Freshwater Shortage Research Articles

Design of MOF-Based Solar Evaporators with Hierarchical Microporous/Nanobridged/Nanogranular Structures for Rapid Interfacial Solar Evaporation and Fresh Water Collection.

Interfacial solar evaporation (ISE) holds considerable promise to solve fresh water shortage, but it is challenging to achieve high evaporation rate (Reva) and fresh water yield in close system. Here, we report design and preparation of MOF-based solar evaporators with hierarchical microporous/nanobridged/nanogranular structures for rapid ISE and fresh water collection in close system. The evaporators are fabricated by growing silicone nanofilaments with variable length as nanobridges on a microporous silicone sponge followed by grafting with polydopamine nanoparticles and Cu-MOF nanocrystals. Integration of the unique structure and excellent photothermal composites endows the evaporators with high Reva of 3.5-20 wt% brines (3.60-2.90 kg m-2 h-1 in open system and 2.38-1.44 kg m-2 h-1 in close system) under simulated 1 sun, high Reva under natural sunlight, excellent salt resistance and high fresh water yield, which surpass most state-of-the-art evaporators. Moreover, when combined with a superhydrophilic cover, the evaporators show much higher average Reva of real seawater, remarkable fresh water yield and excellent long-term stability over one month continuous ISE under natural sunlight. The findings here will promote the development of advanced evaporators via microstructure engineering and their real-world ISE applications.

Vertically aligned aerogel with concaved surface topography coupled ordered channel enable efficient solar-driven desalination

Solar-driven desalination has been regarded as a promising energy-saving and sustainable strategy to address the serious freshwater shortage issue. However, its performance is restricted by low solar energy utilization efficiency, water transport, and serious salt deposition. Herein, an efficient solar-driven interfacial evaporator with high solar energy utilization efficiency, fast water transport and robust salt tolerance was developed, via constructing vertically aligned sodium alginate (SA) aerogel with concave surface topography coupled ordered water transport channel structure. Concaved reflecting valley surface was assembled with 3D hierarchical photothermal networks of 2D MXene synergistic 1D carbon nanotube to enhance light absorption capacity. Concaved surface topography with multiple reflective nanostructure (angle 45°, depth 1.5 cm) owns strong sunlight concentration performance, which effectively avoid the light loss and thus enhance the light-absorption over a broad spectrum (0.3–2.5 μm). In another way, hydrophilic SA aerogel with vertically aligned structure, which also provides ordered channels for fast water/vapor transport and high salt rejection ability via strong wicking and diffusion effect. Solar-driven interfacial evaporator with such unique concaved surface topography that coupled ordered valley channels exhibits excellent evaporation rate (2.81kg m−2h−1) and remarkable solar energy utilizing efficiency (98.52 %), while with excellent antibacterial ability during continuously desalination process. Solar-driven interfacial evaporator with unique concaved surface topography coupled ordered valley channels holds great potential in sustainable water purification and desalination.

Solar-driven salt-free deposition evaporation for simultaneous desalination and electricity generation based on tip-effect and siphon-effect

Solar-driven desalination is a promising way to alleviate the freshwater shortage, while is facing challenges posed by low evaporation rates and severe salt accumulation. Herein, a high-performance two-dimensional (2D) solar absorber with Co3O4 nanoneedle arrays (Co3O4-NN) grown on the surface of reduced graphene oxide-coated pyrolyzed silk cloth (Co3O4-NN/rGO/PSC) was prepared, and a salt-free evaporator system was assembled based on the composite material and siphonage-the flowing water delivery. It is revealed that the evaporation enthalpy of water can be reduced over the 2D solar absorber grown with Co3O4-NN, enabling an evaporation rate of up to 2.35 kg m−2 h−1 in DI water under one solar irradiation. The desalination process can be carried out continuously even with salt concentration up to 20 wt%, due to the timely removal of concentrated brine from the interface with the assistance of directed flowing water. Moreover, the 2D structure and the flowing water also provide an opportunity to convert waste solar heat into electricity in the evaporator based on the seebeck effect, ensuring simultaneous freshwater production and power generation. It is believed that this work provides insights into designing hybrid systems with high evaporation rate, salt resistance, and electricity generation.

