scholarly journals Effect of Mesh Wettability Modification on Atmospheric and Industrial Fog Harvesting

2021 ◽  
Vol 9 ◽  
Author(s):  
Jong Hoon Kang ◽  
Jeong-Won Lee ◽  
Ji Yeon Kim ◽  
Jong Woon Moon ◽  
Hyeon Seo Jang ◽  
...  

Freshwater shortage has been receiving considerable attention, and water harvesting is one of the potential solutions to this water crisis. Several researchers have tried to improve the harvesting capabilities by changing mesh wettability for atmospheric fog harvesting. However, the wettability effect on water harvesting from white plumes has not yet been investigated thoroughly, despite industrial cooling towers being considered as alternative water resources, because of the large amounts of fog plumes generated. In this study, surface wettability was modified with a robust and simple method for practical scaled-up applications, and we explored the influence of mesh wettability on atmospheric and industrial fog harvesting. In atmospheric fog harvesting, both superhydrophilic meshes (SHPMs), and superhydrophobic meshes (SHBMs) were found to improve the harvesting performance, with superhydrophobic treatments providing the best collection efficiency. In contrast, only superhydrophilicity improves the performance in industrial fog harvesting with flat mesh screens. We hypothesize that this research will be useful for mesh design, as it analyzes the influence of mesh wettability on the performance of water collection in both atmospheric and industrial water harvesting.

Nanoscale ◽  
2020 ◽  
Vol 12 (13) ◽  
pp. 6921-6936 ◽  
Author(s):  
Jun Lei ◽  
Zhiguang Guo

In the Namib Desert, beetles can obtain water by fog-basking. In this review, we discussed the water collection rate of surfaces inspired by beetles from three aspects: surface wettability, surface structure and surface distribution.


2021 ◽  
Author(s):  
Souparna Chakraborty ◽  
Abhirup Chaudhuri ◽  
Chirodeep Bakli

Abstract The water crisis affects the lives of millions over the world. Minimizing water losses in major water-consuming industries like power plants is of utmost importance. Since cooling towers lead to huge amounts of water loss, implementing modifications for recovering a fraction of this lost water in the exhaust has been a topic of active research. These modifications are often inspired by biological species, especially in arid regions, which have adapted in different ways by collecting water from fog, and hence biomimetic has become popular for water harvesting techniques. We revisit the fog collection technique most commonly used in nature and compare the relative merits of the same with surface texture and wettability. Arrays of spines of three different configurations were considered in this study — namely cuboidal, cylindrical and conical shapes. A theoretical model is developed to carry out a comparative analysis of these configurations considered. The effects of Laplace pressure gradient, gravity, topography and tilt angle on droplet transportation along the spines were explored to decipher the most efficient water transport and collection route. The observations are explained by performing extensive Molecular Dynamics (MD) simulations to bring out the interplay of surface tension and roughness at the contact line verifying the proposed formulations. The conical-shaped spines exhibited maximum transport and collection efficiency for zero tilt angle. Both cuboidal and cylindrical shaped spines showed little or no water collection when the spines are oriented horizontally. This is due to the Laplace pressure gradient which arises from varying radii of curvature of the conical shaped spine which drives the water droplets towards the base but is absent for the other two cases considered. On the contrary, when there is some finite tilt angle, the contribution of gravity comes into consideration and the water collection rate of the conical and cylindrical spines becomes comparable. Both Laplace pressure gradient and gravity help in water transport in the conical case whereas only gravity assists the water transport process for cylindrical spines. Still, the water collection rate is almost the same for these two scenarios due to enhanced coalescence of liquid droplets for the cylindrical case as is observed from MD simulations. As the droplets coalesce, they get larger and gravity aids the transport process by overcoming the solid-liquid interaction strength. Cuboidal shaped spines show the least efficiency with only gravity to assist the transport process and no coalescence is observed in this case. Moreover, the geometrical disparity makes the tips of conical spines more hydrophobic compared to the others which further ameliorates the water collection efficiency.


2019 ◽  
Vol 489 (5) ◽  
pp. 478-482
Author(s):  
K. A. Emelyanenko ◽  
S. N. Melnikov ◽  
P. I. Proshin ◽  
A. G. Domantovsky ◽  
A. M. Emelyanenko ◽  
...  

The creation of methods for complete and cost-effective collection of water droplets from an aerosol which arises as a by-product of the low-potential heat uptake from industrial devices, is one of the key tasks of rational use of water resources contributing to the improvement of the environment near large industrial enterprises. This paper shows how the application of materials with extreme wettability and a specific surface topography in spray separators can significantly increase the efficiency of water collection.


