Agustina Schenone - Academia.edu (original) (raw)
Papers by Agustina Schenone
Environmental Science and Pollution Research, 2021
A Correction to this paper has been published: 10.1007/s11356-021-15050-7
Fil: Schenone, Agustina Violeta. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Cent... more Fil: Schenone, Agustina Violeta. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Santa Fe. Instituto de Desarrollo Tecnologico para la Industria Quimica. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnologico para la Industria Quimica; Argentina
Environmental Science and Pollution Research, 2021
The degradation of paracetamol (PCT) in an aqueous medium using the Fenton and photo-Fenton react... more The degradation of paracetamol (PCT) in an aqueous medium using the Fenton and photo-Fenton reactions was investigated. The aim of this research was the development of a kinetic model based on a reaction mechanism, which includes two main intermediates of PCT degradation and the local volumetric rate of photon absorption (LVRPA). Ferrioxalate was used as a catalyst and the working pH was adjusted to 5.5 (natural pH). Experimental work was planned through a D-optimal experimental design and performed in a flat plate reactor irradiated by a solar simulator. Hydrogen peroxide (HP) concentration, reaction temperature, and radiation level were the operating parameters. The photo-Fenton reaction allowed to reach a minimum relative PCT concentration of 2.01% compared to 5.04% achieved with Fenton reaction. Moreover, the photo-Fenton system required a 50% shorter reaction time and lower HP concentration than in dark conditions (90 min and 189 mg L -1 vs. 180 min and 334 mg L -1 , respectively). The experimental results were used to estimate the kinetic parameters of the proposed kinetic model employing a nonlinear, multi-parameter regression method. The values obtained from the normalized root-mean-square error (14.52, 1.96, 4.36, 13.16, and 8.72 % for PCT, benzoquinone, hydroquinone, HP, and oxalate, respectively) showed a good agreement between the predicted and experimental data.
Journal of Photochemistry and Photobiology A: Chemistry, 2020
This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Environmental Science and Pollution Research, 2019
A theoretical and experimental study of bisphenol A (BPA) degradation by the UV/H2O2 process in w... more A theoretical and experimental study of bisphenol A (BPA) degradation by the UV/H2O2 process in water is presented. The effects of the H2O2 concentration and the specific rate of photon emission (EP,0) on BPA degradation were investigated. A kinetic model derived from a reaction sequence was employed to predict BPA and hydrogen peroxide concentrations over time using an annular photochemical reactor in batch recirculation mode. The local volumetric rate of photon absorption (LVRPA) inside the photoreactor was computed using a Line Source with Parallel Plane emission model (LSPP). From the proposed kinetic model and the experimental data, the second order rate constants of the reactions between hydroxyl radicals and the main reacting species (H2O2 and BPA) were estimated applying a nonlinear regression method. A good agreement between the kinetic model and experimental data, for a wide range of operating conditions, was obtained. For BPA, H2O2, and TOC concentrations, the calculated root means square errors (RMSE) were 2.3 × 10− 2, 9.8 × 10− 1, and 9.0 × 10− 2 mmol L− 1, respectively. The simplified kinetic model presented in this work can be directly applied to scaling-up and reactor design, since the estimated kinetic constants are independent of the reactor size, shape, and configuration. Further experiments were made by employing low BPA initial concentration (100 μg L− 1) in water and real wastewater. A lower degradation rate of BPA was observed in the real wastewater, although the UV/H2O2 process has also been able to completely degrade the target pollutant in less than 1 h.
Environmental Science and Pollution Research, 2018
A kinetic model describing Fenton and photo-Fenton degradation of paracetamol (PCT) and consumpti... more A kinetic model describing Fenton and photo-Fenton degradation of paracetamol (PCT) and consumption of hydrogen peroxide (H2O2) was proposed. A set of Fenton and photo-Fenton experiments (18 runs in total) was performed by fixing the initial concentration of PCT to 40 mg L−1and varying the initial concentrations of H2O2and ferrous ion, Fe2+. The experimental set-up was a well-stirred annular photoreactor equipped with an actinic BL TL-DK 36 W/10 1SL lamp. Experimental results highlighted that PCT is no more detected by HPLC analysis within a minimum reaction time of 2.5 and a maximum reaction time of 15.0 min. Besides, a maximum conversion of total organic carbon (TOC) of 68.5% was observed after 75 min of reaction in case of using UV radiation and the highest concentrations of the Fenton reagents. The experimental data were used to fit the kinetic model. The radiation field inside the reactor was taken into account through the local volumetric rate of photon absorption, evaluated b...
