Two-stage versus single-stage anaerobic co-digestion on methane synthesis: Energy prospects and microbial community

Autor(es)

Devens, Kauanna Uyara ; Ribeiro, Alexandre Rodrigues ; Camargo, Franciele Pereira ; Sakamoto, Isabel Kimiko ; Varesche, Maria Bernadete Amancio ; Silva, Edson Luiz

• Tipo de documento: Artigo Científico
• Fonte: PROCESS SAFETY AND ENVIRONMENTAL PROTECTION; v. 196, p. 13-pg., 2025-02-14.

Resumo

Cassava processing wastewater (CW), a byproduct generated during cassava processing activities, and glycerol (Gly), a byproduct of biodiesel production processes, have a high concentration of organic matter and digestibility, which provides them with great potential for hydrogen (H2) and methane (CH4) generation. This study evaluated the co-digestion of cassava wastewater and glycerol in a single-stage versus two-stage process using a fluidized bed reactor (AFBR), i.e., a mesophilic acidogenic reactor (MAR) + a sequential mesophilic reactor (SMR) and a mesophilic methanogenic reactor (MMR), operated at mesophilic temperature (30 degrees C). Thus, the effect of increasing the organic matter concentration of 1-12.5 g [chemical oxygen demand] COD.L-1 (50 %:50 % on a COD basis) on CH4 production was verified. Co-digestion consistently yielded methane production in both single and two-stage processes. The two-stage process stood out as the single stage, providing a maximum CH4 Yield (MY) of 341.10 mL CH4. gCOD-cons1 and CH4 production rate (MPR) of 168.23 mL of CH4.L-1. h-1, respectively. Regarding the microbial community, the methanogens Methanobacterium and Methanobrevibacter prevailed. Moreover, the two-stage and single-stage presented energy potentials of 161.23 kJ.d-1 and 54.26 kJ.d-1, in that order. Upon comparative analysis of the performance between two-stage and single-stage methanogenic reactors, it becomes apparent that the co-digestion of CW and Gly in a two-stage configuration exhibited enhancements over the single-stage. (AU)

• Processo FAPESP: 22/10615-1 - Consolidação do conceito de biorrefinaria aplicado ao tratamento biológico de águas residuárias e de resíduos sólidos
• Beneficiário: Marcelo Zaiat
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 15/06246-7 - Aplicação do conceito de biorrefinaria a estações de tratamento biológico de águas residuárias: o controle da poluição ambiental aliado à recuperação de matéria e energia
• Beneficiário: Marcelo Zaiat
• Modalidade de apoio: Auxílio à Pesquisa - Temático