Avaliação do potencial fitoextrator de Hedychium Coronarium “J.Koenig” em pequena bacia degradada

Abstract

The availability of water in Brazil is one of the largest in the world. However, this distribution is not uniform, which results in water in insufficient quantity and quality to meet local needs, a fact that becomes more evident in areas with a predominance of agricultural activity, where water sources can be contaminated by inappropriate practices. Then there is a need for alternative methods for treatment and verification of water quality, such as exploring the potential of plant phytoextraction aiming at phytoremediation of areas and or soils. In phytoextraction, plants act by removing, storing, transferring, stabilizing and rendering the heavy metals present in the soil harmless. These plants are able to tolerate, absorb and translocate high levels of heavy metals that would be toxic to any other organism. The present study explored the use of Hedychium coronarium as a bioindicator of water quality, and its potential for phytoextraction of common pollutants in contaminated rural basins. The collection took place from September to December 2019, in a ruderal area, along the main axis of Lajeado do Pardo (Pardinho) in the municipality of Frederico Westphalen. Data were collected at ten points. The design used was completely randomized in a 5 x 2 factorial scheme, with five plant collection points along Lajeado Pardo and two partitions (rhizome and leaf). Each plant was considered as an experimental unit, using six replicates per treatment. The samples were separated into the rhizome and aerial part fractions and processed by the EDX method, being determined the elements: K2O, CaO, P2O5, SO3, MnO and Fe2O3. Subsequently, analysis of variance (factorial ANOVA) was performed and in the case of significant effects (p <0.05), Tukey's means comparison test was performed. The analysis of variance showed that the interaction between the collection points and the partitioning of the elements (leaf and rhizome) was not significant. There was only an isolated effect of the factors (p <0.05). It was found that the proliferation of the lily-of-swamp is directly related to the lack of ciliary shrub or tree vegetation along the watercourse. With the exception of sulfur and iron, all other averages analyzed showed a statistical difference in element retention between different parts of the plant (leaf and root). It was observed that the basin has contamination by effluents and leaching of agricultural fertilizers, and the elements analyzed are mainly concentrated in the aerial part of the swamp lily, which, despite being exotic, proved effective as a phytoextractor, absorbing contaminating elements present in the water.