Digestão anaeróbia da água residuária da produção de suínos com e sem adição de carcaças de suínos desidratadas e cruas: valorização energética e agronômica

Abstract

Swine production is a fundamental pillar on foodstuff industry, driven by the increasing demand for animal protein. However, the production system has generated substantial amounts of waste, posing challenges to the sustainability field and environmental health. In this context, anaerobic digestion (AD) has come out as a promising solution to face these challenges, since it has provided effective waste management and generated renewable energy. Furthermore, it emphasizes the potential to produce organic fertilizer (biofertilizer), and contributes to better sustainable agricultural practices. Thus, this study aimed at evaluating the effectiveness of anaerobic co-digestion (ACoD) among wastewater (WW) from Piglet Production Units (PPU) and dehydrated swine carcasses. So, the analysis of biogas and methane production, reduction of pathogens in carcasses, and the resulting biofertilizer quality took part of this study. In adittion, a biochemical potential assay (BPA) was carried out to evaluate methane production potential from the produced substrate in different swine production systems. Physical-chemical analyses were performed, including the determination of solids series, pH, electrical conductivity, alkalinity, volatile acidity, and nutrient content. These analyses also provided insights into the interrelations among the studied variables and anaerobic digestion process. Moreover, microbiological analyses evaluated digestion efficiency in reducing pathogens in carcasses. Moreover, biogas and methane production analyses were carried out to verify the specific gas productions. The results revealed that ACoD of PPU from WW in dehydrated carcasses stood out in biogas production (1,182 L kg VS-1) and methane (860 L kg VS-1) when compared to other combinations. BPA results showed a significant potential to produce methane (1,036.7 L kg VS-1) from ACoD of PPU from WW and dehydrated carcasses, when compared to other sectors of swine farming and to Anaerobic Mono-Digestion of PPU from WW (10.5% higher). Furthermore, AD has proved to be efficient in reducing pathogens in carcasses, when it enhanced the microbiological safety of the produced biofertilizer. Multivariate analysis highlighted significant correlations among physical-chemical variables and AD process efficiency. Thus, this study reinforces ACoD as a promising strategy for the sustainable treatment of swine residues. Lastly, by employing AD, it is not only possible to mitigate environmental impacts but also to generate value from residues, as well as to contribute to a more responsible and sustainable swine industry.