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 2019
We report the development of a new analytical method for the quantification of N-(phosphonomethyl... more We report the development of a new analytical method for the quantification of N-(phosphonomethyl)glycine (glyphosate) and (aminomethyl)phosphonic acid (AMPA) by combining spectrofluorimetry and multivariate calibration. In this study, fluorescence spectroscopy was used to quantify glyphosate and AMPA, which were previously derivatized with the fluorogenic reagent: 4-chloro-7-nitrobenzofurazan (NBD-Cl). Fluorescence excitation-emission matrices (EEM) were recorded by exciting between 400 and 500 nm, and measuring the emission between 500 and 610 nm. The second-order data obtained were processed using the Multivariate Curve Resolution with Alternating Least Square (MCR-ALS) methodology. The developed method was used to predict different concentrations of glyphosate and AMPA in validation samples. In addition, the presence of the herbicide was evaluated in real samples: a commercial formulation and a water sample from a cultivated area. For this purpose, the standard addition method was used to study the matrix effect in each case. The ranges of working concentrations obtained for this new method are in agreement with the amounts found in surface water samples near a direct sowing soybean growing region in Argentina.
Journal of hazardous materials, Jan 5, 2018
The effects of four inorganic anions (Cl, SO-, HCO, NO) usually present in groundwater were inves... more The effects of four inorganic anions (Cl, SO-, HCO, NO) usually present in groundwater were investigated on the photo-Fenton degradation of 2,4-dichlorophenoxyacetic acid (2,4-D). A kinetic model derived from a reaction sequence is proposed using the ferrioxalate complex as iron source at pH close to natural conditions (pH = 5). It was demonstrated that oxalate not only maintained iron in solution for the natural groundwater system, but also increased the photochemical activation of the process. Results showed that the minimum conversion of 2,4-D for the simulated groundwater after 180 min was 63.80%. This value was only 14.1% lower than the conversion achieved without anions. However, with all anions together, the consumption of hydrogen peroxide (HP) per mole of herbicide showed an increase with respect to the test without anions. Only one kinetic parameter was estimated for each anion applying a nonlinear regression method. Subsequently, these optimized kinetic constants were use...
South Florida Journal of Environmental and Animal Science
La necesidad de producir más alimentos ha llevado al aumento del uso de pesticidas, entre ellos g... more La necesidad de producir más alimentos ha llevado al aumento del uso de pesticidas, entre ellos glifosato, el cual es ampliamente empleado en la producción de soja transgénica. Esto ha implicado que crezcan los casos de intoxicaciones y contaminación de recursos naturales. Por tal motivo los entes gubernamentales han formulado instrucciones de manipulación y de descarte de los envases comerciales. El objetivo del presente trabajo fue evaluar la capacidad de Candida tropicalis LMFIQ 703 para disminuir la concentración de glifosato en el tercer enjuague de bidones y así reducir el riesgo de impacto ambiental adverso que producen los residuos de pesticida en los envases vacíos almacenados por largos periodos de tiempo. Se sembraron suspensiones de levadura sin adaptación, en soluciones de Credit® Amonio (Ingrediente activo: sal amónica de la N-fosfonometil glicina) con concentración conocida (similar a la del tercer enjuague). Se incubó a 28°C durante 28 días y se realizó el recuento m...
Microchemical Journal, 2016
Journal of environmental management, 2016
A theoretical and experimental study of the photo-Fenton degradation of the herbicide 2,4-dichlor... more A theoretical and experimental study of the photo-Fenton degradation of the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) in water is presented. A kinetic model derived from a reaction sequence is proposed using the ferrioxalate complex as iron source for conditions of pH = 5. The kinetic model was employed to predict the concentrations of 2,4-D, 2,4-dichlorophenol (2,4-DCP), hydrogen peroxide (HP) and oxalate (Ox) in a flat plate laboratory reactor irradiated with a solar simulator. Two types of incident irradiation levels were tested by different combinations of attenuation filters. The effects of the oxalate/Fe(+3) molar ratio (Ox/Fe), the reaction temperature (T) and the 2,4-D/HP molar ratio (R) on the photo-Fenton process were also investigated. For low radiation level and operating conditions of R = 50 and T = 50 °C, a 2,4-D conversion of 95.6% was obtained after 180 min. Moreover, the 2,4-D conversion was almost 100% in only 120 min when the system was operated under the s...
