Determinação das emissões de metano (CH4) em lagoas de estabilização de dejetos de suínos na região de Rio Verde-GO

Abstract

The city of Rio Verde-GO has excelled for having important agro-industrial units with important breeding of cattle, poultry and pigs. The swine farms handle the liquid waste stabilization ponds with or without digesters systems, accumulating them for 2 months to 4 months, and then applied in areas of approximately 100 to 300 acres. Floating gas collection chambers, where the samples are captured biogas emitted to the atmosphere of stabilization ponds and then analyzed the samples in the laboratory of Embrapa Agrobiology were installed, in addition, to conduct sampling of swine manure (DLS) itself to quantification of elements present in it. It was found in this study that the largest emissions of methane (CH4) were in the following descending order of magnitude: 205.3 ± 68.79 Mg CH4 yr-1 for the fattening farm without biodigester (4,000 swines); 123.94 ± 39.17 Mg CH4 yr-1 in the fattening farm with a biodigester (4,000 swines); 11.22 ± 3.0 ton CH4 year-1 for the producing piglets farm with a biodigester (1,008 matrices swines) and 2.75 ± 0.89 Mg CH4 yr-1 in the producing piglets farm with two biodigesters (728 matrices swines), thus proving expected to their farms in production. Interaction in methane (CH4 Mg yr-1) and concentration (mg L-1) macronutrients (N, P and K) present in the DLS was observed for nitrogen (Ntotal) a linear equation y = 0.1797x – 111.81 (R2 0.9844); for phosphorus (P) is the linear equation y = 1.4905x – 25.224 (R2 0.9436); whereas for potassium (K) a linear equation y = 0.0693 – 35.934 (R2 0.9337).