المؤلفون: Fatemeh Asjadi, Maliheh Yaghoobi

المصدر: Scientific Reports, Vol 14, Iss 1, Pp 1-16 (2024)

مصطلحات موضوعية: Brass mesh, Superhydrophobic, Oil/water separation, Electrochemical etching process, Surface modification, Medicine, Science

الوصف: Abstract A facile method for preparing superhydrophobic brass mesh is proposed based on electrochemical etching and surface modification. The impact of processing time and the electric potential of the electrochemical etching were studied on the contact angle (CA) of the mesh. The samples were examined using scanning electron microscopy, Energy-dispersive X-ray spectroscopy analysis, X-ray diffraction, and Fourier-transform infrared spectroscopy. The electrochemical etching process caused the decrement of wires’ thickness and imposed roughness. Results showed more dissolution of zinc than copper under 3 V of the electric potential and the processing times of 3 and 6 min. The optimum condition of electrochemical etching was obtained under the electric voltage of 3 V for a processing time of 6 min, which led to a CA of 155.5 ± 3.2°. The thickness of the mesh wires decreased by 17.7% due to electrochemical etching in this sample. This sample also showed low adhesion for a water drop. The efficiency of oil/water separation was above 95 for the xylene and ethyl acetate in a batch system. The effect of the flow rate of the oil–water mixture on separation efficiency was also examined. The optimum flow rate was 0.8 ml s−1 with a high separation efficiency of 96.8% for xylene/oil separation.

وصف الملف: electronic resource

العلاقة: https://doaj.org/toc/2045-2322Test

الوصول الحر: https://doaj.org/article/2795e0b6710a4dd99c400d0044ccb29aTest

المؤلفون: A. Beagan, A. S. Elakany, Z. Yang, M. E. Mohamed

المصدر: Water Science and Technology, Vol 89, Iss 9, Pp 2512-2522 (2024)

مصطلحات موضوعية: chemical stability, oil absorption capacity, oil–water separation, superhydrophobic, zinc oxide nanoparticles, Environmental technology. Sanitary engineering, TD1-1066

الوصف: This manuscript presents a novel approach for developing an environmentally friendly and effective oil–water separation membrane. Achieving a superhydrophobic (SH) coating on textile fabric (TF) involved a two-step process. Initially, the surface roughness was enhanced by applying bio-zinc oxide (ZnO) nanoparticles obtained from Thymbra spicata L. Subsequently, the roughened surface was modified with stearic acid, a material known for its low surface energy. The bio-ZnO nanoparticles exhibit a circular morphology with an average size of 21 nm. The coating demonstrated remarkable mechanical stability, maintaining SH properties even after an abrasion length of 300 mm. Chemical stability studies revealed that the prepared membrane retained SH properties within a pH range of 5–11, which ensures robust performance. Absorption capacity measurements showcased different capacities for n-hexane (Hex), corn oil (C.O), and silicone oil (S.O), with consistent performance over 10 absorption–desorption cycles. High oil–water separation efficiencies were achieved for hexane, C.O, and S.O, emphasizing the coating's versatility. Flux rate measurements demonstrated that oil passed through the membrane efficiently, with the highest flux observed for Hex. The prepared SH membrane has superior mechanical and chemical stability and high separation efficiencies, which positions it as a promising candidate for diverse industrial applications. HIGHLIGHTS The manuscript introduces an eco-friendly oil–water separation membrane.; A superhydrophobic (SH) coating was achieved via a two-step process involving improving surface roughness and modifying with stearic acid.; The membrane exhibits good mechanical and chemical stability.; The SH membrane demonstrates efficient oil–water separation for various types of oils, making it highly promising for industrial applications.;

وصف الملف: electronic resource

العلاقة: http://wst.iwaponline.com/content/89/9/2512Test; https://doaj.org/toc/0273-1223Test; https://doaj.org/toc/1996-9732Test

