Influência da diluição na biodigestão anaeróbia de dejetos suínos no semiárido Paraíbano.

Abstract

In this study, the influence of dilution in water on the anaerobic digestion of swine manure in batch reactors was evaluated. The experimental design was completely randomized, considering three proportions of dry matter and water (1:12; 1:16 and 1:20) and five replicates. All bioreactors, with capacities of 20 L, were monitored at room temperature for a period of 63 days. The influent and effluent samples from the bioreactors were characterized by means of physical-chemical analyses and the biogas production was quantified. Among the variables analyzed, the contents of total solids, volatile solids, dissolved oxygen, electrical conductivity and accumulated biogas production per mass of dry matter showed significant effects at the 5% probability level. These results proved that dilution influenced the degradation of the swine manure studied. When compared with literature standards, it was observed that the pH values ​​may have prevented better performance of the biodigestion processes. However, there was degradation of organic material and notable biogas production in all treatments. The accumulated biogas production per dry matter mass in the dilutions 1:16 and 1:20 were significantly higher than those obtained in the 1:12 treatment.