Molecularly imprinted catalytic membrane reactor for improved advanced oxidation degradation efficiency of low concentration pollutants

Abstract

Improving the efficiency of advanced oxidation technology to remove low concentration pollutants is one of the important problems in water treatment. In this study, a molecularly imprinted catalytic membrane (MICM) reactor has been designed and developed to solve this problem. The results showed that the MICM rapidly separated and degrade refractory pollutants in complex aqueous media, while significantly improving oxidation efficiency. Compared to Fe3O4, rate constants on the MICM in three different systems were significantly increased 3.5–33-fold, with kobs in persulfate (PS), hydrogen peroxide (H2O2), and peroxymonosulfate (PMS) oxidation systems reaching 0.093 min−1, 0.073 min−1, and 0.142 min−1, respectively. The results of dynamic experiments showed that sulfamethoxazole (SMX) removal efficiencies in MICM/PMS and H2O2 oxidation systems could exceed 90% within 150 min. Studies have shown that the targeting catalysis process of the MICM benefited from a coupling effect, which endows the MICM with stronger hydrophilicity and superior stability. Based on detection results and kinetic calculations, MICMs could not only selectively identify target pollutants, but also adsorb oxidants to promote non-free radical reactions represented by 1O2 in PMS oxide process. This enabled more efficient contact between the oxidant, the targeted pollutant, and the catalytic core of the MICM, increasing the oxidation efficiency. This study may provide reference for improving the efficiency of advanced oxidation processes and the application of molecularly imprinted catalysts.