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A novel solar-assisted multigeneration system is proposed and examined from a thermodynamic perspective, designed to simultaneously produce electricity, distilled water, and refrigeration. The system utilizes solar energy through an absorption refrigeration generator and the heat recovery mechanism of an organic Rankine cycle (ORC). The absorption refrigeration system generates both refrigeration and the necessary heat for a single-effect absorption heat transformer, which in turn produces distilled water and power via an evaporative desalination system and an ORC, respectively. Additionally, two distinct humidification-dehumidification (HDH) desalination systems are integrated to enhance freshwater production. The study evaluates the impact of various operational conditions on key performance parameters, including the coefficient of performance (COP), exergy coefficient of performance (ECOP), simple payback period (SPP), refrigeration capacity, total generated power, and distilled water production. Pareto frontiers are graphically constructed to identify optimal points and their corresponding parameter values. The results show that, with a total solar heat input of 250 kW, the system can generate 21.46 kW of electricity, 71.02 kW of refrigeration, and 100.65 g per second of distilled water. The optimal performance parameters are determined to be a COP of 2.13, an ECOP of 0.19, an SPP of 3.34 years, a power output of 16.77 kW, distilled water production of 99.84 g per second, and a refrigeration capacity of 74.44 kW.

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As global temperatures rise, droughts are becoming more frequent and severe. To predict how drought might affect plant communities, ecologists have traditionally designed drought experiments with controlled watering regimes and rainout shelters. Both treatments have proven effective for simulating soil drought. However, neither are designed to directly modify atmospheric drought. Here, we detail the efficacy of a silica gel atmospheric drought treatment in outdoor mesocosms with and without a co-occurring soil drought treatment. At California State University, Los Angeles, we monitored relative humidity, temperature, and vapor pressure deficit every 10 min for 5 months in bare-ground, open-top mesocosms treated with soil drought (reduced watering) and/or atmospheric drought (silica dehumidification packets suspended 12 cm above soil). We found that silica packets dehumidified these mesocosm microclimates most effectively (-5% RH) when combined with reduced soil water, regardless of the ambient humidity levels of the surrounding air. Further, packets increased microclimate vapor pressure deficit most effectively (+0.4 kPa) when combined with reduced soil water and ambient air temperatures above 20°C. Finally, packets simulated atmospheric drought most consistently when replaced within 3 days of deployment. Our results demonstrate the use of silica packets as effective dehumidification agents in outdoor drought experiments. We emphasize that incorporating atmospheric drought in existing soil drought experiments can improve our understandings of the ecological impacts of drought.

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OBJECTIVE: Nontuberculous mycobacteria (NTM) are environmentally acquired opportunistic pathogens that can cause recalcitrant lung disease. Prior reports have demonstrated links between shower use and infections, yet the aerosolization of NTM from showerheads, as well as the humidity levels that may modulate NTM aerosolization from showerheads is less studied. The objective of the current study was to investigate the role of humidity in NTM aerosolization among showers in homes located in a geographic area with high lung disease incidence, Hawai'i, and test whether deployment of a dehumidifier in well-ventilated bathrooms reduce NTM exposure. RESULTS: Across two sampling events and five showers, existing NTM showerhead biofilms along with shower air were sampled at three points: pre-shower, post-shower, and post-dehumidification. In each of the sampling events, respiratory relevant NTM species were identified from shower biofilms, which were also detected in aerosolized shower air after showering events, but not after the shower was dehumidified and bathrooms vented. While sample size was small, these data suggest running a shower is a possible source of NTM aerosolization and using a commercial household dehumidifier in conjunction with opening bathroom doors and windows may be simple, cost-effective interventions to reduce environmental NTM exposures.

