Direct and indirect electrochemical oxidation of organic pollutants/
Abstract: In recent years, the perspectives of application of electrochemistry for environmental pollution abatement have been thoroughly investigated. The feasibility of electro-chemical incineration of organic substrates in wastewater, in particular, has drawn much attention since pioneering paper...
Na minha lista:
| Principais autores: | , , |
|---|---|
| Formato: | Tese |
| Publicado em: |
|
| Assuntos: | |
| Endereço do item: | https://app.bczm.ufrn.br/home/#/item/222816 |
| Tags: |
Adicionar Tag
Sem tags, seja o primeiro a adicionar uma tag!
|
| Resumo: | Abstract: In recent years, the perspectives of application of electrochemistry for environmental pollution abatement have been thoroughly investigated. The feasibility of electro-chemical incineration of organic substrates in wastewater, in particular, has drawn much attention since pioneering papers by Dabrowski in the 70's, Kirk, Stucki, Kotz, Chettiar and Watkinson in the 80's, and Comninellis in early 90's to ours days.
In these works, the influence of the nature of the electrode material on the faradaic efficiency of the anodic mineralization of organics has been considered in detail, showing that optimal conditions for the process in question are met at high-oxygenoverpotential anodes. Basing on these evidences, Comninellis has proposed a general model, which satisfactorily accounts for the different results described in the literature.
More recent results, obtained at conductive diamond electrodes, characterized by very high oxygen overpotential, also fit in the model predictions quite well. Many model organic substrates, like glucose, aldonic and aldaric acids among others, show a complex reactivity toward the anodic mineralization. In fact, in these cases, besides the central role of adsorbed hydroxyl radicals, also the mode of adsorption of the organic species has to be taken into account.
Simpler molecules, like oxalic acid, also support the view that co-electrosorption of hydroxyl radicals and organic species decides of the rate of the anodic mineralization, volcano-plot-approaches of the type applied long since for ethylene electrochemical oxidation being possibly a good interpretative tool. These considerations afford further evidence to the importance of the nature of the electrode material in electrochemical incineration.
Taking into consideration the role of mediators, like Cl, of particular interest for its common presence in many different types of wastewater, interpretations may be attempted, bringing again the role of the electrode material in a prominent position. Chloride-mediated incineration can be properly accounted for by assumptions on co-adsorbed hydroxy- and chloro-radicals at the electrode surface and on the effect of this on the rate of oxygen evolution reaction. Converting the results of the indirect oxidation, as second alternative in the elimination of the organic pollutants from water.
The aim of this thesis work is emphasizing the role of the electrode material in direct and indirect electrochemical oxidation for wastewater treatment. |
|---|