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1.
J Anim Sci ; 98(5)2020 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-32280983

RESUMEN

This research evaluated a feed additive (benzoic acid, eugenol, thymol, and piperine), associated or not with colistin, in weaned piglets feeding. The parameters evaluated were growth performance, apparent total tract digestibility (ATTD) of nutrients, diarrhea incidence, intestinal morphology, relative weights of digestive organs, microbial diversity, and the percentages of operational taxonomic units of microorganisms in the cecum content of pigs. One-hundred and eight crossbred piglets (5.3 ± 0.5 kg) were used in a three-phase feeding program (21 to 35, 36 to 50, 51 to 65 d of age) and fed a control diet with no inclusion of growth promoter feed additive, a diet with 40 ppm of colistin, a diet with 0.3% of alternative additive, and a diet with 0.3% of alternative additive and 40 ppm of colistin. The diets were based on corn, soybean meal, dairy products, and spray-dried blood plasma and formulated to provide 3.40, 3.38, and 3.20 Mcal of ME/kg and 14.5, 13.3, and 10.9 g/kg of digestible lysine, in phases 1, 2, and 3, respectively. The piglets were housed three per pen, with nine replicates per diet, in a complete randomized block design based on initial BW. The data were submitted to ANOVA and means were separated by Tukey test (5%), using SAS. Pigs fed diets with the alternative feed additive had greater (P < 0.05) ADG (114.3 vs. 91.8 g) and ADFI (190.1 vs. 163.3 g) in phase 1 than pigs fed diets without the product. The alternative additive improved (P < 0.05) ATTD of crude protein (CP) in phase 1 (71.0% vs. 68.6%), gross energy in phases 1 (77.4% vs. 75.2%) and 3 (79.0% vs. 77.1%), and dry matter in phase 3 (79.1% vs. 77.1%). The antibiotic inclusion in the diets increased (P < 0.05) ATTD of CP in phase 1 (71.5% vs. 68.2%). The alternative feed additive tended (P = 0.06) to increase (46%) normal feces frequency, decreased (P < 0.05) goblet cells count (104.3 vs. 118.1) in the jejunum, and decreased (P < 0.05) small intestine (4.60% vs. 4.93%) and colon (1.41% vs. 1.65%) relative weights, compared with pigs not fed with the alternative additive. There was a tendency (P = 0.09) for a lower concentration of Escherichia-Shigella (1.46% vs. 3.5%) and lower (P < 0.05) percentage of Campylobacter (0.52% vs. 10.21%) in the cecum content of piglets fed diets containing essential oils and benzoic acid compared with pigs fed diets without the alternative feed additive. The alternative feed additive was effective in improving growth performance, diets digestibility, and gut health in piglets soon after weaning.


Asunto(s)
Metabolismo Energético/efectos de los fármacos , Aditivos Alimentarios/farmacología , Microbioma Gastrointestinal/efectos de los fármacos , Aceites Volátiles/farmacología , Porcinos/fisiología , Alcaloides/farmacología , Alimentación Animal/análisis , Animales , Benzodioxoles/farmacología , Ácido Benzoico/farmacología , Dieta/veterinaria , Digestión/efectos de los fármacos , Eugenol/farmacología , Tracto Gastrointestinal/microbiología , Tracto Gastrointestinal/fisiología , Masculino , Nutrientes , Piperidinas/farmacología , Alcamidas Poliinsaturadas/farmacología , Glycine max , Porcinos/crecimiento & desarrollo , Porcinos/microbiología , Timol/farmacología , Destete , Zea mays
2.
J Strength Cond Res ; 32(12): 3456-3465, 2018 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-28240708

