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[Display omitted] Energy consumption from air cooling systems in summer, water scarcity in hot regions, and the functional reusability of waste paper are emerging environmental problems. Finding solutions to these problems simultaneously remains a significant challenge. Herein, a superhydrophobic passive cooling Cellulose-CaCO 3 film with hierarchical nano-sheets was fabricated to realize daytime radiative cooling with a temperature drop of 15–20 °C in summer and water harvesting with harvesting efficiency of 387 mg cm−2h−1 bd utilization of recycled waste paper. The superhydrophobic Cellulose-CaCO 3 film demonstrates its self-cleaning properties against inorganic and organic pollutants. Furthermore, the superhydrophobicity of the film was maintained after base/acid corrosions, dynamic water flushing, and thermal treatment at 100 °C for 7 h, exhibiting good durability of the superhydrophobicity. Moreover, the superhydrophobic Cellulose-CaCO 3 film is nonflammable after exposure to fire combustion for 1 min. In addition to waste paper, waste maize straws, and pasteboards were also collected to produce superhydrophobic passive cooling films. Results indicate that the above three cellulose-based raw materials can be well used to prepare durable superhydrophobic passive cooling materials. Environmental toxicology assessments confirm the safety of the material. This study not only provides a protocol for preparing superhydrophobic materials; but also demonstrates their potential for passive cooling and water harvesting. [ABSTRACT FROM AUTHOR]

The research presented in this paper introduces a novel environmental energy‐harvesting technology that harnesses electricity from the evaporation of water using porous structural materials. Specifically, a strategy employing paper‐based hydroelectric generators (p‐HEGs) is proposed to capture the energy produced during water evaporation and convert it into usable electricity. The p‐HEGs offer several advantages, including simplicity in fabrication, low cost, and reusability. To evaluate their effectiveness, the water evaporation‐induced electrical output performance of four different p‐HEGs are compared. Among the variants tested, the p‐HEG combining wood pulp and polyester fiber exhibits the best output performance. At room temperature, this particular p‐HEG generates a short‐circuit current and open‐circuit voltage of ≈0.4 µA and 0.3 V, respectively, thereby demonstrating excellent electrical stability. Furthermore, the electrical current and voltage generated by the p‐HEG through water evaporation are able to power an LED light, both individually and in series and parallel connections. This study delves into the potential of electricity harvesting from water evaporation and establishes it as a viable method for renewable energy applications. [ABSTRACT FROM AUTHOR]

With the increasing demand for freshwater resources, the sustainable and effective utilization of atmospheric water has become a critical issue. Herein, an efficient and stable monolithic water-adsorbent is designed via functionalizing glass fiber paper loaded with two-linker metal-organic frameworks (CGF-mixed-MOFs(Al)). Firstly, a chitosan (CTS) polyelectrolyte layer is constructed on glass fiber paper to improve the MOFs loading capacity (306.71%) through electrostatic interaction and hydrophilic interaction. Subsequently, a series of two-linker metal-organic frameworks (mixed-MOFs(Al)) composed of MIL-160(Al) and Al-fumarate are tailor-made on CGF surface through a situ synthesis self-assembly technology. The resultant mixed-MOFs(Al) monolith exhibits better water harvesting ability and faster adsorption kinetics at low humidity owing to possessing more active adsorption sites. Different from CGF-MIL-160(Al) and CGF-Al-fumarate, the water sorption of CGF-mixed-MOFs(Al) 5 at 30% RH, 25% RH and 20% RH reaches 0.37 g/g, 0.31 g/g and 0.25 g/g, respectively. The lab-scale atmospheric water harvesting device based on CGF-mixed-MOFs(Al) 5 confirms the feasibility of this work-tailored product as a potential water sorbent in low-humidity environments. The cyclability results (50 times) indicate that CGF-mixed-MOFs(Al) 5 maintains good water capture performance, integrity (no MOFs leakage) and crystallinity, which guarantees its working reliability and sustainable benefits. Therefore, our customized water adsorption system provides a simple, long-effective, economical and advanced strategy to capture more fresh water from atmosphere in arid climates. [Display omitted] • The construction of chitosan layer on glass fiber paper promotes high MOFs loading. • Two-linker MOFs involving MIL-160(Al) and Al-fumarate is in-stiu synthesized. • The water adsorption properties of two-linker MOFs can be adjusted by changing the ratio of organic ligands. • The monolithic adsorbent shows high water-harvesting capacity even at low humidity. [ABSTRACT FROM AUTHOR]

Janus membranes with unidirectional liquid transport property have tremendous applications in fields of functional fabrics, water harvesting, smart wound dressings and so on. Paper shows distinct advantages to other materials, such as hydrophilicity, low-cost, flexible and so on. However, there is still less attention on how to construct a Janus paper with unidirectional liquid transport capacity and its functional applications. Here, a multi-pores Janus paper with asymmetric wetting properties is developed through consecutive laser microdrilling, hydrophobic modification and air-plasma treatment. As a result, the prepared Janus paper can allow the water to transport from the hydrophobic side to the hydrophilic side, while it blocks the water to flow in the reverse direction. Meanwhile, it can also achieve antigravity unidirectional water transport. In addition, the mechanism for unidirectional liquid transport is investigated. Finally, as a proof-of-concept, the Janus paper is utilized for applications of information encryption/decryption. [Display omitted] • Multi-pores Janus paper is successfully reported in this manuscript through simple fabrication method. • The Janus paper can unidirectional transport water from the hydrophobic side to its hydrophilic side. • It can also achieve antigravity unidirectional water transport. • The multi-pores Janus paper is utilized for applications of information encryption/decryption. [ABSTRACT FROM AUTHOR]

Sunken green space is one of the urban rainwater collection facilities, which belongs to Low Impact Development (LID) techniques. It plays a key role in the construction of sponge city, and the amount of runoff collection is usually affected by the area of the sunken green space, the infiltration rate of the soil, and the annual runoff collection rate. To determine the minimum soil infiltration rate of sunken green space considering the annual runoff collection ratio of sponge cities, this paper selects a residential district in Hefei city, China, as the case study. Based on 45 years of precipitation data, the designed rainfall corresponding to annual runoff collection ratios of 75%, 80% and 85% is 21.3 mm, 23.4 mm and 27.5 mm, respectively. The characteristics of rainfall infiltration in sunken green space are analyzed by using the water balance model and runoff yield and conflux model. The results reveal that the soil infiltration rate is 1.16×10−4 cm/s~3.88×10−3 cm/s when the sunken depth is 0.1 m~0.3 m and that the ratio of green space area is 5%~25%. The runoff collection of the reconstructed sunken green space is 2.87 times and 1.98 times that of the nonsunken green space and the nonreconstructed sunken green space, respectively. That is to say, under the comprehensive performance of the sunken depth, sunken green space area, the steady soil infiltration rater of the reconstructed sunken green space cannot be less than the value obtained in this paper. Otherwise, the requirements of annual total runoff reduction ratio of the sponge city cannot be met. Therefore, this study provides references for realizing the ratio of annual runoff collection and sponge city construction in similar urban areas. It can also be applied to optimal selection of sunken green space in some sponge city projects. [ABSTRACT FROM AUTHOR]

As arid lands expand across the globe, scholars increasingly turn to the archaeological record for examples of sustainable farming in extreme environments. The arid north coast of Peru was the setting of early and intensive irrigation-based farming; it is also periodically impacted by sudden, heavy rainfall related to the El Niño Southern Oscillation (ENSO) phenomenon. While the sociopolitical effects, technologies, and engineering expertise of these irrigation systems have been thoroughly examined and theorized, little is known about how farmers managed periods of water stress. The aim of this study is to test whether arid zone farming was supported by hybrid, intermittent flood and perennial water source systems in the prehispanic past. An arroyo in the Chicama Valley was selected for preliminary data collection, and these data are presented here: (1) drone photography of the arroyo capturing the aftermath of a recent (2023) rain event; and (2) potassium (K) soil test kit results from samples collected near suspected prehispanic check dam features in the same area. The paper combines these data with comparative examples from the literature to suggest that the prehispanic features functioned as water-harvesting infrastructure. The paper concludes that sustainable, arid zone farming can be supported by hybrid, intermittent flood and perennial water source systems. [ABSTRACT FROM AUTHOR]

