TRACE METALS ACCUMULATION AND THEIR TRANSLOCATION IN PHRAGMITES AUSTRALIS (CAV.) COLLECTED ALONG THE SARNO RIVER

Besides being used, for their dense root system, to consolidate embankments subject to erosion, the aquatic macrophytes play an important role at removing contaminants from the rhizosphere by filtration, adsorption, cation exchange and through chemical changes induced by plant organisms. They have been identified as a group potentially useful for bioremediation and biomonitoring. The Sarno River is the most polluted river in Italy (Campania region) because of many important tanneries and leather factories located along its course, and large agricultural and industrial discharges untreated waste made. Additionally, the area is also disturbed by frequent flooding and mudslides; in the last 20 years, the embankments have ruptured two or three times a year, causing spillover of polluted waters into the adjacent countryside with all the risk to the public health. Therefore, the aim of this work was to quantify the trace metals accumulation in Phragmites australis (Cav.) (roots, stolons, stems and leaves) sampled along the Sarno River. The data obtained were compared to the metal concentrations assayed in the rhizosphere sediments and the interstitial water to assess the bioaccumulation in different organs and bio-extraction. The data showed a decreasing metals content in the following order: root> stolon> leaf> stem highlighting the metal block at the root level. Significant and positive correlations were found between rhizosphere and roots metals, suggesting a common origin. Besides, significant correlation found between Ni assayed in interstitial water and roots suggested this as the other pollution source.