THE INFLUENCE OF FERROUS/FERRIC IONS ON THE EFFICIENCY OF PHOTOCATALYTIC OXIDATION OF POLLUTANTS IN GROUNDWATER

摘要

The complex influence of ferrous / ferric ions on the efficiency of aqueous photocatalytic oxidation (PCO) of 2-ethoxyethanol (2-EE), methyl tert-butyl ether (MTBE) and humic substances (HS) was established. A drastic efficiency increase at lower concentration of ferrous/ferric ions was observed to change to a sharp decrease at higher concentrations for 2-EE and MTBE, whereas for HS only an inhibitive effect of Fe~(2+/3+) on the PCO efficiency was noticed. The authors proposed an explanation for the observed phenomena based on the different sensitivities of pollutants towards radical-oxidation reactions and. the competitive adsorption of metallic ions and pollutants on the TiO_2 surface.