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We investigated the previously unexplored domain of water vapor/gas separation using graphene oxide (GO) membranes, expecting future applications, including gas dehumidifiers and superior humidity controllers. While the importance of manipulation of GO nanosheet size and surface chemistry in traditional water purification and gas separation has been acknowledged, their potential impact on water vapor/gas separation remained unexplored until now. We applied sonication and hydrogen peroxide treatments to GO water dispersions and systematically evaluated the size and surface chemistry of each GO nanosheet. Both treatments reduced the GO nanosheet size to shorten the diffusion length, which improved water permeance. In addition, hydrogen peroxide treatment improved the hydrophilicity of the nanosheet. Our novel findings demonstrate that optimization of GO nanosheet size and the increase in their hydrophilicity via hydrogen peroxide treatments for 5 h significantly enhance water permeance, leading to a remarkable water vapor permeance of 4.6 × 10-6 mol/(m2 s Pa) at 80 °C, a 3.1-fold improvement over original GO membranes, while maintaining a water vapor/nitrogen permeance ratio exceeding 10,000. These results not only provide important insights into the nature of water vapor/gas separation but also suggest innovative methods for optimizing the GO membrane structure.

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Harvesting atmospheric water and converting it into electricity play vital roles in advancing next-generation energy conversion systems. However, the current water harvester systems suffer from a weak water capture ability and poor recyclability due to high diffusion barriers and low sorption kinetics, which significantly limit their practical application. Herein, we drew inspiration from the natural "Pump effect" observed in wood and successfully developed a dual "absorption-adsorption" networked MXene aerogel atmospheric water harvester (MAWH) through ice templating and confining LiCl processes, thereby serving multiple purposes of clean water production, passive dehumidification, and power generation. The MAWH benefits from the dual H-bond network of MXene and cellulose nanocrystals (absorption network) and the hygroscopic properties of lithium chloride (adsorption network). Furthermore, its aligned wood-like channel structure efficiently eliminates water nucleation near the 3D network, resulting in fast moisture absorption. The developed MAWH demonstrates a high moisture absorption ability of 3.12 g g-1 at 90% relative humidity (RH), featuring rapid vapor transport rates and durable cyclic performance. When compared with commercial desiccants such as the 4A molecular sieve and silica gel, the MAWH can reduce the RH from 80% to 20% within just 6 h. Most notably, our integrated MAWH-based water harvesting-power generation system achieves a high voltage of ∼0.12 V at 77% RH, showcasing its potential for practical application. These developed MAWHs are considered as high-performance atmospheric water harvesters in the water collection and power generation field.

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The use of humidification-dehumidification water desalination technology has been shown to be a practical means of meeting the demand for freshwater. The aim of this review is to investigate the impact of salinity on HDH techniques that have various benefits in terms of both economics and the environment, including the capacity to operate at low temperatures, utilize sustainable energy sources, the need for low maintenance, and straightforward construction requirements. Also, in this review, it is observed that the HDH system's components are strong and capable of treating severely salinized water. It can treat water in an appropriate way than other desalination technologies. This technology has recently been commercialized to treat highly salinized generated water. However, more research is needed to determine how salinity affects HDH productivity. According to several research investigations, while the specific thermal energy consumption increased considerably and the productivity of water per unit of time decreased significantly as the salt mass percentage grew, the purity of clean water did not suffer. The rejected brine must be reduced by increasing the total water recovery ratio in the HDH system. Through this review, it was found that brine control is becoming increasingly important in the water processing industry. ZLD systems, which aim to recover both freshwater and solid salts, can be a viable replacement for disposal methods. Finally, through this reviewer, it was concluded that HDH desalination systems may operate with extremely saline water while increasing salinity has a significant influence on system performance.

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The effective management of atmospheric water will create huge value for mankind. Diversified and sustainable biopolymers that are derived from organisms provide rich building blocks for various hygroscopic materials. Here, a comprehensive review of recent advances in developing biopolymers for hygroscopic materials is provided. It is begun with a brief introduction of species diversity and the processes of obtaining various biopolymer materials from organisms. The fabrication of hygroscopic materials is then illustrated, with a specific focus on the use of biopolymer-derived materials as substrates to produce composites and the use of biopolymers as building blocks to fabricate composite gels. Next, the representative applications of biopolymer-derived hygroscopic materials for dehumidification, atmospheric water harvesting, and power generation are systematically presented. An outlook on future challenges and key issues worthy of attention are finally provided.

