The influence of iron ions on the aqueous photocatalytic oxidation of deicing agents

Abstract

An experimental research into aqueous photocatalytic oxidation (PCO) of the deicing compounds, 2-ethoxyethanol (2-EE), diethylene glycol monomethyl ether (DEGMME), and ethylene glycol (EG) was undertaken. The addition of iron ions to the acidic aqueous solutions to be treated displayed complex influence on the oxidation efficiency of the above mentioned substances, resulting in a sharp increase of the PCO efficiency at smaller concentrations of iron ions followed by a drastic decrease with the increasing iron ion concentrations. The phenomena observed can be explained by the electron scavenging effect of the iron ions and the competitive adsorption of iron ions and the oxidized substances on titanium dioxide surface. The carbonic acids determined as the PCO by-products allow outlining some reaction pathways for the substances under consideration.