Reatores com atividade anammox para o pós-tratamento de digestato de resíduo alimentar: avaliação de diferentes estratégias de aeração e da comunidade microbiana

• Ano de defesa: 2018
• Autor(a) principal: Alyne Duarte Pereira
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Minas Gerais; UFMG
• Palavras-chave em Português: Nitrificação parcial; Remoção de nitrogênio; Comunidade microbiana; Anammox; Digestato de resíduo alimentar; Nitrificação; Engenharia sanitária; Águas residuais Tratamento; Saneamento
• Link de acesso: http://hdl.handle.net/1843/BUOS-B9EH8Q

The anaerobic ammonium oxidation (anammox) process is a promising technology for nitrogen removal from wastewaters and is generally associated with other processes, such as partial nitritation (PN). There is still a demand for evaluate the applicability of this process to treat diferente types of wastewaters. This study aims to evaluate the performance of sequencing batch reactors (SBR) with anammox activity in post-treatment of food waste digestate. The experiment was divided into two stages. Stage 1 was performed in a SBR laboratory-scale of 10 L of volume (Lab-SBR) and consisted of three experimental phases: Phase 1 - Enrichment of anammox bacteria; Phase 2 - Application of food waste digestate to Lab-SBR with nitrite supplementation and; Phase 3 - Evaluation of different aeration strategies for development of PN/ anammox process in the reactor. Stage 2 was performed at the Metanization Platform of food waste (pMethar) located at Block 10 from UFMG where a pilot scale SBR (Pilot-SBR) of 500 L of volume was implemented for food waste digestate post-treatment. This stage consisted of the enrichment and development anammox process at pilot scale from activated sludge obtained from wastewater treatment plant. In SBR-Lab, the addition of digestate and nitrite did not affect the nitrogen removal efficiency by anammox process, once the nitrogen load removed was equal to 77.5 g.m-3.d-1, and was not significantly different from that obtained during enrichment phase (81.9 g.m-3.d-1). Among the aeration strategies evaluated, the intermittent strategies with the highest anoxic periods (30 and 45 minutes) compared to the aerobic periods (15 minutes) and lower air flow rate (0.026 L.min-1.Lreactor-1) reached closer values of nitrate production/ ammonium consumption than those reported in the literature for PN/ anammox process (0.17 e 0.21). Median nitrogen removal loads equal to 18.4 and 24.3 g N.m-3.d-1 were obtained under these conditions. Alkalinity supplementation did not significantly alter the nitrogen removal. The microbial community structure was affected by different reactor operating conditions. The abundance of anammox bacteria was reduced from 31 % to 1 % after the first aeration strategies evaluated. After recovery period, the relative abundance of anammox bacteria increased to 15 % and there was replacement of the dominant genus, from Ca. Brocadia to Ca. Jettenia. Denitrifying bacteria were found together with aerobic heterotrophic bacteria in SBR-Lab. In Pilot-SBR low nitrogen load removed was achieved, with a median value equal to 12.2 g N.m-3.d-1 reflecting the difficulty in developing the pilot-scale anammox process from real effluent and without previously enriched sludge. In this reactor, the genus of anammox Ca. Anammoximicrobium was enriched and few taxa of denitrifying bacteria were observed with high abundance. The results demonstrated the potential of reactors with anammox activity for treatment of food waste digestate.