POTENTIAL OF NATIVE FREE-FLOATING SALVINIA BILOBA MACROPHYTES FOR REMOVING ATRAZINE AND CARBENDAZIM FROM AQUEOUS SOLUTION

D. B. LOUREIRO; LARIO, LUCIANA D.; M. SOL. HERRERO; BON, IVÁN CARRALERO; L. M. SALVATIERRA; L. M. PÉREZ

Barcelona

Congreso; International Congress on Water and Sustainability; 2021

International Congress on Water and Sustainability

The potential of autochthonous free-floating Salvinia biloba specimens collected from a shallow lake at the middle Paraná River (Entre Ríos, Argentina) was assessed in order to select native plant species for use in environmental remediation of atrazine and carbendazim polluted waters. Experiments were carried out over 20 days (23 ± 2 °C average room temperature, 100 l m/W light intensity, 12 h photo-period) in glass vessels containing deionized water contaminated with 0; 5.0; 10.0 and 20.0 mg L-1 of atrazine or carbendazim. A decrease in biomass growth was observed in all macrophytes exposed to the pesticides after 20 days. Atrazine showed higher toxic effects evidenced by the symptomatology developed by the plants which caused their death, demonstrating the high sensitivity of S. biloba to this herbicide. Noticeably, lower chlorosis and necrosis were observed in S. biloba specimens treated with carbendazim, even at the higher concentration tested. In general, S. biloba presented a low potential for both atrazine and carbendazim removal. In addition, the percentage of pesticides removed from the solution decreased when the plants were exposed to higher concentrations of the pollutants. This fact probably resulted from the processes of pesticide adsorption by plant biomass. The FTIR-ATR spectrum obtained for S. biloba showed the presence of different functional groups (e.g., carboxyl, phosphate, amide, hydroxyl, sulphate) on the plant surface that could be involved in pesticide biosorption through multiple types of interactions such as π-π interactions, hydrogen bonding, acid-base behavior, ion-exchange properties, and electrostatic attractions. In conclusion, S. biloba was not much effective in removing atrazine and carbendazim from water samples. Therefore, the use of these macrophytes to remediate aquatic environments contaminated with these pesticides seems to be limited.