Banca de DEFESA: JÉSSICA PIRES DE PAIVA BARRETO

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
DISCENTE : JÉSSICA PIRES DE PAIVA BARRETO
DATA : 20/07/2016
HORA: 09:30
LOCAL: Sala de treinamento do NUP-ER
TÍTULO:

STUDY OF sp³/ sp² RATIO ANODES OF BORON DOPED DIAMOND (BDD) IN STRONGLY OXIDIZING AGENTS SPECIES PRODUCTION

PALAVRAS-CHAVES:

Boron Doped Diamond, Oxidants species; Persulfate; Lactuca Sativa.

PÁGINAS: 100
GRANDE ÁREA: Ciências Exatas e da Terra
ÁREA: Química
SUBÁREA: Físico-Química
ESPECIALIDADE: Eletroquímica
RESUMO:

The possibility of preparing synthetic diamond has increased the interest of the scientific community for application of these materials due to their unique characteristics. However, the synthetic diamond doping N, P, B and F become the semiconductor for application in electrochemistry. During the research it was established that the boron-doped diamond (BDD) is an anode that does not favor the chemical adsorption of the species on its surface. Recently, however, the influence of film characteristics (surface roughness, thickness, and impurities boron content sp²) was determined; and these parameters can affect the effectiveness of the anode in the production of strong oxidants and Degradation of organic compounds. For these reasons, study the influence of ratio sp³/sp² provides information about choosing a specific electrode DDB for electrochemical applications. This work has as main objectives to compare anodes DDB with different ratio sp³/sp² 2 to evaluate performance in the production of persulfate applying different current densities, as well as addressing the role that strongly oxidizing species in the degradation of a model compound, Acid Violet 7. Furthermore, the development of a toxicology study using Lactuca sativa through the decontamination efficiency of the synthetic effluent using electrochemically generated persulfate was evaluated. The results clearly show that DDB electrode containing higher graphite content and higher adsorption property on the surface favors the production of significant oxidizer of interest. The best electrolysis time for maximum yield / ideal species was 120 minutes; since subsequent to that time tends to become constant or declining the concentration of persulfate in parallel according to the reaction of oxygen evolution. The electrochemical treatment of the dye Acid Violet 7 using BDD electrodes (sp³ / sp² 175) and DDB (sp³ / sp² 329) showed that for both cases, the elimination of color and degradation of organic matter were affected but a higher degree of mineralization was observed with diamond electrode 329, indicating a better decontamination of effluent. After the electrochemical treatment, the toxicological analyzes showed that the effluent treated with DDB 175 allowed the germination of Lactuca sativa. However, the result is opposite to the degree of mineralization obtained with DDB 329. This behavior was due to the production of significant concentrations of oxidizers and aliphatic acids at the end of electrochemical treatment with DDB 329, preventing seed germination Lactuca sativa.

MEMBROS DA BANCA:
Interno - 1558610 - ANA PAULA DE MELO ALVES GUEDES
Presidente - 1645110 - CARLOS ALBERTO MARTINEZ HUITLE
Externo à Instituição - DANYELLE MEDEIROS DE ARAUJO - CAPES
Externo ao Programa - 1199268 - JAILSON VIEIRA DE MELO
Externo à Instituição - LEONARDO ANDRES CANO - UNLP