Comparative assessment of energy generation from ammonia oxidation by different functional bacterial communities

Autor(es)

Cano, Vitor ; Nolasco, Marcelo A. ; Kurt, Halil ; Long, Chenghua ; Cano, Julio ; Nunes, Sabrina C. ; Chandran, Kartik

• Tipo de documento: Artigo Científico
• Fonte: Science of The Total Environment; v. 869, p. 14-pg., 2023-01-31.

Resumo

Bioelectrochemical ammonia oxidation (BEAO) in a microbial fuel cell (MFC) isa recently discovered process that has the potential to reduce energy consumption in wastewater treatment. However, level of energy and limiting factors of this process in different microbial groups are not fully understood. This study comparatively investigated the BEAO in wastewater treatment by MFCs enriched with different functional groups of bacteria (confirmed by 16S rRNA gene se-quencing): electroactive bacteria (EAB), ammonia oxidizing bacteria (AOB), and anammox bacteria (AnAOB). Ammo-nia oxidation rates of 0.066, 0.083 and 0.082 g NH4+-N L-1 d-1 were achieved by biofilms enriched with EAB, AOB, and AnAOB, respectively. With infiuent 444 +/- 65 mg NH4+-N d-1, nitrite accumulation between 84 and 105 mg N d-1 was observed independently of the biofilm type. The AnAOB-enriched biofilm released electrons at higher poten-tial energy levels (anode potential of 0.253 V vs. SHE) but had high internal resistance (Rint) of 299 Omega, which limits its power density (0.2 W m-3). For AnAOB enriched biofilm, accumulation of nitrite was a limiting factor for power out-put by allowing conventional anammox activity without current generation. AOB enriched biofilm had Rint of 18 +/- 1 Omega and yielded power density of up to 1.4 W m-3. The activity of the AOB-enriched biofilm was not dependent on the accumulation of dissolved oxygen and achieved 1.5 fold higher coulombic efficiency when sulfate was not available. The EAB-enriched biofilm adapted to oxidize ammonia without organic carbon, with Rint of 19 +/- 1 Omega and achieved the highest power density of 11 W m-3. Based on lab-scale experiments (scaling-up factors not considered) energy savings of up to 7 % (AnAOB), 44 % (AOB) and 475 % (EAB) (positive energy balance), compared to conventional nitrification, are projected from the applications of BEAO in wastewater treatment plants. (AU)

• Processo FAPESP: 17/24524-0 - Desenvolvimento de protótipo de célula combustível microbiana para a produção de bioeletricidade no tratamento de resíduos
• Beneficiário: Marcelo Antunes Nolasco
• Modalidade de apoio: Auxílio à Pesquisa - Programa BIOEN - Regular
• Processo FAPESP: 19/06266-9 - Caracterização físico-química de águas residuárias
• Beneficiário: Sabrina Candido Nunes
• Modalidade de apoio: Bolsas no Brasil - Programa Capacitação - Treinamento Técnico
• Processo FAPESP: 17/10325-5 - Célula a combustível microbiana para o tratamento de efluentes com alta carga orgânica: análise de remoção de matéria orgânica e geração de energia
• Beneficiário: Julio Cano
• Modalidade de apoio: Bolsas no Brasil - Iniciação Científica