POTENTIAL OF VETIVER GRASS TO REMOVE OXYTETRACYCLINE AND CIPROFLOXACIN FROM AQUATIC MEDIA: PRELIMINARY RESULTS FROM A HYDROPONIC STUDY

Prolonged persistence and antimicrobial resistance of pharmaceutical compounds have built interest in the search for an innovative, cost effective, and environmentally friendly remediation technique for these emerging contaminants. The present study investigates the potential of vetiver grass (Chrysopogon zizanioides L.), a high biomass, fast growing perennial grass, to remove ciprofloxacin, a major human antibiotic, and oxytetracycline, a widely used veterinary antibiotic. Major fractions of these antibiotics are excreted as active compounds, which are eventually released to the environment through municipal sewage and runoff streams from concentrated animal feeding operations (CAFOs), or as leakage streams from storage structures. This raises the concern of development and spread of antibiotic resistance and potential toxicity towards aquatic species. Phytoremediation is a promising solution because of its high potential of volume reduction of contaminants and cost effectiveness at the same time. Our previous studies demonstrated the effectiveness of vetiver grass in removing monensin and tetracycline, two other widely used human and veterinary antibiotics. The major objectives of this ongoing study are to i) evaluate the potential of using vetiver grass to remove oxytetracycline and ciprofloxacin from aqueous media as function of initial antibiotic concentrations (based on median and maximum concentrations reported in literature) and exposure time, and ii) determine the uptake, translocation, and transformation of oxytetracycline and ciprofloxacin in vetiver grass. Vetiver plants are being grown for 60 days in hydroponic tanks, spiked with the respective antibiotics under greenhouse conditions. Periodic water samples are collected to determine the degree and kinetics of antibiotics removal from the hydroponic media. Plant root and shoot samples are going to be collected at the end of the 60 day period to determine translocation and transformation. Data collection and analysis are currently in progress.