Environmental science and pollution research international, Jan 14, 2016
The solar photo-Fenton degradation of the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) in aqu... more The solar photo-Fenton degradation of the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) in aqueous solution at a natural pH (pH = 5) using ferrioxalate as iron source was investigated. The kinetic model proposed and validated in a previous contribution was used to predict the reactants concentrations during the oxidation process in a non-concentrating pilot-plant solar reactor. The effects of hydrogen peroxide to 2,4-D initial concentration ratios (R), temperature, and radiation levels were studied. Furthermore, the spectral UV/visible and broadband solar radiation fluxes incident on the reactor window were evaluated by the Simple Model for the Atmospheric Radiative Transfer of Sunshine (SMARTS2) code. The complete destruction of 2,4-D and its main intermediate 2,4-dichlorophenol (2,4-DCP) was achieved in all the experimental runs in only 90 and 120 min of reaction, respectively. In agreement with these results, a reduction of toxicity in the system (expressed as % of inhibition ...
A methodology based on second-order data (excitation emission matrices) modeling with one of most... more A methodology based on second-order data (excitation emission matrices) modeling with one of most popular algorithms presenting the second-order advantage, parallel factor analysis (PARAFAC), combined with transference of calibration is proposed to predict the analyte concentration when significant inner filter effects occur, even in the presence of unexpected sample components. The quantitation of phenylephrine hydrochloride (PHE) in water samples (concentrations ranged between 250 and 750 ng mL�1) in the presence of ibuprofen, acetyl salicylic acid and paracetamol (which produce inner filter effect across the useful wavelength range) was achieved. The strategy allows reducing the experimental work and increasing the analytical sensitivity in the determination of the analyte of interest in the presence of unexpected compounds and matrix effect caused by inner filter, avoiding the preparation of a large number of solutions and maintaining acceptable figures of merit. Recoveries betw...
Analytical and bioanalytical chemistry, Jan 30, 2015
The use of the successive projections algorithm (SPA) for elimination of uninformative variables ... more The use of the successive projections algorithm (SPA) for elimination of uninformative variables in interval selection, and unfold partial least squares regression (U-PLS) modeling of excitation-emission matrices (EEM), when under the inner filter effect (IFE) is reported for first time. Post-calibration residual bilinearization (RBL) was employed against events of unknown components in the test samples. The inner filter effect can originate changes in both the shape and intensity of analyte spectra, leading to trilinearity losses in both modes, and thus invalidating most multiway calibration methods. The algorithm presented in this paper was named iSPA-U-PLS/RBL. Both simulated and experimental data sets were used to compare the prediction capability during: (1) simulated EEM; and (2) quantitation of phenylephrine (PHE) in the presence of paracetamol (PAR) (or acetaminophen) in water samples. Test sets containing unexpected components were built in both systems [a single interferen...
Journal of environmental management, Jan 25, 2015
This study reports the application of the photo-Fenton process for the degradation of the herbici... more This study reports the application of the photo-Fenton process for the degradation of the herbicide 2,4-dichlorophenoxyacetic (2,4-D). The objective of this research was the evaluation of the procedure at natural pH (pH = 5) using the ferrioxalate complex as iron source at two incident irradiation levels. For this purpose, different combinations of attenuation filters from a solar simulator were tested. Since the process depends on several parameters, the influence of the temperature (T) and peroxide to 2,4-D initial concentration ratio (R) were investigated and optimized by the application of a three-level factorial experimental design combined with the Response Surface Methodology (RSM). The significance of models and their coefficients were assessed with the analysis of variance (ANOVA). The found optimal conditions were: T = 50 °C and R = 46.3 and T = 41.53 °C and R = 41.46, achieving experimental conversions of 91.4 and 95.9% for the low and high radiation levels, respectively....