الوصول الحر: https://doaj.org/article/bc01968a82e04da798dbdc02d4b860f5Test

المؤلفون: HUA Jian, HU Jiahao, MA Zhongjie, LI Wei, WANG Linhu

المصدر: Gongye shui chuli, Vol 44, Iss 5, Pp 192-197 (2024)

مصطلحات موضوعية: y-shaped tube, oil-water separation, separation efficiency, numerical simulation, Environmental technology. Sanitary engineering, TD1-1066

الوصف: Pipeline-type oil-water separation technology has the advantages of small footprint, high separation efficiency and low cost. A Y-type tubular oil-water separation structure was designed based on the principle of pipeline-type oil-water separation. The effects of internal flow field and external parameters on separation efficiency of Y-tube were studied by adopting standard k-ε turbulence model and mixture multiphase flow model in Fluent numerical simulation software. The results showed that the Y-shaped tube had little disturbance to fluid, stable internal flow field characteristics and was not easy to generate eddy current, which could realize oil-water separation. There was oil-water separation at the junction of branch pipe and main pipe. The oil-water separation efficiency increased gradually with the increase of the oil droplet size. The larger of the oil droplet size, the better the oil phase will float and gather in the upper layer of Y-shaped tube, which effectively improved the oil-water separation efficiency. The inlet velocity had a great influence on the oil-water separation effect. The higher the inlet velocity, the shorter the oil phase floating time, and the lower the separation efficiency of Y-shaped tube. The separation efficiency increased with the increase of branch shunt ratio. When the inlet velocity was 0.5 m/s, the separation efficiency would not increase when the shunt ratio exceeded 0.4. The results provided a new idea for oil-water separation and a theoretical reference for the design of Y-shaped tube.

وصف الملف: electronic resource

العلاقة: https://www.iwt.cn/CN/10.19965/j.cnki.iwt.2023-0396Test; https://doaj.org/toc/1005-829XTest

الوصول الحر: https://doaj.org/article/ad260435ef2242c39bf93451e57b2dc7Test

المؤلفون: Eman Ashour, marwa shalaby, Dina Mohamed Ahmed

المصدر: Port Said Engineering Research Journal, Vol 28, Iss 2, Pp 49-58 (2024)

مصطلحات موضوعية: oil/water separation, uf membrains, membrane modification, Engineering (General). Civil engineering (General), TA1-2040

الوصف: Today, numerous businesses produce significant amounts of wastewater that is greasy. Separating the stable emulsified oil particles from water is the fundamental difficulty in treating oily wastewater. Generally speaking, polymeric membranes are essential in these procedures due to how simple and inexpensive modern separation processing is, as well as how flexible they are. The phase inversion method utilized in this study to create a poly vinyl alcohol (PVC) membrane is demonstrated. In order to increase both permeation flow and fouling resistance, PVC has been modified by the addition of polymeric additives like polyvinylpyrrolidone (PVP). Additionally, in this paper, we compare lab chemical membrane and commercial chemical membrane on the basis of their fluxes, rejection, and characterization. The enhanced PVC/PVP membranes were characterized and evaluated using mechanical strength, porosity, scanning electron microscopy (SEM), Fourier Transform Infrared (FTIR), and water contact angle measurement. The membranes were subsequently tested at a lab size in a cross-flow system with synthetic greasy wastewater as the input.