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This work presents the theoretical and experimental investigation of a solar-powered humidification dehumidification desalination (HDD) system with different humidifier packing materials and a two-stage bubble column dehumidifier (BCD). Naturally available coconut shells (CS) and coconut shells with drilled holes (CSH) on the surface to improve water permeability were used as packing materials in the humidifier, and their performance was compared with that of commercial-type pall ring (PR) and raschig ring (RR) packings. An in-house developed numerical model of the HDD system in conjunction with a flat plate solar water collector was used in this study. Steady-state experimental results showed that CSH packing exhibited the highest volumetric mass transfer coefficient (0.00852 kg/s), resulting in maximum humidifier efficiency (96%) and freshwater yield (2.16 kg/hr), followed by PR (0.00841 kg/s, 94%, and 2.137 kg/hr), CS (0.00831 kg/s, 90%, and 2.127 kg/hr), and RR (0.0081 kg/s, 81%, and 2.087 kg/hr) at feedwater mass flow rate of 1.5 kg/min and humidifier inlet temperature of 75 [Formula: see text]. Furthermore, transient outdoor test results showed that using a two-stage configuration in a BCD increased the daily average effectiveness to 0.93, as against 0.79 for a single-stage BCD. Employing CSH instead of PR and RR packings in the humidifier reduced freshwater costs by 6.2% and 7.6%, respectively.

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1. As global temperatures rise, droughts are becoming more frequent and severe. To predict how drought might affect plant communities, ecologists have traditionally designed experiments with controlled watering regimes and rainout shelters. Both treatments have proven effective for simulating soil drought. However, neither are designed to directly modify atmospheric drought. 2. Here, we detail the efficacy of a silica gel atmospheric drought treatment in outdoor mesocosms with and without a cooccurring soil drought treatment. At California State University, Los Angeles, we monitored relative humidity (RH), temperature, and vapor pressure deficit (VPD) every 10 minutes for five months in a bare-ground experiment featuring mesocosms treated with soil drought (reduced watering) and/or atmospheric drought (silica packets suspended 12 cm above soil). 3. We found that silica packets dehumidified these microclimates most effectively (-5% RH) when combined with reduced soil water, regardless of the ambient humidity levels of the surrounding air. Further, packets increased microclimate VPD most effectively (+0.4 kPa) when combined with reduced soil water and ambient air temperatures above 20°C. Finally, packets simulated atmospheric drought most consistently when replaced within three days of deployment. 4. Our results demonstrate the use of silica packets as effective dehumidification agents in outdoor drought experiments. We emphasize that incorporating atmospheric drought in existing soil drought experiments can improve our understandings of the ecological impacts of drought.

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The water sorption and desorption properties of solid adsorbent materials are crucial in rotary dehumidification systems. Metal organic frameworks (MOFs) and hydrogels are mostly at the laboratory stage due to factors like the synthesis process and yield. In this study, we utilized an eco-friendly and large-scale synthesis method to prepare polyacrylamide (PAM) hydrogels (yielding approximately 500 mL from a single polymerization). Subsequently, PAM was then coated onto glass fiber paper (GFP), which serves as a commonly employed substrate in desiccant wheels. By incorporating the hygroscopic salt LiCl and optimizing the content of each component, the water sorption performance of the composite was notably improved. The water sorption and desorption performances, as well as cycling stability, were evaluated and compared with composites containing aluminum fumarate, LiCl, and GFP (AlFum-LiCl&GFP). The results revealed that PAM-LiCl&GFP outperformed AlFum-LiCl&GFP in terms of sorption capacity throughout various relative humidity (RH) levels. It achieved a water uptake of 1.06 g·g-1 at 25 °C and 30% RH, corresponding to a water sorption rate coefficient K of 15.32 × 10-4 s-1. Furthermore, the lower desorption temperature (60 °C) resulting in a desorption ratio of 82.6%, along with the excellent cycling stability and effective performance as a desiccant wheel module, provide evidence for the potential application of PAM-LiCl&GFP in desiccant wheels.