RESUMEN

Pereira, LA, Nakamura, FY, Moraes, JE, Kitamura, K, Ramos, SP, and Loturco, I. Movement patterns and muscle damage during simulated rugby sevens matches in national team players. J Strength Cond Res 32(12): 3465-3474, 2018-The aim of this study was to analyze the match performance (i.e., distance covered in different intensities), signs of muscle damage (assessed by means of creatine kinase [CK] activity and rate of force development [RFD]), and neuromuscular fatigue (using linear sprint and vertical jump performances) after 3 single-day simulated matches performed by rugby sevens players from the Brazilian National team. Ten male rugby sevens players (25.2 ± 3.6 years; 88.7 ± 7.1 kg; 182.2 ± 6.3 cm) participated in this study. On the day before the matches, the athletes performed a 40-m sprint, a vertical jump assessment, and a maximal isometric force test. In the morning of the match day, blood samples were collected to analyze the CK activity. Afterward, 3 simulated rugby sevens' matches were performed with 2-hour intermission periods. The match performance (encompassing total distance and distance covered in different velocity ranges and body loads [BLs]) was obtained from global positioning system units. The statistical analysis was performed using a mixed model approach and the effect sizes (ESs) of the differences. The statistical significance level was set at p ≤ 0.05. Players were capable of maintaining the match performance when comparing the first and last games. Large (ES > 0.8) and significant (p ≤ 0.05) reductions were demonstrated in the total distance and BL when comparing the second with the first halves. Decrements in the explosive force capacity (assessed by means of RFD) and the squat jump (SJ) were noticed (ES varying from 0.55 to 1.14; p ≤ 0.05). The CK activity increased after the matches (ES = 1.29; p ≤ 0.05). The rugby sevens players were able to maintain the physical performance across 3 successive matches simulating the first day of a tournament. The augmented CK activity and the decreases in the SJ and RFD suggest that increased levels of muscle damage were experienced on the day after the matches. Therefore, the technical staff are encouraged to implement recovery strategies and planned substitutions during multiday tournaments to reduce the impact of accumulated fatigue and muscle damage on subsequent match performance. In addition, specific training strategies aimed at better simulating the match demands need to be implemented in the players' training routines.


Asunto(s)
Rendimiento Atlético/fisiología , Fatiga , Fútbol Americano/fisiología , Movimiento , Músculo Esquelético/lesiones , Aceleración , Adulto , Atletas , Brasil , Sistemas de Información Geográfica , Humanos , Masculino , Carrera/fisiología , Adulto Joven
3.
J Strength Cond Res ; 31(9): 2579-2585, 2017 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-28658079

RESUMEN

Loturco, I, Pereira, LA, Kobal, R, Kitamura, K, Cal Abad, CC, Marques, G, Guerriero, A, Moraes, JE, and Nakamura, FY. Validity and usability of a new system for measuring and monitoring variations in vertical jump performance. J Strength Cond Res 31(9): 2579-2585, 2017-Vertical jump (VJ) height is one of the most sensitive measures to quantify training-related fatigue and athletic performance in elite athletes. Currently, however, there is no equipment designed to graphically deliver the daily performance changes in VJ compared with the smallest worthwhile change (SWC), which is considered essential in "progressive statistics" to judge meaningful performance fluctuations. The aims of the study were to analyze the criterion validity of a new contact mat (i.e., Elite Jump), alongside testing its usability to detect meaningful changes in VJ of elite team sport athletes. A total of 31 athletes participated in the criterion validity part of the study, whereas 17 rugby players participated in the VJ sensitivity part. When compared with the force plate, the contact mat produced squat jump (SJ) and countermovement jump (CMJ) values with very high intraclass correlation coefficients (0.998 and 0.997, respectively) and very low biases (-0.11 and -0.08 cm, respectively), as assessed by the Bland-Altman plot. In addition, during a training microcycle, rugby players presented identical meaningful changes in performance in both SJ and CMJ when comparing the Elite Jump and Hopkins' spreadsheet outputs. Therefore, the contact mat is valid and the proprietary software can properly execute the SWC calculations, providing coaches and researchers with accurate information concerning variations in the physical performance of elite athletes.


Asunto(s)
Atletas , Rendimiento Atlético/fisiología , Prueba de Esfuerzo/métodos , Prueba de Esfuerzo/normas , Adolescente , Adulto , Estudios Transversales , Fatiga/fisiopatología , Humanos , Reproducibilidad de los Resultados , Adulto Joven
4.
J Strength Cond Res ; 31(4): 1127-1131, 2017 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-28328719