وصف الملف: electronic resource

العلاقة: https://pserj.journals.ekb.eg/article_347506_65a9995ef68711be657f2c65b7a8c534.pdfTest; https://doaj.org/toc/1110-6603Test; https://doaj.org/toc/2536-9377Test

الوصول الحر: https://doaj.org/article/5d3091b326b141d4b0e43d5cf464f95fTest

المؤلفون: Jialu Huang, Xu Ran, Litao Sun, Hengchang Bi, Xing Wu

المصدر: Discover Nano, Vol 19, Iss 1, Pp 1-21 (2024)

مصطلحات موضوعية: Membrane separation technology, Water purification, Oil water separation, Antifouling, Stimulus responsiveness, Materials of engineering and construction. Mechanics of materials, TA401-492

الوصف: Abstract Effective treatment of oily wastewater, which is toxic and harmful and causes serious environmental pollution and health risks, has become an important research field. Membrane separation technology has emerged as a key area of investigation in oil–water separation research due to its high separation efficiency, low costs, and user-friendly operation. This review aims to report on the advances in the research of various types of separation membranes around emulsion permeance, separation efficiency, antifouling efficiency, and stimulus responsiveness. Meanwhile, the challenges encountered in oil–water separation membranes are examined, and potential research avenues are identified.

وصف الملف: electronic resource

العلاقة: https://doaj.org/toc/2731-9229Test

الوصول الحر: https://doaj.org/article/6d32f89e4a2a4a38b6e468b9ff29c054Test

المؤلفون: Mohammad Nouri, Mohammad Taghi Sadeghi, AliMorad Rashidi, Reza Norouzbeigi

المصدر: Journal of Petroleum Exploration and Production Technology, Vol 14, Iss 5, Pp 1247-1258 (2024)

مصطلحات موضوعية: Oil water separation, Underwater oleophobic, Nanostructured WO3 coating, Hydrothermal, Petroleum refining. Petroleum products, TP690-692.5, Petrology, QE420-499

الوصف: Abstract To separate oil–water mixtures especially in oil field operations, new energy-efficient methods are urgently required. Conventional separation techniques using demulsifiers for separation of oil–water mixtures or even use of membranes usually suffered from high cost and energy consumption, composition dependency of demulsifiers and fouling or inability of a single membrane to separate all types of oil–water mixtures. This research aimed to synthesize tungsten oxide-coated stainless steel mesh using the hydrothermal method, with a focus on evaluating its effectiveness in oil–water separation. The coating procedure was carried out using hydrothermal techniques, with an emphasis on investigating the impact of precursor concentration, pH levels, reaction temperature and duration, on the separation efficiency of the optimal coating solution. The hydrothermally coated stainless steel mesh was created within a polytetrafluoroethylene reaction vessel, submerged in a 150 ml aqueous solution containing 0.0094 mol of sodium tungstate di-hydrate at pH 3.0, achieved through the addition of hydrochloric acid. Additionally, 1 g of oxalic acid, acting as a chelating agent, was introduced. Subsequently, the mesh underwent a 4 h reaction at 220 °C and was subsequently annealed for 30 min in a 350 °C furnace. Remarkably, the resultant mesh exhibited an exceptional water separation flux of 9870 ± 15 L/hr/m2 when exposed to 1:1 v/v oil–water mixtures. This performance significantly outperformed previous filters designed for similar oil–water separation tasks. The mesh efficiently facilitated the passage of water through the oil–water mixture, achieving an efficiency rate exceeding 98 ± 1%. To gauge its wetting behavior, the hydrophilic/underwater oleophobic filter underwent static contact angle measurements. The filter's wetting mechanism was primarily attributed to its hierarchical surface structure, which enhanced surface hydrophilicity and roughness. Analytical techniques such as XRD, FTIR, and FE-SEM were employed to scrutinize the fabricated filter's composition. These analyses confirmed the successful creation of a nanostructured WO3 coating on both sides of the stainless steel mesh. Moreover, the utilization of commercially available chemicals and straightforward fabrication techniques underscores the promising potential of this approach for large-scale applications.

