Optimization of Binary Adsorption of Metronidazole and Sulfamethoxazole in Aqueous Solution Supported with DFT Calculations

The following supporting information can be downloaded at: https:// www.mdpi.com/article/10.3390/pr11041009/s1Sulfamethoxazole [SMX] and metronidazole [MNZ] are emergent pollutants commonly found in surface water and wastewater, which can cause public health and environmental issues even at trace levels. An efficient alternative for their removal is the application of adsorption technology. The present work evaluated single and binary adsorption processes using granular activated carbon (CAG F400) for SMX and MNZ in an aqueous solution. The binary adsorption process was studied using a Box-Behnken experimental design (RSD), and the results were statistically tested using an analysis of variance. Density functional theory (DFT) modeling was employed to characterize the interactions between the antibiotics and the CAG F400 surface. For the individual adsorption process, adsorption capacities (q(e)) of 1.61 mmol g(-1) for SMX and 1.10 mmol g(-1) for MNZ were obtained. The adsorption isotherm model that best fit experimental data was the Radke-Prausnitz isotherm model. The adsorption mechanism occurs through electrostatic and pi-pi dispersive interactions. For the binary adsorption process, the total binary adsorption capacity achieved was 1.13 mmol g(-1), evidencing competitive adsorption. The significant factors that determine the removal of SMX and MNZ from a binary solution were the solution pH and the initial concentration of antibiotics. From DFT studies, it was found that SMX adsorption on CAG F400 was favored with adsorption energy (E-ads) of -10.36 kcal mol(-1). Finally, the binary adsorption results corroborated that the adsorption process was favorable for both molecules.Consejo Nacional de Ciencia y Tecnologia (CONACyT

Production of molecular weight fractionated hemicelluloses hydrolyzates from spent coffee grounds combining hydrothermal extraction and a multistep ultrafiltration/diafiltration

Producción CientíficaSpent coffee grounds are a huge residual stream from instant coffee makers. The production of spent coffee oil and molecular weight fractionated hemicellulose hydrolysates via supercritical CO2 and a hydrothermal treatment followed by concentration, separation, and purification through cascade ultrafiltration/diafiltration (30-10-5 kDa) was studied. Hemicelluloses extraction yield reached 3.49 g/100 g of dry defatted spent coffee after 40 min at 160 °C. The ultrafiltration system allowed concentrating up to 5-fold certain groups of hemicellulose, being most of them retained in the first membrane. Hemicellulose concentration and molecular weight of the feed exerted a great influence on the mass transfer through the membrane due to the formation of aggregates. However, purification through diafiltration allowed both to decrease by-products retentions from 45.6% to 8.7%, increasing the molecular weight of each fraction. Six hemicellulose products were obtained with purities between 83.7 and 97.8 wt% and weight-average molecular weights between 1641 and 49,733 Da.Ministerio de Economía, Industria y Competitividad (Project CTQ2015-64892-R and FEDER)Ministerio de Educación, Cultura y Deportes (reference FPU15/06366

Inspirational perspectives and principles on the use of catalysts to create sustainability

Producción CientíficaMost of the products on which our welfare state is based are composed of chemicals. The growth of the world's population, its ageing and the continuous improvement of welfare state aspirations augur an increase in the needs for all these everyday products in our lives. A high percentage of these chemicals are synthesised using catalysis. In this perspective paper, we highlight the importance of catalysis, which is at the heart of chemical processes, and therefore one of the tools for creating products that drive sustainability. We have compiled twelve methodological best practices in catalyst design and conception that can serve as inspiration for the creation and improvement of catalysts. We include some application examples to illustrate this.Ministerio de Ciencia, Innovación y Universidades - Agencia Estatal de Investigación - Fondo Europeo de Desarrollo Regional (project PID2019-105975GB-I00

Biorefinery of discarded carrot juice to produce carotenoids and fermentation products

