Compact wirelessly-powered photocatalyst-coated spheres: Concept development and application for oxidative wastewater treatment and membrane fouling control

Abstract

Wirelessly powered photocatalyst-coated spheres (WPS) were successfully developed and wirelessly powered from outside the reactor using resonant inductive coupling. Diverse applications of WPS were demonstrated for the visible light-assisted photocatalytic degradation of methylene blue (textile dye), diclofenac, and triclosan (pharmaceutical compounds) and fouling control of ceramic membranes. These catalyst-coated WPS successfully generated O2− as the main reactive oxygen species (ROS). As demonstrated, these WPS are low-cost, easy to fabricate, have excellent visible light sources, and can be used as the photocatalyst carrier. The acrylic shell of WPS is transparent to light with wavelengths from 300 to 800 nm. Increasing the number of WPS can increase the light intensity proportionally, and 8 WPS can be powered by one power coil outside the reactor. A higher quantity of WPS per reaction volume can be used to improve the reactivity, bringing the use of WPS reactors closer to industrial applications. This is the first report on the use of WPS in the ceramic membrane reactor for fouling control, a 50 % delay compared to control, and highlights the versatility of this system. This work would open up new exploration avenues for membrane fouling control using WPS-based heterogeneous photocatalysis.