RESUMEN

Loturco, I, Kobal, R, Moraes, JE, Kitamura, K, Cal Abad, CC, Pereira, LA, and Nakamura, FY. Predicting the maximum dynamic strength in bench press: the high precision of the bar velocity approach. J Strength Cond Res 31(4): 1127-1131, 2017-The aim of this study was to determine the force-velocity relationship and test the possibility of determining the 1 repetition maximum (1RM) in "free weight" and Smith machine bench presses. Thirty-six male top-level athletes from 3 different sports were submitted to a standardized 1RM bench press assessment (free weight or Smith machine, in randomized order), following standard procedures encompassing lifts performed at 40-100% of 1RM. The mean propulsive velocity (MPV) was measured in all attempts. A linear regression was performed to establish the relationships between bar velocities and 1RM percentages. The actual and predicted 1RM for each exercise were compared using a paired t-test. Although the Smith machine 1RM was higher (10% difference) than the free weight 1RM, in both cases the actual and predicted values did not differ. In addition, the linear relationship between MPV and percentage of 1RM (coefficient of determination ≥95%) allow determination of training intensity based on the bar velocity. The linear relationships between the MPVs and the relative percentages of 1RM throughout the entire range of loads enable coaches to use the MPV to accurately monitor their athletes on a daily basis and accurately determine their actual 1RM without the need to perform standard maximum dynamic strength assessments.


Asunto(s)
Fuerza Muscular/fisiología , Músculo Esquelético/fisiología , Levantamiento de Peso/fisiología , Adulto , Atletas , Humanos , Modelos Lineales , Masculino , Adulto Joven
5.
PLoS One ; 12(1): e0170627, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28114431

RESUMEN

The aim of this study was to evaluate the relation between the maximum mean propulsive power (MPP) obtained in the loaded jump squat (JS) and half squat (HS) exercises and functional performances in vertical jumps, 40 m linear speed (VEL) and change-of-direction (COD) tests, using the median split technique. Twenty-two male rugby sevens players from the Brazilian National Olympic Team (Rio-2016) performed vertical jumping tests (squat and countermovement jumps [SJ and CMJ]), JS and HS exercises, COD speed test and sprinting velocity in 40 m, in this order. Based on the results of the MPP in the JS and HS exercises the participants were divided, using the median split, into four groups as follows: higher JS, lower JS, higher HS, and lower HS. Between-group differences in the functional tasks were detected via magnitude-based inferences. The athletes with higher MPP in the JS were capable of jumping higher and sprinting faster (including the COD speed test) than their weaker counterparts. This pattern was not observed in the HS exercise. To conclude, JS was shown to be more connected to sprinting, COD speed and jumping abilities than HS in elite rugby sevens players and should be preferred for assessing and possibly training elite athletes needing to improve speed-power related abilities.


Asunto(s)
Fútbol Americano , Entrenamiento de Fuerza/métodos , Adulto , Humanos , Masculino , Adulto Joven
6.
J Strength Cond Res ; 31(2): 548-551, 2017 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-27243917

RESUMEN

Nakamura, FY, Pereira, LA, Esco, MR, Flatt, AA, Moraes, JE, Cal Abad, CC, and Loturco, I. Intraday and interday reliability of ultra-short-term heart rate variability in rugby union players. J Strength Cond Res 31(2): 548-551, 2017-The aim of this study was to examine the intraday and interday reliability of ultra-short-term vagal-related heart rate variability (HRV) in elite rugby union players. Forty players from the Brazilian National Rugby Team volunteered to participate in this study. The natural log of the root mean square of successive RR interval differences (lnRMSSD) assessments were performed on 4 different days. The HRV was assessed twice (intraday reliability) on the first day and once per day on the following 3 days (interday reliability). The RR interval recordings were obtained from 2-minute recordings using a portable heart rate monitor. The relative reliability of intraday and interday lnRMSSD measures was analyzed using the intraclass correlation coefficient (ICC). The typical error of measurement (absolute reliability) of intraday and interday lnRMSSD assessments was analyzed using the coefficient of variation (CV). Both intraday (ICC = 0.96; CV = 3.99%) and interday (ICC = 0.90; CV = 7.65%) measures were highly reliable. The ultra-short-term lnRMSSD is a consistent measure for evaluating elite rugby union players, in both intraday and interday settings. This study provides further validity to using this shortened method in practical field conditions with highly trained team sports athletes.


