Caracterização microbiana e avaliação do efeito do fenol em um reator em batelada sequencial com atividade anammox

• Ano de defesa: 2013
• Autor(a) principal: Alyne Duarte Pereira
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Minas Gerais; UFMG
• Palavras-chave em Português: Meio Ambiente e Recursos Hídricos; Saneamento; Engenharia sanitária; Aguas residuais Purificação Oxidação
• Link de acesso: http://hdl.handle.net/1843/BUOS-9CPHYG

The anaerobic ammonia oxidation (anammox) process has been studied for biological nitrogen removal due to its economic attractive and environmental sustainability. The study of the effect of toxic compounds such as phenols, on the anammox activity is important, since this compound is present in many industrial wastewaters rich in ammonia. The aims of the study were to enrich anammox bacteria from activated sludge, to characterize microbial community and to evaluate the effect of increasing concentrations of phenol on the anammox process. A sequential batch reactor (SBR) of 2L was used for anammox enrichment, fed with autotrophic mineral medium at 35 º C and pH around 7.5. The initial concentrations of NH4+-N and NO2--N were 20 mg.L-1, reaching 177 and 160 mg.L-1, respectively. Phenol was added to the reactor from the 335th day till 370th day with influent concentrations ranging from 10 to 300 mg.L-1. Anammox activity was detected after 90 days of RBS operation and after this phase the average ammonium and nitrite removal efficiencies were near 75% and 90%, respectively. The maximum nitrogen removal rate was equal to 390 g N.m-3.d-1. Losses of ammonium and nitrite removal efficiencies of 57% and 15% in RBS were observed when phenol concentrations were nearly to 300 mg.L-1. Anammox bacteria was detected by PCR in all biomass samples collected. FISH analysis (with Amx820 probe) confirmed the presence of cells with the typical morphology of anammox bacteria. By the real time PCR, concentrations of 16S rRNA anammox equal to 4.7 x 1010 copies.g-1 sludge were obtained. The microbial community profiles revealed by PCR-DGGE showed a band that prevailed during all the experiment and had 99% of sequence identity to Candidatus Brocadia sp. 40. The pyrosequencing results from sample collected at 270 days showed that 12.16% of the sequences retrieved closely related to Candidatus Brocadia. Thus, the enrichment of anammox bacteria was successfully performed which was supported by the physical-chemical results and the microbiological characterization. The reactor was able to tolerate high concentrations of phenol (200 mg.L-1) without any anammox inhibition, suggesting that these process can be applied to the treatment of wastewaters containing phenol.