Interação do potássio em solo da zona canavieira via vinhaça

Abstract

The vinasse is rich in nutrients, particularly potassium, but it is classified as waste distillation process the juice of sugarcane for alcohol manufacturing process, which has no current state legislation on the discharge to the environment. Thus, the objective of the study is to evaluate the potassium ion interactions (K+), applied via vinasse in a representative soil of sugarcane zone (coastal board sandy texture) using adsorption isotherms. The methodology was based on physical, chemical and soil mineralogical and batch tests based on the recommendations of the Environmental Protection Agency (EPA-USA), where the experimental curves were adjusted by Langmuir and Freundlich isotherm models using the Sigma Plot 11.0 Software. Regarding the isotherms, the Freundlich model showed better fit the curve in two ways: linear and non-linear (direct adjustment), the non-linear model chosen on the basis of values of the coefficient of determination (R²). The potassium interaction with soil was mainly with organic matter and the presence of soil kaolinite, it had negative ions on the outer surface, thereby promoting the adsorption. The soil potassium adsorption capacity was higher for the first layer (0-20 cm) decreasing in depth.