Water phytoremediation of cadmium and copper using Azolla filiculoidesLam. in a hydroponic system

Abstract

The aim of this work was to evaluate the utility of Azolla filiculoides growing in a hydroponic system for the phytoremediation of continental water polluted with cadmium and copper during 7 days of exposure. Cadmium and copper chloride were added to the medium at concentrations of 0.5-10mg/L and 0.1-25mg/L, respectively. Cadmium and copper levels were measured in each plant using flame atomic absorption spectrophotometry. The analytical methodology used to measure cadmium and copper levels was validated with standard reference material (SRM) - 1570 (spinach) National Institute of Standards and Technology. The results indicated that cadmium and copper phytoremediation was statistically significant with a maximum increase in plant tissue of 1623.20 and 6013.1g/g, respectively. This photosynthetic efficiency was chronically damaged when Azolla filiculoides were exposed to 10mg/L of Cd and 25mg/L of Cu. The Azolla plants were not affected in the other phytoremediation treatments with copper.