Enhanced Peroxymonosulfate\nActivation by a Benzoquinone-Functionalized\nCarbon Nanotube Filter for Micropollutant Degradation

Abstract

The utilization of redox-active quinone-like compounds\nto activate\nperoxymonosulfate (PMS) has become a viable method for decontaminating\npolluted water. However, redox-active compounds must be added <i>ex situ</i> as oxidant activators, which leads to secondary\npollution. Herein, we present a rationally designed new carbon nanotube\nnanohybrid filter that is modified with benzoquinone-containing diamine\nmonomers (AQPDA) for the activation of PMS to achieve the efficient\ndecomposition of micropollutants. The hybrid filtration system effectively\navoids secondary contamination and eliminates the need for electricity,\nthus enhancing the viability and sustainability of the technology.\nSulfamethoxazole (SMX) is used to assess the effectiveness of the\nsystem and to identify the key operational parameters. With optimized\noperational parameters for the system, 100% of the SMX can be removed\nwithin 40 min in recirculating flow mode. Experiments with radical\nquenching and electron paramagnetic resonance studies proved that\nnonradical routes were the dominant process for the destruction of\nSMX. Based on the experiments, working mechanisms and degradation\npathways were proposed. Experimental results illustrated that the\nsystem could resist the interference of background substances in water\nsuch as inorganic anions and humic acid. This research offers a promising\nroute for environmental remediation using quinone-loaded carbon nanotubes.