Anaerobic Digestion of the Liquid Fraction of Fruit and Vegetable Waste: Two-Stage versus Single-Stage Process

Autor(es)

da Silva Jr, Francisco das Chagas Gomes ; Almeida, Priscilla de Souza ; de Menezes, Camila Aparecida ; Duarte, Maira Saldanha ; Silva, Thobias Pereira ; dos Santos, Andre Bezerra ; Zaiat, Marcelo ; Leitao, Renato Carrha

• Tipo de documento: Artigo Científico
• Fonte: ACS OMEGA; v. 10, n. 22, p. 11-pg., 2025-05-29.

Resumo

This study evaluated the anaerobic digestion of the liquid fraction of fruit and vegetable waste to optimize energy recovery through sequential hydrogen and methane production. Two configurations were tested: a single-stage (SS) system using an upflow anaerobic sludge blanket (UASB) reactor and a two-stage (TS) system combining an anaerobic structured bed reactor (AnStBR) with a UASB reactor. The objective was to identify the most efficient configuration under various organic loading rates (OLR). In the AnStBR, OLR ranged from 40 to 80 g COD/Lreactor,day, while in UASB reactors, the OLR range was from 1.5 to 22.0 g COD/Lreactor.day. The TS outperformed the SS in methane production, achieving 3.6 NL CH4/Lreactor.day at an OLR of 22.0 g of COD/Lreactor.day. It also demonstrated a higher energy potential, generating a total of 1554.9 KJ/day-35.7% more efficient than the SS. Additionally, the UASB-TS reactor maintained stability throughout the study, with minimal acid accumulation and an intermediate alkalinity/partial alkalinity ratio (IA:PA) consistently below 0.4, even at elevated OLR. In contrast, the UASB-SS reactor showed signs of acidification at higher OLR. These findings suggest that TS anaerobic digestion offers a more robust and efficient solution for treating high-strength organic waste, enhancing both energy recovery and process stability. (AU)

• 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