2021 ◽  
Vol 18 (3) ◽  
pp. 501-533
Author(s):  
Kui Wan ◽  
Xuelian Gou ◽  
Zhiguang Guo

AbstractWith the explosive growth of the world’s population and the rapid increase in industrial water consumption, the world’s water supply has fallen into crisis. The shortage of fresh water resources has become a global problem, especially in arid regions. In nature, many organisms can collect water from foggy water under harsh conditions, which provides us with inspiration for the development of new functional fog harvesting materials. A large number of bionic special wettable synthetic surfaces are synthesized for water mist collection. In this review, we introduce some water collection phenomena in nature, outline the basic theories of biological water harvesting, and summarize six mechanisms of biological water collection: increased surface wettability, increased water transmission area, long-distance water delivery, water accumulation and storage, condensation promotion, and gravity-driven. Then, the water collection mechanisms of three typical organisms and their synthesis are discussed. And their function, water collection efficiency, new developments in their biomimetic materials are narrated, which are cactus, spider and desert beetles. The study of multiple bionics was inspired by the discovery of Nepenthes’ moist and smooth peristome. The excellent characteristics of a variety of biological water collection structures, combined with each other, are far superior to other single synthetic surfaces. Furthermore, the main problems in the preparation and application of biomimetic fog harvesting materials and the future development trend of materials fog harvesting are prospected.


Author(s):  
Violeta Cabello ◽  
David Romero ◽  
Ana Musicki ◽  
Ângela Guimarães Pereira ◽  
Baltasar Peñate

AbstractThe literature on the water–energy–food nexus has repeatedly signaled the need for transdisciplinary approaches capable of weaving the plurality of knowledge bodies involved in the governance of different resources. To fill this gap, Quantitative Story-Telling (QST) has been proposed as a science for adaptive governance approach that aims at fostering pluralistic and reflexive research processes to overcome narrow framings of water, energy, and food policies as independent domains. Yet, there are few practical applications of QST and most run on a pan-European scale. In this paper, we apply the theory of QST through a practical case study regarding non-conventional water sources as an innovation for water and agricultural governance in the Canary Islands. We present the methods mixed to mobilize different types of knowledge and analyze interconnections between water, energy, and food supply. First, we map and interview relevant knowledge holders to elicit narratives about the current and future roles of alternative water resources in the arid Canarian context. Second, we run a quantitative diagnosis of nexus interconnections related to the use of these resources for irrigation. This analysis provides feedback to the narratives in terms of constraints and uncertainties that might hamper the expectations posed on this innovation. Thirdly, the mixed analysis is used as fuel for discussion in participatory narrative assessment workshops. Our experimental QST process succeeded in co-creating new knowledge regarding the water–energy–food nexus while addressing some relational and epistemological uncertainties in the development of alternative water resources. Yet, the extent to which mainstream socio-technical imaginaries surrounding this innovation were transformed was rather limited. We conclude that the potential of QST within sustainability place-based research resides on its capacity to: (a) bridge different sources of knowledge, including local knowledge; (b) combine both qualitative and quantitative information regarding the sustainable use of local resources, and (c) co-create narratives on desirable and viable socio-technical pathways. Open questions remain as to how to effectively mobilize radically diverse knowledge systems in complex analytical exercises where everyone feels safe to participate.


2007 ◽  
Vol 72 (6) ◽  
pp. 585-590 ◽  
Author(s):  
Morteza Talebi ◽  
Homeyra Safigholi

Arapid, simple, and sensitive procedure based on modified solid phase extraction was developed for the pre-concentration and determination of trace amount of lead in water resources. Lead was reacted with ammonium pyrrolidinedithiocarbamate (APDC) to make a complex. The complex was then collected in a column packed with surfactant-coated alumina. The parameters affecting the collection efficiency and desorption rate of the lead complexes from the column were investigated and optimized. The collection efficiency of the lead complex on the adsorbent was excellent under the optimized conditions. The results obtained from the recovery test showed the capability and reliability of the method for the analysis of trace amounts of lead. The proposed pre-concentration procedure made it possible to apply conventional flame atomic absorption spectrometry (FAAS) for the sensitive determination of trace amounts of lead in water resources. .


Langmuir ◽  
2018 ◽  
Vol 34 (44) ◽  
pp. 13409-13415 ◽  
Author(s):  
Barbara T. W. Ang ◽  
Choon Hwai Yap ◽  
Wee Siang Vincent Lee ◽  
Junmin Xue

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