Producción CientíficaDiscarded carrots are a major food waste that is produced from cultivation to sale. This waste has high humidity, which generates not only economic but also environmental problems, requiring a specific biorefinery for its valorization. The pulp and the juice were separated and received a different treatment. The juice was subjected to a process of separation and purification using several diafiltration cycles (30 kDa) giving rise to a fraction rich in carotenoids (4996.4 μg/g) and a fraction rich in sugars (84.83 ± 3.26 g/L) and nutrients. The carotenoids have potential applications in the food and pharmaceutical industry; therefore, they were formulated through encapsulation with gum Arabic using spray drying and freeze drying. Encapsulation using spray drying was effective as it improved stability in water and reduced degradation by 51.9% compared to unencapsulated carotenoids. The sugar-rich fraction was valorized to obtain lactic acid and ethanol through three types of fermentation: with autochthonous microorganisms, with lactic acid bacteria, and with yeast, resulting in obtaining mostly lactic acid (17.64 ± 1.54 g/L) or ethanol (49.46 ± 0.28 g/L). The addition of 6% (w/v) of NaCl to the medium allowed the production of pure lactic acid with both autochthonous microorganisms and lactic bacteria. Sugar consumption was high (92.4–97.5%) except in cases with autochthonous microorganisms (23.3%) and lactic bacteria (43.8%) where a pH control seems to be necessary for total sugar consumption.Junta de Castilla y León - Fondo Europeo de Desarrollo Regional (project CLU-2019-04)Ministerio de Ciencia, Innovación y Universidades - Fondo Europeo de Desarrollo Regional (project PID2019-105975GB-I00)Ministerio de Educación, Cultura y Deporte (project FPU15/06366

Production of purified hemicellulose-pectin fractions of different molecular weight from discarded carrots by hydrothermal treatment followed by multistep ultrafiltration/diafiltration

Producción CientíficaHemicelluloses and pectins are good candidates as biopolymers for the formation of products such as packaging films. Purified freeze-dried fractions of hemicelluloses and pectins, of different molecular weights, were obtained by treating hydrothermal extracts (140, 160, and 180 °C) of discarded carrots with ultrafiltration membranes (30, 10, 5, and 1 kDa). After each ultrafiltration, several cycles of diafiltration with partial water reuse were applied, obtaining a better separation and purification. A cascade configuration (30-10-5-1 kDa) was used in the 140 and 160 °C extracts, and a mixed configuration (5-10-1 kDa) in the 180 °C extract. High molecular weight hemicelluloses increased in concentration by a factor of 5 in the cascade configuration and by a factor of 16.67 in the mixed configuration. A high removal of free sugars (98.9–99.5 wt%) and by-products (94.4–99.2 wt%) through 1 kDa permeate and diafiltration waters was obtained. The system allowed moving from feeds with molecular weight, polydispersity, and purity in the ranges 9.02–18.83 kDa, 16.2–31.6, and 30.12–33.51 wt% to fractions with values in the ranges 2.59–102.75 kDa, 1.2–4.0, and 73.1–100 wt%.Junta de Castilla y León - Fondo Europeo de Desarrollo Regional (project CLU-2019-04)Ministerio de Ciencia, Innovación y Universidades - Fondo Europeo de Desarrollo Regional (project PID2019-105975GB-I00)Ministerio de Educación, Cultura y Deporte (contract FPU15/06366

Optimal conditions for hemicelluloses extraction from Eucalyptus globulus wood: hydrothermal treatment in a semi-continuous reactor

Producción CientíficaOptimal conditions for hemicellulose extraction from wooden biomass in a semi-continuous system have been assessed in thiswork. This studywould constitute the first stage for a profitable and green industrial process. Eucalyptus globuluswas selected as rawmaterial due to its lowwater consumption, high growth and its efficiency in lignocellulose production.Moreover its cultivation is very popular in southern Europe. Samples of 5.0 g of wood were fractioned using a pressurized hot water semi-continuous system, to produce sugars (pentoses and hexoses) and a solid residue enriched in lignin. Five flow rates between 2.50 and 20.00 mL/min and four temperatures between 135.0 and 285.0 °C were tested in order to maximize the production of sugars, avoiding the formation of degradation products. Optimumconditions for the extraction of hemicellulose were identified at 185.0 °C and 5.00 mL/min, leading to a pentoses yield of 67.409wt%,with 0.702 wt% of degradation products. Almost all the pulp is extracted at 285.0 °C. SEM images show very well the changes in the wood structure at different temperatures. A kinetic model was developed, describing the extraction and hydrolysis of hemicellulose and cellulosewith absolute average deviations around 10% for sugar extracted mass.Junta de Castilla y León (programa de apoyo a proyectos de investigación – Ref. VA330U13

Simulation and flavor compound analysis of dealcoholized beer via one-step vacuum distillation