وصف الملف: electronic resource

العلاقة: https://doaj.org/toc/2190-0558Test; https://doaj.org/toc/2190-0566Test

الوصول الحر: https://doaj.org/article/8a74a332d5b546ebaec24d3c93aa255eTest

المؤلفون: Qibo Zhou, Qibing Chang, Yao Lu, Jing Sun

المصدر: Ceramics, Vol 7, Iss 1, Pp 250-263 (2024)

مصطلحات موضوعية: ceramic membrane, polydopamine, silicification, oil–water separation, Technology, Chemical technology, TP1-1185

الوصف: In recent years, ceramic membranes have received widespread focus in the area of liquid separation because of their high permeability, strong hydrophilicity, and good chemical stability. However, in practical applications, the surface of ceramic membranes is prone to be contaminated, which degrades the permeation flux of ceramic membranes during the separation process. Inspired by mussels, we imitate the biomimetic mineralization process to prepare a ceramic membrane of nano–silica on the pre-modified zirconia surface by co-deposited polydopamine/polyethyleneimine. The modified ceramic membranes were utilized for the purpose of oil–water separation. Separation performance has been tested using a disc ceramic membrane dynamic filtration device. The outcomes revealed an enhanced permeability in the modified membrane, measuring as 159 L m−2 h−1 bar−1, surpassing the separation flux of the unmodified membrane, which was 104 L m−2 h−1 bar−1. The permeation performance of the modified membrane was increased to 1.5 times. Modified ceramic membranes are highly resistant to fouling. From the beginning to the end of separation process, the oil rejection rate of the modified ceramic membrane is always higher than 99%. After a 2 h oil–water separation test run, modified ceramic membrane permeate flux can be restored to 91% after cleaning. It has an enormous capacity for application in the area of oil–water separation.

وصف الملف: electronic resource

العلاقة: https://www.mdpi.com/2571-6131/7/1/16Test; https://doaj.org/toc/2571-6131Test

الوصول الحر: https://doaj.org/article/5fbee706a0bb4f6a9538a29b27e7d663Test

المؤلفون: A. Beagan, C. Chen, M. E. Mohamed

المصدر: Water Science and Technology, Vol 89, Iss 3, Pp 799-810 (2024)

مصطلحات موضوعية: bio-copper, chemical stability, eco-friendly, oil absorption capacity, oil–water separation, superhydrophobic membrane, Environmental technology. Sanitary engineering, TD1-1066

الوصف: The effective separation of oil and water presents a significant global challenge due to the growing prevalence of industrial oily wastewater. In this investigation, a superhydrophobic (SP) coating based on bio-copper (Cu) was successfully created using the grape seed extract and applied onto a textile fabric (TF) to create a highly efficient membrane for oil–water (O–W) separation. The characteristics of the resulting bio-Cu nanoparticles, including surface area, morphology, and composition, were examined. The developed SP TF (STF) membrane, based on bio-Cu, underwent extensive analysis of its wettability, morphology, surface composition, oil absorption capacity, O–W separation performance, flux rate, mechanical stability, and chemical stability. The STF membrane exhibited excellent SP properties, with a high-water contact angle of 156° and a low water sliding angle of 2°, indicating its exceptional ability to repel water. Furthermore, the membrane demonstrated a remarkable oil absorption capacity, separation efficiency, and the flux rate toward three different oils (diesel, corn oil, and kerosene). It displayed good mechanical and chemical stability, with the ability to withstand abrasion and immersion in solutions of different pH values for varying exposure times. These findings highlight the potential of the bio-Cu-based STF membrane as an effective and durable solution for O–W separation applications. HIGHLIGHTS Utilizing an environmentally friendly approach, bio-Cu nanoparticles were synthesized to craft a superhydrophobic (SP) membrane designed for efficient oil–water separation.; The prepared SP membrane demonstrated superior SP efficiency.; The prepared SP membrane exhibited remarkable oil absorption capacity for diverse oils (diesel, corn oil, and kerosene).;

وصف الملف: electronic resource

العلاقة: http://wst.iwaponline.com/content/89/3/799Test; https://doaj.org/toc/0273-1223Test; https://doaj.org/toc/1996-9732Test

الوصول الحر: https://doaj.org/article/f7280d14849b4000af7e8a5d664a6b16Test

المؤلفون: Eyegheleme, Ndidi Lilyann

مرشدي الرسالة: Mechanical Engineering, Boreyko, Jonathan Barton, Qiao, Rui, Staples, Anne E., Cheng, Jiangtao

مصطلحات موضوعية: Synthetic Trees, Negative Liquid Pressure, Transpiration, Porous Media, Oil-Water Separation.

