ULTRAVIOLET- AND SOLAR LIGHT-ACTIVATED NANOSTRUCTURED TiO2 PHOTOCATALYSTS: APPLICATION IN THE DESTRUCTION OF CYANOTOXINS, A GROUP OF EMERGING DRINKING WATER CONTAMINANTS

摘要

The increasing appearance of cyanotoxins in natural, surface, brackish and recreational waters is alarming the environmental and health organizations, as they pose a significant health hazard to humans and animals and to the viability of the ecosystem. These toxic compounds are produced by approximately 50 genera of cyanobacteria and released in the environment (water bodies) as secondary metabolites of cyanobacteria and at the end of their life cycle. Eutrophication of water bodies increases the likelihood of the growth of the hazardous cyanobacteria genera and the formation of cyanobacterial harmful algal blooms (CyanoHABs). Cyanotoxins have a wide range of health effects starting from mild, including skin irritations, to more severe such as liver failure, irreversible damage of the nerves and even death. Regulatory guidelines for the best available technology and maximum contaminant level of cyanobacterial and their toxins are not established yet, even though they have been included in the Contaminant Candidate List (CCL 1 and 2) of the USEPA since 1998. The most commonly found cyanotoxin in CyanoHABs is a hepatotoxin of the group of microcystins, microcystin-LR (MC-LR).