Caracterización fisicoquímica de las aguas industriales generadas por la producción de almidón de yuca mediante el método de vía húmeda

The purpose of this study was to analyze the physical and chemical attributes of liquid waste produced during the extraction of cassava starch. The study focused on determining the levels of various contamination indicators, such as COD, BOD5, and SST. The wastewater from four rallanderias in the "La Balsa" area of the Calderón parish in the Portoviejo canton of Ecuador was sampled during the first half of 2022. The results from a mass balance calculation showed that only 3.06 m3 of residual water is discharged per day from processing 454 kg of starch. This volume of wastewater contains approximately 14 to 18 kg/day of pollutant load, and total cyanide concentrations ranged between 4 and 8 mg CN-/L.El objetivo principal de esta investigación fue identificar las características físicos-químicas de los efluentes líquidos que se generan durante la extracción de almidón de yuca a fin de conocer las concentraciones en las que se encuentran diversos parámetros indicadores de contaminación tales como DQO, DBO5, SST entre otros. Se realizaron muestreos a las aguas residuales de cuatro rallanderías del sitio “La Balsa” de la parroquia Calderón del cantón Portoviejo, Ecuador durante el primer semestre de 2022. Los resultados obtenidos de un balance de masa realizado permitieron conocer que solo en el procesamiento de 454 kg de almidón se descargan alrededor de 3.06 m3 de agua residual por día, determinando así que ese volumen de agua residual contiene aproximadamente de 14 a 18 kg/día de carga contaminante, se encontraron concentraciones de cianuro total que oscilaron entre 4 y 8 mg CN-/L

Caracterización fisicoquímica de las aguas industriales generadas por la producción de almidón de yuca mediante el método de vía húmeda

El objetivo principal de esta investigación fue identificar las características físicos-químicas de los efluentes líquidos que se generan durante la extracción de almidón de yuca a fin de conocer las concentraciones en las que se encuentran diversos parámetros indicadores de contaminación tales como DQO, DBO5, SST entre otros. Se realizaron muestreos a las aguas residuales de cuatro rallanderías del sitio “La Balsa” de la parroquia Calderón del cantón Portoviejo, Ecuador durante el primer semestre de 2022. Los resultados obtenidos de un balance de masa realizado permitieron conocer que solo en el procesamiento de 454 kg de almidón se descargan alrededor de 3.06 m3 de agua residual por día, determinando así que ese volumen de agua residual contiene aproximadamente de 14 a 18 kg/día de carga contaminante, se encontraron concentraciones de cianuro total que oscilaron entre 4 y 8 mg CN-/L

Risk of COVID-19 after natural infection or vaccinationResearch in context

Background: While vaccines have established utility against COVID-19, phase 3 efficacy studies have generally not comprehensively evaluated protection provided by previous infection or hybrid immunity (previous infection plus vaccination). Individual patient data from US government-supported harmonized vaccine trials provide an unprecedented sample population to address this issue. We characterized the protective efficacy of previous SARS-CoV-2 infection and hybrid immunity against COVID-19 early in the pandemic over three-to six-month follow-up and compared with vaccine-associated protection. Methods: In this post-hoc cross-protocol analysis of the Moderna, AstraZeneca, Janssen, and Novavax COVID-19 vaccine clinical trials, we allocated participants into four groups based on previous-infection status at enrolment and treatment: no previous infection/placebo; previous infection/placebo; no previous infection/vaccine; and previous infection/vaccine. The main outcome was RT-PCR-confirmed COVID-19 >7–15 days (per original protocols) after final study injection. We calculated crude and adjusted efficacy measures. Findings: Previous infection/placebo participants had a 92% decreased risk of future COVID-19 compared to no previous infection/placebo participants (overall hazard ratio [HR] ratio: 0.08; 95% CI: 0.05–0.13). Among single-dose Janssen participants, hybrid immunity conferred greater protection than vaccine alone (HR: 0.03; 95% CI: 0.01–0.10). Too few infections were observed to draw statistical inferences comparing hybrid immunity to vaccine alone for other trials. Vaccination, previous infection, and hybrid immunity all provided near-complete protection against severe disease. Interpretation: Previous infection, any hybrid immunity, and two-dose vaccination all provided substantial protection against symptomatic and severe COVID-19 through the early Delta period. Thus, as a surrogate for natural infection, vaccination remains the safest approach to protection. Funding: National Institutes of Health

Risk of COVID-19 after natural infection or vaccinationResearch in context

Summary: Background: While vaccines have established utility against COVID-19, phase 3 efficacy studies have generally not comprehensively evaluated protection provided by previous infection or hybrid immunity (previous infection plus vaccination). Individual patient data from US government-supported harmonized vaccine trials provide an unprecedented sample population to address this issue. We characterized the protective efficacy of previous SARS-CoV-2 infection and hybrid immunity against COVID-19 early in the pandemic over three-to six-month follow-up and compared with vaccine-associated protection. Methods: In this post-hoc cross-protocol analysis of the Moderna, AstraZeneca, Janssen, and Novavax COVID-19 vaccine clinical trials, we allocated participants into four groups based on previous-infection status at enrolment and treatment: no previous infection/placebo; previous infection/placebo; no previous infection/vaccine; and previous infection/vaccine. The main outcome was RT-PCR-confirmed COVID-19 >7–15 days (per original protocols) after final study injection. We calculated crude and adjusted efficacy measures. Findings: Previous infection/placebo participants had a 92% decreased risk of future COVID-19 compared to no previous infection/placebo participants (overall hazard ratio [HR] ratio: 0.08; 95% CI: 0.05–0.13). Among single-dose Janssen participants, hybrid immunity conferred greater protection than vaccine alone (HR: 0.03; 95% CI: 0.01–0.10). Too few infections were observed to draw statistical inferences comparing hybrid immunity to vaccine alone for other trials. Vaccination, previous infection, and hybrid immunity all provided near-complete protection against severe disease. Interpretation: Previous infection, any hybrid immunity, and two-dose vaccination all provided substantial protection against symptomatic and severe COVID-19 through the early Delta period. Thus, as a surrogate for natural infection, vaccination remains the safest approach to protection. Funding: National Institutes of Health