Estudo do potencial fitorremediador de Vernonia condensata (Asteraceae) para solos contaminados com chumbo, cobre, zinco e bioensaio de toxicidade sobre insetos

Abstract

The objective was to evaluate the phytoremediation potential of Vernonia condensata Backer (Asteraceae) in soils previously contaminated with increasing concentrations of 207 82 Pb, 64 29Cu and 65 30Zn, as well as carrying out a toxicity bioassay to analyze the e ects of heavy metals translocated to leaves on insects. For this purpose, two expe riments were carried out. In the rst, the amount of heavy metal in the specimens was measured by means of atomic absorption spectrometry, their translocation to the aerial part, e ects on the production of dry mass in roots and leaves as well as e ects on the growth of the specimens. For 65 30Zn it was found that the specimens had higher metal content in the leaves (potential phytoextractor), in contrast, most of the 64 29Cu e do 207 82 Pb absorbed by the specimens were retained in the roots (phytos tabilizing potential). In the second experiment, the leaves of Vernonia condensata derived from the rst study were used and the mortality rate of arboreal termites Nasutitermes sp. when subjected to dry leaf powder in test arenas for 48 hours. By means of survival analysis using Weibull Regression signi cant results were obtained P −value < 0001 which demonstrated that the leaves of Vernonia condensata cul tivated in soils contaminated by heavy metals promoted harmful e ects on arboreal termites of the genus Natutitermes sp