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Electrochemical redox flow desalination is an emerging method to obtain freshwater; however, the costly requirement for continuously supplying and regenerating redox species limits their practical applications. Recycling of spent lithium-ion batteries is a growing challenge for their sustainable utilization. Existing battery recycling methods often involve massive secondary pollution. Here, we demonstrate a redox flow system to couple redox flow desalination with lithium recovery from spent lithium-ion batteries. The spontaneous reaction between a battery cathode material (LiFePO4) and ferricyanide enables the continuous regeneration of the redox species required for desalination. Several critical operating parameters are optimized, including current density, the concentrations of redox species, salt concentrations of brine, and the amounts of added LiFePO4. With the addition of 0.5920 g of spent LiFePO4 in five consecutive batches, the system can operate over 24 h, achieving 70.46 % lithium recovery in the form of LiCl aqueous solution at the concentration of 6.716 g·L-1. Simultaneously, the brine (25 mL, 10000 ppm NaCl) was desalinated to freshwater. Detailed cost analysis shows that this redox flow system could generate a revenue of ¥ 13.66 per kg of processed spent lithium-ion batteries with low energy consumption (0.77 MJ kg-1) and few greenhouse gas emissions indicating excellent economic and environmental benefits over existing lithium-ion battery recycling technologies, such as pyrometallurgical and hydrometallurgical methods. This work opens a new approach to holistically addressing water and energy challenges to achieve sustainable development.
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Suministros de Energía Eléctrica , Litio , Sales (Química) , Reciclaje/métodos , Agua , Iones , Oxidación-ReducciónRESUMEN
High energy consumption and low salt removal rate are key barriers to realizing practical electrochemical seawater desalination processes. Here, we demonstrate a novel solar-driven redox flow desalination device with double photoelectrodes to achieve efficient desalination without electrical energy consumption. The device consists of three parts: one photoanode unit, one photocathode unit, and one redox flow desalination unit sandwiched between the two photoelectrode units. The photoelectrode units include a TiO2 photoanode and a NiO photocathode sensitized with N719 dye, triiodide/iodide redox electrolyte, and graphite paper integrated electrodes decorated with 3,4-ethylene-dioxythiophene. Two salt feeds are located between two ferro/ferricyanide redox flow chambers. Under light illumination, high-quality freshwater is obtained from brackish water containing different concentrations of NaCl from 1000 to 12,000 ppm with a high NaCl removal rate. The device can work in multiple desalination cycles without significant performance declines. Furthermore, natural seawater with an ionic conductivity of 53.45 mS cm-1 is desalinated to freshwater. This new design opens opportunities to realize efficient and practical solar-driven desalination processes.
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Cloruro de Sodio , Purificación del Agua , Agua de Mar , Luz Solar , Oxidación-ReducciónRESUMEN
BACKGROUND: One-third of preschool children in Myanmar were stunted in 2015-2016, and three-quarters of children 6-23 mo had inadequate diet diversity. In response, a large-scale nutrition-sensitive social protection program was implemented over 2016-2019. In 2020, however, Myanmar's economy was hit hard by the COVID-19 pandemic and harder still by a military takeover in 2021. OBJECTIVE: The objective of this study was to examine whether former beneficiaries of this program experienced better food security, food consumption, and diet diversity outcomes in the wake of major economic shocks. METHODS: In a previous cluster-randomized controlled trial conducted over 2016-2019, pregnant women and their children aged <2 y were randomly assigned to either: 1) CASH; 2) CASH + social and behavioral change communication (SBCC); or 3) a control group. Subsamples of these former participants were then resurveyed 10 times from June 2020 to December 2021 during Myanmar's protracted economic crisis. Randomized treatment exposure was used in a regression analysis to test for postprogram impacts on Food Insecurity Experience Scale indicators, household food consumption, and maternal and child diet diversity. We also examined the impacts on household income as a secondary outcome and potential impact pathway. RESULTS: Both intervention arms reported lower food insecurity, more frequent consumption of nutritious foods, and more diverse maternal and child diets compared with households in the control group. However, the improved dietary outcomes were larger for mothers and children exposed to CASH+SBCC compared with CASH, as was their monthly household income. CONCLUSIONS: The findings suggest that a program combining cash transfers with nutrition-related education can yield sustained benefits 1-2 y after the program was completed. This strengthens the evidence to support the expansion and scale-up of nutrition-sensitive social welfare programs to redress chronic malnutrition and enhance nutritional resilience in the face of a severe economic crisis.
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COVID-19 , Recesión Económica , Preescolar , Humanos , Femenino , Embarazo , Mianmar , Pandemias , COVID-19/epidemiología , COVID-19/prevención & control , Dieta , Abastecimiento de Alimentos , Seguridad AlimentariaRESUMEN
SYNOPSIS: : The single function of salt removal limits the further development of the CDI system. A multi-function CDI device is proposed to achieve electrochemical desalination, organics degradation and dichromate ion removal.
