Water-compatible Janus molecularly imprinted particles with mouth-like opening: Rapid removal of pharmaceuticals from hospital effluents

Pharmaceuticals in hospital effluents, often discharged into the public sewage network without sufficient treatment, have shown negative impacts to the human health and aquatic environment. However, the conventional adsorbents used to remove these micropollutants had several deficiencies, including slow uptake kinetics and poor selectivity. To overcome these challenges, water-compatible Janus MIP particles (J-MIPs) with mouth-like openings were synthesized using seeded interfacial polymerization in this work. Among the series of J-MIPs, the selected J-MIP3 showed fast binding kinetics (∼40 s) towards the target pollutant. The theoretical and instrumental analysis suggested that the electrostatic interaction, hydrogen bond and hydrophobic reaction constituted the dominant mechanism for J-MIP3's recognition of target pharmaceutical. Selectivity and robustness tests indicated that the synthetic method was promising in practical application. Finally, the feasibility of the J-MIP3 fixed-bed column in the rapid removal of propranolol (PRO) from hospital effluents was successfully demonstrated. Compared to the activated carbon fixed-bed column, the J-MIP3 fixed-bed column showed at least 7-fold enhancement in its treatment efficiency. To the best of our knowledge, this is the first time that the accelerated mass transfer and fast removal of the pharmaceutical from wastewater have been achieved by the synthetic receptor with asymmetric structure. We believe the present study will open new avenues for the development of multi-functional molecularly imprinted polymers as well as Janus materials in environmental science.