Axial compressive behavior of low-alkalinity seawater sea-sand concrete column reinforced with hydrophobic longitudinal SFCBs and FRP hoops

To address corrosion problem of steel bars and shortage of freshwater and river sand in marine and offshore structures, a novel hydrophobic-modified longitudinal steel-FRP composite bars (SFCB) and FRP hoops reinforced low-alkalinity seawater sea-sand concrete (SWSSC) is developed. However, axial compressive behavior of hybrid SFCB and FRP reinforced columns is not clear and the applicability of existing design methods is low. Here, nine hybrid reinforced columns have been designed and tested. Typical failure modes of columns and axial compressive behavior of constituent materials (i.e., hydrophobic reinforcements and low-alkalinity SWSSC) are investigated. It is found that the synergistic confining effect formed by hybrid reinforcement are significant. The mesh confinement formed by densely distributed FRP hoops and longitudinal SFCBs improves the local buckling behavior, and effectively constrains the lateral expansion of concrete core, resulting in improved compressive strength and ductility of column. The compressive contribution of single longitudinal SFCB to ultimate load capacity of column can be enhanced effectively, up to 36.3 %, by increasing steel content of SFCB. Based on this, a prediction model of hybrid reinforced columns is proposed, which can accurately evaluate the ultimate load capacity. This work provides valuable experimental observations and load capacity model for hybrid reinforced column, which promote its design and application in marine engineering.

Clean water harvesting and power generation by solar-absorbing Germanium@k-carrageenan evaporator demonstrating superior energy conversion

The deterioration of climate exacerbates the freshwater crisis. Solar-thermal interfacial evaporation, using sunlight as a driving energy source, is a promising approach to provide an effective solution to freshwater shortages. However, the low energy conversion efficiency and expensive evaporator manufacturing are still to be resolved. Herein, a strategy of clean water harvesting by solar-absorbing germanium@k-carrageenan (Ge@CA) evaporator demonstrating superior energy conversion is proposed. The Ge nanoparticles exhibit a significant solar absorption of 92.33% to achieve efficient solar-thermal conversion. The CA hydrogel provides three-dimensional water transmission channels to the evaporating surface. Meanwhile, the Ge nanoparticles can be fabricated by a facile ball-milling method. The CA as a cheap biomass can be easily interacted with KCl to obtain the porous hydrogel. Taking the advantages of Ge nanoparticles and CA hydrogel, the Janus-type Ge@CA hydrogel evaporator can achieve an evaporation rate of 2.88 kg m−2·h−1 and a solar-vapor conversion efficiency of 82.65% under 1 sun irradiation. Furthermore, the evaporator can produce thermoelectricity with the output voltage of 140.95 mV and the short-circuit current of 13.32 mA, yielding a power of 1.17 W m−2. This reported solar device has huge potential for cutting-edge solar harvesting and usage.

Osmotic pressure regulated sodium alginate-graphene oxide hydrogel as a draw agent in forward osmosis desalination

The freshwater shortage has become a global issue due to the population explosion. As an effective response to the water crisis, forward osmosis (FO) desalination technology is applied because of its comparatively low membrane fouling and low energy consumption. Hydrogels, as draw solutions in FO, have received increasing attention due to their properties of no reverse solute flux, and strong water recovery capability. However, the concentration in the feed solution is below 8000 ppm restricted by the lack of a clear mechanism for osmotic pressure regulation. In this work, a sodium alginate-graphene oxide (SA-GO) hydrogel was proposed with excellent performance in drawing water. The hydrogel has a homogeneous porous structure that enables easy water recovery through compression. When the SA-GO-1 hydrogel was used for the treatment of the simulated seawater (35,000 ppm NaCl solutions), the initial water flux achieved 0.4429 L m−2 h−1 (LMH), and the average water flux remained at 0.1783LMH. In contrast to conventional tactics, the osmotic pressure of hydrogel was regulated based on Flory-Rehner theory (FR). Moreover, the interaction energy was computed to reveal the mechanism of osmotic pressure regulation. This strategy provides a potential solution for the design of high-performance draw solutions for FO systems.

