Phytoremediation of antibiotic-contaminated wastewater: Insight into the comparison of ciprofloxacin absorption, migration, and transformation process at different growth stages of E. crassipes

Abstract

The selection of aquatic plants at different growth stages and their absorption, migration, and transformation mechanisms has yet to be clarified. In this study, Eichhornia crassipes at the seedling and mature stages were selected to uptake antibiotics under hydroponic conditions. The results showed that the enrichment of ciprofloxacin (CIP) in roots at the seedling and mature stages were 7.72～2114.39 μg g−1 and 0.07～3711.33 μg g−1, respectively. The enrichment of CIP in aerial parts at the seedling and mature stages were 16.38～24.24 μg g−1 and 9.55～20.13 μg g−1, respectively. The translocation from roots to aerial parts at the seedling stage was high, as evidenced by the relatively higher transfer factor (TF). In addition, eight and ten major metabolic products were observed in the tissues of seeding and mature stage of E. crassipes, respectively. The metabolic pathway of CIP was short at the maturity stage, and CIP had a strong upward migration ability at the seedling stage, facilitating long-time photodegradation. However, E. crassipes exhibited a poor CIP tolerance at the mature stage and decayed relatively early. Therefore, the seedling stage of E. crassipes was proposed to be applied for phytoremediation, and these findings might improve the ability to phytoremediation of antibiotic-contaminated water.