Estudo comparativo da aplicaÃÃo de vinhaÃa tratada e in natura em solos sob cultivo de cana-de-aÃÃcar

AUTOR(ES)
DATA DE PUBLICAÇÃO

2008

RESUMO

Brazil is the world leader in sugarcane plantation. Its economical exploration generates residues, standing out the vinasse. Due to the problems of ecological and social order caused by the vinasse, the most plausible solution for its disposition is the application to the soil as fertilizer. However, that application requests studies to guide the management of the residue. The main objective of the present work was to evaluate the natural attenuation of the system soil-plant concerning to the pollutants of the vinasse. In order to achieve this objective, forty drainage lisimeters were installed, distributed in parallel transects, distanced among themselves of 100 m, in an area of 7 hectares planted with sugar cane, where occurs two types of soils with distinct characteristics: sandy and clay. Mathematical modeling of the kinetics vinasse degradation was performed, parameters of the plant (diameter and height of the stem) and productivity as function of different vinasse dosages: in natura and treated in reactor of the type UASB were evaluated. Samples of soils were collected for physical and chemical characterization of the area and respirometric tests were accomplished to determine the kinetics degradation of the residue in the soil. The nutritional stage of the plants was determined to verify the cycle of nutrients, and it was analyzed the leached of the lisimeters to check the risk of contamination of the groundwater. Two collects of the water leached from the lisimeters were done. Parameters of quality of water were analyzed, standing out among them DQO, DBO and nitrate that can be indicative of the efficiency of the soil as treatment system. The biodegradation of the organic pollutants in the soil was evaluated using the respirometric method of Bartha. The laboratory experimental device was composed of 30 respirometers. The statistical analysis of the experiment design was done by a multivariate repeated measures design. It was tested different doses of vinasse (treated and in nature) as function of the potassium content in the soil according with the recommendation of CETESB. To model the residual kinetics degradation and growth in diameter and height of the stems, the models of Chapman- Richards, Von Bertalanffy and Monomolecular or of Kinetics of First Order were used. The results indicate that the biodegradation of different doses of vinasse in the soil was efficient as treatment considering the removal of DQO and DBO of the residue. The resulting equations of the model of Chapman-Richards were the most efficient in all of the situations tested in this work. The productivity of sugarcane fertilized with vinasse natura was higher than treated vinasse and the control by the test of Tukey at the level of 5% of probabilities. The clay soil was more productive than the sandy soil and the vinasse in natura with dosages of 300 and 500 m3.ha-1 produced equivalents of 104 and 122 ton.ha-1 for the sandy and clay soils, and the treated vinasse produced 79 and 87 ton.ha-1 with dosages of 300 e 820 m3.ha-1 for the sandy and clay soils, respectively

ASSUNTO(S)

lisÃmetro vinasse respirometria natural attenuation engenharia civil vinhaÃa respirometer mathematical modeling atenuaÃÃo natural modelagem matemÃtica lisimeters engenharia civil

ACESSO AO ARTIGO

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