Efficient adsorption of Levofloxacin from aqueous solution using calcium alginate/metal organic frameworks composite beads

As a typical metal-organic framework material, UiO-66 has good potential for removing pharmaceuticals and personal care products from water. However, the application of this powdery adsorbent has been limited by the difficult recovery from the liquid. To overcome this weakness, we prepared composite beads constituted by sodium alginate and UiO-66 by solidification in CaCl2 solution. The material was characterized by SEM, FTIR, XRD, BET, and TGA methods. These composite beads were applied to remove a common antibiotic Levofloxacin (LOFX) from water, and the experimental parameters (i.e., initial LOFX concentration, adsorption time, pH, and adsorbent dose) were optimized. The adsorption data could be satisfactorily fitted to the Langmuir isotherm model (R-2=0.9871) and the pseudo-second-order kinetic model (R-2=0.9990). The regeneration experiment of the composite beads revealed that the adsorption efficiency of levofloxacin was higher than 70% even after 5 cycles. [GRAPHICS] .