Hollow carbon fiber wrapped by regular rGO wave-like folds for efficient solar driven interfacial water steam generation

Efficient seawater desalination is an effective way to solve the shortages of fresh water and energy but with limitations of the low fresh water production rate and high cost. Here, a hollow carbon fiber (HCF) wrapped by regular reduced graphene oxide (rGO) wave-like folds (rGO@HCF) is prepared on account of the differences in thermal shrinkage performance between graphene oxide (GO) and willow catkins fiber. Under one sun irradiation (1 kW m−2), the dry and wet surface temperature of the resulting evaporator reached up to 119.1 °C and 61.7 °C, respectively, and the water steam production rate reached 3.42 kg m−2 h−1. Also, for the outdoor experiment, the rGO@HCF exhibits good evaporator performance which reach up 27.8 kg m−2 day−1. Additionally, rGO@HCF also shows good seawater desalination performance and excellent durability for longtime work. DSC results indicate that the evaporation enthalpy of bulk water and adsorbed water decreased from 2503.92 to 1020.54 J g−1. The excellent evaporating performance is mainly attributed to the regular wave-like microstructure surface of the HCF, which can enhance the light absorption, reduced the vaporization enthalpy of the adsorption water. The findings not only introduce a novel approach for agricultural utilization, but also establish a crucial theoretical foundation for the design of regular wave-like microstructures.

Tailoring the covalent organic frameworks based polymer materials for solar-driven atmospheric water harvesting

Atmospheric water harvesting through reticular materials is an innovation that has the potential to change the world. Here, this study offers a technique for creating a solar-powered hygroscopic polymer material for atmospheric water harvesting with the reticular materials. The results show that the porous hygroscopic polymer materials can achieve high performance with high vapor capture (up to ac. 28.8–49.7 mg/g at 28–38 %RH and 25 ℃), rapid photothermal conversion efficiency (up to 32.2 ℃ within 15 min under 1000 W/m−2 light at 25 ℃), a low desorption temperature (lower than 40 ℃), and an effective water release rate. Besides, the material also has excellent water-retention properties, which can effectively store desorbed liquid water in polymer networks for use by vegetation during water demand periods. The strategy opens new avenues for atmospheric water-harvesting materials, which will hopefully solve the global crisis of freshwater shortages.

Enhanced Atmospheric Water Harvesting Performance by Three-Dimensional Carbon Fiber Felt Structure.

Freshwater shortages and the uneven distribution of water resources are critical issues for economic development and human life, and collecting water vapor in the air is one of the important ways to alleviate these issues. In recent years, adsorption-based atmospheric water harvesting (AWH) techniques have received much attention, and the core difficulty in establishing an efficient system is to develop a highly efficient functional material for AWH. In this work, an AWH material was prepared consisting of carbon fiber felt as a three-dimensional skeleton and loaded with poly(vinyl alcohol) immobilized LiCl and graphite, as a water capture and release functional material. A 24 h water capture-3 h water release test was carried out at room temperature, showing excellent water collection ability of 0.907 g·g-1 of water at 30% relative humidity (RH) and 2.429 g·g-1 of water at 80% RH. Using a 2 h capture-2 h release cycling test, the sample demonstrated a stable water capture-release performance. An outdoor field test was conducted, showing water collection efficiencies of up to 60%. We believe that the carbon fiber felt can provide good mechanical properties and achieve a high mass loading of the functional materials, and the composite material has a simple manufacturing process and realizes energy saving and sustainable water harvesting.

Cloud seeding in the Middle East: a problematic solution to freshwater shortage

ABSTRACT Several Middle Eastern states seed clouds to help overcome the problem of deficit in freshwater supply. The global result of cloud seeding is far from certain, but Middle Eastern states are prepared to take the risk to increase their freshwater resource. There is no agreement between the stakeholders. Iran accuses several upwind states of stealing its clouds and reducing its rain. This paper looks at the cloud-seeding operations in the world with a focus on the Middle East. Cloud seeding is far from certain and it creates security concerns for downwind states or regions. International regulation seems to be required after a large-scale review of all the evidence from cloud-seeding endeavours.

A robust and low-cost blended-fiber-based evaporator with high efficiency for solar desalination

The solar-driven interfacial evaporation (SDIE) is a clean and efficient technology to mitigate freshwater shortages. A robust and low-cost evaporator is essential for the practical implementation of SDIE systems. Herein, we design a fantastic blended-fiber-based evaporator using weaving techniques. This mixture fabric is crafted using polyethylene terephthalate fibers and linen threads. It makes full use of the excellent light absorption, tensile strength, and corrosion resistance of polyethylene terephthalate fibers. Meanwhile, the mixture fabric reserves exceptional air permeability and water supply capability of linen thread. We optimize the density of the mixture fabric by adjusting the reed count and the weft count. It is found that the combination of the 40 reed and a single weft yarn produces the most effective and stable evaporator. The optimized mixture fabric makes a good trade-off between the water supply to the evaporator and solar-thermal evaporation. As a result, the evaporator achieves a high evaporation rate and efficiency (~1.53kg/m2/h, ~ 90%) under 1 sun illumination, which surpasses most of the existing two-dimensional evaporators based on metal nanomaterials, polymers, carbon-based materials, and fabrics. Our work opens a new horizon for the development of efficient, scalable, flexible, low-cost, corrosion-resistant, and stable evaporators.

