, P recovery efficiency, and their fate during Geobacter-induced vivianite recovery process. The experimental results showed that low and medium concentrations of Cu and Zn prolonged the Fe reduction and P recovery time but had little effect on the final P recovery efficiency. However, high concentrations of Cu and Zn ultimately inhibit vivianite formation. In addition, the different concentrations of Cu and Zn showed different effects on the morphology of the recovered vivianite. The migration of Cu and Zn was analysed by stepwise extraction of heavy metals in the vivianite. Medium concentrations of Cu and Zn were more likely to co-precipitate with vivianite, while adsorption was the primary mechanism at low concentrations. Furthermore, there were differences in the fate of Cu and Zn, and a competition mechanism was observed. Finally, we found that increasing the Fe/P ratio can significantly reduce the residues of heavy metals in vivianite. It also increased the adsorbed Cu and Zn proportion and reduced co-precipitation. These results provide insights into improving the efficiency of vivianite recovery and managing the environmental risks of heavy metal in the recovered product.

Metal clusters are emerging as efficient H 2 O 2 activators to remove organic pollutants in advanced oxidation processes. However, these processes are still dependent on particle size and large doses of H 2 O 2 . To solve these issues, more uniform small-size catalysts that require less H 2 O 2 and in-situ H 2 O 2 synthesis should be pursued. Here we employed a simple way to synthesize subnano FeN x clusters and demonstrated its high activity for multiple pollutant removal even at low H 2 O 2 concentrations and a wide pH range. These excellent properties motivated us to further immobilize it in a filter, achieving nearly 100% pollutant degradation and H 2 O 2 utilization. Moreover, a full-body hydrophobic engineered cathode was developed for stable in-situ H 2 O 2 electro-synthesis over 320 h. The H 2 O 2 generation cell can be integrated with the Fenton filter to realize comprehensive improvements in efficacy, sustainability, application potential, and reduction of operating costs. This study offers insight into integrating metal clusters with electrochemical systems for high efficiency and low-cost treatment of recalcitrant wastewater.

Adsorption is a promising technology for removing and recovering phosphorus (P) from wastewater. However, the chemical-intensive regeneration of adsorbents increases carbon emissions and introduces potential secondary pollution. Most existing approaches cannot achieve simultaneous P desorption and selective recovery. For this purpose, a new-type electrochemically assisted phosphate desorption and recovery (EPDR) process was investigated and developed for the efficient desorption and recovery of P and simultaneous regeneration of the adsorbent in situ. In the EPDR process, the adsorbent amorphous zirconium oxide (am-ZrO2) coated carbon felt (CF) was employed as a cathode in an anion-exchange membrane (AEM) water electrolysis cell for P adsorption/ desorption and recovery. The P desorption and recovery efficiency from the adsorbent were over 90% at 3.5 V. It was found that the high concentration of OH- at the cathode surface derived from water splitting reaction and electrodialysis under the applied electric field was playing a critical role in the desorption process. Low concentrations of P in actual wastewater were effectively removed, concentrated and recovered under multiple adsorption-desorption cycles with easy-to-scale-up stacked EPDR. The nature of reagent-free, high efficiency and selectivity make EPDR the foundation for developing a cost-effective and green technology for sustainable phosphorus management.

The photo-Fenton process provides a sustainable and cost-effective strategy for removing refractory organic contaminants in environmental remediation. Herein, a high-efficient Fe-doped g-C3N4 photocatalyst (Fe@CN10) with a unique 3D porous mesh structure was prepared by one-pot thermal polymerization for ultrafast degradation of azo dyes, antibiotics, and phenolic acids under visible light irradiation. Fe@CN10 exhibited a synergy between adsorption-degradation processes due to the co-existence of Fe3C and Fe3N active sites but also had the self-regulation to form an acidic microenvironment at the catalyst-substrate interface. Methyl orange (MO) was degraded by Fe@CN10 with a rate up to 140.32 mg/Lmin-1 based on the cooperation of free radicals (·OH and ·O2−) and h+ in heterogeneous photo-Fenton systems. The excellent photocatalytic performance was also enhanced by in-situ generated non-free radicals (1O2 and h+) as well as H2O2 (49.24 - 83.11 μM) from photo-self-Fenton reactions. Additionally, sponge/Fe@CN10 was filled in continuous flow reactors for nearly 100% MO degradation and ideal H2O2 utilization over 150 hours of operation when treating artificial wastewater. This work provided a facile route to prepare highly-active Fe-doped photocatalysts and the development of green photocatalytic systems for wastewater treatment in the future.