Examinando por Materia "HERBICIDAS"
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Artículo de Publicación Periódica Abatement of 2,4-D by H2O2 solar photolysis and solar photo-Fenton-like process with minute Fe(III) concentrations(2018-11) Serra-Clusellas, Anna; De Angelis, Laura; Lin, Chung-Ho; Vo, Phuc; Bayati, Mohamed; Sumner, Lloyd; Lei, Zhentian; Amaral, Nathalia B.; Bertini, Liliana María; Mazza, José; Pizzio, Luis R.; Stripeikis, Jorge; Rengifo-Herrera, Julian A.; Fidalgo de Cortalezzi, María Marta"The Photo-Fenton-like (PF-like) process with minute Fe(III) concentrations and the Hydrogen Peroxide Photolysis (HPP), using Xe-lamp or solar light as sources of irradiation, were efficiently applied to eliminate the herbicide 2,4-D from water. PF-like experiments concerning ferric and H2O2 concentrations of 0.6 mg L 1 and 20 mg L 1 respectively, using Xenon lamps (Xe-lamps) as a source of irradiation and 2,4-D concentrations of 10 mg L 1 at pH 3.6, exhibited complete 2,4-D egradation and 77% dissolved organic carbon (DOC) removal after 30 min and 6 h of irradiation respectively whereas HPP (in absence of ferric ions) experiments showed a 2,4-D reduction and DOC removal of 90% and 7% respectively after 6 h of irradiation. At pH 7.0, HPP process achieved a 2,4-D abatement of approximately 75% and a DOC removal of 4% after 6 h. PF-like exhibited slightly improved 2,4-D and DOC removals (80% and 12% respectively) after the same irradiation time probably due to the low pH reduction (from 7.0 to 5.6). Several chlorinated-aromatic intermediates were identified by HPLC-MS. These by-products were efficiently removed by PF at pH 3.6, whereas at neutral PF-like and acid or neutral HPP, they were not efficiently degraded. With natural solar light irradiation, 10 and 1 mg L 1 of 2,4-D were abated using minor H2O2 concentrations (3, 6, 10 and 20 mg L 1 ) and iron at 0.6 mg L 1 in Milli-Q water. Similar results to Xe-lamp experiments were obtained, where solar UV-B þ A light H2O2 photolysis (HPSP) and solar photo-Fenton-like (SPF-like) played an important role and even at low H2O2 and ferric concentrations of 3 and 0.6 mg L 1 respectively, 2,4-D was efficiently removed at pH 3.6. Simulated surface water at pH 3.6 containing 1 mg L 1 2,4-D, 20 mg L 1 H2O2 and 0.6 mg L 1 Fe(III) under natural sunlight irradiation efficiently removed the herbicide and its main metabolite 2,4-DCP after 30 min of treatment while at neutral pH, 40% of herbicide degradation was achieved. In the case of very low iron concentrations (0.05 mg L 1) at acid pH, 150 min of solar treatment was required to remove 2,4-D."Tesis de maestría El control de malezas en el cultivo de Zea mays: encapsulamiento y adsorción de los herbicidas como una alternativa para disminuir el impacto ambiental negativo derivado de su aplicación. Avances en el desarrollo de formulaciones de liberación controlada de atrazina, paraquat y 2,4-D(2021-05) Vignolo, Patricia Julieta; Errea, María Inés"En este trabajo de tesis se realizó un relevamiento bibliográfico de los avances científicos recientes en el desarrollo de las formulaciones de liberación controlada de atrazina, paraquat y 2,4-D. Del análisis crítico de los resultados presentados por los diferentes autores surge un escenario alentador, dado que han demostrado tener la misma eficiencia de manejo de malezas con menor impacto ambiental. Lamentablemente, aun no hay muchas formulaciones de liberación controlada disponibles en el mercado, lo cual limita su utilización, pero a la vez es un incentivo para continuar investigando y trabajando en los procesos de regulación que permitan expandir la utilización de esta tecnología para el manejo de malezas."Artículo de Publicación Periódica Glyphosate and AMPA removal from water by solar induced processes using low Fe(III) or Fe(II) concentrations(2019-11) Serra-Clusellas, Anna; De Angelis, Laura; Beltramo, Mercedes; Bava, Melina Ailén; de Frankenberg, María