Magnetic microsphere to remove tetracycline from water: Adsorption, H2O2 oxidation and regeneration

Antibiotics emerge as potential ecological risk in the environment, and adsorption process is a promising way to remove such chemicals. We developed a simple way to produce a kind of magnetic polystyrene EDTA microsphere (MPEM), via solvothermal treatment with ferric ammonium oxalate. The resins acquired good adsorptive, oxidative and magnetic properties to remove tetracycline (TC) in water. The characterization revealed that magnetic nanoparticles had attached on the surface of microsphere, enhancing the adsorption and oxidation of TC molecule. The Langmuir model fitted the isotherms well with a maximum capacity of 166 mg/g. The rate constant of first order kinetics to remove TC by adsorption was 0.145 h−1, while after adding H2O2, the rate constant rocketed to 2.36 h−1. Meanwhile, MPEM capacity was also regenerated by catalyzing H2O2 oxidation, with the adsorption capacity remained 90% after 10 rounds of recycling. In addition, the mechanisms of adsorption and regeneration were also explored. This material with H2O2 oxidation realized adsorption, degradation, separation and reuse simultaneously, showing great potential to remove dissolved antibiotics like tetracycline and other pollutants from water environment.