Flumequine Accumulation in Potamogeton pusillus Under Hydroponic Conditions

MARÍA EUGENIA VALDÉS; F. L. CORTES; D. A. WUNDERLIN; MONFERRÁN M.V.

Dublin

Congreso; SETAC EUROPE 33RD ANNUAL MEETING; 2023

SETAC EUROPE

Water pollution by veterinary antibiotics (VA) is an increasing worldwide problem, due to intensive animal production practices. Phytoremediation is a low-cost and eco-friendly technology to remove emerging pollutants by the use of plants and associated microorganisms. Nevertheless, operational conditions need to be optimized to achieve efficient removals. Potamogeton pusillus is a submerged rooted macrophyte that has proven to be a good accumulator of metals. In this study, we proposed to evaluate the removal of flumequine (VA) by P. pusillus and its accumulation in the macrophyte organs. To achieve this goal, we exposed the macrophyte (8 g w.w./L) in hydroponic conditions: Hoagland nutrient solution with or without flumequine at 50 and 500 μg/L, during 14 days. Static experiments were performed in a greenhouse room without temperature/light control (n = 4). Hoagland nutrient solution was renewed every 7 days. Water samples were taken at 0, 2, 5, 7 and 14 days for flumequine analysis by UPLC-MS/MS. At the end of the experiments, macrophytes were carefully washed with distilled water; roots, stem and leaves separated, freezed using liquid nitrogen and homogenized to perform extractions. Flumequine was analysed in each organ by an adapted QuEChERs extraction method, followed by UPLC-MS/MS quantification. Leaves were extracted with ethanol 96% V/V to perform pigments analysis by spectrophotometry. After 14 days, flumequine removal from water was greater at 50 μg/L (62±15%) compared to the exposure at 500 μg/L (38±12 %). Flumequine accumulation by P. Pusillus was dose-dependent, with roots showing the higher concentration (7±2 μg/g w.w. and 40±7 μg/g w.w. upon exposure to 50 and 500 μg/L, respectively), followed by leaves (2,3±0,3 μg/g w.w.; 13±2 μg/g w.w.) and stems (0,9±0,4 μg/g w.w.; 5±1 μg/g w.w.). Pigments content (chlorophyll-a, chlorophyll-b, pheophytins and carotenoids) decreased after 14 days but ratios of damage (chl-b/chl-a; pheo-a/chl-a) were ≤ 1, indicating no significant damage. Taking into account removal percentages and accumulation of flumequine by P. pusillus, this macrophyte could be considered a good candidate for phytoextraction, although further studies under more complex and real conditions are necessary to fully assess this point.