Selective Removal of Sulfamethoxazole by Molecularly Imprinted Channel Catalyst Activating Persulfate Based on Interfacial Confinement

Abstract

The excessive discharge of sulfamethoxazole (SMX) is substantially threatening the water safety, calling for effective technologies for targeted removing of antibiotics from wastewater. In this work, a molecularly imprinted channel (MIC) catalyst was developed to specifically eliminate SMX from water by confining SMX in the catalyst and mediating electron transfer for free radical production. The MIC catalyst exhibited the performance of specific recognition and efficient degradation for SMX with the imprinting factor above 4.0 and 95% removal. In situ attenuated total reflection Fourier transform infrared spectroscopy results revealed that the selective adsorption was performed by the weak interaction of hydrogen bonding, π–π conjugation, and electrostatic interaction. The MIC catalyst can accelerate the oxidizing rate over threefold enhancement of kobs compared with the non-imprinted system with the assistance of interfacial confinement. Meanwhile, electron transfer facilitated the cycling of Fe species, which ensures the maximum utilization of oxidant. Finally, MIC catalysts showed a favorable degradation for SMX and COD in pharmaceutical wastewaters. This work provides an insight into the effective removal of refractory antibiotics with high toxicity in wastewater.