Asunto(s)
Atletas , Fútbol Americano/fisiología , Frecuencia Cardíaca/fisiología , Adulto , Brasil , Humanos , Masculino , Monitoreo Fisiológico , Reproducibilidad de los Resultados , Adulto Joven
7.
J Sports Med Phys Fitness ; 57(12): 1549-1556, 2017 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-27813392

RESUMEN

BACKGROUND: The aim of this study was to compare backs and forwards rugby union players recruited to a National team in the following physical and physiological indicators: anthropometrics, squat jump (SJ), countermovement jump (CMJ), 10- and 30-meter sprint, resting heart rate variability (HRV), Yo-Yo Test and heart rate (HR) at 2 minutes of test. METHODS: The measurements were performed on the first day of a training camp planned to finely select the players who would participate in the 2016 America's Rugby Championship. The magnitude-based inference was used in the comparisons. RESULTS: Backs demonstrated almost certainly greater distance in the Yo-Yo Test (backs: 2305.9±231.3 meters; forwards: 1802.4±361.2 meters), higher vertical jump height in both SJ and CMJ (SJ: 44.0±5.3 cm vs. 37.6±5.4 cm; CMJ: 46.1±5.0 cm vs. 40.0±5.5 cm, for backs and forwards respectively), and superior sprint velocity in 10- and 30-m (10-m: 6.02±0.23 m.s-1 vs. 5.51±0.34 m.s-1; 30-m: 7.46±0.25 m.s-1 vs. 6.89±0.37 m.s-1, for backs and forwards respectively) than the forwards. In contrast, forwards were almost certainly taller and heavier than backs, and displayed higher sprint momentum in 10- and 30-meters (10 meters: 513.0±51.6 kg.m.s-1 vs. 598.4±53.1 kg.m.s-1; 30 meters: 635.3±56.1 kg.m.s-1 vs. 749.0±70.5 kg.m.s-1, for backs and forwards respectively). The submaximal HR in the first 2-minutes of the Yo-Yo test was likely lower in the backs than in the forwards (77.6±5.1% of the maximal HR vs. 81.3±5.4% of the maximal HR for backs and forwards respectively), while HRV indices were not different between backs and forwards. CONCLUSIONS: Playing position appears to be determined by the players' physical and physiological characteristics in top-level rugby union, and the submaximal HR measured during Yo-Yo test can be a simple alternative to discriminate backs and forwards.


Asunto(s)
Ejercicio Físico/psicología , Fútbol Americano/fisiología , Adulto , Brasil , Estudios Transversales , Ejercicio Físico/fisiología , Prueba de Esfuerzo/métodos , Frecuencia Cardíaca/fisiología , Humanos , Masculino , Resistencia Física/fisiología , Adulto Joven
8.
An Acad Bras Cienc ; 88(2): 983-8, 2016 May 31.
Artículo en Inglés | MEDLINE | ID: mdl-27254452

RESUMEN

Quail egg production has experienced a steep rise in the last decade. Nutrition is the main factor affecting productive potential in the poultry industry, as appropriate nutritional management is necessary to ensure the maintenance of optimal physical conditions, growth and the production of high quality products. Meat and bone meal (MBM) has often been used in the poultry industry as an alternative and cost-effective source of protein in partial replacement of corn and soybean meal. However, there have been no studies to date that have investigated the effect of dietary MBM on the performance of quail or on the costs of production in the starter phase. This is particularly important considering that this phase is characterized by large investments by producers, without immediate economic return. In this study, we investigated whether partial replacement of soybean meal (SBM) by meat and bone meal (MBM) in the diet of Japanese quail during the starter phase is a viable alternative that would maintain or improve their productive and economic performance. Our results show that the inclusion of MBM in the diet of quail reduces feeding costs by up to 6% without impairing productive performance.


