POTENCIAL DE CONTAMINAÇÃO DO SOLO APÓS PROCESSO DE COMPOSTAGEM EM PÁTIO NÃO IMPERMEABILIZADO

Abstract

The aim of this study was analyse leaching of soil profile, in 0,2 and 0,5 meters of deep, through chemical elements( nitrate, sodium, potassium and phosphor) contained in the leachate percolated from composting piles of university restaurant food waste. The research was conducted at Federal University of Lavras. The composting piles were built based on the carbon to nitrogen (C:N) ratio of each material to be composted. The composted wastes were food scraps from University restaurant at Federal University of Lavras, sludge from Sewage Treatment Plant, Maravalha/ sawdust and grass (Panicum maximum Jacq cv Colonião). Were evaluated four treatments, as described: T1 (grass, food waste from university restaurant and water); T2( grass, food waste from university restaurant, sludge and water); T3 (Maravalha/ sawdust, food waste from university restaurant and water) and T4 (Maravalha/ sawdust, waste from university restaurant, sludge and water). After 120 days, it occurred increase of sodium concentration in T1, T2, T3 and T4 due to presence of food waste of University restaurant in all treatments. The concentrations of potassium obtained higher values in T1 and T2, in 0.20 m, due to the presence of grass. There was no increase in Nitrate in 0.2 m, after 120 days. However in T2 and T4 were observed high values of this element in 0.5 m, because of the presence of sludge in treatment’s composition. Thus with nitrate leaching in low layers, it is necessary waterproofing the soil, in order to avoid contamination in water table.