Submitted by Setor de Tratamento da Informa??o - BC/PUCRS (tede2@pucrs.br) on 2016-05-17T12:27:44Z No. of bitstreams: 1 DIS_GIULIA_PIETA_PEREZ_COMPLETO.pdf: 2021457 bytes, checksum: 522d4e2075aed41c7efa9ad1ee873a31 (MD5) / Made available in DSpace on 2016-05-17T12:27:44Z (GMT). No. of bitstreams: 1 DIS_GIULIA_PIETA_PEREZ_COMPLETO.pdf: 2021457 bytes, checksum: 522d4e2075aed41c7efa9ad1ee873a31 (MD5) Previous issue date: 2016-03-28 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / Urea is an organic contaminant on ultrapure water production for semiconductors, remove it is hard due to its molecular characteristics of non-volatile, tough oxidation, non-ionic, high soluble and low molecular weight. This paper had been studied the dissolved urea oxidation by hypobromite, formed in situ from reaction between sodium bromide and sodium hypochlorite. The experimental tests evaluated the hypobromite formation through the time of hypobromite formation, the urea removal was quantified by TOC data (total organic carbon), on this case were performed different conditions of hypobomite concentrations, pH of solution containing urea, time of urea oxidation and bromate concentration. Either the pH, as the time of hypobromite formation do not affect the amount of urea reduced. Otherwise, the hypobromite concentration and bromide sodium concentration interfered its results. The hypobromite is capable to reduce main part of urea dissolved in water when in absence of others NOM (natural organic matter). The best results on this study were achieved with ultrapure water used as solvent, hypobromite concentration of 3 mgL-1. / A ureia ? um contaminante org?nico na produ??o de ?gua ultrapura para semicondutores, sua remo??o ? dif?cil devido as suas caracter?sticas de n?ovolatilidade, dif?cil oxida??o, car?ter n?o i?nico, altamente sol?vel em ?gua e baixa massa molar. Nesse trabalho foi estudada a remo??o da ureia dissolvida em ?gua atrav?s da oxida??o do ?on hipobromito, formado in situ pela rea??o de brometo de s?dio e hipoclorito de s?dio. Na parte experimental foi avaliada a forma??o do ?on hipobromito atrav?s da varia??o do tempo de forma??o do mesmo, e analisada a remo??o de ureia atrav?s dos valores de COT (carbono org?nico total), neste caso foram alterados os valores de concentra??o de hipobromito, concentra??o de brometo final, tempo de oxida??o com a ureia e pH da rea??o. Foram observadas que, tanto o pH como o tempo de forma??o de hipobromito n?o interferem na efici?ncia de remo??o da ureia, ao contr?rio da concentra??o de hipobromito e concentra??o de brometo utilizado. Verificou-se que hipobromito ? capaz de remover quase completamente a ureia presente em ?gua quando em aus?ncia de NOM (material org?nico de ocorr?ncia natural). Os melhores resultados obtidos foram com ?gua ultrapura e concentra??o de 3 mgL-1 de hipobromito.