Efeito da aplicação de lodo de ETEI em solo com elevado teor de cobre: fitodisponibilidade e ecotoxicidade

Abstract

The aim of this work was to verify the effects of the application of sludge from an effluent treatment plant of an egg pasteurization industry in high copper soil. A vase test was performed, out with black oats (Avena strigosa Schreb) as a test plant in a typical Red Latosol contaminated with copper concentration of 75.0 kg.(ha.year)-1, which corresponds to the maximum allowed soil concentration by the Environmental Company of the State of São Paulo. The treatments consisted of sludge doses based on the supply of plant Nitrogen demand. In order to verify the effects, the dry and fresh mass production of the plant and the absorption of copper by the roots (contentes in apoplast and symplast) and aerial part were evaluated. In addition, was evaluated the effect of the association (contaminated soil + sludge doses) in the reproduction of collembolans Folsomia candida through a chronic toxicity test. The application of sludge did not significantly interfere in the production of fresh and dry mass of black oats, but presented changes in the bioavailability of copper. Copper and sludge doses did not affect collembolans reproduction. However, black oats showed to be an important phytoextractor, accumulating copper especially in the roots and presenting similar absorptions between the apoplast and symplast compartments.