Efficient desalination in fluorinated multilayered covalent organic framework: Tunning the energy landscape inside the nanochannel

The design and construction of advanced nanochannels can significantly enhance the performance of reverse osmosis (RO) membranes in desalination, offering potential solutions to the severe freshwater shortage crisis. In this study, we investigated the desalination performance of nanochannels formed by multilayered covalent organic frameworks (COF) that had undergone various types of chemical functionalization, through nonequilibrium molecular dynamics simulations. Our data reveals that fluorination of the nanochannel results in the most impressive desalination performance, as evidenced by significant improvements in both water permeability (increasing from 39.1 to 100.1 L cm−2 day−1 MPa−1) and salt rejection (rising from 91.9 % to 97.1 %). Especially, in multilayered systems, fluorinated nanochannel mitigates the typical decline in water permeability with increasing membrane thickness. For the working mechanism, the free energy analysis indicates that fluorination contributes to a smooth energy landscape for water molecules inside the nanochannel, reducing their interaction with the nanochannel, which results in a more dispersed arrangement of water molecules with fewer hydrogen bonds and a significantly enhanced water velocity, thus facilitating their fast and unobstructed permeation. Therefore, this study offers a promising semipermeable membrane for high-efficiency desalination, achieved through fluorination. It also demonstrates an indicative approach for advanced channel design through fluorination engineering.

Achieving solar-thermal driven dual functional device utilizing flexible PDA coated sponge integrated thermoelectric module design for water purification and power generation

The design of an efficient solar energy collector for solar-thermal-driven water purification and power generation is a promising strategy to concurrently mitigate the shortage of fresh water and energy crises. However, harvesting low-grade thermal energy in an eco-friendly and cost-effective manner through solar-thermal materials for water evaporation and electric cogeneration remains challenging. Herein, we demonstrate a dual-functional device integrating solar-thermally driven water purification and thermo-induced power generation. This typical design, fabricated via polydopamine (PDA) tightly deposited onto melamine sponges (PDA@Sponge) via H-bonds, along with a thermoelectric generator (PDA@Sponge/TEG), showcases superior solar-thermal-driven dual-functional application. The critically structurally adjustable PDA@Sponge possesses excellent homogeneity and stability, weakening interfacial hydrogen bonding between water molecules, favoring the evaporation and overflow of water molecules. The optimal serrated design achieves a water evaporation rate of up to ∼1.50 kg −2h−1, with an efficiency of ∼ 94.04 % under one sun, surpassing the most of previous reports, owing to its special tip thermal localization effect and rational water transportation management. Simultaneously, the designed PDA@Sponge/TEG yields an open-circuit voltage and short circuit current of 55 mV and 22 mA, respectively, along with a maximal output power of 162 μW (40.5 μW/cm2) at a load resistance of 7.5 Ω, under one sun and room temperature. Notably, such a device, after multiple series connections, can charge a capacitor to 1.5 V within 1 min, capable of powering low-energy electronic devices such as smartwatches and LED lights. By efficiently integrating of multiple solar-thermal-driven processes, our research promotes the design of multifunctional devices to promise an approach for desalinating seawater, purifying wastewater, and powering low-energy electronics, especially in remote areas lacking power stations and/or water treatment facilities.

A multistage assembled laminar membrane for solar thermal conversion and nighttime electricity production

Interfacial solar-driven evaporation technology has great potential to address freshwater shortages. Despite significant progress in developing efficient evaporators, the challenge of evaporation rates of two-dimensional evaporators still needs to be solved. In addition, interfacial solar-driven evaporation relies on solar energy to trigger the evaporation of thin water layers at the water–air interfaces. It thus may be at risk of interruption in the absence of sunlight. To overcome these challenges, we have intelligently assembled different functional components to form a multistage assembled laminar membrane used for interfacial solar-driven evaporation during the day and power generation at night. Specifically, solar evaporation achieved a high evaporation rate of 1.78 kg m−2h−1 under single solar irradiation. Desalination and water purification capabilities were also demonstrated. More notably, the membrane also showed its worth as an electrical generator in overcast weather or nights, delivering a voltage of 309 mV and a current of 2 μA. The voltage and current can be multiplied by connecting four membranes in series and parallel to 1.1 V and 8.8 μA, respectively. This powers a calculator directly and stores excess electricity in a capacitor, which can be as high as 2 V in 2000 s. This innovation shows promising applications in next-generation freshwater production and power generation.