Environmental Science and Pollution Research, 2021
A Correction to this paper has been published: 10.1007/s11356-021-15050-7
Fil: Schenone, Agustina Violeta. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Cent... more Fil: Schenone, Agustina Violeta. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Santa Fe. Instituto de Desarrollo Tecnologico para la Industria Quimica. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnologico para la Industria Quimica; Argentina
Environmental Science and Pollution Research, 2021
The degradation of paracetamol (PCT) in an aqueous medium using the Fenton and photo-Fenton react... more The degradation of paracetamol (PCT) in an aqueous medium using the Fenton and photo-Fenton reactions was investigated. The aim of this research was the development of a kinetic model based on a reaction mechanism, which includes two main intermediates of PCT degradation and the local volumetric rate of photon absorption (LVRPA). Ferrioxalate was used as a catalyst and the working pH was adjusted to 5.5 (natural pH). Experimental work was planned through a D-optimal experimental design and performed in a flat plate reactor irradiated by a solar simulator. Hydrogen peroxide (HP) concentration, reaction temperature, and radiation level were the operating parameters. The photo-Fenton reaction allowed to reach a minimum relative PCT concentration of 2.01% compared to 5.04% achieved with Fenton reaction. Moreover, the photo-Fenton system required a 50% shorter reaction time and lower HP concentration than in dark conditions (90 min and 189 mg L -1 vs. 180 min and 334 mg L -1 , respectively). The experimental results were used to estimate the kinetic parameters of the proposed kinetic model employing a nonlinear, multi-parameter regression method. The values obtained from the normalized root-mean-square error (14.52, 1.96, 4.36, 13.16, and 8.72 % for PCT, benzoquinone, hydroquinone, HP, and oxalate, respectively) showed a good agreement between the predicted and experimental data.
Journal of Photochemistry and Photobiology A: Chemistry, 2020
This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Environmental Science and Pollution Research, 2019
A theoretical and experimental study of bisphenol A (BPA) degradation by the UV/H2O2 process in w... more A theoretical and experimental study of bisphenol A (BPA) degradation by the UV/H2O2 process in water is presented. The effects of the H2O2 concentration and the specific rate of photon emission (EP,0) on BPA degradation were investigated. A kinetic model derived from a reaction sequence was employed to predict BPA and hydrogen peroxide concentrations over time using an annular photochemical reactor in batch recirculation mode. The local volumetric rate of photon absorption (LVRPA) inside the photoreactor was computed using a Line Source with Parallel Plane emission model (LSPP). From the proposed kinetic model and the experimental data, the second order rate constants of the reactions between hydroxyl radicals and the main reacting species (H2O2 and BPA) were estimated applying a nonlinear regression method. A good agreement between the kinetic model and experimental data, for a wide range of operating conditions, was obtained. For BPA, H2O2, and TOC concentrations, the calculated root means square errors (RMSE) were 2.3 × 10− 2, 9.8 × 10− 1, and 9.0 × 10− 2 mmol L− 1, respectively. The simplified kinetic model presented in this work can be directly applied to scaling-up and reactor design, since the estimated kinetic constants are independent of the reactor size, shape, and configuration. Further experiments were made by employing low BPA initial concentration (100 μg L− 1) in water and real wastewater. A lower degradation rate of BPA was observed in the real wastewater, although the UV/H2O2 process has also been able to completely degrade the target pollutant in less than 1 h.
Environmental Science and Pollution Research, 2018
A kinetic model describing Fenton and photo-Fenton degradation of paracetamol (PCT) and consumpti... more A kinetic model describing Fenton and photo-Fenton degradation of paracetamol (PCT) and consumption of hydrogen peroxide (H2O2) was proposed. A set of Fenton and photo-Fenton experiments (18 runs in total) was performed by fixing the initial concentration of PCT to 40 mg L−1and varying the initial concentrations of H2O2and ferrous ion, Fe2+. The experimental set-up was a well-stirred annular photoreactor equipped with an actinic BL TL-DK 36 W/10 1SL lamp. Experimental results highlighted that PCT is no more detected by HPLC analysis within a minimum reaction time of 2.5 and a maximum reaction time of 15.0 min. Besides, a maximum conversion of total organic carbon (TOC) of 68.5% was observed after 75 min of reaction in case of using UV radiation and the highest concentrations of the Fenton reagents. The experimental data were used to fit the kinetic model. The radiation field inside the reactor was taken into account through the local volumetric rate of photon absorption, evaluated b...
