Uso de Brassica juncea (L.) Czern, Helianthus annus L. e Mimosa bimucronata (DC.) O. Kuntze na fitorremediação de solos contaminados com chumbo e níquel

Abstract

Phytoremediation is a soil decontamination technique in which the potential of plant species is used to extract metals and other contaminants from the environment. Brassica juncea (L.) Czern (Mustard), Helianthus annus L. (Sunflower) and Mimosa bimucronata (DC.) O. Kuntze (Maricá) species were used to extract lead and nickel from soils. For the accomplishment of the procedure, it was made the follow-up throughout 11 weeks of two simultaneous experiments in which the soil used was Red Latosol collected within the limits of the Federal Technological University of Paraná. In experiment 1, 2 kg (dry mass) was used in polypropylene pots contaminated with lead acetate and nickel sulfate at concentrations of 0.5, 1.0, 2.0 and 5.0 g/kg of lead and nickel, to identify the phytoremediation potential of Brassica juncea (L.) Czern and Helianthus annus L. For the second experiment, 1 kg (dry mass) of lead acetate contaminated soil was used at concentrations of 0.25, 0.5 and 1.0 g / kg to verify that Mimosa bimucronata (DC.) and O. Kuntze have phytoremediation potential. The experiment was performed in triplicate. Sample digestion was based on the parameters stipulated by the USEPA 3050B Methodology. After the digestion procedure, the samples were analyzed by flame atomic absorption spectrophotometer. It was observed that the species that are considered hyperaccumulating (Sunflower and Mustard) presented more satisfactory results than Maricá for phytoextraction. For lead, Sunflower and Mustard were able to extract more than 90% of the contaminant and for nickel it was possible to verify extraction above 85%. Maricá was able to extract up to 55% lead from the samples.