Anaerobic mono-and co-digestion of fruit and vegetable residues: Effects on biogas yield and biofertilizer /Mono e codigestao anaerobia de residuos de frutas e vegetais: Efeitos no rendimento de biogas e no biofertilizante

• Published in: Revista brasileira de engenharia agrícola e ambiental 2024-11, Vol.28 (11), p.1
• Main Authors: Hinterholz, Bruna, de M. Costa, Monica S.S, de Lucas, Jorge, Jr, da S. Pereira, Edilene, Buligon, Eduardo L, de Lima, Jessica C, Marostica, Ritieli
• Format: Article
• Language: English
• ISSN: 1415-4366
• DOI: 10.1590/1807-1929/agriambi.v28n11e280349

The proper disposal of fruit and vegetable waste is essential to promote environmental sustainability, reduce the carbon footprint, improve soil quality, and contribute to the transition to a circular economy. This study examined the impact of incorporating dairy cattle wastewater (DCWW) into anaerobic co-digestion with fruit and vegetable residues and utilization of the resulting biofertilizer as a diluent in the anaerobic mono-digestion of fruit and vegetable residues (recycle). The specific biogas and methane production and the agronomic quality of the biofertilizer were evaluated in a semi-continuous trial. Two startup strategies were employed: initially, the reactors were entirely fed with inoculum (biofertilizer derived from DCWW), and fruit and vegetable residue feedstock was gradually introduced. Anaerobic co-digestion of fruit and vegetable residues with DCWW yielded the highest specific production of biogas and methane at 720 and 436 L [kg.sup.-1] of volatile solids (VS), respectively. The addition of DCWW increases fruit and vegetable residue alkalinity by 249% and reduces the volatile acidity by 83.4%. Anaerobic mono-digestion of fruit and vegetable residues enhances macronutrient recovery in the biofertilizer through recycle. Logistically, directing fruit and vegetable residues to rural areas for anaerobic co-digestion with DCWW promotes agricultural biofertilizer use. Key words: specific biogas and methane production, process stability, nutrient recovery, recycle A destinacao adequada dos residuos de frutas e vegetais e fundamental para promover a sustentabilidade ambiental, reduzir a pegada de carbono, melhorar a qualidade do solo e contribuir para a transicao para uma economia circular. Neste estudo, foram avaliados os efeitos da adicao de agua residuaria da bovinocultura de leite em codigestao anaerobia com residuos de frutas e vegetais e o uso do biofertilizante como diluente na monodigestao anaerobia dos residuos de frutas e vegetais (reciclo). A producao especifica de biogas e metano, bem como a qualidade agronomica do biofertilizante em um estudo semicontinuo, foram avaliados. Foram utilizadas duas estrategias para partida dos reatores: o abastecimento inicial dos reatores totalmente com inoculo (biofertilizante proveniente da digestao anaerobia da agua residuaria da bovinocultura de leite) e a progressao de carga para os residuos de frutas e vegetais. A maior producao especifica de biogas e metano foi atingida pela codigestao anaerobi