FRBA - Publicaciones en Congresos, Conferencias y Jornadas

Permanent URI for this collectionhttp://48.217.138.120/handle/20.500.12272/2340

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    Caracterización reológica de nanofluidos basados en hierro para remoción in situ de contaminantes inorgánicos
    (Luis Fernandez Luco (compilador), 2022) Crespi, Julieta; Binetti Basterrechea, Gian Franco; Quici, Natalia
    Las nanopartículas de hierro cerovalente son materiales eficaces para remoción de contaminantes presentes en agua. La estabilización de suspensiones acuosas de nanopartículas empleando polielectrolitos evita su aglomeración y precipitación y permite formar nanofluidos con buenas propiedades de transporte en lecho poroso. Estos nanofluidos son útiles para el tratamiento in situ de aguas subsuperficiales por inyección en suelo. El diseño de un sistema de inyección a escala real requiere conocer las características de transporte de los nanofluidos siendo para ello fundamental las medidas de viscosidad, así como también el empleo de herramientas de modelado matemático y curvas de ruptura de los nanofluidos en columnas rellenas de medio poroso. En este trabajo se estudiaron nanofluidos estables de nanopartículas de hierro cerovalente y carboximetilcelulosa, empleados con éxito a escala laboratorio y piloto en ensayos de transporte. Los nanofluidos se caracterizaron reológicamente empleando un reómetro híbrido y se realizaron ensayos de flujo y oscilatorios para determinar el comportamiento de la viscosidad y de los módulos elástico y viscoso. Se compararon dos suspensiones con distintas cantidades de nanopartículas y carboximetilcelulosa y, adicionalmente, se estudiaron soluciones de carboximetilcelulosa de igual concentración. Luego, se ajustaron los resultados de los ensayos de flujo empleando diversos modelos reológicos para describir el comportamiento de los nanofluidos y las soluciones de carboximetilcelulosa. Se observó que la viscosidad de los nanofluidos disminuye respecto de las soluciones de carboximetilcelulosa de igual concentración. Se obtuvieron en general buenos ajustes empleando los modelos de Ley de la Potencia, Herschel-Bulkley y Cross.
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    Iron nanoparticles based nanofluids for in situ environmental remediation
    (Oscar Pagola (Asociación Argentina de Ingenieros Químicos), 2024) Crespi, Julieta; Binetti Basterrechea, Gian Franco; Finoli, Agostina Sol; Montesinos, Victor Nahuel; Quici, Natalia
    In this work, stabilization of commercial nZVI (NANOFER STAR, hereafter NSTAR, provided by NANOIRON s.r.o.) with carboxymethyl cellulose (CMC) was studied. NFs prepared with CMC (CMC-NSTAR) were compared and with NFs prepared without CMC (b-NSTAR). Stabilization was evaluated by sedimentation rate analysis of the nanoparticles in CMC-NSTAR versus b-NSTAR. The mobility of both stabilized and non-stabilized NFs was studied in columns filled with porous media at laboratory and pilot scale. NFs were injected upwards in the column with a peristaltic pump, and the nZVI concentration was monitored with turbidity measurement at the outlet stream. Then, NFs reactivity for the removal of aqueous Cr(VI) was tested in batch and columns experiments. In the batch experiments, 15 mg L-1 Cr(VI) solutions and the NFs were mixed with an orbital shaker, with a Fe:Cr molar ratio = 10. In the column experiments, a porous media bed was loaded with 0.5 g of n-NSTAR and then a 100 mg L-1 Cr(VI) solution was injected upwards.
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    Iron nanoparticles based nanofluids for in situ environmental remediation
    (2023) Crespi, Julieta; Binetti Basterrechea, Gian Franco; Finoli, Agostina Sol; Montesinos, Victor Nahuel; Quici, Natalia
    The injection of nanoscale zerovalent iron particles (nZVI) suspensions in the ground is a technology employed for in situ water and soil remediation. Due to its nature, nZVI forming these nanofluids (NFs), tend to agglomerate, but this can be overcome by polyelectrolyte coatings, that also improve their mobility. In this work, stabilization of nZVI with carboxymethylcellulose (CMC) was studied. NFs prepared with CMC (CMC-NSTAR) were compared with non-stabilized NFs (b-NSTAR). First, the stabilization efficiency was evaluated by the analysis of the nanoparticles sedimentation rate. Then, the mobility of stabilized and non-stabilized NFs was studied in columns filled with porous media at laboratory and pilot scale. Finally, NFs reactivity for the removal of aqueous Cr(VI) was tested in batch and columns experiments. In the column experiments, a porous media bed was loaded with NSTAR and then a Cr(VI) solution was injected upwards. CMC-NSTAR showed good mobility at both scales being successfully eluted from the porous media. In the case of b-NSTAR, the accumulation of nanoparticles in the bottom of the column was observed and elution was not achieved. Using b-NSTAR as reactive barrier, a total removal of 15.5 mg Cr(VI)/g Fe was achieved. Better removal rates were found in batch experiments (22.8 mg Cr(VI)/g Fe). Reactivity experiments in batch with CMC-NSTAR showed 39.9 mg Cr(VI)/g Fe removal. In conclusion, the NF was proved to have good transport properties and Cr(VI) removal capacity.