The novelty of the paper is the analysis of the possibilities of reducing the operating costs of a mine water pumping station in an abandoned coal mine. To meet the energy needs of the pumping station and reduce the carbon footprint, "green" energy from a photovoltaic farm was used. Surplus green energy generated during peak production is stored in the form of green hydrogen from the water electrolysis process. Rainwater and process water are still underutilized sources for increasing water resources and reducing water stress in the European Union. The article presents the possibilities of using these waters, after purification, in the production of green hydrogen by electrolysis. The article also presents three variants that ensure the energy self-sufficiency of the proposed concepts of operation of the pumping station. [ABSTRACT FROM AUTHOR]

This paper combines archaeology and earth sciences within the public use sector of the Sierra de las Quijadas National Park. The native peoples occupied this territory lacking surface water for at least the last thousand years. Archaeology shows a differential use of the landscape. Numerous quarry-workshop sites exist in the mountainous sector and residential spaces in the eastern foothills. Geomorphology suggests that rainfall events are channeled into the ephemeral streams in the foothills. This contribution analyzes the type of spatial relationship between these geoforms and the sites, as well as its causes. It is proposed that the local groups select with high frequency the ephemeral riverbeds to locate their residential bases. Several materialities show this relationship, including historic dams and combustion features, understood as structures related to water harvesting. In multiple latitudes, humans could persistently occupy territories with arid and semi-arid climates through the recurrent use of these types of watercourses. This is a consequence of their ability to channel and retain water for longer than the surrounding landscape. The case study presented here is a new example, emerging from the edge of the South American Arid Diagonal, about the people of the deserts and how they structured, and still structure, their landscape from the development of water management strategies concerning the prevailing geomorphology. [ABSTRACT FROM AUTHOR]

With the increasing prominence of extreme climate events and the construction and development of scenic areas, strengthening the management of rainwater resources in scenic areas has become an urgent need to enhance the capability to resist rain-induced flooding disasters and utilize rainwater resources for building safe, ecological, and sustainable scenic areas. In this paper, the Yesanpo scenic area was taken as the research object. Based on topographic and hydrometeorological data, the soil conservation service (SCS) model and ArcGIS spatial analysis tools were used to simulate the inundation areas resulting from an extreme daily rainfall event that 100-year return period within the research region, and comprehensively analyze the inundation areas. Drawing inspiration from the concept of resilience in ecology, this study proposed the construction of rainwater resource management strategies at three levels of ecological resilience, facility resilience, and social resilience. These strategies aimed to facilitate the transformation of stormwater from disaster to resource, thereby enhancing the systemic resilience of the Yesanpo scenic area against floods and water scarcity issues. At the same time, these strategies promoted the construction of resource-saving and environmentally friendly scenic spots, committed to treat rainwater as a valuable resource, and achieved the goal of rainwater recycling, providing a new perspective for promoting the sustainable development of scenic spots. [ABSTRACT FROM AUTHOR]

In Algeria, at the present time, there are no rainwater harvesting systems (RWHS) registered with the public authorities as an alternative to the public water supply. This is explained by numerous factors, the most important being inhabitants' acceptance. The aim of this article is to investigate the current level of acceptance of an RWHS as a viable method for backing up the public water supply system. Our hypothesis is that inhabitants' acceptance can be improved by the increasing awareness of the benefits of an RWHS. For the purposes of this study, an RWHS located in northern Algeria was designed, and its benefits were measured and discussed with the direct participation of residents living in the building. The first benefit was the potential potable water saving (PPWS) and the second was the benefit-cost ratio (BCR). The PPWS was estimated at 51 m3/year. The BCR was estimated at 7% (15% with local council funding). This paper shows that, in the case of an existing building, inhabitant acceptance of an RWHS depends on three factors: (1) the amount of rainwater delivered by the RWHS; (2) the cost of building and managing it; and (3) the extent of the modifications made to the building. [ABSTRACT FROM AUTHOR]

Triboelectric nanogenerators (TENG) have shown great potential in harvesting energy from water. For the TENG that harvests water energy, surface hydrophobicity is crucial for its performance. In this paper, we prepare a hydrophobic composite film of Polyvinylidene Fluoride/Polydimethylsiloxane/Polytetrafluoroethylene (PVDF/PDMS/PTFE) and an electrode of Polyaniline/Carbon nanotubes/Silver nanowires (PANI/CNTs/AgNWs) by electrospinning technology and a doping method, respectively, which are served as the friction layer and top electrode of TENG. The contact angle of the hydrophobic film and electrode both reach over 120°, which makes the separation process between water and the interface complete and promotes the output of TENG. The open-circuit voltage (Voc) and short-circuit current (Isc) can reach 150 V and 60 μA approximately. In addition, the composite electrode can be applied in the preparation of complex electrode shapes. Furthermore, the different reactions of TENG to different liquids indicate that it may contribute to liquid-type sensing systems. This work presents an efficient approach to fabricating hydrophobic films and electrodes, laying a foundation for the development of TENG for harvesting water energy. [ABSTRACT FROM AUTHOR]

During the development of the urban water system from 1.0 to 3.0, the impervious surface area gradually increased, hindering the natural infiltration and self-purification process of urban rainwater, resulting in serious urban water pollution, urban waterlogging in the rainy season, and groundwater problems. Since water will seep into the ground, serious water pollution will cause damage to the ground. Therefore, in dealing with urban rainwater problems, we want to use the sponge's ability to absorb and store water to build our cities into sponge cities. In this paper, we have constructed a sponge city planning and information system development based on geographic information fuzzy processing. We use differentiated fuzzy processing methods to eliminate classified information to achieve a perfect combination with nearby images and use ordinary fuzzy processing methods to solve the problem of nonconfidential information. This paper discusses the impact of natural topography on the planning and construction of sponge cities, including whether natural topography will affect rainwater, whether it will affect the distribution of different strata, and whether it will affect the utilization of groundwater resources. The basic functions of this platform are provided by a series of functions of GIS, and multiple modules are developed according to management requirements. The initial state of street view data is a lot of fisheye lens photos and corresponding point location information, which are displayed online after data preprocessing, detection information, editing information, and blurring processing. [ABSTRACT FROM AUTHOR]

In water-scarce regions where fog is abundant, the population can rely on this resource to obtain fresh water. The potential to harvest fog is confirmed by Large Fog Collector projects worldwide, which are reviewed. Mostly maintenance issues due to environmental and complex social factors compromise the sustainability of such projects. The researchers endeavour to resolve these issues by developing enhanced materials, while others use biomimetic design, hence creating innovative collectors. The objective of this paper is to survey and review the state of the art and develop a framework of different types of innovative fog collectors, including conceptual, experimental and operational aspects. [ABSTRACT FROM AUTHOR]

The main potential benefits of rainwater harvesting, namely water saving and storm water management, are easily evaluable at a building scale when well-known behavioral models are used. However, the evaluation is often more complex at an urban scale, due to a lack of building characteristics and demographic data. In the present paper, we propose a method, which is based on the representative building concept that can be used to quantify the potential benefits of rainwater harvesting at different scales, that is, from the building scale to the district and city scales. Particular attention has been paid to the sizing of the system so that it can be used for different rainwater collection purposes. The method has been applied to the city of Turin (Italy) considering different scenarios: 1) domestic use (e.g., toilet flushing and the washing machine), where buildings are independent of each other, and 2) two public uses (the irrigation of public green areas and street washing), for which we have hypothesized that the rainwater collection takes place at a district scale. The non-potable water saving for domestic use varies across the city from 29% to 62%, according to the characteristics of the buildings, while the reduction of the flow peak conveyed to the sewerage system, during extreme storms, is quite constant (in the 57–67% range). Irrigation and street washing require a lower amount of water, thus about 80% of water can be saved, but the retention efficiency is low, and a slight reduction in the flow peaks can be expected. The aim of the methodology presented in this work is to provide a suitable decision-making tool for policy makers and urban planners to evaluate the capability and efficiency of rainwater harvesting systems for buildings, districts, and cities. [ABSTRACT FROM AUTHOR]

