Phytoremediation capacity of Hydrocotyle ranunculoides L. f., in waters contaminated with mercury

Abstract

The objective was to evaluate the phytoremediation capacity of the plant species H. ranunculoides L. f., In relation to the contamination of water samples with mercury at different concentrations. For which three stages were carried out, the first was the collection and cultivation in a hydroponic system, the second the contamination with mercury (II) in laboratory water samples and the third evaluated the phytoremediation capacity. For the analysis of mercury, the Atomic Absorption Spectrophotometry (AAS) technique was used. Morphological and compositional alterations were also evaluated. Exposure of the plant species to mercury contamination at concentrations of 0.1, 0.5, 1.0, 2.0, and 5.0 ppm lasted 15 days. In the results, they show that the 1.0 ppm concentration generates chlorosis and at 5.0 ppm necrosis; As for the length of the root, stem and leaves, a proportional decrease was observed in the mercury concentration. Internal morphology shows alterations by mercury at the cell wall level, tissue organization and vascular system, both in root, stem and leaf. In the composition, a decrease in the percentage of humidity, ashes, proteins, fats and fiber and an increase in the percentage of carbohydrates were observed, in different concentrations. The bioaccumulation factor was greater than 1000 mg / L up to the 1.0 ppm concentration of mercury. The translocation factor in concentrations 0.1 and 0.5 ppm Hg2 + is> 1mg / L and in concentrations of 1.0, 2.0 and 5.0 ppm Hg2 + mercury is found in a higher proportion in the root.