separation efficiency
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2022 ◽  
Vol 429 ◽  
pp. 132285
Author(s):  
Wanru Feng ◽  
Hao Wu ◽  
Junsu Jin ◽  
Dahuan Liu ◽  
Hong Meng ◽  
...  

2022 ◽  
Author(s):  
Qian Gu ◽  
Pingping Jiang ◽  
Kai Zhang ◽  
Yirui Shen ◽  
Yan Leng ◽  
...  

Abstract Porous C3N4 (PCN) is favored by researchers because it has more surface active sites, higher specific surface area and stronger light absorption ability than traditional g-C3N4. In this study, cerium dioxide nanoparticles (CeO2-NPs) with mixed valence state of Ce3+ and Ce4+ were doped into the PCN framework by a two-step method. The results indicate that CeO2-NPs are highly dispersed in the PCN framework, which leads to a narrower band gap, a wider range of the light response and an improved the separation efficiency of photogenerated charge in PCN. Moreover, the specific surface area (145.69 m2•g-1) of CeO2-NPs doped PCN is a 25.5 % enhancement than that of PCN (116.13 m2•g-1). In the experiment of photocatalytic selective oxidation of benzyl alcohol, CeO2-NPs doped porous C3N4 exhibits excellent photocatalytic activity, especially Ce-PCN-30. The conversion rate of benzyl alcohol reaches 74.9 % using Ce-PCN-30 as photocatalyst by 8 hours of illumination, which is 25.7 % higher than that of pure porous C3N4. Additionally, CeO2-NPs doped porous C3N4 also exhibits better photocatalytic efficiency for other aromatic alcohols.


Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 508
Author(s):  
Jijun Tang ◽  
Zhengzhou Duan ◽  
Qinyun Xu ◽  
Chuwen Li ◽  
Dongmei Hou ◽  
...  

In the study, ZIF-8@BIOI composites were synthesized by the hydrothermal method and then calcined to acquire the ZnO@Bi5O7I composite as a novel composite for the photocatalytic deterioration of the antibiotic tetracycline (TC). The prepared ZnO@Bi5O7I composites were physically and chemically characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Brunauer–Emmet–Teller (BET) surface area, UV–Vis diffuse reflectance spectroscopy (DRS), emission fluorescence spectra, transient photocurrent response, electrochemical impedance spectra and Mott–Schottky. Among the composites formed an n–n heterojunction, which increased the separation efficiency of electrons and holes and the efficiency of charge transfer. After the photocatalytic degradation test of TC, it showed that ZnO@Bi5O7I (2:1) had the best photodegradation effect with an 86.2% removal rate, which provides a new approach to the treatment of antibiotics such as TC in wastewater.


Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 460
Author(s):  
Zenon Ziobrowski ◽  
Adam Rotkegel

The comparison study of CO2 removal efficiency from flue gases at low pressures and temperatures is presented, based on commonly used methods and materials. Our own experimental results were compared and analyzed for different methods of CO2 removal from flue gases: absorption in a packed column, adsorption in a packed column and membrane separation on polymeric and ceramic membranes, as well as on the developed supported ionic liquid membranes (SILMs). The efficiency and competitiveness comparison of the investigated methods showed that SILMs obtained by coating of the polydimethylsiloxane (PDMS) membrane with 1-ethyl-3-methylimidazolium acetate ([Emim][Ac]) exhibit a high ideal CO2/N2 selectivity of 152, permeability of 2400 barrer and long term stability. Inexpensive and selective SILMs were prepared applying commercial membranes. Under similar experimental conditions, the absorption in aqueous Monoethanolamine (MEA) solutions is much faster than in ionic liquids (ILs), but gas and liquid flow rates in packed column sprayed with IL are limited due to the much higher viscosity and lower diffusion coefficient of IL. For CO2 adsorption on activated carbons impregnated with amine or IL, only a small improvement in the adsorption properties was achieved. The experimental research was compared with the literature data to find a feasible solution based on commercially available methods and materials.


2022 ◽  
Author(s):  
Hong Li ◽  
Xingqiang Cui ◽  
Weizhe Song ◽  
Zhanyuan Yang ◽  
Yanhui Li ◽  
...  

