TOLERANCE AND HYPERACCUMULATION OF COPPER IN PONTEDERIA PARVIFLORA ALEXANDER

Abstract

This paper presents the behaviour of Pontederia parviflora Alexander in a copper sulfate solution in order to evaluate its phytoexctracting and accumulating capacity of this metal. Individuals of P. parviflora Alexander were collected in Papagaios Stream and transported to the Federal Technological University of Paraná; washed with tap water to eliminate the sediment e cleansed with distilled water. Then, it was planted 150 g of fresh mass of plant in recipients with capacity of 2 L containing nutritional Clark solution (CLARK, 1975) and 30 mg/L of copper sulfate solution. The absorption capacity test of the specie was conducted during 7 days with samplings in interval of 24 h. The absorption of the metal was greater in roots than in the shoots. According to ANOVA test, this result was significant and presented high value of the absorption constants to the roots and stem (k = 1.4 and k = 1.8, respectively). P. parviflora absorbed concentrations higher than the limit of toxicity, allowing to classify it in the category of resistant to the metal. Moreover, this plant can be classified as hiperaccumulater because it accumulated 1200 mg/kg of metal in its root. This, it is possible to indicate it to usage in treatment of effluents with high load of heavy metals. Key words: Phytotreatment. Kinetics. Copper. Treatment. Aquatic Macrophytes. First Order.