Abstract
Advanced oxidation processes based on peroxymonosulfate (PMS) for the removal of quaternary ammonium compounds have challenges, including high metal leaching and excessive oxidant consumption, which limit their practical application. In this work, Fe atoms were firstly intercalated into the structure of the zeolite through ion exchange and then transformed into Fe prussian blue analog (Fe PBA) in-situ through coprecipitation followed by a calcination process. Through immobilizing the reactive catalytic center to a specific site, the leaching rate of Fe was compressed to about 0.25 mg·L-1, accounting for only 6 % of the Fe PBA without zeolite immobilization. The incorporation of zeolite has triggered increased hydrophilicity while retaining the negatively charged property of Fe PBA, implying enhanced dispersity of the catalyst in the aqueous environment and attraction towards benzalkonium chloride (BAC) and PMS molecules. Intuitively, the reactive oxidative species (ROS) generated through PMS activation require less diffusion distance to encounter BAC molecules, as they are confined within the microenvironment around the surface due to this weak electrostatic attraction. Therefore, an increase in ROS utilization efficiency was observed with a significant reduction in PMS dosage. Remarkably, 99.83 % of BAC (10 mg·L-1) was eliminated within 60 min with only 0.5 mM PMS, which is much lower than the reported 5–100 mM PMS. More importantly, the post-annealing brought an increased amount of graphitic carbon, which enhanced singlet oxygen production and further improved the degradation efficiency of BAC molecules due to its unique selectivity. This study presents a feasible strategy for simultaneously enhancing PMS utilization and reducing metal ion leaching.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call