Effect of microalgae (Tetraselmis chui Butcher 1959) on growth and survival of nile tilapia (Oreochromis niloticus Linnaeus 1758) reared in low salinity biofloc system

Addition of microalgae in the biofloc system may improve growth and survival of Nile tilapia. Also, culturing Nile tilapia in saline water biofloc system may be an adaptation for freshwater shortage. In this study, the growth and survival of Nile tilapia cultured in a low salinity biofloc system with added microalgae was investigated. Increasing salinity in the culture system was done by gradually adding sea water into acclimatization container (618 L, v) on weekly basis for 4 weeks until 9 psu salinity was reached. Tilapia were allowed to adapt to salinity change for one week and fed with commercial feed twice a day until satiation. The biofloc experiment was conducted with 3 microalgal density treatments (5, 15 and 25 × 104 cells. mL-1) in triplicates. Average initial weight of experimental fish was 4.82 ± 0.76 g. Tilapia were reared for 40 days in aquaria (35 × 35 × 40 cm, l × w × h, 15 L, v) containing 8 individuals fish in each aquarium. The commercial pellets were delivered twice per day at 5% of tilapia biomass until satiation. T. chui was added to the tilapia culture every week. This study showed that the addition of microalgae did not affect the fish weight gain, specific growth rate and survival (p0.05). However, feed conversion ratio and culture productivity were better in tilapia supplied with weekly addition of T. chui at 15 × 104 cells mL-1 compared to other densities tested.Keywords:SalineBioflocMicroalgae

Photothermal water evaporation and purification on the interface evaporator constructed by Cu@Bi2WO6-C

Photothermal evaporation is an efficient way to utilize solar energy to desalinate seawater for freshwater resources, which can effectively alleviate the press on accessing to freshwater in water-scarce countries and regions. Here, a highly efficient ternary composite consisting of Bi2WO6, copper and carbon is developed as a photothermal conversion material for solar-driven water evaporation (SDWE) systems. This composite is coated on the top of a base consisting of expanded polystyrene (EPS) foam and hydrophilic fiber paper to construct an interface evaporator, enabling sustainable solar-driven freshwater production. Due to its wide light absorbing range, localized photothermal conversion and low evaporation enthalpy, the solar steam generation (SSG) through Cu@Bi2WO6-based evaporator could be accelerated, thus a high evaporation rate of 2.07 kg m−2 h−1 and an evaporation efficiency of 97 % are obtained under one sun, outperforming the-state-of-art evaporators. This work proposes a feasible way to deal with freshwater shortage.

Thermal and aerodynamic characteristics of air cooled condenserfor steam turbine power unit

THE PURPOSE. Increased water consumption at power plants leads to a deterioration of the environmental situation not only in countries with limited water supply sources, but also in countries with significant reserves of fresh water. There is a need to consider the possibility of using an air condenser as an alternative use in industrial water supply systems at a power plant. To present a methodology for calculating the main characteristics of a condenser (condensation and reflux sections), to estimate the aerodynamic resistance and fan power for an air-cooled condenser as part of a steam turbine power unit. Determine the influence of air temperature and pressure in the condenser on the calculation of the air condenser. To develop recommendations for the selection of parameters of air condensers operating as part of steam turbine power units. METHODS. Methods for designing heat exchangers, modeling and intensifying heat exchange processes were used in the course of calculating an air condenser unit. RESULTS. A method for calculating an air-cooled condenser for a 110 MW condensing turbine has been developed. The analysis of the calculation of the heat transfer coefficient is given. The analysis of the values of the heat exchange area of the condensing unit is presented. The effect of pressure in the condenser on the main calculated characteristics of the condenser is shown. Recommendations for the selection of the fan capacity in the condenser and the design temperature of the cooling air have been developed. CONCLUSION. The issue of using air coolers in the power industry is still poorly covered in the literature, however, environmental problems and the shortage of fresh water are becoming more and more urgent all over the world. The development of air-cooling systems is a very topical issue for modern power engineering. It is shown that for stationary installations of condensation of water vapor, the most suitable is the hipped-roof arrangement of the heat-exchange sections with the lower arrangement of the fans. Quantitative estimates of the change in the heat transfer coefficient and the area of the heat-exchange surface are given for the pressure range of 8…20 kPa. The power consumption of the fan depends significantly on the temperature of the cooling air and the vacuum in the condenser.

