Avaliação do uso da Erythrina velutina Willd como agente fitorremediador de solo agrícola contaminado com hidrocarbonetos policíclicos aromáticos

Abstract

Polycyclic aromatic hydrocarbons (HPA) are organic compounds present in the environment considered to be pollutants, which have carcinogenic and mutagenic potential. One of the techniques used to remove pollutants from the environment is phytoremediation, which uses plants to recover contaminated soil and has advantages due to its permanent nature, besides being economically viable. The aim of this work was soil remediation using the Erythrina velutina Willd plant species to remove PAH. The selection of this species was based on its characteristics such as rapid growth and elongated roots, among other characteristics that make them phytoremediation potentials. Its seeds were submitted to germination tests with rates of approximately 70% in soils containing PAH. The experiment was carried out with a soil sample from the Usina São José do Pinheiro, located in Laranjeiras/SE. This soil was classified as eutrophic Red-Yellow Argisol and its characterization indicated to be a soil rich in organic matter. While the levels of aluminum, sodium and potassium were low, those of calcium, magnesium and phosphorus were high. The 16 PAH USEPA were extracted by ultrasound and analyzed by gas chromatography coupled with mass spectrometry. Erythrina velutina showed a removal efficiency that ranged from 31.6 to 100% for the 16 PAH in the total period of 120 days, and the sum of the HPA present in the soil showed 70% reduction at the end of the evaluated period. In the analysis of mulungu leaves, HPA concentrations ranged from 8.60 to 343,91 ng g-1 , and only lower molar compounds were detected. In the roots were found concentrations between 5.72 to 509.63 ng g-1 and of the 16 PAH evaluated only acenaphthen was not detected. During the phytoremediation period, the species showed good removal capacity of the studied compounds, and their development was not inhibited in the presence of contaminants and, therefore, can be indicated as a viable species for reforestation of degraded areas.