Preparation of phenol-formaldehyde composite modified with chitosan for the simultaneous removal of antibiotics and heavy metal ions in waters.

In current study, a new adsorbent based on aminated phenol-formaldehyde composite was prepared using chitosan as modifier. Various techniques were adopted to characterize the morphology and structure of the prepared adsorbent. Due to the abundant amino groups, the obtained adsorbent presented satisfactory adsorption performance towards fluoroquinolones (FQs) and heavy metal ions (including Cu2+, Cd2+ and Pb2+) by means of multiple forces including electrostatic, H-bonding, π-π stacking interactions (for FQs) and chelating force (for heavy metal ions). Studies about the adsorption kinetics, isotherm and thermodynamics were performed to inspect the adsorption behaviors of studied FQs and heavy metal ions on the new adsorbent. After optimizing the adsorption parameters, the obtained adsorbent were employed to remove FQs, Cu2+, Cd2+ and Pb2+ in various environmental waters. The removal rates for FQs and heavy metal ions were 91.8-98.6 % and 94.4-98.5 %, respectively, which were significantly higher than that obtained on unmodified phenol-formaldehyde resin (20.7-49.0 % for FQs and 35.1-43.0 % for heavy metal ions). At the same time, the adsorbent exhibited good preparation repeatability in different batches, acceptable stability and reusability. The current study well demonstrated the potential application of the new adsorbent in the simultaneous removal of organic and inorganic pollutants from aqueous waters.