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 2019
We report the development of a new analytical method for the quantification of N-(phosphonomethyl... more We report the development of a new analytical method for the quantification of N-(phosphonomethyl)glycine (glyphosate) and (aminomethyl)phosphonic acid (AMPA) by combining spectrofluorimetry and multivariate calibration. In this study, fluorescence spectroscopy was used to quantify glyphosate and AMPA, which were previously derivatized with the fluorogenic reagent: 4-chloro-7-nitrobenzofurazan (NBD-Cl). Fluorescence excitation-emission matrices (EEM) were recorded by exciting between 400 and 500 nm, and measuring the emission between 500 and 610 nm. The second-order data obtained were processed using the Multivariate Curve Resolution with Alternating Least Square (MCR-ALS) methodology. The developed method was used to predict different concentrations of glyphosate and AMPA in validation samples. In addition, the presence of the herbicide was evaluated in real samples: a commercial formulation and a water sample from a cultivated area. For this purpose, the standard addition method was used to study the matrix effect in each case. The ranges of working concentrations obtained for this new method are in agreement with the amounts found in surface water samples near a direct sowing soybean growing region in Argentina.
Journal of hazardous materials, Jan 5, 2018
The effects of four inorganic anions (Cl, SO-, HCO, NO) usually present in groundwater were inves... more The effects of four inorganic anions (Cl, SO-, HCO, NO) usually present in groundwater were investigated on the photo-Fenton degradation of 2,4-dichlorophenoxyacetic acid (2,4-D). A kinetic model derived from a reaction sequence is proposed using the ferrioxalate complex as iron source at pH close to natural conditions (pH = 5). It was demonstrated that oxalate not only maintained iron in solution for the natural groundwater system, but also increased the photochemical activation of the process. Results showed that the minimum conversion of 2,4-D for the simulated groundwater after 180 min was 63.80%. This value was only 14.1% lower than the conversion achieved without anions. However, with all anions together, the consumption of hydrogen peroxide (HP) per mole of herbicide showed an increase with respect to the test without anions. Only one kinetic parameter was estimated for each anion applying a nonlinear regression method. Subsequently, these optimized kinetic constants were use...
South Florida Journal of Environmental and Animal Science
La necesidad de producir más alimentos ha llevado al aumento del uso de pesticidas, entre ellos g... more La necesidad de producir más alimentos ha llevado al aumento del uso de pesticidas, entre ellos glifosato, el cual es ampliamente empleado en la producción de soja transgénica. Esto ha implicado que crezcan los casos de intoxicaciones y contaminación de recursos naturales. Por tal motivo los entes gubernamentales han formulado instrucciones de manipulación y de descarte de los envases comerciales. El objetivo del presente trabajo fue evaluar la capacidad de Candida tropicalis LMFIQ 703 para disminuir la concentración de glifosato en el tercer enjuague de bidones y así reducir el riesgo de impacto ambiental adverso que producen los residuos de pesticida en los envases vacíos almacenados por largos periodos de tiempo. Se sembraron suspensiones de levadura sin adaptación, en soluciones de Credit® Amonio (Ingrediente activo: sal amónica de la N-fosfonometil glicina) con concentración conocida (similar a la del tercer enjuague). Se incubó a 28°C durante 28 días y se realizó el recuento m...
Microchemical Journal, 2016
Journal of environmental management, 2016
A theoretical and experimental study of the photo-Fenton degradation of the herbicide 2,4-dichlor... more A theoretical and experimental study of the photo-Fenton degradation of the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) in water is presented. A kinetic model derived from a reaction sequence is proposed using the ferrioxalate complex as iron source for conditions of pH = 5. The kinetic model was employed to predict the concentrations of 2,4-D, 2,4-dichlorophenol (2,4-DCP), hydrogen peroxide (HP) and oxalate (Ox) in a flat plate laboratory reactor irradiated with a solar simulator. Two types of incident irradiation levels were tested by different combinations of attenuation filters. The effects of the oxalate/Fe(+3) molar ratio (Ox/Fe), the reaction temperature (T) and the 2,4-D/HP molar ratio (R) on the photo-Fenton process were also investigated. For low radiation level and operating conditions of R = 50 and T = 50 °C, a 2,4-D conversion of 95.6% was obtained after 180 min. Moreover, the 2,4-D conversion was almost 100% in only 120 min when the system was operated under the s...