Producción CientíficaThe coupled operation of vacuum distillation process to produce alcohol free beer at laboratory scale and Aspen HYSYS simulation software was studied to define the chemical changes during the dealcoholization process in the aroma profiles of 2 different lager beers. At the lab-scale process, 2 different parameters were chosen to dealcoholize beer samples, 102 mbar at 50 °C and 200 mbar at 67 °C. Samples taken at different steps of the process were analyzed by HS-SPME–GC–MS focusing on the concentration of 7 flavor compounds, 5 alcohols and 2 esters. For simulation process, the EoS parameters of the Wilson-2 property package were adjusted to the experimental data and one more pressure was tested (60 mbar). Simulation methods represent a viable alternative to predict results of the volatile compound composition of a final dealcoholized beer.Junta de Castilla y León (programa de apoyo a proyectos de investigación – Ref. VA330U13

Autocatalytic kinetic model for thermogravimetric analysis and composition estimation of biomass and polymeric fractions

Producción CientíficaA comprehensive kinetic model of slow pyrolysis of biomass during a thermogravimetric analysis (TGA) has been developed, including the simulation of variable heating rates, composition estimation and structural analysis of biomass. Biomass was assumed as a matrix of three solid global components (hemicellulose, cellulose and lignin) in which water and oil can be also present. Kinetics were based on an auto-catalytic model because it can simulate the degradation in cellulosic materials, as the cleavage of the biopolymers produce oligomers that accelerate the further depolymerisation. The reaction pathway followed the Waterloo’s mechanism, which stablishes that all solid compounds decompose into volatiles and charcoal. This mechanism was completed by the vapourization of water and oil, and assuming that the formed charcoal can break into volatiles by a slow reaction. The set was solved by the 8th Runge–Kutta’s method and validated by the Simplex Nelder–Mead and Broyden–Fletcher–Goldfarb–Shanno’s methods. The development of this model has a high interest because it can help to understand how the conversion from biomass to biochemicals takes place.Junta de Castilla y León (programa de apoyo a proyectos de investigación – Ref. VA330U13

Two-phase modelling and simulation of the hydrothermal fractionation of holm oak in a packed bed reactor with hot pressurized water

Producción CientíficaHydrothermal fractionation has been thoroughly studied in order to develop a sustainable process to recover the sugars and/or the biopolymers contained in biomass. However, a physico-chemical model which considers the main involved physical phenomena, like porosity variations, has not been fully developed yet. Thus, the objective of this work was to approach a more realistic model than other yet published, incorporating also a novel reaction pathway for biomass fractionation. It establishes that cellulose and hemicellulose begin their fractionation in the solid, breaking in water-soluble oligomers and sugar. Besides, deacetylation reactions and insoluble oligomer formation from cellulose were considered. Kinetics followed the Arrhenius׳ law and and it has been demonstrated that an autocatalytic kinetic model can be successfully used to simulate the biomass breaking in soluble oligomers. The process was carried out in a tubular reactor charged with 5 g of holm oak and continuously fed with hot pressurized water. To assess the mass transfer between the solid and liquid, 4 volumetric flows (5 mL/min, 10 mL/min, 20 mL/min and 40 mL/min) and two particle diameters (3 mm and 6 mm) were used. In the same way, temperature was set between 175 °C and 207 °C. The latter was the main variable due to its effect in biomass solubility and kinetics. The model was solved by the Runge-Kutta׳s method with 8th order of convergence and its discretization was performed by a new modification of the orthogonal collocation method on finite elements. It was validated by fitting total organic carbon (TOC) with Absolute Average Deviation (A.A.D. between 16.3% and 55.8%), acetic acid concentration (A.A.D. between 44.4% and 84.4%) and pH profiles (A.A.D. between 5.6% and 9.7%). Besides, the mass transfer between the solid and the liquid was checked and the deviations of the simulation were lower than 8.5%.Junta de Castilla y León (programa de apoyo a proyectos de investigación – Ref. VA330U13

Otras voces de la Revolución mexicana: visiones desde Estados Unidos y Canadá

Introducción; VIVENCIAS DE FRONTERA; Cónsules; Félix Díaz y el exilio mexicano / Peter V. N. Henderson y Héctor L. Zarauz López; Segregación y utopía social en el sur de Texas: los motivos del Plan de San Diego; VISIONES DE LA REVOLUCIÓN; Jack London y su relación de amor-odio con la Revolución mexicana / Ana Rosa Suárez Argüello; Los canadienses y la Revolución mexicana; La prensa afroamericana y la Revolución mexicana / Ben Vinson iii; México, la política de la diferencia en tiempos de la revolución / Juan Manuel de la Sern