Asunto(s)
Alimentación Animal , Crianza de Animales Domésticos , Coturnix/crecimiento & desarrollo , Carne , Minerales , Fenómenos Fisiológicos Nutricionales de los Animales , Animales , Productos Biológicos , Bovinos
9.
J Strength Cond Res ; 30(9): 2433-9, 2016 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-26817744

RESUMEN

Kobal, R, Nakamura, FY, Moraes, JE, Coelho, M, Kitamura, K, Cal Abad, CC, Pereira, LA, and Loturco, I. Physical performance of Brazilian rugby players from different age categories and competitive levels. J Strength Cond Res 30(9): 2433-2439, 2016-The aim of this study was to compare the anthropometric characteristics and physical capacities (vertical jumping, speed, agility, and endurance abilities) among different age categories of Brazilian rugby players from the same high-level club and to compare their respective data with those obtained from the national team players. Eighty-eight men Brazilian rugby players from 4 different age categories were divided into 4 different groups (i.e., under-15 [U-15], under-17 [U-17], under-19 [U-19], and professional senior team [PRO]) and a group composed of players from the Brazilian national team (NAT). Anthropometric measures (i.e., height and body mass), squat jump (SJ) and countermovement jump (CMJ) tests , 2 agility tests (change of direction [COD] and proagility), 40-m sprinting, and the Yo-Yo endurance test (level 1) were compared among the groups using an analysis of covariance (multivariable multivariate analysis of covariance) with the body mass as a covariate. The NAT group demonstrated significantly greater performances in all variables compared with the U-15, U-17, U-19, and PRO groups (p ≤ 0.05). Moreover, the PRO group demonstrated better performances in vertical jumping assessments (i.e., SJs and CMJs) and agility tests (i.e., COD and proagility) than the younger categories (p ≤ 0.05). Finally, except for the U-15 group, no significant differences were found between the young age-categories in sprint and endurance capacities. These findings show that, throughout the maturation process, rugby players improve their muscle power and agility abilities without presenting significant increases in endurance and sprinting capacities. Importantly, this does not hold true for players from the NAT group, who presented superior performance in all assessed physical variables (in comparison with the younger age and PRO categories).


Asunto(s)
Rendimiento Atlético/fisiología , Fútbol Americano/fisiología , Resistencia Física/fisiología , Aptitud Física/fisiología , Adolescente , Adulto , Distribución por Edad , Antropometría , Rendimiento Atlético/estadística & datos numéricos , Brasil , Estudios Transversales , Prueba de Esfuerzo , Humanos , Masculino , Adulto Joven
10.
Environ Technol ; 35(1-4): 364-71, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24600876

RESUMEN

In this work, a saline aqueous solution of phenol, 2,4-dichlorophenoxyacetic acid (2,4-D) and 2,4-dichlorophenol (2,4-DCP) was treated by the photo-Fenton process in a falling-film solar reactor. The influence of the parameters such as initial pH (5-7), initial concentration of Fe2+ (1-2.5mM) and rate of H202 addition (1.87-3.74mmol min-1) was investigated. The efficiency of photodegradation was determined from the removal of dissolved organic carbon (DOC), described by the species degradation of phenol, 2,4-D and 2,4-DCP. Response surface methodology was employed to assess the effects of the variables investigated, i.e. [Fe2+], [H202] and pH, in the photo-Fenton process with solar irradiation. The results reveal that the variables' initial concentration of Fe2+ and H202 presents predominant effect on pollutants' degradation in terms of DOC removal, while pH showed no influence. Under the most adequate experimental conditions, about 85% DOC removal was obtained in 180 min by using a reaction system employed here, and total removal of phenol, 2,4- and 2,4-DCP mixture in about 30min.


Asunto(s)
Ácido 2,4-Diclorofenoxiacético/química , Peróxido de Hidrógeno/química , Hierro/química , Fenoles/química , Fotoquímica/instrumentación , Cloruro de Sodio/química , Energía Solar , Purificación del Agua/instrumentación , Ácido 2,4-Diclorofenoxiacético/aislamiento & purificación , Ácido 2,4-Diclorofenoxiacético/efectos de la radiación , Mezclas Complejas/química , Mezclas Complejas/aislamiento & purificación , Mezclas Complejas/efectos de la radiación , Suministros de Energía Eléctrica , Diseño de Equipo , Análisis de Falla de Equipo , Peróxido de Hidrógeno/efectos de la radiación , Hierro/efectos de la radiación , Fenoles/aislamiento & purificación , Fenoles/efectos de la radiación , Fotoquímica/métodos , Cloruro de Sodio/efectos de la radiación
11.
Water Sci Technol ; 69(4): 768-74, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24569275

