Ion exchange-based magnetic micro-cleaners harness multiple effects to enhance antibiotics removal

The widespread misuse of antibiotics has created significant environmental and public health concerns due to their persistence in aquatic ecosystems. Therefore, effective strategies for antibiotics removal are urgently needed. Here we propose an ion-exchange-based magnetic micro-cleaner to enhance antibiotic removal from contaminated water bodies through multiple effects. The micro-cleaner is composed of two functionally complementary modules, heterojunction catalysts (Fe₃O₄/MIL-101Fe) and magnetic anionic ion-exchange resin (mAIEX). The mAIEX generates pH gradients and phoretic flows, i.e., flow induced by chemical gradient for the assembly of catalyst, local pH regulation to activate the catalyst and enhanced transport/enrichment of antibiotic for improved treatment efficiency. Benefited from above merits, a high antibiotic removal efficiency of 98 % in 40 ppm solution is reached within 90 min without requiring global pH regulation or mixing. With the assistance of a magnet, the micro-cleaner can removal antibiotics in hard-to-reach tunnels or spaces. This work presents a novel solution for efficient antibiotics removal at low energy consumption and secondly pollution.