TY - JOUR AU - Marin, Danieli Fernanda Canaver AU - Mendoza, Lívia Mendes AU - Carvalho Júnior, Romário Pereira de AU - Maintinguer, Sandra Imaculada PY - 2022/09/26 Y2 - 2024/03/28 TI - Reuse of expired dairy products and sewage in the production of biogas by anaerobic digestion JF - Revista Engenharia na Agricultura - REVENG JA - Reveng VL - 30 IS - Contínua SE - Recursos Hídricos e Ambientais DO - 10.13083/reveng.v30i1.13936 UR - https://periodicos.ufv.br/reveng/article/view/13936 SP - 303-310 AB - <p>Dairy industry is a prominent sector of the agro-industry with global production of 906 million tonnes of milk. Several dairy products are wasted due their high perishability. Anaerobic digestion is a sustainable alternative for reducing this waste aiming biogas production. This study evaluated the co-digestion of expired dairy products (EDP) with synthetic sewage from two assays using two types of dairy waste, separately: Assay I (EDP mixture of 80% of milk + 15% of yogurt + 5% of milk cream) and Assay II (industrial raw mixture of EDP). Both assays were composed of 20 g COD L<sup>-1</sup> (Chemical Oxygen Demand per Liter) using anaerobic batch reactors (1.0 L) assembled in duplicates with 0.5 L headspace (N<sub>2</sub>) and working volume of 0.5 L with initial pH 8.2, at 37 °C, in a static mode. The cumulative CH<sub>4</sub> productions were 2722.5 NmL in 31 days of operation (Assay I) and 3140.0 NmL in 25 days of operation (Assay II). Equivalent CH<sub>4</sub> yields were obtained for the both assays with ~330 NmLCH4 g COD<sub>rem</sub><sup>-1</sup>. Carbohydrates and COD removals were 96.8% and 98.0%; 87.3% and 89.4%, respectively. The co-digestion of EDP with sewage was effective to CH<sub>4</sub> production with efficient organic matter removal. These results encourage new strategies for reuse of expired dairy products by the use of anaerobic digestion.</p> ER -