A high-performance low-humidity sensor and moisture-enabled electric generator are prepared through a mesoporous silica-mediated polymerizable deep eutectic solvent platform. The strong hydrophilicity and high ionic conductivity of ionogels are the main reasons for realizing dual-function devices. This work provides a novel approach for the combination of humidity detection and utilization. [Display omitted] • Mesoporous silica/polymerizable deep eutectic solvent functionalized ionogels were prepared by UV light stimulation. • Mesoporous silica containing abundant hydroxyl groups can regulate the intermolecular forces in polymer networks. • Low-humidity sensing and moisture-enabled electric generation can be realized simultaneously through functionalized ionogels. Although technologies related to humidity detection and utilization, such as humidity sensors, atmospheric water harvesting, energy collection, and moisture-enabled electrical generation technologies, have been widely reported, there is still an urgent need for effective monitoring and utilization of humidity in low-humidity places. An ideal low-humidity sensor requires a high response, fast response time and low humidity hysteresis. Soft ion power supplies inspired by electric eels convert the chemical potential energy of ion gradients into electrical energy by utilizing humidity, but their production is challenging. This paper reports a new strategy for developing functionalized ionogels based on mesoporous silica and a polymerizable deep eutectic solvent (SiO 2 @PDES). Due to their strong hydrophilicity, high ionic conductivity, excellent adhesion, flexibility and mechanical strength, SiO 2 @PDES ionogels can not only detect low humidity but also generate electric power through a reasonably designed device structure. In the 5–30% RH range, the response of the SiO 2 @PDES humidity sensor reaches 1600%, with negligible humidity hysteresis (0.8% RH). As a biomimetic soft ion power supply, SiO 2 @PDES ionogels generate a high open-circuit voltage of ∼600 mV at 33% RH, which expands the environmental adaptability of moisture-enabled electrical generation equipment. In addition, the excellent moisture-enabled electrical generation performance endows portable wearable power supplies with high potential for applications such as charging capacitors and lighting LEDs. [ABSTRACT FROM AUTHOR]

Droughts are the most expensive climate disasters as they leave long-term and chronic impacts on the ecosystem, agriculture, and human society. The intensity, frequency, and duration of drought events have increased over the years and are expected to worsen in the future on a regional and planetary/global scale. Nature-based solutions (NBS) such as wetland and floodplain restorations, green infrastructures, rainwater harvesting, etc., are highlighted as effective solutions to cope with the future impacts of these events. While the role of NBS in coping with the impacts of other disasters, such as floods, has been extensively studied, there has been a lack of comprehensive review of NBS targeting drought. The following paper provides a unique critical state-of-the-art literature review of individual drought-related NBS around the world, in Europe, and particularly in Belgium, and assesses the critical differences between the NBS applied globally and in Flanders. An extensive literature review was conducted to systematically analyze NBS, listing the type, the location, the status of the implementation, and the possible recommendations proposed to optimize future NBS applications. Finally, a comparison is made between small- and large-scale applications of NBS. By analyzing all these aspects, especially the level of effectiveness and recommendations, insight was gained into the future potential of NBS and possible improvements. The research indicated a lack of scientific publications, especially in Belgium. Hence, grey literature was also included in the literature review. Only four papers included a quantitative assessment regarding the effectiveness of drought on a global level, all stating a positive impact on groundwater recharge. In contrast, at regional and country levels, the performance of NBS was not quantified. The number of large-scale implementations is low, where landscape- or watershed-scale holistic approaches to drought mitigation are still scarce. Some successfully implemented projects are only very local and have a long realization time, two aspects that limit achieving visible impact at a larger scale. Among the many NBS, wetlands are recognized as highly effective in coping with drought but are still degraded or lost despite their significant restoration potential. A common effectiveness evaluation framework shall be followed, which gives policymakers a clear view of the different NBS investment options. Furthermore, a more collaborative approach is recommended globally, including different stakeholder groups, with specific attention to the local communities. To conclude, future research should increase the evidence base and implementation of drought-mitigating NBS. • Drought-mitigating Nature-Based Solutions (NBS) are systematically reviewed. • Few NBS studies focus on drought compared to other hazards such as floods. • Most NBS implementations are located in Europe. • Effectiveness is not well quantified for implemented NBS. • For achieving considerable drought mitigation, large-scale NBS are needed. [ABSTRACT FROM AUTHOR]

Harvesting atmospheric water by solar regenerated desiccants is a promising water source that is energy-efficient, environmentally clean, and viable. However, the generated amounts of water are still insignificant. Therefore, more intensive fundamental research must be undertaken involving experiments and modeling. This paper describes several experiments, which were conducted to predict and improve the behavior of water absorption/desorption by the Calcium Chloride (CaCl2) desiccant, where the uncertainty did not exceed ±3.5%. The absorption effect in a deep container was studied experimentally and then amplified by pumping air into the solution. The latter measured water absorption/desorption by a thin solution layer under variable ambient conditions. Pumping air inside deep liquid desiccant containers increased the water absorption rate to 3.75% per hour, yet when using a thin layer of the solution, it was found to have increased to 6.5% per hour under the same conditions. The maximum amount of absorbed water and water vapor partial pressure relation was investigated, and the mean absolute error between the proposed formula and measured water content was 6.9%. An empirical formula, a one-dimensional mathematical model, was then developed by coupling three differential equations and compared to experimental data. The mean absolute error of the model was found to be 3.13% and 7.32% for absorption and desorption, respectively. Governing mathematical conservation equations were subsequently formulated. The mathematical and empirical models were combined and solved numerically. Findings obtained from the simulation were compared to experimental data. Additionally, several scenarios were modeled and tested for Jeddah, Saudi Arabia, under various conditions. [ABSTRACT FROM AUTHOR]

Typical spontaneous movement behaviors of condensate droplets include coalescence-induced jumping, gravity-driven sliding, and directional migration by wettability gradient. However, in the study of humid air condensation, it is uncommon to efficiently synergize two or three behaviors to enhance condensation capacity on a large surface. In this paper, droplet self-migration and gravity-driven sliding are successfully synergized by laser etching inverted trapezoidal superhydrophilic channels on the upper half of a 40 × 80 mm2 quasi-liquid surface. The dimension of droplets on the hydrophobic zone is effectively confined through rapid detachment of millimeter-scale droplets at the tip of the water-filled channels and subsequent frequent sweeping on the lower hydrophobic zone. Comparative analysis reveals that when the topline and baseline of the inverted trapezoidal superhydrophilic channel are set at 1.5 mm and 0.2 mm respectively, the surface exhibits the highest frequency of droplet formation in channels while utilizing coalescence-induced detachment of double droplets as its primary departure mode which achieves the most efficient detachment from the channel tips. Compared with a 1 mm vertical striped biphilic surface (directional-migration behavior only), this surface synergizes three movement behaviors of millimeter-scale droplets and demonstrates a remarkable increase in water harvesting rate by 33.0% in the best case. This experimental study not only provides a novel approach for the facile and large-scale fabrication of patterns on biphilic surfaces, but also offers different insight into synergizing various mobility behaviors of droplet at the millimeter-scale during humid air condensation. • Efficient synergism of multiple droplet behaviors is realized on biphilic surface. • Trapezoidal patterned surface achieves condensation enhancement in humid air. • Coalescence-induced sliding leads to effective departure of millimeter-scale droplets. • A facile way to fabricate an efficient biphilic surface with large area is introduced. [ABSTRACT FROM AUTHOR]

The scope of this paper is to review different types of sustainable water harvesting methods from the atmospheric fogs and dew. In this paper, we report upon the water collection performance of various fog collectors around the world. We also review technical aspects of fog collector feasibility studies and the efficiency improvements. Modern fog harvesting innovations are often bioinspired technology. Fog harvesting technology is obviously limited by global fog occurrence. In contrast, dew water harvester is available everywhere but requires a cooled condensing surface. In this review, the dew water collection systems is divided into three categories: i) dew water harvesting using radiative cooling surface, ii) solar-regenerated desiccant system and iii) active condensation technology. The key target in all these approaches is the development of an atmospheric water collector that can produce water regardless of the humidity level, geographical location, low in cost and can be made using local materials. [ABSTRACT FROM AUTHOR]

