Preparation of polydopamine nanofibers mat as a recyclable and efficient adsorbent for simultaneous adsorption of multiple tetracyclines in water

Abstract Particle usage form or rigorous and complex preparation procedures limits the practical applications of the most adsorbents for tetracyclines (TCs). Herein, novel polydopamine nanofibers mat (PDA-NFsM) has been simply synthesized by a facile one-step polymerization method. The pH effect, adsorption kinetics, adsorption isotherms, as well as the competitive adsorption behaviors of the three kinds of tetracyclines (TCs), including chlortetracycline hydrochloride (CTC), oxytetracycline (OTC) and tetracycline hydrochloride (TC) on PDA-NFsM has been systematically studied. The mass transfer efficiency of PDA-NFsM is extremely high, almost 88.9%, 85.3% and 82.6% of the equilibrium adsorption capacities of CTC, OTC and TC have been achieved in the first 2 min of the adsorption process, which is superior to many other reported materials. The maximum adsorption capacity of PDA-NFsM for TCs at 25 °C could reach up to 86.2–161.3 mg/g. Furthermore, the possible adsorption mechanisms were studied by theoretical calculation and spectral analysis. Hydrogen bond was proved to be the main interaction mechanism between the adsorbates and the sorbent. As a kind of “monolithic” material, the PDA-NFsM can be easily separated from liquid mediums. Moreover, the excellent reusability endows PDA-NFsM with great value in practical application.