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Sorption dehumidification, as an energy-saving and eco-friendly approach, has been emerging in application for air dehumidification. Here, a prospective method is proposed to prepare biomass-based hygroscopic aerogels that are easily applicable, sustainable, high-efficient, and recyclable. The chitosan-based aerogel with a porous and hydrophilic network acts as the carrier and water reservoir for the uniformly distributed lithium chloride hygroscopic salt, and provides the hygroscopic salt with more liberal water channels to facilitate moisture capture and transfer. As a consequence, the prepared chitosan/polyvinyl alcohol@lithium chloride (chitosan/PVA@LiCl) hygroscopic aerogel exhibits an excellent moisture absorption capacity of up to 2.77 g g-1 at a relative humidity of 90 %. Meanwhile, as the chitosan/PVA@LiCl aerogel is set in a closed space about 2200 times larger than its own volume, the relative humidity can be reduced from 90 % to 32 % within 2 h, and further lower to 25 % after 4 h. Furthermore, combined with multi-walled carbon nanotubes, the photothermal hygroscopic aerogel is obtained that can rapidly desorb water under sunlight, thus to realize energy-free cycle. Overall, the renewable biomass-based aerogel materials with the advantages of simple preparation and excellent hygroscopic performance provides a new path for the development of sorption dehumidification technology.

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Ultrafiltration (UF) polymeric membranes are widely used in water treatment and support desalination and gas separation membranes. In this article, we enhance the performance of Polysulfone (PSF) mixed matrix membranes (MMMs) by dispersing different concentrations of thermally reduced graphene (TRG) nanofillers. The UF PSF-TRG MMMs were fabricated via the phase inversion process, and the impact of TRG loading on the characteristics of the membrane, including hydrophilicity, porosity, roughness, and morphology, were analyzed using a contact angle measurement, atomic force microscopy (AFM), scanning electron microscopy (SEM), and dynamic mechanical analysis. Incorporating TRG into the PSF matrix led to favorable effects in the instantaneous de-mixing during phase inversion, increasing the porosity and hydrophilicity of MMMs and improving the mechanical properties of the membranes. Moreover, membrane performance was examined to remove dispersed oil from oil-water emulsion and support air-dehumidification membranes. MMM performance in terms of flux and oil rejection was superior to the control PSF membrane. Incorporating 0.25% TRG into PSF resulted in a 70% water flux increase and higher oil rejection compared to the control PSF membrane. As a support for air-dehumidification membranes, the MMM also demonstrated enhanced humidity reduction and an over 20% increase in water vapor permeance over the control PSF membrane. These results indicate that the PSF-TRG MMMs are an excellent candidate for reliable oil-water separation and as a support for air-dehumidification membranes.

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The use of radiant panels in homes has increased recently because they do not cause a drafty feeling, unlike air conditioners. However, air conditioners are more power-efficient than radiant panels and have a higher coefficient of performance (COP). Therefore, combining radiant panels and air conditioning can provide an optimal solution for thermal control in residences. Energy simulation (ES) and computational fluid dynamics (CFD) can be used to simulate such environments. ES is suitable for non-steady state calculations, and combined with appropriate modeling, enables an accurate estimation of power consumption. Effective dehumidification becomes necessary, during summer as the relative humidity in a room increases. Both air conditioners and radiant panels can achieve this. This study developed a simulation tool that incorporates the effects of dehumidification. Based on a relative evaluation, a case was proposed where both energy efficiency and comfort were satisfied by jointly using air conditioners and radiant panels. The study found that a small number of panels could achieve the most balanced operation. The results of this study can serve as a reference for general housing, and the developed simulation tool can be applied to product development and building material design.