New and effective combination of an absorption desalination systems with adsorption and humidification-dehumidification desalination systems utilizing internal heat recovery methods

The fast growth in population and the need for human comfort leads to a significant rise in freshwater shortage and energy usage. This article provides new and effective combinations between absorption (ABDC), adsorption (ADDC), and humidification-dehumidification (HDH) desalination plants. Four new configurations employing different external and internal heat recovery methods between the plants and their components are proposed to enhance the overall system performance, water production, and utilization of the used energy. In all configurations, the solar water heating system is used to power the ABDC. While the ADDC and HDH were powered by the heat recovery from condensation, absorption, or generation processes. Internal heat recovery methods are also applied between the evaporator and condenser in ABDC and ADDC plants to increase energy utilization. The results are evaluated and compared with standalone ABDC results and with previous related studies at different conditions. The production share percentage (%) from each plant for the suggested configurations with regeneration temperatures is also investigated. The maximum water production is achieved by the fourth configuration (3 m3.day−1 with a gain output ratio (GOR) of 1.316 at 120 °C) when the ADDC is worked by the outlet hot water from the ABDC, and internal heat recovery utilized between the condensation and evaporation components of both ABDC and ADDC. The highest GOR is obtained from the second configuration (1.714 at 90 °C). The finding expressed that the proposed configurations have a better performance than traditional ABDC systems. Also, the proposed configurations express another advantage over traditional ABDC, that the configurations have the potential at low-temperature heat sources (55–65 °C) to improve the water productivity to about 455 % and GOR to about 120 %.

High‐Power‐Density Hybrid Acid/Alkali Zinc–Air Battery for High‐Efficiency Desalination

AbstractThe electrochemical desalination technique is recognized as a promising solution to alleviate freshwater shortages, challenges yet persists in achieving optimal energy efficiency and cost‐effectiveness. Herein, a hybrid acid/alkali zinc air desalination battery (hAA‐ZADB) capable of concurrent desalination and high‐power density is reported. To improve cathodic efficiency and cost‐effectiveness, an electrocatalyst with dual atomic Fe–Mn sites on porous dodecahedral carbon (Mn‐Fe/p‐DC) is fabricated through a simple direct pyrolysis strategy for oxygen reduction reaction (ORR). The Mn–Fe/p‐DC‐900 electrocatalyst demonstrates exceptional electrocatalytic activity (E1/2 = 0.8 V in 0.5 m H2SO4) for ORR. This innovative hybrid acid/alkali cell design, coupled with advanced electrocatalysts, empowers the hAA‐ZADB system to achieve outstanding performance benchmarks with a high open circuit voltage of 2.22 V, an impressive power density of 375 mW cm−2, and notably elevated energy output of 106.9 kJ mol−1 even at a current density of 100 mA cm−2 during desalination. Distinguishing this work is its additional functionality, evident in a rapid salt removal rate of 3.64 mg cm−2 min−1 during desalination, achieving an impressive 88.67% removal of 0.6 M NaCl. This study highlights the promising potential of employing metallic air batteries for a self‐powered desalination technique applicable to specific scenarios.

A new Janus mesh membrane with ultrafast directional water transportation and improved fog collection

Fog collection materials have been intensively investigated and can potentially be used to alleviate freshwater shortages. However, developing highly efficient fog collection materials remains challenging. Requisite improvements in fog collection technology are the ultrafast transportation of captured water and the effective regeneration of fresh regions on the surfaces of fog collection materials. Herein, a novel Janus mesh membrane (JMM) with an alternating hydrophobic–superhydrophilic-patterned hydrophobic surface and asymmetric wettability interface is prepared by a selective liquid-phase surface oxidation strategy. The unique structure and high-contrast wettability of the JMM enable ultrafast directional transportation of tiny water droplets (< 0.1 µL), thereby achieving an excellent water collection efficiency of 15.28 g h−1 cm−2, which is much higher than those of conventional Janus membranes. The JMM functioned as a versatile fog collector and maintained continuous fog collection regardless of the fog flow direction. This study offers a novel approach for preparing innovative fog collection materials and establishes a foundation for developing advanced fog collection systems suitable for diverse applications.