Singlet Oxygen in the Environment

Aquatic Phototransformation of Organic Contaminants Induced by Coloured Dissolved Natural Organic Matter

“…Since only a fraction of the latter are capable of inducing the transformation of dissolved compounds (by energy transfer [40] or oxidation [41]), singlet oxygen is potentially capable of inducing higher depletion rates than reactive triplet states. However, the second-order reaction rate constants of many organic contaminants with singlet oxygen are relatively low (several orders of magnitude below the diffusion limit), and the relevance of singlet oxygen for the depletion of organic contaminants in natural waters could be shown only in a relatively small number of cases [12,52].…”

Evaluation of conceptual models of natural organic matter (humus) from a consideration of the chemical and biochemical processes of humification

“…NOM also may undergo photochemical reactions by indirect processes in which photo-activated organic or inorganic species react with unactivated molecules (Goldstone and others, 2002;Faust, 1999;Larson and Marley, 1999;Zafiriou and others, 1984). Zafiriou and others (1984) pointed out that there is evidence that manganese, iron, copper, mercury, tantalum, carbon, nitrogen, oxygen, sulfur, chlorine, bromine, and iodine species enter into photochemical reactions in surface waters.…”

Quantitative structure‐activity relationships for oxidation reactions of organic chemicals in water

“…Singlet oxygen is a reactive, excited‐state species of oxygen that has been the subject of intense investigation in chemistry and biology for several decades [104]. In the aquatic environment, singlet oxygen is relevant as a photooxidant in sunlit surface waters, where it is generated by roughly 1% of the photons absorbed by the DOM [105]. Singlet oxygen is rather short lived in aqueous solution (lifetime of 3‐4 μs [19]) but can nevertheless efficiently interact with a variety of solutes.…”