Eficiencia de la absorción de cobre (Cu) y cromo (Cr), una propuesta de fitorremediación de efluentes mediada por Typha domingensis

Abstract

The rapid growth of world population and the consequent demand for natural resources are reflected in the environmental problems that affect the whole planet, one of these problems is the increasing contamination of water resources by heavy metals. Paraguay does not escape from this problem, the rivers, streams and lakes pollution increases progressively, having the high heavy metals content as one of the most dangerous component. Typha dominguensis, better known as totora (South America), is a cosmopolitan marsh plant, widely adapted in both the Eastern and Western regions of Paraguay. This species is studied for its bioremediation properties of polluted waters. In the Multidisciplinary Center for Technological Research CEMIT/UNA, the experiment was carried out to evaluate the absorption of heavy metals commonly found in wastewater: chromium and copper, in aqueous solutions, in three different concentrations, in three repetitions. The used design was completely random. T. domingensis plants were conditioned in the CEMIT greenhouse starting from seeds arranged in buckets with 50 L of metal solution, with 5 plants each bucket. Initially the plants were acclimatized for a 30 days period, later were exposed to metallic solutions. The chromium and copper content, pH, O₂ and temperature values of metallic solution were taken on days 1, 17 and 45 from initial exposure, samples were analyzed in the Water Quality Laboratory of CEMIT/UNA. Metallic solutions without treatment with T. dominguensis plants and plants without contact with metallic solutions were used as a control. The results were collated by the statistical program InfoStat® performing an ANOVA and Tukey's test. The results indicated significant differences in the removal of the content of copper and chromium in the three concentrations of metallic solutions, thus demonstrating that the plant has the ability to absorb heavy metals, however in the controls (metallic solutions without plants) it was not observed changes in the content of these two metals.