Environmental science and pollution research international, Jan 14, 2016
The solar photo-Fenton degradation of the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) in aqu... more The solar photo-Fenton degradation of the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) in aqueous solution at a natural pH (pH = 5) using ferrioxalate as iron source was investigated. The kinetic model proposed and validated in a previous contribution was used to predict the reactants concentrations during the oxidation process in a non-concentrating pilot-plant solar reactor. The effects of hydrogen peroxide to 2,4-D initial concentration ratios (R), temperature, and radiation levels were studied. Furthermore, the spectral UV/visible and broadband solar radiation fluxes incident on the reactor window were evaluated by the Simple Model for the Atmospheric Radiative Transfer of Sunshine (SMARTS2) code. The complete destruction of 2,4-D and its main intermediate 2,4-dichlorophenol (2,4-DCP) was achieved in all the experimental runs in only 90 and 120 min of reaction, respectively. In agreement with these results, a reduction of toxicity in the system (expressed as % of inhibition ...
A methodology based on second-order data (excitation emission matrices) modeling with one of most... more A methodology based on second-order data (excitation emission matrices) modeling with one of most popular algorithms presenting the second-order advantage, parallel factor analysis (PARAFAC), combined with transference of calibration is proposed to predict the analyte concentration when significant inner filter effects occur, even in the presence of unexpected sample components. The quantitation of phenylephrine hydrochloride (PHE) in water samples (concentrations ranged between 250 and 750 ng mL�1) in the presence of ibuprofen, acetyl salicylic acid and paracetamol (which produce inner filter effect across the useful wavelength range) was achieved. The strategy allows reducing the experimental work and increasing the analytical sensitivity in the determination of the analyte of interest in the presence of unexpected compounds and matrix effect caused by inner filter, avoiding the preparation of a large number of solutions and maintaining acceptable figures of merit. Recoveries betw...
Analytical and bioanalytical chemistry, Jan 30, 2015
The use of the successive projections algorithm (SPA) for elimination of uninformative variables ... more The use of the successive projections algorithm (SPA) for elimination of uninformative variables in interval selection, and unfold partial least squares regression (U-PLS) modeling of excitation-emission matrices (EEM), when under the inner filter effect (IFE) is reported for first time. Post-calibration residual bilinearization (RBL) was employed against events of unknown components in the test samples. The inner filter effect can originate changes in both the shape and intensity of analyte spectra, leading to trilinearity losses in both modes, and thus invalidating most multiway calibration methods. The algorithm presented in this paper was named iSPA-U-PLS/RBL. Both simulated and experimental data sets were used to compare the prediction capability during: (1) simulated EEM; and (2) quantitation of phenylephrine (PHE) in the presence of paracetamol (PAR) (or acetaminophen) in water samples. Test sets containing unexpected components were built in both systems [a single interferen...
Journal of environmental management, Jan 25, 2015
This study reports the application of the photo-Fenton process for the degradation of the herbici... more This study reports the application of the photo-Fenton process for the degradation of the herbicide 2,4-dichlorophenoxyacetic (2,4-D). The objective of this research was the evaluation of the procedure at natural pH (pH = 5) using the ferrioxalate complex as iron source at two incident irradiation levels. For this purpose, different combinations of attenuation filters from a solar simulator were tested. Since the process depends on several parameters, the influence of the temperature (T) and peroxide to 2,4-D initial concentration ratio (R) were investigated and optimized by the application of a three-level factorial experimental design combined with the Response Surface Methodology (RSM). The significance of models and their coefficients were assessed with the analysis of variance (ANOVA). The found optimal conditions were: T = 50 °C and R = 46.3 and T = 41.53 °C and R = 41.46, achieving experimental conversions of 91.4 and 95.9% for the low and high radiation levels, respectively....