Estudo da condutividade hidráulica e do potencial de lixiviação de fósforo em colunas de solo compactado

Abstract

To present research it was developed in the Universidade Estadual do Oeste do Paraná -UNIOESTE, using the Laboratório de Geotecnia for assembly of the experiment and the Laboratório de Saneamento for chemical analyses. The coming of the processes liquid and solid residues and activities agro industries have as characteristic common to high nutrients load, above all Nitrogen and Phosphorous. When these materials are disposed in a of wastes contention system without correct impermeabilization it can happen the contamination of the groundwater. The objective of this work is to verify the quality of typical distroferric Red Oxisol, of wide regional occurrence, compacted in what it says respect to the permeability; the lixiviation potential of the phosphate; accumulation of the phosphate in the soil and the alterations happened in the soil matrix after the percolation of the swine effluent. The experiment was driven in laboratory scale, being set up a total of 27 columns of PVC tubes, of 1,15m of length and 0,10m of diameter, being in the compacted base 0,03m of soil in three moisture contents (28, 32 and 36%) and applied gross swine effluent (E1), diluted swine effluent (E2) and distilled water (E3), making three repetitions, percolating for at the most 15 days or 8 times the total volume of pores (VP), picking up samples of 25 mL, evaluating the pH, CE and phosphate. Then the columns were dismounted, removing the hydraulic load and dividing the soil in three increments: 0 to -1 cm, -1 at -2 cm and -2 to -3 cm. Discarded the middle increment. It was conduced the analysis of the content organic matter (MO), total and uptake of phosphorous, it was also determined the pH, the zero point charge (ZPC) and the surface potential. The results showed reduction in the permeability with the application of swine effluent to at levels that indicate a possible colmatation; the measures of electric conductivity (CE) were smaller than the initials in the effluents, and the retention of particles was shown with an decrease in the soil surface potential; as the percolation of the phosphate, it was minimum and it happened in the treatments with the soil was not appropriately compacted. The soil analysis showed that the phosphate was retained in the superior increment.