EVALUATION OF AUTOCHTHONOUS FREE-FLOATING MACROPHYTES FOR USE IN THE PHYTOREMEDIATION OF INDUSTRIAL WASTEWATER CONTAMINATED WITH HEAVY METALS

W. T. ZEVALLOS; L. M. SALVATIERRA; D. B. LOUREIRO; J. MORATÓ FARRERAS; L. M. PÉREZ

Terrassa, Barcelona

Conferencia; I International Congress on Water and Sustainability; 2017

School of Industrial, Aerospace and Audiovisual Engineering of Terrassa (ESEIAAT) of the Universitat Politècnica de Catalunya · BarcelonaTech (UPC)

Plant-based systems for treatment of contaminated environments (phytoremediation) have been proved to be highly efficient in removing several pollutants, especially heavy metals. The range of plant species used in phytoremediation processes is generally low and mainly restricted to emerging ones. However, in strictly aquatic and high-flow treatment systems, the use of free floating plants could be more adequate. For a treatment system based on phytoremediation strategies be propitious and sustainable, it is essential that plant species used for system design are not only efficient in pollutants removal, but also abundant at region, easily accessible, and do not require special culture conditions. Considering these features, at the present work, we firstly evaluate the capacity to adapt and reproduce at laboratory «indoor» conditions of different autochthonous aquatic macrophytes obtained from the Paraná River (Argentina). We also study the potential of the plants to remove heavy metals from artificially-contaminated water samples in batch-operated lagoons. From different pre-selected species, only Salvinia biloba Raddi (synonym name Salvinia herzogii de la Sota) showed a wide capacity of adaptation and reproduction in greenhouse conditions. Moreover, S. biloba lead (Pb2+) removal ability was evaluated in water samples contaminated with three metal concentrations (4.8±0.3, 9.1±0.4 and 19.6±0.5 mg/L) at different exposure times (0-24 h), showing a high efficiency in the pollutant elimination. Additionally, the compartmentalization analysis indicates that surface adsorption was found to be the predominant mechanism for Pb2+ removal at the first 24 h under the tested conditions. Finally, the bioconcentration factor (BCF) was calculated at the end of the exposure time reflecting both hyperaccumulation capacity and high metal tolerance. Our results suggest that incorporation of S. biloba in wastewater treatment systems could be a successful strategy to efficiently remove heavy metals by bioremediation processes. In addition, the use of compartmentalization analysis is propitious to gain a full insight into metal removal process.