Leaching columns with sandy and clay texture soils and application of biosolids

Résumé

The objective of this research was to evaluate the contaminant potential of the leachate from soils treated with increasing doses of biosolids. The experiment was carried out in protected cultivation in clayey (Eutrophic RED LATOSOL) and sandy texture (Dystrophic YELLOW RED LATOSOL) soils. The experimental design was completely randomized with five treatments, six repetitions and two soil types: T1 - absence of biosolids, T2-T6, respectively 0, 15, 30, 45 and 60 ton ha^-1 of biosolids. The vessels (leaching column) were made by PVC tubes 0.50 m high and 0.10 m in diameter at its base is adapted a perforated PVC cap for collecting the leached material. Each column was filled with 3,141.6 cm³ soil (sandy or clayey), of which the amounts of biosolid. After this stage, the plots were taken to 70% of the field capacity incubated for 60 days and after that period the leachate was collected and evaluated as: pH, electrical conductivity and contents of K, Ca and Mg. The results indicated that increased doses of biosolids lead to elevated pH. It was concluded that the clay soil supported higher doses of biosolids in relation to the sandy soil, presenting leachates with lower pollutant potential.