Chapter 23: Singlet Oxygen Mediated Photodegradation of Water Contaminants

This chapter contains a brief compilation and discussion about two aspects of the contribution of photogenerated singlet molecular oxygen (O₂(¹Δ_g)) to environmental sustainability, in the context of surface-waters contamination. The first point assessed was the importance of the oxidative species in the photopromoted generation of humic substances, a well-known family of native photosensitizers. The second aspect evaluated was referred to the cooperative photosensitizing effect of humic substances and riboflavin in the O₂(¹Δ_g)-mediated degradation of hydroxy-aromatic compounds. Riboflavin is also known as a natural component of surface waters and hydroxy-aromatic derivatives are considered archetypal water pollutants.