Viabilidade do aproveitamento agrícola de lixiviado de aterro sanitário na cultura de girassol

Abstract

The leachate from landfill has become a challenge in large urban centers, since it has a high complexity in its composition that makes the treatment more difficult. Considering the fact that a disabled landfill continues to produce this effluent at least for 50 years, the research on more efficient destination for this leachate is important. In this context, it is also known that this type of effluent is a source of nutrients to plants, such as nitrogen and potassium. Thus, the agriculture can be considered as a noblest destination to reuse these wastewaters, through a proper management and that does not cause phytotoxicity. The present study evaluated: the viability of the agricultural use of raw leachate (LB) coming from the landfill Metropolitan Garden of Gramacho - RJ and leachate treated by electro-Fenton (LTEF) and distillation (LTD1 and LTD2) on the germination of sunflower seeds; the LB use in growth, nutrition and soil attributes in sunflower seedling cultivation and dynamics and effect of LB in soil columns, evaluating the properties of the soil and its solution. From the results obtained on this research, the distillation treatment was more efficient in the DQO removal and others parameters like an alternative of LB treatment. The LTD2 showed best yields in germinability, but the LB showed good yield up to the dose of 25%, which deserves to be highlighted, because it represents an economy with possible treatments. The LB used in the experiment with sunflower seedlings demonstrated to be a by-product of agronomic interest because it presents nutrients to plants (N and K), and had real possibilities for use in sunflower crop cultivation. The greatest concern with the LB use was not the metals, but the salinity and the chloride, because they percolate combined with the solo solution. Among rational destination alternatives, analyzing the raw and treated LB use as source of nutrients or to the hydro needs in agricultural crops demonstrated the power to guarantee the water reuse and the agricultural inputs reduction, but with the proper planning and management that do not cause toxicity into the soil and into the plant