Highly efficient visible-LED-driven photocatalytic degradation of tetracycline and rhodamine B over Bi2WO6/BiVO4 heterostructures decorated with silver and graphene synthesized by a novel green method.

Visible-light-driven Bi2WO6/BiVO4 (BWO/BVO) heterostructures were obtained by joining BWO and BVO n-type semiconductors. A novel and green metathesis-assisted molten salt route was applied to synthesize BWO/BVO. This route is straightforward, high-yield, intermediate temperature, and was successful for obtaining BWO/BVO heterostructures with several ratios (1:1, 1:2, 2:1 w/w). Besides, the 1BWO/1BVO was decorated with Ag nanoparticles (Ag-NPs, 6 wt.%) and graphene (G, 3 wt.%), applying simple and environmentally responsible procedures. The heterostructures were characterized by XRD, Raman, UV-Vis DRS, TEM/HRTEM, PL, and Zeta potential techniques. Ag-NPs and G effectively boosted the photocatalytic activity of 1BWO/1BVO for degrading tetracycline (TC) and rhodamine B (RhB) pollutants. A lab-made 19-W blue LED photoreactor was designed, constructed, and operated to induce the photoactivity of BWO/BVO heterostructures. The low-rated power consumption of the photoreactor (0.01-0.04 kWh) vs. the percent degradation of TC or RhB (%XTC = 73, %XRhB = 100%) is one of the outstanding features of this study. Besides, scavenger tests determined that holes and superoxides are the main oxidative species that produced TC and RhB oxidation. Ag/1BWO/1BVO exhibited high stability in reuse photocatalytic cycles.

Data for the synthesis, characterization, and use of xerogels as adsorbents for the removal of fluoride and bromide in aqueous phase.

Groundwater with high fluoride concentrations has been recognized as one of the serious concerns worldwide. Besides, the fluoride released into the groundwater by slow dissolution of fluoride-containing rocks, various industries also contribute to fluoride pollution [1]. Excess intake of fluoride leads to various health problems such as dental and skeletal fluorosis, cancer, infertility, brain damage, thyroid diseases, etc. [2]. On the other hand, bromide is naturally present in surface and groundwater sources. However, during the chlorination process, bromide can be oxidized to HOBr, which can react with natural organic matter in water to form brominated organic disinfection byproducts, which are very harmful to human health [3]. Among various methods for water treatment, the adsorption process has been widely used and seems to be an efficient and attractive method for the removal of many contaminants in water, such as anions, in terms of cost, simplicity of design, and operation [4], [5]. In the past years, xerogels and carbon xerogels, a new type of adsorbents, which are synthesized by the sol-gel polycondensation of resorcinol and formaldehyde, have gained attention due to their moldable texture and chemical properties [6]. Moreover, melamine addition in resorcinol and formaldehyde xerogels adds basic groups on its surface, favouring Lewis acid-base interactions between xerogels and other components by adsorption [7]. In this data article, the synthesis of three resorcinol-formaldehyde (R/F) xerogels with an increasing amount of melamine (M) was carried out by colloidal polymerization (molar ratios of M/R = 0.5, M/R = 1.0, and M/R = 2.0). Additionally, samples of M/R = 0.5 xerogel were carbonized at 400, 450, and 550 °C under an inert atmosphere to increase their specific area. Organic and carbon xerogels obtained were characterized by FTIR, TGA, SEM, Physisorption of N2, and the pH at the point of zero charge (pHPZC). All organic xerogels were also tested as adsorbents on the removal of fluoride and bromide ions from aqueous phase. The Freundlich, Langmuir, and Radke-Prausnitz isotherm models were applied to interpret the experimental data from adsorption equilibrium. Additionally, the data of the mass of the xerogel needed to remove fluoride and bromide from groundwater and fulfill the maximum concentration levels are also included.

Contribución de las organizaciones sociales "ollas comunes" a la alimentación de la población chilena en tiempos de pandemia por COVID-19

RESUMEN Las "ollas comunes" (OC) son organizaciones sociales temporales que entregan alimentación gratuita en periodos de crisis. En Chile, resurgen el año 2020 a raíz de la pandemia del COVID-19, y si bien han aparecido en otros períodos de la historia, no ha sido cuantificada su contribución. El objetivo de este estudio fue determinar su contribución a la alimentación y nutrición de las/os chilenas/os, mediante la caracterización y análisis de su oferta alimentaria. Se realizó un estudio descriptivo mediante la aplicación de una encuesta online a voluntarias/os de todo el territorio nacional, la cual incluyó una caracterización del encuestado/a, de la OC que representa y de las preparaciones ofrecidas, en base a lo cual se obtuvo el aporte calórico y nutricional. Contestaron 117 OC (5,1% zona norte, 85,5% centro y 9,4% sur) cuya contribución principal fue con almuerzos (95,9%) con una mediana de 150 (p25: 100 - p75: 200) raciones diarias, compuestas por plato de fondo (95,9%), pan (80,5%) y ensalada (74,8%). Las preparaciones más prevalentes fueron legumbres (91,1%), arroz (78%) y fideos (77,2%). Estos almuerzos aportaron en promedio un 23% del requerimiento energético diario y aportan con el 35% del requerimiento de fibra, pero su aporte en vitamina B12, zinc y hierro fue bajo respecto del requerimiento y aporte esperado para el tiempo de comida. Hasta la fecha, estos datos son los primeros publicados sobre el tema, siendo útiles para determinar su aporte a la seguridad alimentaria del país en tiempos de crisis.