• The spring-actuated manner provides a quick and complete contact-separation. • The self-adaptive soft contact significantly increases the contact area. • The two solid–solid contacts enhance the SSEP-TENG's output performances. • The soft contact efficiently reduces the wear to the SSEP-TENG. • Self-powered GPS wireless positioning and tracking was powered by the SSEP-TENG. The global increasing energy shortage has prompted extensive research into exploiting environmentally friendly clean energy. As one of the most promising new energy candidates, water wave energy has been regarded as a prominent clean energy. Therefore, it is imperative to develop highly efficient techniques for harvesting water wave energy. The advent of triboelectric nanogenerators (TENGs), aiming to capture low-frequency, large-scale, and random energy, aroused significant attention. However, traditional TENGs for wave energy harvesting are always limited by the small contact area and incomplete separation. In this paper, a soft-contact and self-adaptive ellipsoidal-pendular-structured TENG (SSEP-TENG) is designed for harvesting water wave energy. Compared to traditional spherical TENGs, the unique spring-actuated soft contact not only effectively increases the contact area and reduces the wear to the TENG, but creates a quick and complete contact-separation process, which effectively improves the SSEP-TENG's output performance. Moreover, the synergy of the two solid–solid contact-separations enhances the SSEP-TENG's output performance. Finally, the maritime IoT application, a self-powered Global Positioning System (GPS) wireless positioning and tracking, was successfully realized by the SSEP-TENG, including the tracked target's longitude, latitude, altitude, and other location information. This work demonstrates the advantage of the SSEP-TENG in harvesting wave energy. [ABSTRACT FROM AUTHOR]

Floating platforms are an economical option for offshore energy harvesting in deep water sea. Lightweight design and structural stability are most important concerns in the design of floating foundations under the premise of ensuring load-bearing capacity. Topology optimization has proven to be a successful method for determining the optimal material distribution with the desired stiffness, strength, and robustness of the subjected design structure. In this paper, a novel lightweight multifunctional offshore floating platform design is proposed utilizing the density-based topology optimization method for the combined utilization of wind-solar-wave energy. Firstly, based on the extreme sea conditions in the South China Sea, the minimum compliance subject to the prescribed volume percentage is formulated and an innovative platform structure is carried out by interoperating the variable density method in the ANSYS AQWA module. Secondly, the optimized floating platform structure was strength-checked based on the maximum von Mises stresses under extreme loading conditions specified in the DNV code. The total mass of the novel optimized structure is 40.82% of the primary structure. Moreover, the platform stiffness and durability have been significantly enhanced. [ABSTRACT FROM AUTHOR]

With high hydrothermal stability and hydrophilicity, MIL-100(Fe) has potential applications in sorption-based atmospheric water harvesting (SAWH). This paper reports the water vapor adsorption properties of MIL-100(Fe) prepared by solvent and solvent-free methods. Performance tests show that the MIL-100(Fe) prepared by solvent-free method has more advantages. To further improve the performance of the adsorbent, the composite adsorbent MgCl 2 @MIL-100(Fe) was obtained by impregnating MIL-100(Fe) with MgCl 2 solution. The results showed that the composite adsorbent had good adsorption performance, desorption properties, and fast adsorption rate. The equilibrium adsorption capacities of the composite adsorbent with 35% salt content were 0.533 g/g and 1.062 g/g at 25 °C with the relative humidity (RH) of 35% and 80%, respectively, which were 1.51 times and 1.74 times of the adsorption capacity of MIL-100(Fe) under the same working conditions. This showed that the solvent-free synthesized MIL-100(Fe) and its composite adsorbent have the potential for application in SAWH. This paper compares the solvent-free synthesis of MIL-100(Fe) with the hydrothermal synthesis of MIL-100(Fe) with solvent. Then, by evaluating the various properties (characterizations, adsorption performance, cycle stability, preparation cost, etc.) of materials prepared by two different methods, it is determined whether the MIL-100(Fe) prepared by the solvent-free synthesis method is more suitable for water vapor adsorption. Eventually, to further improve the adsorption performance of this material, MIL-100(Fe) was impregnated in MgCl 2 solution to develop a new composite adsorbent MgCl 2 @MIL-100(Fe) for further study. [Display omitted] • The solvent-free synthesized MIL-100(Fe) has excellent adsorption performance and cycle stability. • The composite adsorbent MgCl 2 @MIL-100(Fe) has rapid adsorption kinetics. • The adsorption capacity of the composite adsorbent with an MgCl 2 mass fraction of 35% can reach 1.062 g/g. • The composite adsorbent has good water absorption at low relative humidity, which can reach 0.533 g/g. [ABSTRACT FROM AUTHOR]

Non-conventional water resources have emerged as means to meet or supplement irrigation demand for reforestation and agriculture in water scarce regions. Irrigation by condensation is an inexhaustible resource of water for irrigation, the combination of high relative humidity, the air temperature and the low temperature of water circulating through a closed loop system. Irrigation by condensation are designed primarily to arid and semi-arid areas, where groundwater is deep and fresh water sources are rare. Air humidity is a potential source of freshwater that is accessible everywhere and can be used for crop irrigation. This paper presents a review of atmospheric water harvesting used for the purpose of valorization for crop irrigation. The aim of this study is to present methods of collecting air humidity for the purpose of valorization for crop irrigation. [ABSTRACT FROM AUTHOR]

Understanding of extreme weather conditions at the site of interest is essentially required in the design of engineering structures so that the structures can withstand weather stresses. This paper presents an analysis of extreme values of meteorological elements observed at Narora site for the last three decades (1989–2019). The elements considered are extreme air temperature (°C), minimum relative humidity (%), extreme wind gust (km/h), maximum rainfall (mm) in a day and a month, and annual rainfall. The extreme value analysis reveals that the maximum air temperature, maximum wind gust at 30 m, maximum monthly rainfall, and maximum annual rainfall obey Fisher-Tippett Type-1/Gumbel extreme value distribution, whereas minimum air temperature, minimum relative humidity (%), annual daily maximum rainfall (mm), and annual minimum rainfall (mm) obey Fisher-Tippett Type-2/Frechet extreme value distribution function. Distribution function parameters, i.e., location, scale, and shape parameter for each variable, have been determined. Extreme values corresponding to return periods of 50, 100, and 1000 years are worked out using best fit linear regression curve as a compliance of the Atomic Energy Regulatory Board Safety Guide Recommendations. The derived extreme values are particularly useful to designer for arriving at suitable design basis values of different elements to ensure the safety of the reactors and other civil structures in Narora region, with respect to stresses due to weather conditions. Extreme values corresponding to return periods of 50 and 100 years at Narora are compared with corresponding values at other three nuclear reactor sites in India, namely, Tarapur, Kalpakkam, and Trombay. In addition, the time series pattern analysis of rainfall for 31 years at the Narora site closely following the 2-year moving average rainfall data pattern. These results can be used for water harvesting, irrigation, and floods management plans in the future. [ABSTRACT FROM AUTHOR]

This paper reports the condensation and subsequent motion of water droplets on bi-philic surfaces, surfaces that are patterned with regions of different wettability. Bi-philic surfaces can enhance the water collection efficiency: droplets condensing on hydrophobic regions wick into hydrophilic drain channels when droplets grow to a certain size, renewing the condensation on the dry hydrophobic region. The onset of drain phenomenon can be triggered by multiple events with distinct nature ranging from gravity, direct contact between a droplet and a drain channel, to a mutual coalescence between droplets. This paper focuses on the effect of the length scale of hydrophobic regions on the dynamics of mutual coalescence between droplets and subsequent drainage. The main hypothesis was that, when the drop size is sufficient, the kinetic energy associated with a coalescence of droplets may cause dynamic advancing of a newly formed drop, leading to further coalescence with nearby droplets and ultimately to a chain reaction. We fabricate bi-philic surfaces with hydrophilic and hydrophobic stripes, and the result confirms that coalescing droplets, when the length scale of droplets increases beyond 0.2 mm, indeed display dynamic expansion and chain reaction. Multiple droplets can thus migrate to hydrophilic drain simultaneously even when the initial motion of the droplets was not triggered by the direct contact between the droplet and the hydrophilic drain. Efficiency of drain due to mutual coalescence of droplets varies depending on the length scale of bi-philic patterns, and the drain phenomenon reaches its peak when the width of hydrophobic stripes is between 800 μm and 1 mm. The Ohnesorge number of droplets draining on noted surfaces is between 0.0042 and 0.0037 respectively. The observed length scale of bi-philic patterns matches that on the Stenocara beetle’s fog harvesting back surface. This match between length scales suggests that the surface of the insect is optimized for the drain of harvested water. [ABSTRACT FROM AUTHOR]

