Produção de biogás e biofertilizante através da biodigestão anaeróbia de resíduos da indústria avícola: esterco de aves e ovos brancos

Abstract

The intensification of poultry farming generates large volumes of organic waste, demanding sustainable management strategies. Anaerobic digestion emerges as a promising alternative, enabling the treatment of these residues and the simultaneous production of biogas and biofertilizers. This experimental study aimed to assess the technical feasibility of using a laboratory-scale anaerobic biodigester for biogas production from poultry waste, as well as to evaluate the potential of the resulting digestate for use as a biofertilizer in soil restoration. The experiment was conducted at the Laboratório de Pesquisa em Bioninsumos (LaPeBi), using nine anaerobic reactors of 3 liters, distributed into three treatments in triplicate: Control (water + manure), Treatment B (higher proportion of manure and eggs), and Treatment C (equal proportions of manure, eggs, and vinasse). Reactors were maintained at 25 °C, and biogas production was monitored daily by liquid displacement (STP). Weekly samples were collected for pH, fixed total solids (FTS), and volatile total solids (VTS) analyses. Treatment C presented the highest cumulative biogas production (829 mL) and greater process stability, a statistically significant difference compared to the other treatments, confirming its superior anaerobic digestion efficiency. Treatment B showed intermediate production but greater variability among replicates, suggesting lower operational stability. The Control treatment did not produce measurable biogas, highlighting the importance of co-digestion and complementary nutrient supply. pH remained mostly within the optimal range for methanogenesis (6.6–7.4). FTS and VTS values indicated greater organic matter degradation in Treatment C, although without statistical difference compared to Treatment B, reinforcing the potential of vinasse as a co-substrate. The results demonstrate that co-digestion of poultry manure with white eggs and vinasse is an effective strategy to enhance biogas production at laboratory scale while producing a digestate with potential agricultural applications. Further experiments are recommended to monitor the complete digestion cycle and optimize operational conditions, aiming to maximize production at larger scales.