Título

Competitive kinetics versus stopped flow method for determining the degradation rate constants of steroids by ozonation.

Autor

ALBERTO LOPEZ LOPEZ

VALENTIN FLORES PAYAN

ELIZABETH LEON BECERRIL

LEONEL HERNANDEZ MENA

RAMIRO VALLEJO RODRIGUEZ

Nivel de Acceso

Acceso Abierto

Referencia de publicación

doi: 10.1186/s40064-016-2782-4

Resumen o descripción

"Steroids are classified as endocrine disrupting chemicals; they are persistent with low

biodegradability and are hardly degraded by conventional methods. Ozonation process

has been effective for steroids degradation and the determination of the kinetics

is a fundamental aspect for the design and operation of the reactor. This study assessed

two methods: competitive kinetics and stopped flow, for determining the degradation

kinetics of two steroids, estradiol (E2) and ethinylestradiol (EE2) in spiked water.

Experiments were performed at pH 6, 21 °C, and using tertbutyl alcohol as scavenger

of hydroxyl radicals; competitive kinetics method used sodium phenolate as reference

compound. For the stopped flow, the experiments were performed in a BioLogic SFM-

3000/S equipment. For both methods, the second order rate constants were in the

order of 106 and 105 M−1 s−1 for E2 and EE2 respectively. The competitive kinetics can

be applied with assurance and reliability but needing an additional analysis method

to measure the residual concentrations. Stopped flow method allows the evaluation

of the degradation kinetics in milliseconds and avoids the use of additional analytical

methodologies; this method allows determining the reaction times on line. The methods

are applicable for degradation of other emerging contaminants or other steroids

and could be applied in water treatment at industrial level. Finally, it is important to

consider the resources available to implement the most appropriate method, either

competitive kinetics or the stopped-flow method".

Editor

SpringerPlus

Fecha de publicación

18 de julio de 2016

Tipo de publicación

Artículo

Versión de la publicación

Versión publicada

Formato

application/pdf

Fuente

SpringerPlus 2016

Idioma

Inglés

Audiencia

Estudiantes

Investigadores

Repositorio Orígen

Repositorio Institucional de CIATEJ

Descargas

383

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