Hydrophobic Microenvironment Mediated Fenton-Like Beads for Efficiently Confining Free Radicals in Vicinity of Water-Soluble Contaminants

Abstract

Heterogeneous Fenton process can produce reactive oxygen species (ROS) on the catalysts surface; however, it will decay quickly in bulk solution, resulting in low utilization rate. Herein, we design a hydrophobic microenvironment mediated polymer beads (HMPBs) as an alternative platform to immobilize Fenton-like catalysts for efficiently confining ROS in hydrophilic area and improving mass transfer. Molecular dynamics simulation predicted that diffusion of reactants will slow down on mixed hydrophilic/hydrophobic interface so that the short-lived ROS can oxidize contaminants efficiently. Consequently, the optimal HMPBs exhibits remarkably increased degradation kinetic constants, which is about 4.4 and 1.5-fold improvement in comparison with single hydrophilic and hydrophobic beads, respectively. The continuous flow degradation system with packed column type is further developed to expanded its application for Fenton-like oxidation. Altogether, this work revealed the wettability effects on the Fenton chemstrity, manifesting a deeper understanding of ROS-based reaction behaviors on special wettability interface.

Keywords: Fenton oxidation, Hydrophobic microenvironment, Interface confinement, Beads, Continuous flow degradation