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A middle-aged female presented with lower abdominal pain associated with nausea and vomiting and was admitted to the acute hospital. She was thoroughly investigated and treated presumably as having a urinary tract infection. However, she was admitted again shortly after discharge with persistent symptoms. A careful evaluation and review were done, and she was diagnosed with nutcracker syndrome based on the clinical assessment, computed tomography (CT), and ultrasound (US) findings.
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In this work, a solar-driven redox flow desalination system is reported, which combines a solar cell based on a Bi2O3 photoanode and a redox flow desalination cell through an integrated electrode. The Bi2O3 film was prepared through a simple one-step water bath deposition method and served as a photoanode after the coating of the N719 dye. The activated carbon (AC)-coated graphite paper served as both the integrated electrode and counter electrode. The I3-/I- redox electrolyte circulates in the solar cell channel between the photoanode and intergrated electrode, while the [Fe(CN)6]4-/[Fe(CN)6]3- electrolyte circulates in the redox flow desalination part between the integrated electrode and counter electrode. This dye-sensitized solar-driven desalination cell is capable of achieving a maximum salt removal rate of 62.89 µg/(cm2·min) without consuming any electrical power. The combination of the solar cell and redox flow desalination is highly efficient with double functions of desalination and energy release using light as a driving force. This current research work is significant for the development of efficient and stable photoanode materials in photoelectrochemical desalination.
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Herein, we propose a novel design of photo-assisted battery desalination, which provides the tri-function within a single device including the photo-assisted charge (electrical energy saving), energy storage, and desalination (salt removal). The photoelectrode (N719/TiO2) is directly integrated into the zinc-iodide (Zn-I) battery with the desalination stream in the middle portion of the device. This architecture can provide a reduced energy consumption up to 50%, an energy output of 42 W h mol-1NaCl, and a desalination rate of 13 µg/cm2 min-1. This work is significant for the inter-discipline study of the redox flow energy storage and energy-saving desalination.
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Myanmar first experienced the COVID-19 crisis as a relatively brief economic shock in early 2020, before the economy was later engulfed by a prolonged surge in COVID-19 cases from September 2020 onwards. To analyze poverty and food security in Myanmar during 2020 we surveyed over 2000 households per month from June-December in urban Yangon and the rural dry zone. By June, households had suffered dramatic increases in poverty, but even steeper increases accompanied the rise in COVID-19 cases from September onwards. Increases in poverty were much larger in urban areas, although poverty was always more prevalent in the rural sample. However, urban households were twice as likely to report food insecurity experiences, suggesting rural populations felt less food insecure throughout the crisis.
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The freshwater scarcity and increasing energy demand are two challenging global issues. Herein, we propose a new route for desalination, self-sustained visible-light-driven electrochemical redox desalination. We propose a novel device architecture involving internal integration of a quasi-solid-state dye-sensitized solar cell and continuous redox-flow desalination units with a bifunctional platinized-graphite-paper electrode. Both the solar cell and redox-flow desalination units are integrated using the bifunctional electrode with one side facing the solar cell operating as a positive electrode and the other side facing the redox-flow desalination unit operating as a negative electrode. The solar cell contains a gel-based tri-iodide/iodide redox couple sandwiched between an N719 dye-modified photoanode and cathode. In contrast, the redox-flow desalination consists of re-circulating ferro/ferricyanide redox couple sandwiched between the anode and cathode with two salt streams located between these electrodes. The performances of bifunctional electrodes in both redox couples were thoroughly investigated by electrochemical characterization. The brackish feed can be continuously desalted to the freshwater level by utilizing visible light illumination. As a device, this architecture combines energy conversion and water desalination. This concept bypasses the need for electrical energy consumption for desalination, which provides a novel structural design using photodesalination to facilitate the development of self-sustained solar desalination technologies.
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The effect of chemical modification of mesoporous TiO2 electrodes by 2-(4-butoxyphenyl)-N-hydroxyacetamide (BPHA) before dye adsorption is investigated in dye-sensitized solar cells (DSCs). Two organic dyes, LEG4 and Dyenamo blue, were used in combination with the cobalt (II/III) tris(bipyridine) redox couple. The photovoltaic performance of the DSCs is clearly enhanced by BPHA. Preadsorption of mesoporous TiO2 electrodes with BPHA lowered the amount of adsorbed dye but improved the short-circuit current densities and the power conversion efficiencies by 10-20%, while keeping the open-circuit potential essentially unaffected. Notably, BPHA improved the LEG4 performance, whereas it has been reported for this dye that chenodeoxycholic acid as a coadsorbent lowers solar cell efficiency. Faster dye regeneration was found to be one reason for improved performance, but improved electron injection efficiency may also contribute to the favorable effect of BPHA.