Concentração de metais pesados em espécies arbóreas utilizadas para revegetação de área contaminada

Abstract

Concentração de metais pesados em espécies arbóreas utilizadas para revegetação de área contaminada 1Heavy metals concentration in tree species used for revegetation of contaminated area ), evidenciando contaminação com esse elemento. Os maiores teores dos metais pesados foram encontrados na fração residual (F5), indicando baixa disponibilidade destes elementos no substrato. Com relação ao Cd, elevadas concentrações também foram encontradas na fração trocável F2, considerada uma fração em que os contaminantes se apresentam com certa mobilidade e biodisponibilidade. As espécies vegetais estudadas apresentaram desenvolvimento dentro dos padrões normais, mostrando tolerância a áreas contaminadas com Cd, que tendeu a se acumular nas raízes das plantas, com exceção da Córdia -africana. Palavras-chave:Arborização. Revegetação. Solos-descontaminação.ABSTRACT -This study aims to evaluate the potential of tree species Cordia africana Lam., Mimosa caesalpineafolia Benth., Acacia angustissima (Mill.) Ktze. and Anadenanthera colubrina (Vell.) Brenan in the phytostabilization of heavy metal from a substrate contaminated. Four specimens of each tree specie were randomly determined for evaluations. Substrate samples were collected in the projection of the canopy trees of each specimen at depths 0-10, 10-30 and 30-50 cm for determining pseudototal concentration and chemical fractionation of heavy metals.Were collected data on roots depth, diameter at breast height, canopy diameter and plant height for each specimen. Samples of root, stem, bark and leaf were collected for analysis of heavy metals zinc (Zn), manganese (Mn), cadmium (Cd), lead (Pb) and copper (Cu). The Cd concentration in the substrate was above the investigation value defined by CONAMA (3,0 mg kg -1 ), showing contamination with this element. However, the highest concentrations of other studied heavy metals were found in the residual fraction (F5), indicating low availability of these elements in the substrate. High concentrations of Cd were also found in the exchangeable fraction F2, which is considered a fraction in which contaminants are present with some mobility and bioavailability. The plants showed development within the normal patterns, showing tolerance to Cd-contaminated areas, which tended to accumulate in the roots, except in the Córdia -africana.

Negative Effects on Photosynthesis and Chloroplast Pigments Exposed to Lead and Aluminum: A Meta-Analysis

“…Also, it has many taxa of great ornamental potential, is commonly planted in urban areas and, for this reason, suffers from contamination by toxic metals (Marques et al, 2018). Pereira et al (2012), when studying the use of this family in the reforestation of contaminated areas, concluded that metals in the soil were at concentrations above the safe values established by legislation and that the plants established in the contaminated site were tolerant.…”

Metals Phytoextraction by Cordia africana from Soils Contaminated with Oil Drilling Waste

“…A combined approach with the goal of immobilizing or removing contaminants, followed by a ground cover, would be promising to recover the biological activity of soils (Evangelou et al, 2007). Pereira et al (2012Pereira et al ( , 2013 (Lorenzi et al, 2003).…”

Crescimento Micelial De Fungos Micorrízicos Arbusculares E Formação De Micorriza Em Solo Contaminado Por Cádmio

“…Nos processos de fitorremediação, os poluentes inorgânicos como os metais pesados não podem ser decompostos, porém são estabilizados no solo ou permanecem retidos nos tecidos de plantas hiperacumuladoras (COBBETT; GOLDSBROUGH, 2002;PEREIRA et al, 2012). Nesse sentido, são diversos os mecanismos que regem o potencial de tolerância das espécies utilizadas no processo de fitorremediação do solo.…”