Photochemical Degradation of Hydrophilic Xenobiotics in the UV/H2O2‐process. Influence of Humic Matter on the Degradation Rate of 2‐Amino‐1‐naphthalenesulfonate and Ethylenediaminetetraacetate

Abstract

AbstractPhotochemical oxidation methods are able to eliminate hydrophilic xenobiotics with a high efficiency. In waters with high DOC values caused by humic substances (HS) which are able to absorb UV light, problems can result. The degradation rates of the micropollutants using irradiation wavelengths in the range between λ = 200 nm to λ = 260 nm are significantly influenced by HS. This is mainly caused by the high absorption of the HS at shorter wavelength. In the presence of HS, the photolytic degradation of EDTA and FeEDTA was slowed down by an inner filter effect. A similar tendency could be seen for the photolytic degradation of 2‐amino‐1‐naphthalenesulfonate where additional effects to the inner filter effect were also operating. In the UV/H2O2‐process, the decrease of the degradation rate could be assigned to the ability of the HS to scavenge HO radicals.