Potential effect and accumulation of veterinary antibiotics in Phragmites australis under hydroponic conditions

Potential effect of ciprofloxacin HCl (CIP), oxytetracycline HCl (OTC) and sulfamethazine (SM2) on the common wetland plant (Phragmites australis) was evaluated by measuring root activity, antioxidant enzymes and chlorophyll in leaf, and a study of the accumulation of antibiotics in plant was also included. Plants were incubated in six containers for 62 days and exposed to antibiotics at concentrations of 0, 0.1, 1, 10, 100, and 1000 μg/L in nutrient solutions. Results illustrated that high antibiotics concentrations (>10 μg/L) had a toxic effect on root activity and leaf chlorophyll, while hormesis occurred at low antibiotics concentrations (0.1–1 μg/L). As antibiotics dosages increased, superoxide dismutase and catalase activity significantly declined (5–55% and 9–58%), while peroxidase activity significantly increased. P. australis accumulated antibiotics via passive absorption, exposure to 1000 μg/L concentrations led to higher CIP, OTC, and SM2 contents in plants (13,834, 6901 and 2047 ng/g dry weight, respectively) than did exposure to 0.1 μg/L concentrations (345, 165, and 24 ng/g dry weight, respectively). The total antibiotics content in all plants followed the sequence CIP > OTC > SM2, and the distribution of all antibiotics followed the sequence root > leaf > stem. These preliminary results indicated that P. australis could both absorb and tolerate antibiotics concentrations typically found in wastewater.

► Antibiotics induce both the toxic effect and hormesis on chlorophyll and root. ► Antibiotics accumulation in plant had a positive correlation to expose content. ► Highly water soluble antibiotics are most likely to be taken up by plant. ► Antibiotics could be converted into their epimers in plants.