Produção de biogás, caracterização e aproveitamento agrícola do biofertilizante obtido na digestão da manipueira / Biogas production, characterization and agricultural use of the biofertilizer obtained in the cassava digestion




During the cassava roots processing, large quantities of waste are generated, among which stands out the manipueira, an effluent that has high polluting load, but on the other hand can be used as fertilizer and energy source. In this context, this study aimed to examine the anaerobic digestion of manipueira process, seeking to quantify the biogas produced its characterization and the use of the agricultural biofertilizer generated. The experiment was performed in the Laboratory of Anaerobic Digestion of the Department of Agricultural Engineering (DEA), located at the cassava Federal University of Viçosa (UFV). The substrate used was the wastewater from cassava starch previously characterized. It were used nine (09), laboratorial digerters, operating in just one charge, with a total capacity of 3.1 L and useful, 2 L. The bark of the cassava was added to the effluent in order to reach the three (03) total solids concentrations desired, which formed the treatments with three replications. In the DEA/UFVs Water Quality Laboratory, analyses were carried out, which includes the analyses of total solids (TS), fixed solids (FS) and volatile solids (VS) of the affluent and the effluent generated in the process. Based on the results, it was found that the greatest reductions of TS and VS were observed in the concentration of 4.5 dag L-1, TS. The greatest potential for biogas production, 1.39 L kg-1, VS removed, was observed in the concentration of 8 dag L-1, TS. In the experiment of the use of biofertilizer, carried out in the Anaerobic Digestion Laboratory of the DEA, corn grown in plastic pots put in benches and filled with 5 L of Cambisol Haplic soil Tb Distrophic Latossolic. The fertilization was made based on the recommendations for this culture and the biofertilizer was applied when the plants reached approximately 10 cm of height. The treatments were designated by the BiDj initials, in that Bi indicated the biofertilizer produced by TS concentration of the substrate (i from 1 to 3) and Dj, the dosage applied (j 1 to 3). The control treatment was represented by the conventional fertilization. Regarding the soil, the treatments associated with higher doses of biofertilizer resulted in electrical conductivity values that differed from the control, as well as the concentrations of calcium + magnesium, total phosphorus, potassium and total sodium available. The application of biofertilizers associated with the lower dose did not alter the concentration of the chemicals elements evaluated. There was no change in variables evaluated in the plant.


digestão anaeróbia resíduos agroindustriais construcoes rurais e ambiencia organic fertilizer agroindustrial residues adubação orgânica anaerobic digestion

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