Natural Zeolite's Adsorption of Levofloxacin in Water and the Effects of Environmental Factors

Natural zeolites (NZ) were used as an adsorbent to remove levofloxacin (LEV) in water. Through static adsorption experiments combined with the XRD, FTIR, and XRF characterization methods, the structure of NZ, the effect of NZ adsorption on LEV and the adsorption mechanism were discussed. The effects of environmental factors, including humic acid and ammonia nitrogen, on the adsorption effect were studied. The XRD analysis showed that the NZ used was clinoptilolite. When the initial concentration of LEV was 20 mg/L, the NZ reached adsorption saturation. The optimal pH was 6.5. The adsorption process was in accordance with the Langmuir isothermal model and the maximum adsorption capacity is 23.65 mg/g. The adsorption mechanisms were ion exchange and hydrogen bonding. The presence of humic acid and ammonia nitrogen significantly reduced the adsorption capacity of LEV. It is speculated that site competition and electrostatic competition inhibited the adsorption of LEV.