Degradación de índigo carmín mediante procesos avanzados de oxidación empleando ozono catalizado con diferentes metales.

La industria textil es el mayor consumidor de agua dulce de alta calidad por kg de material manufacturado debido a ello, la naturaleza de sus procesos de producción contribuye significativamente a la contaminación de agua. Grandes cantidades de diferentes colorantes son empleados en las industrias textiles sin embargo, aproximadamente 15% de la producción mundial total de colorantes se pierde durante el proceso de teñido. Los contaminantes provenientes de la industria textil a menudo contienen productos químicos como el formaldehído, colorantes azoicos, dioxinas y metales pesados, que suponen un riesgo para los seres humanos y el medio ambiente. Los compuestos mencionados han sido encontrados en las aguas residuales después de haber lavado los textiles en casa, aun el lavado en seco contribuye a la incineración de estos contaminantes los cuales son arrojados y encontrados en la atmósfera después de la incineración. El lanzamiento de estos efluentes industriales tóxicos, recalcitrantes y con contenido de color en los efluentes son una fuente dramática de la contaminación estética y contribuyen de la misma forma a la perturbación de la vida acuática. Ya que los colorantes textiles están diseñados y se caracterizan por ser resistentes a la acción microbiana, química, térmica y la degradación fotolítica son difíciles de degradar o remover de los efluentes. Para evitar la acumulación peligrosa de tintes y colorantes en el medio acuático, diversos esfuerzos de investigación han sido objeto de estudio en el desarrollo de Procesos Avanzados de Oxidación (POA) eficientes para lograr su eliminación en aguas residuales industriales y minimizar el impacto que han generado. Es bien conocido que en condiciones experimentales los POA son efectivos debido a la formación de agentes oxidantes potentes tales como radicales hidroxilo (HO•) los cuales son capaces de oxidar materia orgánica contaminante. El objetivo de este trabajo fue evaluar el efecto de los sistemas metálicos de Fe y Cu soportados y no soportados en conjunto con el proceso de ozonación para la degradación de índigo carmín y su principal producto de degradación, ácido isatina-5-sulfónico hasta su mineralización parcial. 8 Mediante el método de reducción química se sintetizaron partículas metálicas a partir de Fe(II), Cu(II) y Fe/Cu. Los resultados para el sistema bimetálico Fe/Cu en conjunto con el proceso de ozonación fueron eficientes no sólo en términos de eliminación de índigo carmín, también fue promovida la degradación ácido isatina-5-sulfónico. En todos los casos, la generación de radicales oxidantes capaces de la degradación de índigo carmín es llevado a cabo a través de reacciones Fenton, Fenton-like y ozonación. El grado más alto de mineralización en términos de COT y reducción de DQO para la molécula de índigo carmín (94 y 95% respectivamente) se logró después de 10 minutos de ozonación a un valor de pH 3, con una dosis de ozono de 0.005 gL-1, 1000 mgL-1 para el sistema bimetálico Fe/Cu. En adición, partículas metálicas de hierro fueron evaluadas en un soporte de tipo orgánico usando residuos de Pimienta dioica L. Merrill, evaluando de igual manera, la remoción índigo carmín por ozonación. El material impregnado con partículas metálicas de hierro (MPS/Fe) también resulta eficiente en la degradación de índigo carmín y de los subproductos generados durante el proceso de ozonación. La ozonación catalizada mediante este material conduce a alcanzar una velocidad de reacción dos veces más rápido que empleando la ozonación sola. El uso de la MPS/Fe permite la eliminación de 76% de TOC después de sólo 20 min de ozonación. El uso de este material mejora las propiedades del mismo de tal manera que puede ser utilizado al menos tres veces sin con porcentajes de reuso similares en posteriores procesos bajo las mismas condiciones

Ozonation enhancement by Fe-Cu bimetallic particles

The aim of this work was to assess the effect of the bimetallic system Fe–Cu on the ozonation efficiency of indigo carmine and its main degradation product, isatin-5-sulfonic acid. As reference, experiments with single metal particles were also conducted. The metallic systems were synthesized by a chemical reduc- tion method and characterized by EPR and HR-SEM/EDS. Cu and Fe oxidation states were found to be 2 + . The ozonation process was carried out in an up-flow bubble column. The organic compounds concentra- tion was determined by UV–vis spectroscopy. The degree of oxidation and mineralization was determined by COD and TOC measurements, respectively. The effect of pH was also studied. It was found that the use of the bimetallic system not only considerably (by three times) improves the ozonation rate but also the mineralization degree of indigo carmine. The best results (97% indigo carmine removal and 92% of TOC removal) were obtained at pH 3 and with 10 0 0 mg/l of Fe/Cu particles.PRODEP 03.5/13/5257 y CONACY

