Wet air oxidation of trinitrophenol with activated carbon catalysts: Effect of textural properties on the mechanism of degradation

• Tipo: Artigo em Revista Científica Internacional
• Data: 2010

Autores

Sergio Morales Torres (Autor) FEUP; Adrian M T Silva (Autor) FEUP; Agustin F Perez Cadenas (Autor) Outra; Joaquim L Faria (Autor) FEUP; Francisco J Maldonado Hodar (Autor) Outra; Jose L Figueiredo (Autor) FEUP; Francisco Carrasco Marin (Autor) Outra

Revista

Título: Applied Catalysis B: Environmental

Vol. 100

Páginas: 310-317

ISSN: 0926-3373

Editora: Elsevier

Indexação

ISI Web of Knowledge - 20 Citações

Scopus - 27 Citações

Classificação Científica

FOS: Ciências da engenharia e tecnologias > Engenharia química

Outras Informações

ID Authenticus: P-003-1XE

DOI: 10.1016/j.apcatb.2010.08.007

Abstract (EN): Activated carbons (ACs), with different activation degrees, were obtained by chemical activation of olive stones and tested for the removal of 2,4,6-trinitrophenol (TNP) from aqueous solutions by catalytic wet air oxidation (CWAO). These materials were characterized using different techniques (e.g., N-2 and CO2 adsorption, temperature programmed desorption, immersion calorimetry and scanning electron microscopy). The non-catalytic oxidation of TNP in water, at 473 K and 0.7 MPa of oxygen partial pressure, is negligible, while the use of ACs as catalysts leads to complete removal of this organic compound. Competition between adsorption and catalytic oxidation reaction pathways, occurring simultaneously in the CWAO process, depends on the carbon porous texture. The extent of oxidation is given by the amount of nitrates formed during reaction. When a highly microporous carbon with large surface area (S-BET = 1530 m(2)/g) is used, all dissolved TNP is adsorbed and oxidation takes place in wide micropores. However, when using a carbon material with low surface area (S-BET = 121 m(2)/g) and low microporosity, TNP degradation will also occur on the external surface area, since there is enough TNP available in the bulk liquid media; in this case fast degradation takes place on the carbon macro-mesopores. Following that, the degradation mechanism is always heterogeneous but takes place in different ranges of porosity and depends on the amount of dissolved TNP. In addition, the surface chemistry of the carbon materials is modified during the CWAO process due to the presence of oxygen at the conditions employed.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 8