title: Fate of antimicrobials in duckweed Lemna minor wastewater treatment systems.
abstract: The fate of four antimicrobials (cefadroxil, CFD; metronidazole, METRO; trimethoprim, TRI; sulfamethoxazole, SMX) was studied in Lemna minor systems and the role of different mechanisms on their removal was evaluated. All micropollutants were significantly removed in batch experiments with active Lemna minor; the highest removal was observed for CFD (100% in 14 d), followed by METRO (96%), SMX (73%) and TRI (59%) during 24 d of the experiment. Calculation of kinetic constants for hydrolysis, photodegradation, sorption to biomass and plant uptake revealed significant differences depending on the compound and the studied mechanism. For METRO, TRI and SMX the kinetic constants of plant uptake were by far higher comparing to those of the other mechanisms. The transformation products of antimicrobials were identified using UHPLC-QToF-MS. Two were the main degradation pathways for TRI; hydroxylation takes place during both phyto- and photodegradation, while demethylation occurs only in absence of Lemna minor. The operation of a continuous-flow duckweed system showed METRO and TRI removal equal to 71±11% and 61±8%, respectively. The application of mass balance and the use of published biodegradation constants showed that plant uptake and biodegradation were the major mechanisms governing METRO removal; the most important mechanism for TRI was plant uptake.
authors.affiliation: Water and Air Quality Laboratory, Department of Environment, University of the Aegean, University Hill, 81100, Mytilene, Greece.
authors.forename: Evangelia I
authors.initials: EI
authors.lastname: Iatrou
authors.affiliation: Water and Air Quality Laboratory, Department of Environment, University of the Aegean, University Hill, 81100, Mytilene, Greece.
authors.forename: Georgia
authors.initials: G
authors.lastname: Gatidou
authors.affiliation: Laboratory of Analytical Chemistry, Department of Chemistry, National and Kapodistrian University of Athens, Panepistimioupolis Zografou, 15771, Athens, Greece.
authors.forename: Dimitrios
authors.initials: D
authors.lastname: Damalas
authors.affiliation: Laboratory of Analytical Chemistry, Department of Chemistry, National and Kapodistrian University of Athens, Panepistimioupolis Zografou, 15771, Athens, Greece.
authors.forename: Nikolaos S
authors.initials: NS
authors.lastname: Thomaidis
authors.affiliation: Water and Air Quality Laboratory, Department of Environment, University of the Aegean, University Hill, 81100, Mytilene, Greece. Electronic address: astas@env.aegean.gr.
authors.forename: Athanasios S
authors.initials: AS
authors.lastname: Stasinakis
mesh_terms: D000327:Adsorption; D035961:Alismatales / Q000187:drug effects / Q000378:metabolism*; D000890:Anti-Infective Agents / Q000302:isolation & purification / Q000378:metabolism* / Q000633:toxicity; D001673:Biodegradation, Environmental; D019149:Bioreactors; D006868:Hydrolysis; D010782:Photolysis; D018675:Toxicity Tests; D014874:Water Pollutants, Chemical / Q000302:isolation & purification / Q000378:metabolism* / Q000633:toxicity; D018508:Water Purification / Q000379:methods*
chemical_list: D000890:Anti-Infective Agents; D014874:Water Pollutants, Chemical
keywords: Constructed wetlands; Elimination; Micropollutants; Pharmaceuticals; Plant uptake