Directional water harvesting is a special ability of flora and fauna in nature. Wettability-patterned surfaces inspired by natural structures have been extensively researched and could be a great potential avenue for easing water shortage. However, preparation strategies for these nature-inspired cases, including UV irradiation with mask technology, femtosecond laser direct writing and chemical treatment, are time-consuming, cost-ineffective and environmentally unfriendly. In this paper, robust and durable superhydrophobic (SHB) glass substrate was prepared by using laser-induced backward transfer technique and fluoroalkylsilane modification. Then wedge-shaped superhydrophilic (SHL) patterns on the SHB surfaces were rapidly constructed by inexpensive and commercially available fibre laser ablation for fog harvesting. This facile, cost-effective and non-corrosive preparation method described herein could be an alternative way to construct SHL–SHB patterns on glass substrate, which could be used for microfluidic devices, droplet manipulation and cell screening. [ABSTRACT FROM AUTHOR]

Pluvial flooding is a result of overland flow and ponding before the runoff enters any watercourse, drainage system or sewer, or cannot enter it because the network is full to capacity, usually caused by intense rainfall. River and coastal floods get the most attention since they are largest and last the longest, while pluvial floods are relatively marginalized in research. Therefore, the main goal of this research was to show risk posed by pluvial floods, their connection to current global climate change processes, present effects of flooding in European cities, as well as what we can expect in the future. Furthermore, the aims were to present and get more familiar with scientific projects, strategies, directives and measures devised both on national and international levels, that deal with urban pluvial flood issues across the European continent. Climate change projections indicate that there will be an increase in the frequency and intensity of rainfall events throughout Europe and along with ongoing urbanization, the problem of pluvial flooding will most certainly require more attention, which it is starting to receive. Some countries have already developed their strategies and initiatives and implemented both structural and non-structural measures, such as spatial planning, constructional measures, information systems, reducing land sealing through policies, building codes and standards, on-site improvement of retention, infiltration, evaporation, and rainfall water recycling with the use of green roofs, permeable or porous pavements, rain gardening or urban rainwater harvesting. At the same time, there are numerous research papers, studies, conferences and workshops devoted to the problem of pluvial flooding and its management carried out in an attempt to properly deal with this hazard. [ABSTRACT FROM AUTHOR]

• Trinary micro-porous 32/4/4 MgO/PVDF/PMMA blend with atmospheric window emissivity and solar reflectivity exceeding 97% is developed. • Compared to the baseline radiative cooling materials, trinary micro-porous 32/4/4 MgO/PVDF/PMMA blend enhanced surface temperature suppression by 1.6 ℃ at daytime. • Functionalized glass-PDMS micro-pillar heat exchanger chills water by 2.5 ℃ at an efficiency of 6.3% at nighttime. • Compared to the saturation limits, reduced temperature reduction and efficiency for low Peclet number low is attributed to axial conductive viscous dissipation. Chilled water harvesting is a fundamental application of passive radiative cooling and promotes energy conservation for space cooling in buildings potentially, which relies on well-designed radiative cooling materials and heat transfer interface. This paper reports a scenario leading to viscous dissipative thermo-photonic energy conversion, which takes place in low Peclet number regime of an order of magnitude of 100, where heat transfer is non-Graetzian. Compared to benchmarked glass-polydimethylsiloxane radiative cooler and barium sulphate coating, a newly developed trinary micro-porous 32/4/4 magnesium-oxide/poly(vinylidene-fluoride)/poly(methyl-methacrylate) radiative cooling blend, featuring high atmospheric window emissivity and solar reflectivity, both exceeding 97%, demonstrated a superior cooling performance with additional temperature reduction of 1.6 °C at daytime. Meanwhile, it chilled water at a flow rate of 6.3 µL/s by 1.3 °C upon coating on a glass-polydimethylsiloxane micro-pillar heat exchanger. Quantitative evaluation on the chilled water capacity was carried out at nighttime when the system ran pseudo-steadily. Cooling power measurement on a radiative cooler of same materials recorded a cooling power of 134 W/m2 which is close to the ideal limit. And measured water temperature reduction and cooling efficiency were 2.5 °C and 6.3% respectively. They were significantly lower than the saturation limit. Degraded thermal and energy conversion performances, attributive to extended Graetzian viscous dissipation, were discussed theoretically. [ABSTRACT FROM AUTHOR]

This paper addresses on-site supplementary household water sources with a focus on groundwater abstraction, rainwater harvesting and greywater reuse as available non-potable water sources to residential consumers. An end-use model is presented and used to assess the theoretical impact of household water sources on potable water demand in formal residential areas. Reliable potable municipal supply to urban consumers via the water distribution system is typically linked to relatively low uptake of household water sources. However, stringent water restrictions in some large South African cities that prohibit outdoor use and reports of intermittent water supply, have led to increased uptake of household sources in South Africa. This paper describes the legal position regarding such sources in South Africa, and describes an end-use model to assess the theoretical impact on water demand in formal residential areas. The model provides valuable strategic direction and indicates a significant theoretical reduction in potable municipal water demand of between 55% and 69% for relatively large properties when household sources are maximally utilised (when compared to exclusive unrestricted municipal use as a baseline). This load reduction on piped reticulation systems could be an advantage in order to augment municipal supply, but water service planning and demand management are complicated by the introduction and possible future decommissioning, of any household water source. The extent of both positive and negative impacts of household water sources requires further research. [ABSTRACT FROM AUTHOR]

Water resources in dry environments are becoming scarcer, especially under the changing climate. In response, rainwater harvesting (RWH) is being reemphasized with calls to revive the practice. Ancient knowledge on RWH - mainly the collection through runoff, storage, and use of rainwater for various purposes - is still relevant, especially for dry environments. However, many old practices and technologies may not be suitable or feasible for the present and future. Little has been done to modernize and (or) develop new practices and technologies based on ancient indigenous knowledge. Modernizing old practices or developing new ones and using them in integrated rangelands restoration packages with enabling policy environment can unlock their potential in many water-scarce regions of the world. This paper reviews the state-of-the-art of micro-catchment rainwater harvesting (MIRWH) in dry environments and discusses the opportunities available and the major obstacles faced in using it to restore degraded agro-pastoral ecosystems and support their sustainability. The review highlights the knowledge behind it, the practices developed over the years, and their relevance to today and the future. The paper indicates areas of modernization that can make it more feasible for the future of the dry environments, especially their role in mitigating and adapting to climate change. Conventional and passive approaches to restoring/rehabilitating degraded dry agro-pastoral ecosystems are either too slow to show an obvious impact or not progressing satisfactorily. One main reason is that, because of land degradation, the majority of rain falling on such ecosystems and needed for revegetation is lost with little benefit being gained. Adopting a more progressive intervention to alter the processes of degradation and move towards new system equilibrium is required. MIRWH can enable a large portion of this otherwise lost rainwater to be stored in the soil, and, if used in an integrated packages including suitable plant species and sound grazing management, it may support meaningful vegetation growth and help system restoration. The Badia Benchmark project, implemented by ICARDA in Jordan and Syria, has demonstrated the potential for adoption at large scale in similar environments. This case study illustrates the potential and the constraints of this practice. [ABSTRACT FROM AUTHOR]

Water scarcity is a particularly severe challenge in arid climates. Since a substantial amount of water vapor is present in the atmosphere, adsorption-based atmospheric water harvesting (ABAWH) is a promising technology to address the scarcity of freshwater resources using clean and economical energy sources. Meanwhile, climate change caused by CO 2 emissions has become one of the most significant concerns, and countries around the world are now working to achieve "carbon neutrality". In this respect, metal-organic frameworks (MOFs) have great potential for water harvesting and carbon capture on account of their high porosity, good designability, and excellent adsorption properties. In this paper, the development of MOFs in the field of adsorption is reviewed, and the adsorption characteristics and mechanism of MOFs are described. In addition, existing transport models for porous media are reviewed and predicted to be potentially applicable to MOFs. Particularly, this paper focuses on summarizing achievements of ABAWH so far and suggesting enhancements. Methods to improve carbon capture capacity are also concluded and discussed. Furthermore, some suggestions are presented to address the difficulties of industrial applications of MOFs. This review aims to providing technical insight to revisit existing technologies, research gaps, and scope for further development. It is desired to provide a reference for MOFs in terms of water harvester design and performance improvement of selective CO 2 capture, thus promoting the large-scale industrial applications of MOFs. [Display omitted] [ABSTRACT FROM AUTHOR]

