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- Artículo de Publicación PeriódicaAbatement 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."
- Artículo de Publicación PeriódicaGlyphosate 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."