Efficiency of Saccharomyces Cerevisiae in Ceftriaxone Removal from Aquatic Environments: Kinetic, Isotherm of Absorption and Thermodynamics Study

Background & objectives: Antibiotics are potentially harmful contaminants, which can cause harmful effects on environmental equilibrium of ecosystems and the food chain. The aim of this study was to investigate the removal of ceftriaxone antibiotic by Saccharomyces Cerevisiae biosorbent from aquatic environments. Methods: This experimental study was conducted in a lab-scale batch reactor as discontinuous. The fungus strain was collected from the “Persian Type Culture Collection of Iran”. After activating fungus strain, the plates were placed in incubator for 7 to 10 days at 25°C. Fungus cultures were transferred to a potato dextrose agar medium (PDA) in the form of dry ice and subsequently cultivated in potato dextrose broth (PDB) medium. In order to determine the adsorption efficiency of ceftriaxone from aqueous solutions, the impact of variables effected on adsorption including pH, initial concentration of antibiotic, biosorbent dose, contact time and temperature were investigated. The physical, structural and surface properties of produced biosorbent were determined by FTIR, SEM and BET techniques. Also, thermodynamic parameters, adsorption isotherms and adsorption kinetics were studied. Ceftriaxone concentrations were measured by UV-Visible spectrophotometer in 276 nm wavelength. Results: The results showed that the maximum absorption of ceftriaxone was 78% at pH=6, the initial ceftriaxone concentration of 10 mg/L, the absorbent dose of 0.75 g, the contact time of 120 min and temperature of 25°C. The surface adsorption of Ceftriaxone on biosorbent was followed by Langmuir isotherm (R2=0.903), and kinetic processes were more correlated with the Pseudo-second order model (R2=0.961). Conclusion: It can be concluded from present study that the biosorbent produced from baker's yeast can be used as an effective and inexpensive adsorbent for ceftriaxone removal from aqueous solutions.