Technology parks promote science, technology and innovation through their components, such as high-tech companies, universities and incubators. They show a significant increase in the number of units, especially in emerging countries such as Brazil. Unlike the industrial and logistic parks that, due to functional requirements, have their pre-determined and standardized architectural and urban characteristics, technological parks have in the innovation, their main characteristic, the possibility of proposing more suitable spaces for urban innovation. The Roof Mosaic is an approach that seeks self-sufficiency in urban areas from the food-energy-water nexus, using rooftops to produce food, renewable energy and rainwater harvesting. The integration between technology parks and Roof Mosaic can be advantageous since their roofs have a lower slope and greater design flexibility than other parks and can, therefore, contribute to the sustainable development of cities. The aim of this paper is to evaluate the potential of technology parks when implementing the Roof Mosaic. A case study underway was used, which is the Federal University of Rio de Janeiro (UFRJ) Technology Park (Rio de Janeiro, Brazil). The results from the case study show the potential for: 100% food self-sufficiency using hydroponic production of lettuces and tomatoes, meeting the demands of approximately 3,300 people; 45.2% for energy generated from photovoltaic panels; and 43% for water reusing rainwater harvesting. The potential of avoided CO 2 emissions using rainwater for non-potable purposes, food production and renewable energy, presented of nearly 805 tons of avoided CO 2 equivalents. [ABSTRACT FROM AUTHOR]

Human exposure to arsenic (As) through the consumption of rice (Oryza sativa L.) is a worldwide health concern. In this paper, we evaluated the major causes for high inorganic As levels in cooked rice foods, and the potential of post-harvesting and cooking options for decreasing inorganic As content in cooked rice, focusing particularly on As endemic areas. The key factors for high As concentration in cooked rice in As endemic areas are: (1) rice cultivation on As-contaminated paddy soils; (2) use of raw rice grains which exceed 200 μg kg−1 of inorganic As to cook rice; and (3) use of As-contaminated water for cooking rice. In vitro and in vivo methods can provide useful information regarding the bioaccessibility of As in the gastrointestinal tract. Urinary levels of As can also be used as a valid measure of As exposure in humans. Polishing of raw rice grains has been found to be a method to decrease total As content in cooked rice. Sequential washing of raw rice grains and use of an excess volume of water for cooking also decrease As content in cooked rice. The major concern with those methods (i.e. polishing of raw rice, sequential washing of raw rice, and use of excess volume of water for cooking rice) is the decreased nutrient content in the cooked rice. Cooking rice in percolating water has recently gained significant attention as a way to decrease As content in cooked rice. Introducing and promoting rainwater harvesting systems in As endemic areas may be a sustainable way of reducing the use of As-contaminated water for cooking purposes. In conclusion, post-harvesting methods and changes in cooking practices could reduce As content in cooked rice to a greater extent. Research gaps and directions for future studies in relation to different post-harvesting and cooking practices, and rainwater harvesting systems are also discussed in this review. Unlabelled Image • As-containing water and raw rice lead to increased As levels in cooked rice grains • Rice cooking in percolating water can significantly reduce inorganic As content • Use of rainwater is a sustainable way of reducing As levels in cooked rice • Loss of nutrients from cooked rice under different techniques needs to be minimized • In vivo methods revealed >85% of inorganic As is absorbed by gastrointestinal tract [ABSTRACT FROM AUTHOR]

Sustainable urban drainage systems (SUDS) or eco-drainage system has been implemented in developed countries. The aims of the construction of the system are; to minimize surface runoff by capturing and temporarily retain it, to improve the quality of surface runoff, to infiltrate stormwater, to increase evapotranspiration, and enhance landscape aesthetic value. Learning from the success of the implementation of SUDS in developed countries, the paper presents a model of eco-drainage system for residential area in Indonesia, which consists of rainwater harvesting system (RWHS) and retention ponds. A simulation of stormwater and surface runoff utilization is also presented. At 14,602.26 m2 bare land in Mojokerto Regency, which is transformed into residential area, the model of eco-drainage system could reduce surface runoff volume almost by 70%. It is recommended to adjust the dimension of rainwater storage tank and retention ponds in order to reduce more surface runoff volume. [ABSTRACT FROM AUTHOR]

Designing urban water infrastructure systems for environmental sustainability requires consideration of hydrologic performance design criteria and results from life cycle assessment (LCA). The objective of this paper is to present a study of merging hydrologic and LCA criteria into the evaluation of the environmental sustainability of rainwater harvesting (RWH) to control combined sewer overflows (CSOs). A case study of the City of Toledo, Ohio combined sewer system serves as the platform to investigate the two approaches and to compare RWH with centralized gray infrastructure strategies for controlling CSOs. Results show that the four RWH scenarios studied (two RWH-only: one to supply toilet flushing demand and the other to serve as extended detention; and two hybrids based on combining the two previous with gray infrastructure) delivered higher combined sewage volumes to wastewater treatment facilities compared to a gray infrastructure-only scenario. This resulted in elevated life cycle global warming potential (GWP) impacts (1.10 kg CO2e per 1 m² of reduced CSOs) on average for the four RWH scenarios. The gray infrastructure-only scenario reduced GWP impacts because it included sewer separation leading to lowered amounts of combined sewage volume treated (-1.89 kgCO2e per 1 m² of reduced CSOs). But, due to the untreated stormwater discharges to receiving waters, the gray infrastructure-only scenario led to a higher ecotoxicity water (ETW) impact [-12.11 comparative toxic unit for ecotoxicity (CTU eco) per 1 m² of reduced CSOs] compared to the RWH scenarios (-19.62 CTU eco per 1 m² of reduced CSOs on average). In conclusion, the new watershed-scale LCA framework led to more information on the CSO control strategies compared to hydrologic-only analysis, but it created a more complicated decision. Information from Toledo water stakeholders must be taken into account before nominating a scenario as the one that globally outperforms the others according the multi-hydrologic-LCA criteria. [ABSTRACT FROM AUTHOR]

Atmospheric water harvesting (AWH) technology, a new strategy to address the scarcity of fresh water, can be used to collect water from ambient air to produce clean water. Materials with moisture absorption-desorption capabilities are the key to AWH technology. Therefore, this paper reports a starch-derived photoresponsive atmospheric water-harvesting material with an acrylic acid (AA)/acrylamide (AM)-grafted starch hydrogel as the backbone, carboxylated carbon nanotubes (FCNTs) as the solar absorber, and lithium chloride (LiCl) as the water absorber. It was found that the hydrogel had good hygroscopicity in the relative humidity range of 25%–90%, and the adsorption capacity reached 8.5 g g−1 at 90% relative humidity. This hydrogel could recycle collected water vapor, and its performance and economy were found to be better than those of most reported atmospheric water harvesting materials. This material is driven by solar energy to release adsorbed water, and more than 94% of the adsorbed water was released quickly over a wide solar intensity range of 0.5–2 kW m−2. When used in the natural environment during the night/day cycle, this hydrogel was reversibly hygroscopic and achieved clean water production. This highlights the potential of biopolymers for atmospheric water harvesting applications. AWH diagram based on CFA-LiCl developed in this study. [Display omitted] • Starch-derived photoresponsive hydrogels were combined with LiCl to enhance the collection of atmospheric water. • When the relative humidity was 90%, the adsorption capacity reached 8.5 g g−1. • Rapid release of adsorbed water was achieved under natural light conditions. • The raw materials were environmentally friendly, and the preparation process was simple. [ABSTRACT FROM AUTHOR]

Dehumidification and water harvesting require high efficiency technologies. Compared with traditional materials, thermo-responsive materials (e.g., PNIPAM) can achieve low temperature regeneration, due to the lower critical solution temperature (LCST) features. To clarify the water adsorption and releasing performance of thermo-responsive polymers and further propose the potential research of the application in energy field, this paper reviews the existed research for three aspects: synthesis, water adsorption/desorption kinetics and application. Firstly, the grafting of thermo-responsive polymers on traditional materials and modification of thermo-responsive polymers for improving the adsorption/desorption performance is concluded. Secondly, the swelling and shrinking, the interaction with water during adsorption and releasing processes is reviewed. At last, the applications of the water vapor adsorption and water releasing features of thermo-responsive materials in energy field is summarized, including dehumidification, water harvesting, passive cooling and potential improvement for testing devices. Through the literature review, it can be generalized that the thermo-responsive polymer-based adsorbents have high water adsorption capacity and low regeneration temperature requirement, becoming a potential adsorbent for dehumidification and water harvesting. For the water adsorption and desorption, the temperature related heat and mass transfer kinetics requires further research, especially the thermodynamic model. The hybrid thermo-responsive polymer dehumidification and water harvesting units and systems have good application prospect, which requires research for both design and optimization. [Display omitted] • Water adsorption/desorption kinetics of thermo-responsive materials is reviewed. • Application of thermo-responsive materials for energy saving is summarized. • High water adsorption amount, low desorption energy of thermo-responsive materials. • Water adsorption/desorption thermodynamic and heat-mass transfer model is required. • Research on dehumidification and water harvesting unit and systems is recommended. [ABSTRACT FROM AUTHOR]