Abstract To improve the photocathodic protection performance of traditional TiO2 photoanodes for metals, constructing a Z-scheme heterojunction is one of the most promising and creative strategies. Herein, we fabricated a novel Z-scheme MgIn2S4 nanosheets/TiO2 nanotube nanocomposite through anodization and hydrothermal method. The optimized Z-scheme MgIn2S4/TiO2 nanocomposites exhibited stronger visible light absorption, higher separation efficiency of photoelectrons and photocathodic protection performances in comparison to pure TiO2. The theoretical analysis and experimental results show that the Z-scheme heterojunction and oxygen vacancies jointly improved the separation efficiency of photogenerated electron-hole pairs and visible light absorption capacity, thereby improving the photoelectric conversion performance of the MgIn2S4/TiO2 nanocomposites. Furthermore, the influence of the precursor solution concentration on the photocathodic protection performances of the composites was investigated. As a result, when the concentration of magnesium source in the precursor solution was 0.06 mmol, the prepared MgIn2S4/TiO2-0.06 displayed the best photocathodic protection performance. In addition, the hydroxyl radicals (•OH) generated in the electron spin resonance (ESR) experiment verified the Z-scheme heterojunction mechanism of the MgIn2S4/TiO2 composite, and also demonstrated the excellent redox performance of the composite. This work provides valuable reference for the construction of high-performance Z-scheme heterojunctions for photocathode protection of metals.


Minerals ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 72
Author(s):  
Anna Vanderbruggen ◽  
Aliza Salces ◽  
Alexandra Ferreira ◽  
Martin Rudolph ◽  
Rodrigo Serna-Guerrero

The comminution of spent lithium-ion batteries (LIBs) produces a powder containing the active cell components, commonly referred to as “black mass.” Recently, froth flotation has been proposed to treat the fine fraction of black mass (<100 µm) as a method to separate anodic graphite particles from cathodic lithium metal oxides (LMOs). So far, pyrolysis has been considered as an effective treatment to remove organic binders in the black mass in preparation for flotation separation. In this work, the flotation performance of a pyrolyzed black mass obtained from an industrial recycling plant was improved by adding a pre-treatment step consisting of mechanical attrition with and without kerosene addition. The LMO recovery in the underflow product increased from 70% to 85% and the graphite recovery remained similar, around 86% recovery in the overflow product. To understand the flotation behavior, the spent black mass from pyrolyzed LIBs was compared to a model black mass, comprising fully liberated LMOs and graphite particles. In addition, ultrafine hydrophilic particles were added to the flotation feed as an entrainment tracer, showing that the LMO recovery in overflow products is a combination of entrainment and true flotation mechanisms. This study highlights that adding kerosene during attrition enhances the emulsification of kerosene, simultaneously increasing its (partial) spread on the LMOs, graphite, and residual binder, with a subsequent reduction in selectivity.


Materials ◽  
2022 ◽  
Vol 15 (1) ◽  
pp. 376
Author(s):  
Hanyu Wen ◽  
Yu-I Hsu ◽  
Hiroshi Uyama

Oil separation is crucial for avoiding environmental pollution originating from industrial wastewater and oil spillage; therefore, it is essential to develop techniques for oil separation. Herein, a new membrane with superhydrophilicity was synthesized by a facile, green, and low-cost method. First, cellulose non-woven fabric (CNWF) was modified by poly (catechin) (pCA), which has good antioxidant and antibacterial activities, to make it unaffected by ultraviolet light and to improve the stability of the structure. Then, hydrolyzed polydimethylsiloxane (PDMS) was coated on the pCA@CNWF surface via chemical bonding to make the composite hydrophobic. This durable superhydrophobic fabric can be used to separate various oil/water mixtures by gravity-driven forces with high separation efficiency (over 98.9%). Additionally, the PDMS-pCA@CNWF possesses the advantages of flexibility, high efficiency, and an outstanding self-cleaning performance, and demonstrates significant potential for applications in various environments, even under various harsh conditions, which make it very promising for the treatment of oil pollution in practical applications.


2022 ◽  
Author(s):  
Abir Chakravorty

Development of desalination technologies has been identified as vital to fulfilling future water demand. Directional solvent extraction is one of the promising membrane-less seawater desalination method. Membrane based desalination technologies incur a higher cost and are subjected to fouling after certain period of time of operation and needs regular maintenance and monitoring. It is believed that, overcoming these drawbacks is possible by working in the millimeter scale through the incorporation of pulsatile flow and air damper. This work presents a theoretical approach designed for a certain nominal length of an air damper, placed on the top of the extraction column, with the flow in the desalination unit being semi pulsatile combined with secondary pulsation generated due to air suspension during solvent extraction applied for desalination operation. Henceforth a theoretical approach based on the above stated parameters, it is found theoretically that with increase in flow pulsation amplitude and frequency the extracted salt concentration in solvent increases. The application of infra red radiation in preheating section with the help of a infrared heating device is the crucial part of DSE process, cooling is planned to achieve via a heat exchanger or atmospheric cooling. The total exergy and energy calculations will be conducted to see the energy requirement for the process. It is planned to calculate the salt separation efficiency of sea water (on the basis of WHO guidelines) to fresh water, alongwith flow rate and processing time.


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