• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 1
  • Tagged with
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Estudo de materiais alternativos para a remo??o de compostos org?nicos de efluentes por oxida??o an?dica

Vale J?nior, Edilson do 28 November 2016 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-07-03T12:42:01Z No. of bitstreams: 1 EdilsonDoValeJunior_DISSERT.pdf: 1539679 bytes, checksum: 4a56d1012ec29d3c011274d08b737e16 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-07-06T14:12:27Z (GMT) No. of bitstreams: 1 EdilsonDoValeJunior_DISSERT.pdf: 1539679 bytes, checksum: 4a56d1012ec29d3c011274d08b737e16 (MD5) / Made available in DSpace on 2017-07-06T14:12:27Z (GMT). No. of bitstreams: 1 EdilsonDoValeJunior_DISSERT.pdf: 1539679 bytes, checksum: 4a56d1012ec29d3c011274d08b737e16 (MD5) Previous issue date: 2016-11-28 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / A oxida??o an?dica ? um tipo de processo eletroqu?mico oxidativo avan?ado, no qual possibilita a degrada??o e mineraliza??o de compostos org?nicos. Essa mineraliza??o ocorre preferencialmente de duas formas. A primeira acontece devido a transfer?ncia de carga diretamente na superf?cie do ?nodo e a segunda ocorre atrav?s de uma oxida??o indireta mediante a gera??o de esp?cies fortemente oxidantes, as quais podem ser fisicamente adsorvidas na forma de radicais hidroxila (?OH), ou quimicamente adsorvidas, na superf?cie do eletrodo. Uma maior taxa de tratamento ? obtida quando os radicais est?o fisicamente adsorvidos, as rea??es que possibilitam a degrada??o do substrato org?nico de interesse. Na literatura, dois materiais catal?ticos se destacam para a degrada??o e mineraliza??o de compostos org?nicos, s?o eles os eletrodos de diamante dopado com boro (DDB) e platina (Pt). Por?m ambos apresentam algumas limita??es que inviabilizam o so da tecnologia eletroqu?mica em escala industrial. Logo, v?rios pesquisadores t?m dedicado grandes esfor?os para identificar materiais eletr?dicos mais acess?veis como uma alternativa para reduzir o investimento inicial e os custos operacionais. Este ? o caso de ?nodos dimensionais est?veis e outros ?nodos met?licos. Neste contexto, ligas baseadas em estanho foram consideradas como uma alternativa interessante, utilizando-as como ?nodos, para o processo de oxida??o an?dica. Portanto, neste trabalho, um ?nodo formado por uma liga de Sn-Cu Sb (Babbitt) foi sintetizado a partir da tecnologia de aspers?o t?rmica a frio para avaliar a sua potencial aplica??o para tratamentos eletroqu?micos, como um novo material ?nodico m?dico e est?vel. As propriedades eletrocatal?ticas do ?nodo sintetizado foram testadas na redu??o da descolora??o e da demanda qu?mica de oxig?nio (DQO) do corante az?ico Azul ?cido 29. Al?m disso, a evolu??o de esp?cies inorg?nicas nitrogenadas e ?cidos carbox?licos gerados pela quebra da mol?cula pela oxida??o foi avaliada por meio de an?lise por HPLC. / Anodic oxidation is a type of advanced oxidative electrochemical process, in which it allows the degradation and mineralization of organic compounds. This mineralization occurs preferably in two ways. The first occurs due to the transfer of charge directly on the surface of the anode and the second occurs through indirect oxidation through the generation of strongly oxidizing species, which can be physically adsorbed in the form of hydroxyl (OH) radicals or chemically adsorbed, On the surface of the electrode. A higher rate of treatment is obtained when the radicals are physically adsorbed, the reactions that allow the degradation of the organic substrate of interest. In the literature, two catalytic materials stand out for the degradation and mineralization of organic compounds, such as boron doped diamond (DDB) and platinum (Pt) electrodes. But both have some limitations that prevent so the electrochemical technology on an industrial scale. Therefore, many researchers have devoted great efforts to identify more affordable electrodic materials as an alternative to reduce the initial investment and operating costs. This is the case of dimensional stable anodes and other metal anodes. In this context, tin-based alloys were considered as an interesting alternative, using them as anodes, for the anodic oxidation process. Therefore, in this work, an anode formed by a Sn-Cu Sb alloy (Babbitt) was synthesized from the cold gas spray technology to evaluate its potential application for electrochemical treatments, such as a new cheap and stable anode material. The electrocatalytic properties of the synthesized anode were tested to reduce the decolorization and chemical oxygen demand (COD) of azido blue Acid 29. Moreover, the evolution of nitrogenous inorganic species and carboxylic acids generated by the breakdown of the molecule by oxidation was evaluated by means of HPLC analysis.

Page generated in 0.1443 seconds