Ozonation of Indigo Carmine Enhanced by Fe/ Pimenta dioica

Green synthesis of metallic particles has become an economic way to improve and protect the environment by decreasing the use of toxic chemicals and eliminating dyes. The synthesis of metal particles is gaining more importance due to its simplicity, rapid rate of synthesis of particles, and environmentally friendly. The present work aims to report a novel and environmentally friendly method for the synthesis of iron particles using deoiled Pimenta dioica L. Merrill husk as support. The indigo carmine removal efficiency by ozonation and catalyzed ozonation is also presented. Synthesized materials were characterized by N2 physisorption and scanning electron microscopy (SEM/EDS). By UV-Vis spectrophotometry the removal efficiency of indigo carmine was found to be nearly 100% after only 20 minutes of treatment under pH 3 and with a catalyst loading of 1000 mgL−1. Analytical techniques such as determination of the total organic carbon content (TOC) and chemical oxygen demand (COD) showed that iron particles supported on deoiled Pimenta dioica L. Merrill husk can be efficiently employed to degrade indigo carmine and achieved a partial mineralization (conversion to CO2 and H2O) of the molecule. From the results can be inferred that the prepared biocomposite increases the hydroxyl radicals generation

Pretreatment of Real Wastewater from the Chocolate Manufacturing Industry through an Integrated Process of Electrocoagulation and Sand Filtration

En este artículo se analizó el efecto de un proceso acoplado de electrocoagulación y filtración, para remover partículas suspendidas en un agua residual procedente de una industria de chocolates.The purpose of this study was to evaluate the efficiency of removal of suspended solids in terms of turbidity, color, and chemical oxygen demand (COD) when integrating the electrocoagulation process using aluminum sacrificial anodes and the sand filtration process as a pretreatment of wastewater from the chocolate manufacturing plant in Toluca, México. Wastewater from the chocolate manufacturing industry used in this study is classified as nontoxic, but is characterized as having a high content of color (5952 ± 76 Pt-Co), turbidity (1648 ± 49 FAU), and COD (3608 ± 250 mg/L). Therefore, enhanced performance could be achieved by combining pretreatment techniques to increase the efficiencies of the physical, chemical, and biological treatments. In the integrated process, there was a turbidity reduction of 96.1 ± 0.2% and an increase in dissolved oxygen from 3.8 ± 0.05 mg/L (inlet sand filtration) to 6.05 ± 0.03 mg/L (outlet sand filtration) after 120 min of treatment. These results indicate good water quality necessary for all forms of elemental life. Color and COD removals were 98.2 ± 0.2% and 39.02 ± 2.2%, respectively, during the electrocoagulation process (0.2915 mA/cm2 current density and 120 min of treatment). The proposed integrated process could be an attractive alternative of pretreatment of real wastewater to increase water quality of conventional treatments

The evolution of the ventilatory ratio is a prognostic factor in mechanically ventilated COVID-19 ARDS patients

Background: Mortality due to COVID-19 is high, especially in patients requiring mechanical ventilation. The purpose of the study is to investigate associations between mortality and variables measured during the first three days of mechanical ventilation in patients with COVID-19 intubated at ICU admission. Methods: Multicenter, observational, cohort study includes consecutive patients with COVID-19 admitted to 44 Spanish ICUs between February 25 and July 31, 2020, who required intubation at ICU admission and mechanical ventilation for more than three days. We collected demographic and clinical data prior to admission; information about clinical evolution at days 1 and 3 of mechanical ventilation; and outcomes. Results: Of the 2,095 patients with COVID-19 admitted to the ICU, 1,118 (53.3%) were intubated at day 1 and remained under mechanical ventilation at day three. From days 1 to 3, PaO2/FiO2 increased from 115.6 [80.0-171.2] to 180.0 [135.4-227.9] mmHg and the ventilatory ratio from 1.73 [1.33-2.25] to 1.96 [1.61-2.40]. In-hospital mortality was 38.7%. A higher increase between ICU admission and day 3 in the ventilatory ratio (OR 1.04 [CI 1.01-1.07], p = 0.030) and creatinine levels (OR 1.05 [CI 1.01-1.09], p = 0.005) and a lower increase in platelet counts (OR 0.96 [CI 0.93-1.00], p = 0.037) were independently associated with a higher risk of death. No association between mortality and the PaO2/FiO2 variation was observed (OR 0.99 [CI 0.95 to 1.02], p = 0.47). Conclusions: Higher ventilatory ratio and its increase at day 3 is associated with mortality in patients with COVID-19 receiving mechanical ventilation at ICU admission. No association was found in the PaO2/FiO2 variation