Josefina; Vigliarolo, Julián; Di Giovanni, Nicolás; Stripeikis, Jorge; Rengifo-Herrera, Julián A.; Fidalgo de Cortalezzi, María Marta"A solar photo-Fenton-like (SPF-like) process is explored for the removal of 1 mg L−1 glyphosate and its main degradation by-product, aminomethylphosphonic acid (AMPA), from Milli-Q water by means of low Fe(III) concentrations (0.6–2 mg L−1) at pH = 2.8 and variable H2O2 concentrations at the laboratory scale. The research is focused on glyphosate and AMPA oxidation, which present similar toxicity patterns. A 1 mg L−1 glyphosate solution requires 5–6 h of the SPF-like process to be degraded when a minute Fe(III) concentration (0.6 mg L−1) is used in acidic water. Glyphosate abatement time is diminished to 2 h when the Fe(III) concentration is increased to 2 mg L−1. At pH levels above 2.8, the herbicide is partially adsorbed onto the colloids of iron oxyIJhydroxide) compounds. AMPA requires a higher oxidative power than glyphosate to be degraded, and more than 6 h of solar treatment are needed, using 10 mg L−1 h−1 H2O2 and 2 mg L−1 Fe(III) at acidic pH. Solar photo-Fenton (SPF), using 4 mg L−1 Fe(II) and 10 mg L−1 h−1 H2O2 at pH = 2.8, must be applied to achieve practically total AMPA removal in 6 h of irradiation. SPF-like and SPF treatments led to 70% and 80% mineralization, respectively, under the best operational conditions. This work demonstrates that SPF-like and SPF at low Fe(III) or Fe(II) concentrations are effective treatments for the removal of glyphosate from water at acidic pH. Continuous addition of H2O2 is required for AMPA abatement."Proyecto final de Grado Producción de herbicidas formulados a partir de 2,4-D éster: proyecto de inversión para la incorporación de una línea sintetizadora a una planta formuladora de agroquímicos(2019) Caramutti Godoy, Mathias Rubén; Mihura, Juan Bautista; Ranallo, Lucas Nahuel; Sánchez López, Anselmo; Sucari, Ramiro Andrés; Vásquez, Ramiro Gustavo; Frías Silva, Santiago"Sigma Agro es una empresa argentina de producción de productos fitosanitarios. Dentro de su catálogo de productos, se comercializan herbicidas en base 2,4-D éster. Estos se encuentran en una etapa de crecimiento en el mercado local y actualmente la compañía los produce a fasón en otras plantas de agroquímicos del país. En el presente trabajo se realiza un estudio de prefactibilidad para la síntesis de dichos herbicidas en la planta de Sigma Agro. Asimismo, se estudian las distintas aristas del proyecto, analizando la factibilidad técnica y financiera, desarrollando un estudio integral de Ingeniería Industrial."Artículo de Publicación Periódica Trielectrode plasma reactor for water treatment(2020-04) Giuliani, Leandro; De Angelis, Laura; Díaz Bukvic, Gema; Zanini, Matías; Minotti, Fernando; Errea, María Inés; Grondona, Diana"The water pollution due to emerging organic pollutants, such as agrochemicals, has become a topic of growing interest worldwide. The increase of pollutants in aquatic systems stimulated the development of new strategies for water remediation. Plasma technology is an advanced oxidation process which has proved to be an efficient method for organic matter degradation. In this work, a novel design of a trielectrode plasma reactor based on a a dielectric barrier discharge extended to a third electrode operated in ambient air is presented. The water to be treated flows through a gutter with low impedance and far from the electrodes connected to the voltage sources.The reactor operates in ambient air; it does not rely on the use of expensive inert gases. The design of the reactor is easily scalable. The performance of the reactor, in terms of the removal efficiency and the energy yield, was tested in an aqueous solution of the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D), one of the most widely used around the world. The reactor presents a good efficiency in the removal of the herbicide 2,4-D and values of energy yield of about 240 mg/kWh."