Bioacessibilidade e fitoatenuação de Cd, Pb E Zn por milho em solo poluído por escória metalúrgica e tratado com biochar

Abstract

The improper disposal of mining waste is a problem worldwide. Slag containing heavy metals can pollute soil and water and contaminate animals and humans. The bahian city of Santo Amaro had a lead smelter that, for years, polluted its territory with the smoke from the chimneys and the slag improperly deposited throughout the city. In order to understand the dynamics of stabilized metals in soils conditioned with biochar, the present work aimed to evaluate the effects of applying biochar to a soil polluted by multiple metals on the bioaccessibility, availability and absorption of As, Cd, Pb and Zn by plants and on the phytoattenuation process, aiming to indicate an economically and environmentally sustainable way for remediation of contaminated soils. For this, an experiment was carried out in a greenhouse with increasing doses of vermin (equivalent to 0, 5, 10, 20 and 30 t ha-1) applied to polluted soil in the municipality of Santo Amaro-Ba and cultivated with corn. After cultivation, the levels of metals in the roots and shoots, nutrients in the shoots, the fractionation of metals in the soil and bioaccessibility tests were determined. In addition to the evaluation of physiological parameters (chlorophyll fluorescence, gas exchange and chlorophyll contents). The results showed that biochar can be indicated as a ameliorating for heavy metals in phytoattenuation or phytostabilization programs in the Santo Amaro contaminated soil, since it promoted a decrease in the mobility and availability of metals in the soil, with an improvement in the production of dry matter and photosynthetic attributes of corn plants.