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Porous low-pressure membranes have been used as active membranes in water treatment and as support for thin-film composite membranes used in water desalination and gas separation applications. In this article, microfiltration polysulfone (PSf)mixed-matrix membranes (MMM) containing amine-functionalized graphene oxide (GO-NH2) were fabricated via a phase inversion process and characterized using XPS, SEM, AFM, DMA, XRD, and contact angle measurements. The effect of GO-NH2 concentration on membrane morphology, hydrophilicity, mechanical properties, and oil-water separation performance was analyzed. Significant enhancements in membrane hydrophilicity, porosity, mechanical properties, permeability, and selectivity were achieved at very low GO-NH2 concentrations (0.05-0.2 wt.%). In particular, the water permeability of the membrane containing 0.2 wt.% GO-NH2 was 92% higher than the pure PSf membrane, and the oil rejection reached 95.6% compared to 91.7% for the pure PSf membrane. The membrane stiffness was also increased by 98% compared to the pure PSf membrane. Importantly, the antifouling characteristics of the PSf-GO-NH2 MMMs were significantly improved. When filtering 100 ppm bovine serum albumin (BSA) solution, the PSf-GO-NH2 MMMs demonstrated a slower flux decline and an impressive flux recovery after washing. Notably, the control membrane showed a flux recovery of only 69%, while the membrane with 0.2 wt.% GO-NH2 demonstrated an exceptional flux recovery of 88%. Furthermore, the membranes exhibited enhanced humidity removal performance, with a permeance increase from 13,710 to 16,408. These results indicate that the PSf-GO-NH2 MMM is an excellent candidate for reliable oil-water separation and humidity control applications, with notable improvements in antifouling performance.

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We present a novel power-to-water (P2W) battery that can store electricity as thermal energy and discharge it as a heat source for hygroscopic solution desorption. The battery can work in two scenarios: atmospheric water harvesting (AWH) and dehumidification. The involvement of high-grade energy and sophisticated design enables better sorption kinetics and storage density. A proof-of-concept prototype verified the feasibility and achieved a record-breaking water production rate of more than 10.2 g (Ldevice h)-1. Also, the battery can achieve a round-trip efficiency of 90% for AWH and 68% for dehumidification in large-scale storage. The inexpensive storage medium contributes to a very low cost per energy (∼20 $ kWh-1) which means that P2W batteries excel in short- and long-duration storage. The long-term transient performance studies demonstrate impressive competitiveness over the traditional AWH and vapor-compression dehumidification systems. P2W provides new directions for the development of versatile, scalable, repeatable, and sustainable energy storage systems.

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Rational control of the humidity in specific environments plays an important role in green building, equipment protection, etc. A smart apparatus that can actively expel inner moisture and largely prevent outer liquid penetration can be highly desirable. Through the integration of the Janus interface with unidirectional liquid manipulation and the solar evaporating layer, here, a Janus solar dehumidifying interface (JSDI) is designed for the switchable moisture management of an indoor environment. By covering with the JSDI roof, the continuous elimination of inner water is achieved via outward condensate delivery and solar evaporation on sunny days. On rainy days, JSDI with a hydrophobic lower surface can largely hamper inward liquid leakage and then spontaneously drain the accumulated water via a siphoning structure. The real-world water evaporation rate via the JSDI is ≈0.38 kg m-2 h-1 on an autumn day, showing a promising function of in situ moisture expelling. In addition, the JSDI is made of natural materials that are easy to scale up with a cost of four dollars per square meter. It is envisioned that the JSDI may meet the wide requirements of indoor dehumidification and update the understanding of the integration of Janus interfaces and solar steam generation.

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Graphene oxide (GO) has attracted attention as an excellent membrane material for water treatment and desalination owing to its high mechanical strength, hydrophilicity, and permeability. In this study, composite membranes were prepared by coating GO on various polymeric porous substrates (polyethersulfone, cellulose ester, and polytetrafluoroethylene) using suction filtration and casting methods. The composite membranes were used for dehumidification, that is, water vapor separation in the gas phase. GO layers were successfully prepared via filtration rather than casting, irrespective of the type of polymeric substrate used. The dehumidification composite membranes with a GO layer thickness of less than 100 nm showed a water permeance greater than 1.0 × 10-6 mol/(m2 s Pa) and a H2O/N2 separation factor higher than 104 at 25 °C and 90-100% humidity. The GO composite membranes were fabricated in a reproducible manner and showed stable performance as a function of time. Furthermore, the membranes maintained high permeance and selectivity at 80°C, indicating that it is useful as a water vapor separation membrane.