Background: Water Sensitive Urban Design (WSUD) systems are frequently used as part of a stormwater harvesting treatment trains (e.g. biofilters (bio-retentions and rain-gardens) and wetlands). However, validation frameworks for such systems do not exist, limiting their adoption for end-uses such as drinking water. The first stage in the validation framework is pre-validation, which prepares information for further validation monitoring. Objectives: A pre-validation roadmap, consisting of five steps, is suggested in this paper. Detailed methods for investigating target micropollutants in stormwater, and determining challenge conditions for biofilters and wetlands, are provided. Methods: A literature review was undertaken to identify and quantify micropollutants in stormwater. MUSIC V5.1 was utilized to simulate the behaviour of the systems based on 30-year rainfall data in three distinct climate zones; outputs were evaluated to identify the threshold of operational variables, including length of dry periods (LDPs) and volume of water treated per event. Results: The paper highlights that a number of micropollutants were found in stormwater at levels above various worldwide drinking water guidelines (eight pesticides, benzene, benzo(a)pyrene, pentachlorophenol, di-(2-ethylhexyl)-phthalate and a total of polychlorinated biphenyls). The 95th percentile LDPs was exponentially related to system design area while the 5th percentile length of dry periods remained within short durations (i.e. 2–8 hours). 95th percentile volume of water treated per event was exponentially related to system design area as a percentage of an impervious catchment area. Conclusions: The out-comings of this study show that pre-validation could be completed through a roadmap consisting of a series of steps; this will help in the validation of stormwater treatment systems. [ABSTRACT FROM AUTHOR]

A promising way to address the growing demand for water supply and improve the liveability of cities is to invest in decentralised multifunctional urban water technologies. However, the adoption of multifunctional water technologies is a complex issue that requires cross-disciplinary approaches. This paper uses an agent-based model that integrates economic and environmental factors to explore and simulate the decision-making and interactions of two types of agents: a regulator and households. The model is applied to evaluate strategies to increase the adoption of rainwater tanks in a suburb of Melbourne, a city that has often suffered from severe droughts. The model was able to replicate the uptake of rainwater tanks by households for 2005–2014, the period known as the ‘Millennium Drought’. Results indicate that using economic instruments alone may have been insufficient to promote the adoption of rainwater tanks, and that water restrictions have had a major impact on the uptake. [ABSTRACT FROM AUTHOR]

Decentralized rainwater harvesting (RWH) from roof runoff can complement the centralized supply of mains (drinking) water for a range of contexts, to assist in alleviating issues of water security. However, treatment to potable standard of harvested rainwater is not widespread. Consequently a comparative life cycle analysis (LCA) of decentralized and centralized potable water supply has not previously been undertaken. In this paper we describe a novel point-of-use (POU) treatment device, which was used to treat harvested rainwater to potable standard. We then provide a performance assessment for this system and an LCA with a comparison to centralized supply. Results of the performance assessment indicate a water saving efficiency (E T ) of between 0.6 and 100%, depending on rainfall (0.6 from April when rainfall was significantly below average). This highlights that the POU device was able to deal with the scale of roof runoff supply originating from a RWH system at a commercial building scale. The LCA results suggest that potable water produced from this decentralized RWH POU system currently performs more poorly than centralized water from an environmental perspective. Its impacts in most categories would be significantly reduced if the electricity consumed by the system were supplied from a renewable source such as solar PV or wind turbines instead of the UK grid. Priority should be given to optimizing the energy efficiency and exploring opportunities for combined use with renewable energy technologies in order to improve the environmental performance of POU treatment devices. [ABSTRACT FROM AUTHOR]

Over 50% of wetlands in the world have been lost in the past century, and the remaining wetlands have been degraded to different degrees because of the adverse influences of human activities and climate change impacts. Though protected under Ramser convention, the situation of Haleji wetland complex and Hadero wildlife sanctuary is not very promising. The current paper is focusing to revitalize the abandoned and devastated Ramsar site "Haleji Wetland Complex" and a forgotten wetland "Hadero Wildlife Sanctuary", situated in Thatta district, Sindh province of Pakistan. Both these wetlands are of great importance for natural habitat and reducing risk of coastal disasters and floods. The study mainly employed Arc-Hydro tools using remotely sensed data of ASTER GDEM 2 to determine the topography of both wetlands and their possibilities to connect with freshwater sources, and leeway to increase their respective water holding capacity. The study reveals that all the three wetlands can be re-connected with Indus River to turn them into fresh water bodies for sustaining natural habitat and increasing water harvesting capacities to cater human drinking water needs. [ABSTRACT FROM AUTHOR]

This paper explores optimal tank size for domestic rainwater harvesting systems in Asian tropical climates. A total of 128 locations in Vietnam covering three regional climate patterns were selected for the study. The system behavior was simulated on a daily basis using between 27 and 32 years of rainfall data. Annual water cost was investigated to determine optimal tank size. The relationship among optimal size, climate and system conditions was also analyzed. Results of the study emphasize the economic benefit of rainwater harvesting for the whole study area. The optimal tank size for a non-potable rainwater harvesting system has a range of 1.2-2.6 m³, exhibiting 19-65% supply efficiency and a payback period of 7-17 years. Extended system scenarios reveal a contrast in the influences of demand and roof area on optimal size in relation to rainfall amount. The roof area is critical in determining optimal size in the low rainfall area while the demand is important in the high rainfall area. Although there is a certain degree of variability in optimal tank size, it does not considerably undermine the economic benefit of a rainwater harvesting system. [ABSTRACT FROM AUTHOR]

South Africa is a semi-arid developing country facing water and energy insecurity. There are colossal challenges in reliably providing these resources amid growing population, increased urbanization and improved living standards causing increased demand for these resources. Development of new supply centralized systems comes at an exorbitant cost, whereas decentralized systems are touted as an attractive alternative. Grey water recycling and rain water harvesting at buildings level is such an alternative that can provide water for non-potable uses. However, there are technological challenges of optimally operating such systems while ensuring efficient use of associated energy. This paper introduces two control strategies; open loop optimal control and closed-loop model predictive control (MPC) strategies aimed at ensuring safe and reliable operation of the grey water recycling and rain water harvesting system while efficiently using associated energy. From the case study, the proposed system with either control strategy can save the cost of water and waste water by up to 32.3% and 29.5% respectively, while leading to 35.7% in energy cost savings and 31.5% in total operational cost savings in a month. Adoption of these systems would have a huge environmental effect in reducing demand for sewerage services, conservation of water hence reducing demand for potable water as well as increasing the energy efficiency. Furthermore, the system would increase the reliability and security of water supply. Despite the benefits, the system does not pay within its lifetime and therefore, government intervention is required so as to make it economically attractive. High cost of implementation coupled with low potable and waste water tariffs harbour adoption of these systems. Appropriate regulations, policies, incentives and public education are necessary to support such novel technologies in ensuring resource conservation, efficiency and security are achieved. [ABSTRACT FROM AUTHOR]

