Degradação do corante vermelho reativo 239 por ozonização e avaliação do efeito dos subprodutos no desempenho e comunidade microbiana de sistema MBBR

• Ano de defesa: 2019
• Autor(a) principal: Dias, Natália Costa
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal do Rio de Janeiro; Brasil; Instituto Alberto Luiz Coimbra de Pós-Graduação e Pesquisa de Engenharia; Programa de Pós-Graduação em Engenharia Química; UFRJ
• Palavras-chave em Português: Corante azo; Ozonização; MBBR; CNPQ::ENGENHARIAS::ENGENHARIA QUIMICA::PROCESSOS INDUSTRIAIS DE ENGENHARIA QUIMICA
• Link de acesso: http://hdl.handle.net/11422/20200

This study evaluated the association of the ozonation and biological processes for the degradation of reactive red 239 (RR 239) azo dye and its by-products. Ozonation tests were performed in batch with 50 mg/L the azo dye, 20 mg/L the ozone and at pH 7. The degradation of the RR 239 ozonation products was performed continuously in a single biofilm moving bed reactor (MBBR) and two MBBRs in series. Complete color removal was achieved after 12 min of ozonation. COD (62%) and DOC (35%) removals and increasing ozone consumption indicated incomplete mineralization of RR 239. Absence of dye toxicity using Vibrio fischeri was obtained after 4 min of ozonation. The RR 239 ozonation products identified were aniline, phenol, catechol and 4-amino6-chloro-1,3,5-triazine-ol. The degradation of ozonation by-products by a single MBBR led to the adaptation of heterotrophic bacteria to the ozonated effluent. Ammonium removal (40%) demonstrated the inhibition of nitrification by ozonation by-products. When degradation was performed by two MBBRs in series, the low ammonium removal (40%) revealed that the change from a single to two reactors did not improve nitrification. Tests with dye-free synthetic medium confirmed that the AOB were inhibited by the compound 4-amino-6-chloro-1,3,5-triazin-ol, not metabolized by the MBBR system. The association of ozonation and biological processes was efficient in removing RR 239, however, MBBR was fragile in the presence of triazine compounds, x which is toxic and inhibitory to nitrifiers, as confirmed by microbial community structure analysis through the 16S rRNA gene sequencing of biofilm samples.