The adsorption property of in-situ synthesis of MOF in alginate gel for ofloxacin in the wastewater

ABSTRACT Although metal–organic frameworks (MOFs) are advantageous to the removal of organic pollutants, the general MOFs in powder form is disadvantageous to their practical applications. In-situ MOF synthesis in alginate gel is a good way to fabricate an MOF composite for many applications, which is different from blending MOF particles with polymers. In-situ synthesis of Zeolitic Imidazolate Framework-8 (ZIF-8) in alginate gel is in the form of beads with rough wrinkles and has many pores inside. When used as an absorbent, in-situ synthesis of ZIF-8 in alginate gel could remove 97.7 ± 0.9% of ofloxacin from ofloxacin solution and the equilibrium adsorption capacity is up to 160.6 ± 1.3 mg/g. During the adsorption, ofloxacin is first brought into the gel by the solvent exchange and gel microchannel adsorption, and it can then be absorbed by in-situ ZIF-8. Moreover, the adsorption efficiency can reach 85.5% even after four cycles of adsorption. We believe that in-situ synthesis of ZIF-8 in alginate gel will be an appropriate material for the removal of ofloxacin in the wastewater. GRAPHICAL ABSTRACT