Efficient removal of antibiotics from wastewater by chitosan/polyethyleneimine/Ti3C2 MXene composite hydrogels: Synthesis, adsorption, kinetics and mechanisms

A novel chitosan-based composite hydrogel (CS/PEI-MXene) made of polyethyleneimine and Ti 3 C 2 MXene as modifiers and acrolein as crosslinker has been synthesized simply and conveniently, which could be applied in the removal of residual antibiotic pharmaceuticals (chlortetracycline (CTC), ibuprofen (IBU), etc.) from aqueous environments. The CS/PEI-MXene was used as an adsorbent for chlortetracycline and ibuprofen. The removal rates of CTC and IBU could be achieved to 91.1 % and 99.25 %, respectively. In addition, the reusability of CS/PEI-MXene for CTC and IBU appeared good capacity, and the removal rate was maintained at approximately 70 % after five cycles. FT-IR, XPS, and zeta potential were used to show that the hydrogel was successfully synthesized, and its physicochemical characteristics were studied. Systematically examined were conducted on the effects of pH (3−10), contact time (0–120 min), and temperature (30–40 °C) on the adsorption efficiency of CS/PEI-MXene. The adsorption mechanism of CS/PEI-MXene on CTC and IBU mainly included electrostatic interactions and hydrogen bonding. Overall, the development of MXene based hydrogel adsorbent will provide a practical approach to the treatment of wastewater containing antibiotic pharmaceuticals and have great potential for practical applications.