On the basis of the method used by Reinsch and Solovyeva, the aluminum based MOF material CAU-10-H (CAU stand for Christian-Albrechts-University) was synthesized by multiplying the amount of aluminum sulfate octahydrate and isophthalic acid by 10 times. CAU-10-H (b) is obtained after washing. In order to improve the water vapor adsorption performance of pure CAU-10-H (b), lithium chloride (LiCl) solution was compounded with CAU-10-H (b) by impregnation method to obtain a composite adsorbent CAU-10-H (L) and its adsorption characteristics were studied. The results showed that the composite adsorbent showed good adsorption and desorption performance under test conditions. Among them, the equilibrium adsorption capacity of the composite adsorbent with 33.1% LiCl content is 0.5007 g/g after 30 cycles, which is about 1.675 times of the adsorption capacity of pure CAU-10-H (b) under the same conditions. This shows the potential of the composite adsorbent to be used in the air-water extraction system. In this paper, aluminum based MOF material CAU-10-H [Al (OH) (m -BDC) 2, CAU stand for Christian Albrechts University] was synthesized. The performance test proves the performance advantage of CAU-10-H (b). In order to improve the adsorption performance of the adsorbent, the composite adsorbent CAU-10-H (L) was synthesized by impregnation. The composite adsorbent showed good desorption performance. This demonstrates the potential of the composite adsorbent for use in air-water extraction systems. [Display omitted] • Aluminum based MOF: CAU-10-H (CAU stand for Christian-Albrechts-University) was prepared by solvothermal synthesis using aluminum sulfate octahydrate and isophthalic acid as raw materials. • The sample of CAU-10-H after washing is named CAU-10-H (b). The microstructure characterization and open adsorption performance tests were done for CAU-10-H(b). • In order to improve the water vapor adsorption performance of CAU-10-H (b), a composite adsorbent CAU-10-H (L) was synthesized by impregnating CAU-10-H (b) with lithium chloride (LiCl) solution. • The water vapor adsorption capacity of the composite adsorbent is higher than that of CAU-10-H (b). The equilibrium adsorption capacity of the composite adsorbent with a mass fraction of 33.1% LiCl is about 1.675 times that of CAU-10-H (b). • The composite adsorbent has good desorption performance, high desorption rate, low desorption temperature, and can reduce energy consumption in practical application. [ABSTRACT FROM AUTHOR]

The efficiency of photovoltaic panels decreases as the panels' temperature increases, which results in deduction of electricity generation. In order to reduce this effect, different cooling methods were proposed and investigated. This paper reviews the previous work on cooling PV cells and concludes that the cost-effectiveness, design feasibility and minimal energy consumption are the important design consideration for cooling systems. Based on these considerations, this paper reports a passive cooling method that utilizes rainwater as cooling media and a gas expansion device to distribute the rainwater. The gas is thermally expanded from receiving solar radiation as such the amount of water it pushes to flow over the PV cells is proportional with the solar radiation it received. The paper reports a design and simulation of such a system for a domestic house application. In the paper, a relationship of the gas chamber size, solar radiation and gas expansion volume was established for evaluation with respect to the variation of gas temperature and the amount of rainwater used for cooling. A heat transfer model was used to evaluate the performance of the cells by cooling with this passive device. The results show that on a design day, the passive cooling system reduces the temperature of the cells and increases electrical efficiency of the PV panel by 8.3%. The payback period of this system is <14 years. [ABSTRACT FROM AUTHOR]

Deposition of pollutants by cloud water exceeds deposition by precipitation and dry deposition in many high elevation settings. This larger loading of pollutants in these environments is due to a combination of factors such as high frequency of cloud immersion, high wind speeds, orographic enhancement of precipitation, and large leaf area of tree species typical in these environments. Fog-impacted coastal ecosystems also experience increased pollutant deposition similar to cloud-impacted high elevation sites. Therefore, development of meaningful critical load values and total nitrogen budgets for high-elevation and fog-impacted sites requires reliable cloud and fog water deposition estimates. The cost and labor intensity of cloud/fog water sample collection have made it difficult to conduct long-term studies that would provide the data needed to develop accurate estimates. Current understanding of fog formation, transport, and the role of fog and cloud deposition in hydrogeological and biogeochemical cycles is incomplete due, in part, to lack of a concerted interdisciplinary approach to the problem. Historically, these obstacles have limited interest in and collection of cloud and fog water samples. In addition to measurements of cloud/fog chemical composition, documenting fog/cloud deposition fluxes of pollutant and nutrient species requires knowledge of cloud/fog physical properties, frequency and duration of fog/cloud interception with landscapes, properties of vegetation on those landscapes, and properties of the wind that drive droplet/vegetation interactions. Because drop deposition efficiency is dependent on drop size, it is also important to consider variations in fog/cloud drop composition with drop size as species enriched in larger/smaller drops will experience enhanced/reduced deposition rates. This paper presents summary results from a small U.S. cloud water monitoring network that operated from the mid-nineties through 2011, as well as a brief qualitative review of other cloud and fog water studies conducted in the United States (including Puerto Rico), Europe, South America/Pacific, and Asia. Current collection methods are also reviewed. Recent scientific efforts by the National Atmospheric Deposition Program's (NADP) Total Deposition Science Committee and NADP's Critical Loads of Atmospheric Deposition Science Committee have identified occult (cloud/fog) deposition as a "need" in developing critical loads for ecosystems that experience significant cloud and fog impaction. To this end, remaining knowledge gaps and suggestions for future research to investigate these gaps are explored. • At elevations above 800m cloud water samples are usually 5–20 times more acidic than rainwater. • Impacts of N deposition on alpine/subalpine regions are numerous and substantial. • Deposition loads of 10–40 kg N/ha/year in high-elevation areas in the eastern US are much higher than in the west. • Productivity and species shifts may have already occurred in eastern alpine ecosystems. • This paper is a qualitative summary of existing knowledge on cloud/fog water deposition. [ABSTRACT FROM AUTHOR]

The tenets of sustainable development are often ignored by growing cities in developing countries. Salt Lake City, located on the eastern fringes of Kolkata, despite being a planned township, has failed to manage its water resources in a sustainable way. Results from the study show that the water supplied at the households is hard in nature, saline, and replete with dissolved solids. The problem is further aggravated due to over-extraction of groundwater resources, resulting in an intense fall of the groundwater level in the area. This paper attempts to suggest measures for sustainable water resource management, with particular emphasis on rainwater harvesting. [ABSTRACT FROM AUTHOR]

Rainwater, which is used for drinking purposes near Hanoi, Vietnam, was analysed for water quality based on 1.5 years of monitoring data. In total, 23 samples were collected from different points within two rainwater harvesting systems (RWHSs). Most parameters met the standard except micro-organisms. Coliform and Escherichia coli ( E. coli ) were detected when the rainwater was not treated with ultraviolet (UV) light; however, analysis of rainwater after UV sterilisation showed no trace of micro-organisms. The RWHSs appear to provide drinking water of relatively good quality compared with surface water and groundwater. The superior quality of the rainwater suggests the necessity for new drinking rainwater standards because applying all of the drinking water quality standards to rainwater is highly inefficient. The traditionally implemented standards could cause more difficulties for developing countries using RWHSs installed decentralized as a source of drinking water, particularly in areas not well supplied with testing equipment, because such countries must bear the expense and time for these measures. This paper proposes the necessity of rainwater quality guideline, which could serve as a safe and cost-effective alternative to provide an access to safe drinking water. [ABSTRACT FROM AUTHOR]

This paper attempts to relate farm-level technologies in a semi-arid area with economic viability, taking risk analysis into consideration. Data gathered from various sources, such as a household baseline survey, farm trials, agricultural experts and government agencies, were used. Crop yields, crop prices, and prices for key production inputs, mainly fertiliser and rainwater harvesting through tied-ridges, were simulated for the net economic return distributions, e.g., pearl millet, groundnuts, and sunflower under different farm-technologies scenarios using a farm simulation model. The results indicate that an intercrop of pearl millet and groundnuts is the most economically viable farming system compared with other alternative scenarios if supplemented with rainwater harvesting technology. Risk neutral and risk-averse farmers both prefer this approach. If these technologies are geographically considered and synthesised, they may be cost-effective for farmers with implications for the current and future livelihood and productivity of crops in rural semi-arid areas. [ABSTRACT FROM PUBLISHER]

Many cities around the world have reached a critical situation when it comes to energy and water supply, threatening the urban sustainable development. From an engineering and architecture perspective it is mandatory to design cities taking into account energy and water issues to achieve high living and sustainability standards. The aim of this paper is to develop an optimization model for the planning of residential urban districts with special consideration of renewables and water harvesting integration. The optimization model is multi-objective which uses a genetic algorithm to minimize the system life cycle costs, and maximize renewables and water harvesting reliability through dynamic simulations. The developed model can be used for spatial optimization design of new urban districts. It can also be employed for analyzing the performances of existing urban districts under an energy-water-economic viewpoint. The optimization results show that the reliability of the hybrid renewables based power system can vary between 40 and 95% depending on the scenarios considered regarding the built environment area and on the cases concerning the overall electric load. The levelized cost of electricity vary between 0.096 and 0.212 $/kW h. The maximum water harvesting system reliability vary between 30% and 100% depending on the built environment area distribution. For reliabilities below 20% the levelized cost of water is kept below 1 $/m 3 making competitive with the network water tariff. [ABSTRACT FROM AUTHOR]