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The hollow fiber membrane modules act as dehumidifiers and regenerators to avoid gas-liquid entrainment problems in direct-contact dehumidification systems. A solar-driven hollow fiber membrane dehumidification experimental rig was designed to investigate its performance from July to September in Guilin, China. The dehumidification, regeneration, and cooling performance of the system between 8:30 and 17:30 are analyzed. The energy utilization of the solar collector and system is investigated. The results show that solar radiation has a significant influence on the system. The hourly regeneration of the system has the same trend as the temperature of solar hot water, which ranges from 0.13 g/s to 0.36 g/s. The regeneration capacity of the dehumidification system is always larger than the dehumidification capacity after 10:30, which increases the solution concentration and the dehumidification performance. Further, it ensures stable system operation when the solar radiation is lower (15:30-17:50). In addition, the hourly dehumidification capacity and efficiency of the system ranges from 0.15 g/s to 0.23 g/s and 52.4 to 71.3%, respectively, with good dehumidification performance. The COP of the system and solar collector have the same trend, in which their maximum values are 0.874 and 0.634, respectively, with high energy utilization efficiency. The solar-driven hollow fiber membrane liquid dehumidification system performs better in regions with larger solar radiation.

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The membrane-based liquid desiccant dehumidification system is a newly developed method in the field of air dehumidification. In this study, double-layer nanofibrous membranes (DLNMs) with directional vapor transport and water repellency for liquid dehumidification were fabricated by a simple electrospinning process. Specifically, the combination of thermoplastic polyurethane nanofibrous membrane and polyvinylidene fluoride (PVDF) nanofibrous membrane forms a cone-like structure in DLNMs, resulting in directional vapor transportation. The nanoporous structure and rough surface of PVDF nanofibrous membrane provide waterproof performance for DLNMs. Compare with the commercial membranes, the proposed DLNMs have a significantly higher water vapor permeability coefficient, which is as high as 539.67 g·µm m-2·24 h·Pa. This study not only provides a new route to construct a directional vapor transport and waterproof membrane, but also demonstrates the huge application prospect of the nanofibrous membrane formed by electrospinning in the field of solution dehumidification.

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From the starting of the pandemic different transmission routes of the pathogen was brought into the spotlight by researchers from different disciplines. This matter in high-altitudes was more boosted as the main parameters were not exactly realized. In this review we are about to highlight the possibility of consuming contaminated water generated form solar water desalination/disinfection systems in highlands. Three systems including solar still, solar disinfection (which experimented by the authors in 2019 in high altitude) and humidification-dehumidification were consider in this context. Ascribe to the risks of pathogens transmission in solar desalination/disinfection systems where the water resources are heavily polluted in every corner of the world, highlighting the risk of consuming water in high-altitude where there are many other parameters associated with spread of pathogen is of great importance. As it was reported, reliability of solar desalination and solar water disinfections systems against contaminated water by the novel coronavirus remained on the question because the virus can be transmitted by vapor in solar stills due to tiny particle size (60-140 nm) and would not be killed by solar disinfections due to low-temperature of operation <40 °C while for HDH contamination of both water and air by sars-cov-2 could be a concern. Although the SARS-CoV-2 is not a waterborne pathogen, its capability to replicate in stomach and infection of gastrointestinal glandular suggested the potential of transmission via fecal-oral. Eventually, it was concluded that using solar-based water treatment as drinking water in high altitude regions should be cautiously consider and recommendations and considerations are presented. Importantly, this critical review not only about the ongoing pandemic, but it aims is to highlight the importance of produced drinking water by systems for future epidemic/pandemic to prevent spread and entering a pathogen particularly in high-altitude regions via a new routes.