الوصف: This dissertation delves into the theory, design and fabrication, and practical uses of synthetic trees that replicate the transpiration mechanisms of natural trees. The first chapter provides an in-depth explanation of how natural trees utilize hydraulic mechanisms to draw water from the soil, through their roots, and up to their leaves, sustaining hydration through transpiration. This process is reliant on the difference in relative humidity between the leaf and the ambient to promote evaporation, and synthetic trees replicate this cycle by integrating reservoirs and conduits with wetted nanopores, mimicking the negative Laplace pressure seen in natural trees. Chapter 2 presents a detailed theoretical framework for transpiration in synthetic trees. These trees feature a vertical array of tubes connected to a nanoporous synthetic leaf. Our model considers the impact of convective gas flow on the leaf, minimizing the diffusive boundary layer and directly influencing the leaf's negative Laplace pressure. We next analyze how the rate of evaporation and tree morphology affect the required Laplace pressure for mass conservation, in an ambient environment with an appreciable diffusive boundary layer. Our model considers the changing dynamics of the menisci, including their capability to adjust their contact angle and withdraw into nanopores to self-stabilize. We then determine conditions where transpiration is limited by evaporation or constrained by the leaf's maximum Laplace pressure, across various tree geometries and ambient conditions. In Chapter 3, the focus shifts to a practical application, as the insights from the previous chapters guide the creation of a synthetic tree for water harvesting. Solar steam generation employing a porous evaporator, with a 3D design extending beyond the free surface to mitigate heat losses, is used to demonstrate how transpiration, rather than capillarity, can raise water up glass tubes, and improve liquid transport heights over conventional methods. Chapter 4 expands on the synthetic tree concept, proposing a mobile desalination water container driven by transpiration. The container features a ring-shaped fin designed to absorb solar heat, increasing water evaporation from a nanoporous synthetic leaf. This approach combines reverse osmosis and thermal evaporation, offering a promising solution for obtaining fresh water from seawater. In Chapter 5, the study explores transpiration-powered oil-water filtration using synthetic trees. Our approach showcases the potential for natural separation of oil and water in various applications, without the need for a pump and in opposition to gravity. Chapter 6 modifies the synthetic tree design to selectively absorb and retain oil from oil-water emulsions. When water evaporates from the synthetic leaf, enabled by the generated negative suction within, oil is then drawn and contained within the system through oleophilic and hydrophobic membranes. This approach offers a sustainable method for oil spill clean-up, oil extraction and purification. Chapter 7 experimentally investigates how to eliminate the capillary driving force in synthetic trees. By over-filling the synthetic leaf's top surface to remove existing concave menisci, the study hypothesizes gravity as a replacement mechanism for negative pressure, with the water in hydrostatic columns held in tension by the overlying water supported within the porous leaf. In summary, these engineered hydraulic systems offer novel approaches to water harvesting, desalination, oil-water filtration, and the cleanup of oil spills, and the study of synthetic trees opens up a realm of possibilities for sustainable water management and environmental remediation, showcasing the potential of biomimicry in solving pressing global challenges.
Doctor of Philosophy
This dissertation explores the concept of synthetic trees designed to mimic the transpiration cycle of natural trees for various applications. The first chapter provides a detailed explanation on how this is achieved. The second chapter introduces the theoretical model, highlighting the interplay between suction pressure, spontaneous flow, and tree geometry in surface tension powered water flow. In Chapter 3, the findings inform the design of a synthetic tree for water harvesting through solar steam generation. Overcoming constraints of floating evaporators, this tree demonstrates enhanced water condensation compared to traditional reservoirs, and the use of transpiration in the tubes allow for greater height flexibility. Chapter 4 presents a theoretical design for a portable desalinating water bottle powered by transpiration. Inspired by mangrove trees, the bottle utilizes solar heat absorption, a nanoporous synthetic leaf, and reverse osmosis to spontaneously enable desalination. The hybrid approach enhances thermal evaporation and pre-filters salt, potentially producing a daily extraction of one liter of fresh water from seawater. Chapter 5 explores oil-water filtration using surface tension power in synthetic trees. Operating without pumps and against gravity, this spontaneous phase separation demonstrates potential applications in oil spill cleanup, wastewater purification, and oil extraction. In Chapter 6, the synthetic tree is further modified to selectively take up and contain only oil from an oil-water emulsion. Driven by the surface tension mechanism, oil enters the tree through oil loving and water membranes, yielding high-purity oil samples, and offering innovative solutions for various environmental and industrial challenges. Chapter 7 investigates how to stop capillary forces in synthetic trees. When water evaporates from the leaves, it creates suction, pulling water from the soil through the xylem to keep the tree hydrated. We filled the top of the synthetic leaf to remove the curved surfaces that cause capillary tension. Surprisingly, water in the vertical tubes still held against gravity. This led us to consider a new idea: gravity might be replacing surface tension, with columns of water in the tree held in tension by the water above them in the leaf. Overall, this research on synthetic trees suggests exciting new ways to address environmental issues and manage water resources sustainably, underlying the power of nature-inspired solutions.