RESUMEN

An artificial neural network (ANN) was implemented for modeling phenol mineralization in aqueous solution using the photo-Fenton process. The experiments were conducted in a photochemical multi-lamp reactor equipped with twelve fluorescent black light lamps (40 W each) irradiating UV light. A three-layer neural network was optimized in order to model the behavior of the process. The concentrations of ferrous ions and hydrogen peroxide, and the reaction time were introduced as inputs of the network and the efficiency of phenol mineralization was expressed in terms of dissolved organic carbon (DOC) as an output. Both concentrations of Fe(2+) and H2O2 were shown to be significant parameters on the phenol mineralization process. The ANN model provided the best result through the application of six neurons in the hidden layer, resulting in a high determination coefficient. The ANN model was shown to be efficient in the simulation of phenol mineralization through the photo-Fenton process using a multi-lamp reactor.


Asunto(s)
Reactores Biológicos , Luz , Modelos Teóricos , Redes Neurales de la Computación , Fenol/química
12.
J Hazard Mater ; 176(1-3): 402-13, 2010 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-20005036

RESUMEN

The objective of this paper is to develop and validate a mechanistic model for the degradation of phenol by the Fenton process. Experiments were performed in semi-batch operation, in which phenol, catechol and hydroquinone concentrations were measured. Using the methodology described in Pontes and Pinto [R.F.F. Pontes, J.M. Pinto, Analysis of integrated kinetic and flow models for anaerobic digesters, Chemical Engineering Journal 122 (1-2) (2006) 65-80], a stoichiometric model was first developed, with 53 reactions and 26 compounds, followed by the corresponding kinetic model. Sensitivity analysis was performed to determine the most influential kinetic parameters of the model that were estimated with the obtained experimental results. The adjusted model was used to analyze the impact of the initial concentration and flow rate of reactants on the efficiency of the Fenton process to degrade phenol. Moreover, the model was applied to evaluate the treatment cost of wastewater contaminated with phenol in order to meet environmental standards.


Asunto(s)
Peróxido de Hidrógeno/química , Hierro/química , Modelos Químicos , Fenol/química , Purificación del Agua/métodos , Catecoles/química , Hidroquinonas/química , Residuos Industriales , Cinética , Contaminantes Químicos del Agua/química
13.
Environ Sci Technol ; 41(24): 8459-63, 2007 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-18200879

RESUMEN

The inhibition of the photo-Fenton (Fe2+/Fe3+, H2O2, UV light) degradation of synthetic phenol wastewater solutions by chloride ions is shown to affect primarily the photochemical step of the process, having only a slight effect on the thermal or Fenton step. Kinetic studies of the reactions of oxoiron (IV) (FeO2+) with phenol indicate that, if FeO2+ is formed in the photo-Fenton degradation, its role is probably minor. Finally, it is shown that, for both a synthetic phenol wastewater and an aqueous extract of Brazilian gasoline, the inhibition of the photo-Fenton degradation of the organic material in the presence of chloride ion can be circumvented by maintaining the pH of the medium at or slightly above 3 throughout the process, even in the presence of significant amounts of added chloride ion (0.5 M).


Asunto(s)
Cloruros/química , Fotoquímica , Aniones , Catálisis , Concentración de Iones de Hidrógeno , Cinética
14.
Photochem Photobiol ; 82(1): 208-12, 2006.
Artículo en Inglés | MEDLINE | ID: mdl-16117568

RESUMEN

The photo-Fenton reaction (Fe2+/Fe3+, H2O2, UV light) is strongly inhibited by high concentrations of added chloride ion. In this work, the effect of added chloride ion on the photocatalytic step that converts Fe(III) back to Fe(II) is studied by nanosecond laser flash photolysis over a wide range of pH (1.0-3.3) and concentrations of Fe(III) (0.1-1.0 mM) and chloride ion (0.05-0.75 M). An explicit mechanistic model based on the preferential formation of the less-reactive Cl2*- radical anion via two routes (competitive photolysis of the iron(III)-chloride complex to chlorine atoms instead of the desired hydroxyl radical and pH-dependent scavenging of the hydroxyl radical by chloride ion) is proposed. This model, which fits the laser flash photolysis data for the production and decay of Cl2*- over the entire range of conditions investigated, suggests that inhibition of the photocatalytic step of the photo-Fenton process in the presence of chloride ion can be circumvented by maintaining the pH of the medium at or slightly above 3.0 throughout the reaction.

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