Magnetic surface molecularly imprinted polymer for selective adsorption of quinoline from coking wastewater

Quinoline, a refractory organic pollutant in coking wastewater, will harm human health and the environment if discharged directly. However, if recycled, it has considerable economic value. To realise the efficient and selective adsorption of quinoline from coking wastewater, a novel magnetic surface molecularly imprinted polymer (SMIP/MCNSs) was prepared for the specific removal and recycling of quinoline, using magnetic carbon nanospheres (MCNSs) as a carrier, quinoline as a template molecule, and acrylamide (AAm) as a functional monomer. The key preparation conditions were systematically optimised. The structure, morphology, and adsorption behaviours of SMIP/MCNSs were investigated in detail. With an imprinted layer thickness of approximately 9 nm, SMIP/MCNSs exhibits favourable magnetic responsivity, good adsorption performance, and reusability. Owing to the existence of imprinted cavities, for an initial quinoline concentration of 50 mg L-1, a high adsorption capacity qe (76.63 mg g−1) and high partition coefficient PC (0.847 mg g−1 μM−1) for SMIP/MCNSs are obtained. Competitive adsorption experiments revealed that SMIP/MCNSs possesses a greater affinity towards quinoline than towards other analogues, indicating its high quinoline selectivity. Moreover, SMIP/MCNSs shows a particular binding property for quinoline in real coking wastewater. Therefore, SMIP/MCNSs shows promise for the selective removal and enrichment recovery of quinoline in wastewater.