وصف الملف: ETD; application/pdf

الإتاحة: https://hdl.handle.net/10919/118743Test

المؤلفون: Reza Ghamarpoor, Masoud Jamshidi, Zainab Allawi Kadhim Alhaeehm

المصدر: Results in Engineering, Vol 22, Iss , Pp 102270- (2024)

مصطلحات موضوعية: Oil/water separation, New coupling agent, Nanoparticles, Nanocomposite, Environmental remediation, Technology

الوصف: Design and synthesis of a new sorbent with high performances of oil-water separation is one of the challenges to the world community. Herein, a superhydrophobic/novel coupling agent (NCA) containing several vinyl groups was synthesized. Also, vinyl isocyanate (VI) and tetraethoxysilane (TEOS) reacted with a synergetic strategy of crosslinked networks through the click reaction under N2 gas atmosphere. 1H NMR and FTIR analyses confirmed the formation of NCA with the SiC10H18O6N2 chemical formula. Then, NCA was grafted on the nanoparticles at different amounts by sol-gel method. It was found that the surface modification of nanoparticles enhanced the water contact angle (WCA) from 60° to 163°. In the following, nanoparticles with and without NCA were applied at different contents to tire rubber compound. The uniform dispersion/distribution of the grafted nano fillers with NCA in polymer matrix and the strong filler-polymer interactions enhanced crosslink density and improved the mechanical performances of the rubber sample. The prepared nanocomposites were tested against absorption of different oils. The results showed that the superior nanocomposite with modified nanoparticles (i.e. TR-TNS5) had a separation efficiency of over 90 % compared to the nanocomposite with pure nanoparticles (i.e. TR-NS5) which had a separation efficiency of less than 30 %. Also, the separation cycle of nanocomposites improved by 95 % after addition of the modified nanoparticles (from 240 to 440 cycles). The modified nanocomposite illustrated contact angles of 153.22° and 13.34° with water and oil droplets, respectively. The results showed that the modified rubbery nanocomposite confirmed superior mechanical and oil-water separation performances.

وصف الملف: electronic resource

العلاقة: http://www.sciencedirect.com/science/article/pii/S2590123024005255Test; https://doaj.org/toc/2590-1230Test

الوصول الحر: https://doaj.org/article/44684fb91a394039867c0ade7dd97794Test