Showing papers by "F. Javier Benitez published in 2012"

Combined chemical oxidation and membrane filtration techniques applied to the removal of some selected pharmaceuticals from water systems.

Abstract: The elimination of five selected pharmaceuticals (amoxicillin, hydrochlorothiazide, metoprolol, naproxen and phenacetin) dissolved in different water systems (two natural water matrices and a secondary effluent) was carried out by sequential processes constituted by membrane filtration and chemical oxidation stages. Different configurations of those two stages were applied. In a first group, a pretreatment consisting in a membrane filtration (ultrafiltration or nanofiltration) was conducted; and the permeate and retentate effluents produced were afterwards treated by chemical oxidation, using ozone or chlorine. In a second group, the pretreatment consisted in a chemical oxidation stage (by using ozone, chlorine, O3/H2O2, UV or UV/H2O2) followed by a nanofiltration process. The main objective of this set of experiments was the comparison of the efficiencies reached by using different systems and configurations in order to optimize the elimination of those pollutants from the selected water matrices. Result...

Elimination of the Emerging Contaminants Amitriptyline Hydrochloride, Methyl Salicylate, and 2-Phenoxyethanol in Ultrapure Water and Secondary Effluents by Photolytic and Radicalary Pathways

Abstract: Chemical degradation of the pharmaceuticals and personal care products (PPCPs) amitriptyline hydrochloride, methyl salicylate, and 2-phenoxyethanol by means of several advanced oxidation processes, including 254 nm UV radiation and Fenton’s reagent, has been studied in different water matrixes, such as ultrapure (UP) and surface waters and two secondary effluents from wastewater treatment plants. The influence of the operating variables on the elimination of these compounds in UP water was established, and kinetic parameters for their degradation, such as quantum yields along a pH range of 3–11 and second-order rate constants for their oxidation by hydroxyl radicals, were determined. Specifically, for the reactions of oxidation of the three PPCPs with hydroxyl radicals, the use of a competition kinetic model in Fenton’s reagent experiments allowed evaluation of their rate constants, whose values were (10.3 ± 0.3) × 109 M–1·s–1 for amitriptyline hydrochloride, (7.1 ± 0.1) × 109 M–1·s–1 for methyl salicylat...