ABSTRACT "Communal Pots" (CP) are temporary social organizations that provide free food in times of crisis. In Chile, as a result of the COVID-19 pandemic, in 2020 the CP resurfaced and, although they have appeared in other periods of history, how they benefitted the population is unknown. The objective of this study is to determine the contribution of the CP to the diet and nutrition of Chileans, through the characterization and analysis of their food supply. For this, a descriptive study was carried out based on an online survey sent to volunteers from all over the country after signing the informed consent. The survey included characterization of the respondent and the CP they represented, the preparations offered by the CP, based on which the caloric and nutritional contribution was obtained. In total, 117 CP answered; 5.1% from the north, 85.5% from the center and 9.4% from the south of Chile. Their main contribution was providing lunches (95.9%) with a median of 150 (p25: 100 - p75: 200) daily rations, made up of a main entree (95.9%), bread (80.5%) and salad (74.8%). The most popular preparations were legumes (91.1%), rice (78%) and noodles (77.2%). These lunches provide an average of 23% of the daily energy requirement and 35% of the fiber requirement, but their contribution of vitamin B12 (2.5%), zinc (25%) and iron (28% req. woman) was low regarding the requirement and expected contribution for the meal time. To date, these data are the first published, to report on the real influence of this social movement in the country's food security in times of crisis.

Indicadores de transformación de alimentos consumidos en Chile para su uso en planificación de minutas / Food processing indicators consumed in Chile for use in menu planning

Muchos de los alimentos consumidos a diario sufren previamente algún grado de transformación, desde mínimas operaciones de limpieza hasta cambios mayores producto de la cocción. Estas operaciones culinarias pueden afectar el volumen y/o peso de los alimentos, lo que implica una diferencia entre lo adquirido y lo realmente servido al plato. Algunos alimentos pierden gramaje mientras otros lo aumentan, dependiendo del alimento y del tipo y condiciones de la operación culinaria aplicada. Lo anterior influye en la planificación de minutas afectando el presupuesto y las raciones servidas. Para considerar estas variaciones se deben aplicar los indicadores de transformación de alimentos (ITA) que cuantifican las pérdidas por operaciones preliminares y los cambios generados por la cocción. El objetivo de este estudio fue obtener los ITA para distintos alimentos consumidos en Chile bajo diferentes operaciones culinarias. Para ello los alimentos fueron pesados, en bruto y neto, luego de lo cual se calcularon sus ITA correspondientes. Los indicadores obtenidos representan una estandarización nacional, no publicada previamente, cuya principal utilidad es la planificación de minutas, aunque también contribuyen a afinar el cálculo de la composición química de alimentos y preparaciones y al análisis de encuestas de consumo, lo que representa un aporte al área de alimentos y alimentación colectiva en Chile(AU)

Many of the foods we eat suffer some grade of previous transformation, which can go from minimal cleaning operations to major transformations resulting from the application of heat. These actions produce a change in the volume and / or weight of the food, which implies a variation between the food that is acquired or bought and the food that is actually served and / or consumed. These variations could result in loss or gain in weight, depending on the type of food and the type and conditions of the culinary operation applied. On the other hand, these variations have implications in the planning of the menus since they can affect the budget and the quantities of the portion presented in the plate. In order to take these changes into account, the food transformation indices (ITA) must be applied, which consider losses due to preliminary operations and changes generated by cooking processes. The aim of this study was to obtain the different ITAs resulting from culinary operations carried out on food consumed in Chile. For this, the food was weighed, gross and net, calculating for each one the corresponding ITA. The indicators obtained represent a national standardization, not previously published, whose greatest usefulness is the planning of menus, although they are also useful in calculating the chemical composition of food and meals, and for intake survey analysis, being a contribution to the food area and the area of collective food in Chile(AU)

Simultaneous removal of metronidazole and Pb(II) from aqueous solution onto bifunctional activated carbons.

In this work, it was analyzed the behavior of three commercial activated carbons with different textural and chemical properties to adsorb individually metronidazole and lead ions from aqueous solution. Afterwards, the activated carbons were modified with citric acid to remove both compounds simultaneously. Both sets of activated carbons were characterized chemically and texturally. XPS analysis was performed to corroborate the adsorption mechanism of lead on the surface of the carbons. Finally, the intraparticle diffusion of both adsorbates was elucidated by the application of diffusional model in three dimensions. The results evidenced that adsorption mechanism for MNZ and Pb(II) is independent, the adsorption for MNZ is governed by π-π dispersive interactions, whereas Pb(II) adsorption is mainly controlled by electrostatic interactions. The binary adsorption equilibrium shows that the adsorption of MNZ is independent from the concentration of Pb(II), whereas the adsorption of Pb(II) is affected by the presence of MNZ at low concentrations (0.1 mmol L-1), but it remains almost constant at concentrations of MNZ between 0.1 and 1.5 mmol L-1. Finally, the mass transport of MNZ was faster than Pb(II) from the solution to the external surface of activated carbon and the mass flux of MNZ inside the particle was superior to the mass flux of Pb(II). Lastly, there might be an obstruction phenomenon with MNZ impeding Pb(II) to reach the active sites placed into the carbon's microporosity structure. Graphical abstract.

Mujeres indígenas protagonistas de la historia

Durante mucho tiempo, los pueblos indígenas y las mujeres indígenas se encontraban ausentes del escenario político, económico y social del país.

Mujeres indígenas protagonistas de la historia / Indigenous women leading of the history

El presente trabajo, constituye la primera fase de una sistematización mas extensa acerca de la experiencia de trabajo con las mujeres indígenas de la amazonía; que profundizará las particularidades de cada pueblo.(au)