Effects of Reagent Concentrations on Advanced Oxidation of Amoxicillin by Photo-Fenton Treatment

The degradation and mineralization of amoxicillin in an aqueous solution was accomplished by using a photo-Fenton treatment. An ultraviolet light source with a 254-nm wavelength was used with hydrogen peroxide (H(2)O(2)) and iron(II). The effects of reagent concentrations on amoxicillin degradation and mineralization were investigated systematically by using the Box-Behnken statistical experiment design. Amoxicillin (10-200 mgL(-1)), H(2)O(2) (10-500 mgL(-1)), and iron(II) (0-50 mgL(-1)) concentrations were considered independent variables; the percent amoxicillin degradation and the total organic carbon (TOC) removal (mineralization) were the objective functions to be maximized. Both H(2)O(2) and iron(II) concentrations affected the extent of the amoxicillin degradation and mineralization. The amoxicillin degradation was completed within 2.5 min, and 53% mineralization took place within 60 min. The optimum H(2)O(2): Fe: amoxicillin ratio that resulted in complete amoxicillin degradation and 53% mineralization was 100: 40: 105 mgL(-1). DOI: 10.1061/(ASCE)EE.1943-7870.0000344. (C) 2011 American Society of Civil Engineers

Advanced oxidation of amoxicillin by Fenton's reagent treatment

Advanced oxidation of amoxicillin was realized in aqueous solution by using Fenton's reagent treatment. Box-Behnken statistical experiment design was used to determine the effects of reagent concentrations on amoxicillin degradation and mineralization. Amoxicillin (10-200 mg L-1), hydrogen peroxide (10-500 mg L-1) and Fe(II) (0-50 mg L-1) concentrations were considered as independent variables in batch oxidation experiments. Percent amoxicillin and total organic carbon (TOC) removals (mineralization) were considered as the objective functions to be maximized. Required reaction times were 2.5 min and 15 min, respectively for degradation and mineralization of amoxicillin. Both peroxide and amoxicillin concentrations affected the extent of amoxicillin degradation and mineralization. Complete amoxicillin degradation was obtained within 2.5 min while 37% mineralization took place within 15 min. The optimum peroxide/Fe/amoxicillin ratio resulting in complete amoxicillin degradation and 37% mineralization was 255/25/105 mg L-1. (C) 2010 Elsevier B.V. All rights reserved

A statistical experiment design approach for advanced oxidation of Direct Red azo-dye by photo-Fenton treatment

Advanced oxidation of an azo-dye, Direct Red 28 (DR 28) by photo-Fenton treatment was investigated in batch experiments using Box-Behnken statistical experiment design and the response surface analysis. Dyestuff (DR 28), H2O2 and Fe(II) concentrations were selected as independent variables in Box-Behnken design while color and total organic carbon (TOC) removal (mineralization) were considered as the response functions. Color removal increased with increasing H2O2 and Fe(II) concentrations up to a certain level. High concentrations of H2O2 and Fe(II) adversely affected the color and TOC removals due to hydroxyl radical scavenging effects of high oxidant and catalyst concentrations. Both H2O2 and Fe(II) concentration had profound effects on decolorization. Percent color removal was higher than TOC removal indicating formation of colorless organic intermediates. Complete color removal was achieved within 5 min while complete mineralization took nearly 15 min. The optimal reagent doses varied depending on the initial dyestuff dose. For the highest dyestuff concentration tested, the optimal H2O2/Fe(II)/dyestuff ratio resulting in the maximum color removal (100%) was predicted to be 715/71/250 (mg L-1), while this ratio was 1550/96.5/250 for maximum mineralization (97.5%). (C) 2008 Elsevier B.V. All rights reserved

Advanced Oxidation of Direct Red (DR 28) by Fenton Treatment

Advanced oxidation of Direct Red 28 (DR 28) in aqueous solution by Fenton's reagent using FeSO4 as source of Fe (II) was investigated. Effects of the dyestuff and the reagent concentrations (H2O2 and Fe (II)) on oxidation of the azo dye were investigated by using a Box-Behnken statistical experiment design and the surface response analysis. Degradation and mineralization (conversion to CO2 and H2O) of the azo dye by Fenton treatment was evaluated following total organic carbon (TOC) and color removal. Dyestuff removal increased with increasing H2O2 and Fe (II) concentrations up to a certain level. Fe (II) had a more profound effect on dyestuff removal as compared to H2O2. Complete color removal (100%) was achieved in 5 minutes. However, mineralization of the dyestuff took 15 minutes and required higher doses of H2O2. Percent color removal was always higher than TOC removal indicating formation of colorless organic intermediates. Optimal H2O2/Fe (II)/dyestuff ratio resulting in the maximum TOC (99.2%) and color (100%) removals was found to be 1450/78/235(mg L-1)

Use of l-Arginine with Growth Hormone-Releasing Hormone (GHRH) and the Endocrine Response

Arginine is one of the most common natural amino acids that takes part to the structure of the messenger ribonucleic acid (mRNA). In mammals l-arginine is a semiessential or an essential amino acid depending on age