Sustainable adsorptive removal of antibiotics from aqueous streams using Fe3O4-functionalized MIL101(Fe) chitosan composite beads

In this study, we synthesized recyclable Fe3O4-functionalized MIL101(Fe) chitosan composite beads for the removal of tetracycline (TC), doxycycline (DC) and ciprofloxacin (CFX) antibiotics from aqueous streams. More than 99% removal efficiency for each antibiotic was achieved at optimum pH, dosage, concentration and contact time. Langmuir adsorption isotherms and pseudo-second-ord er kinetic model were suitable with correlation coefficient values close to 1 for all the antibiotics. Adsorption capacities of 45.33, 33.20 and 31.30 mg g(-1) for TC, DC and CFX, respectively, were reported by the synthesized Fe3O4-functionalized MIL101(Fe) chitosan composite beads. The Fe3O4-functionalized MIL101(Fe) chitosan composite beads were also tested for their regeneration ability, and a remarkable regeneration ability over up to 5 cycles was observed. The adsorption of TC, DC and CFX on the surface of Fe3O4-functionalized MIL101(Fe) chitosan composite beads was governed by the pi-pi interaction, H-bonding and electrostatic interaction between the antibiotics and adsorbent due to protonation, deprotonation and cation exchange in the aqueous solution. These results showed a good prospect for applying the reported beads towards removing antibiotics from pharmaceutical industry wastewater.

Automated summary

In this study, recyclable Fe3O4-functionalized MIL101(Fe) chitosan composite beads were synthesized for efficient removal of tetracycline, doxycycline, and ciprofloxacin antibiotics from water. The beads showed high removal efficiency (>99%) for all antibiotics under optimum conditions, and demonstrated excellent regeneration ability for up to 5 cycles. The adsorption mechanism involved pi-pi interaction, H-bonding, and electrostatic interaction between the antibiotics and the adsorbent. The results highlight the potential of these beads for antibiotic removal from pharmaceutical industry wastewater.