Clonal chromosomal mosaicism and loss of chromosome Y in elderly men increase vulnerability for SARS-CoV-2

The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, COVID-19) had an estimated overall case fatality ratio of 1.38% (pre-vaccination), being 53% higher in males and increasing exponentially with age. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, we found 133 cases (1.42%) with detectable clonal mosaicism for chromosome alterations (mCA) and 226 males (5.08%) with acquired loss of chromosome Y (LOY). Individuals with clonal mosaic events (mCA and/or LOY) showed a 54% increase in the risk of COVID-19 lethality. LOY is associated with transcriptomic biomarkers of immune dysfunction, pro-coagulation activity and cardiovascular risk. Interferon-induced genes involved in the initial immune response to SARS-CoV-2 are also down-regulated in LOY. Thus, mCA and LOY underlie at least part of the sex-biased severity and mortality of COVID-19 in aging patients. Given its potential therapeutic and prognostic relevance, evaluation of clonal mosaicism should be implemented as biomarker of COVID-19 severity in elderly people. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, individuals with clonal mosaic events (clonal mosaicism for chromosome alterations and/or loss of chromosome Y) showed an increased risk of COVID-19 lethality

Relationship, importance, and development of analytical techniques: COD, BOD, and, TOC in water—An overview through time

Article Highlights A development perspective of each of the techniques is shown over the years The relation between COD, BOD and TOC is presented In COD, it was observed that modifications are related to the change of reagents looking for faster oxidation Changes in BOD focus on reducing response time and measuring the response to biodegradation TOC exhibited modifications in obtaining a more sensitive and precise respons

Pb(II) Removal Process in a Packed Column System with Xanthation-Modified Deoiled Allspice Husk

The present research dealt with lead removal using modified Pimenta dioica L. Merrill as biosorbent in a batch and in continuous flow column systems, respectively. The allspice husk residues were modified first with a treatment through the xanthation reaction. For the adsorption tests, the atomic adsorption spectrophotometry method was used to determine the lead concentrations in the liquid samples. In the kinetic batch study (10 mg of sorbent in 10 mL of 25 mg L−1 lead solution), the removal efficiency was 99% (adsorption capacity of 25.8 mg g−1). The kinetic data followed the pseudo-second-order model. The adsorption isotherm was fitted to the Freundlich model, where constants were Kf and 1/n (8.06 mg(1-1/n) g−1 L1/n and 0.52), corresponding to adsorption capacities of 8 and 62 mg g−1, at liquid equilibrium concentration of 1 and 50 mg L−1, respectively. In the continuous flow systems where lead solution of 50 mg L−1 was treated in 2 columns of 5 cm (4.45 g) and 10 cm (9.07 g) bed heights, the dynamic adsorption capacity obtained by fitting the Thomas model was 29.114 mg g−1 and 45.322 mg g−1, respectively

Pretreatment of Real Wastewater from the Chocolate Manufacturing Industry through an Integrated Process of Electrocoagulation and Sand Filtration

The purpose of this study was to evaluate the efficiency of removal of suspended solids in terms of turbidity, color, and chemical oxygen demand (COD) when integrating the electrocoagulation process using aluminum sacrificial anodes and the sand filtration process as a pretreatment of wastewater from the chocolate manufacturing plant in Toluca, México. Wastewater from the chocolate manufacturing industry used in this study is classified as nontoxic, but is characterized as having a high content of color (5952 ± 76 Pt-Co), turbidity (1648 ± 49 FAU), and COD (3608 ± 250 mg/L). Therefore, enhanced performance could be achieved by combining pretreatment techniques to increase the efficiencies of the physical, chemical, and biological treatments. In the integrated process, there was a turbidity reduction of 96.1 ± 0.2% and an increase in dissolved oxygen from 3.8 ± 0.05 mg/L (inlet sand filtration) to 6.05 ± 0.03 mg/L (outlet sand filtration) after 120 min of treatment. These results indicate good water quality necessary for all forms of elemental life. Color and COD removals were 98.2 ± 0.2% and 39.02 ± 2.2%, respectively, during the electrocoagulation process (0.2915 mA/cm2 current density and 120 min of treatment). The proposed integrated process could be an attractive alternative of pretreatment of real wastewater to increase water quality of conventional treatments