Advanced oxidation processes based on the in situ activation of oxidants via UVC and solar radiation for the simultaneous elimination of microcontaminants and pathogens

Abstract

The contamination of surface water by contaminants of emerging concern and, more recently, by pathogenic bacteria is increasingly attracting the attention of the scientific community and society to avoid the risk of diseases and the production of superbugs. In this sense, this postdoctoral project aims to study the in situ activation of oxidants (H2O2, S2O82-, HSO5- and HOCl) by irradiating the system with UVC light, UVA light in the presence of Fe3+ ion and the complex agent ethylenediamine-N,N'-disuccinic acid (EDDS) for use in neutral solutions, as well as to use this last process on a semi-pilot scale and using natural solar radiation. These processes will be used for the simultaneous elimination of an endocrine disruptor, antibiotic, and pesticide in addition to the bacteria Escherichia coli, Salmonella typhimurium and Bacillus subtilis. The performance of the UVC/Oxidants, UVA/Oxidants/Fe3+-EDDS, and Solar/Oxidants/Fe3+-EDDS processes will be monitored by the concentrations decay of organics and bacteria, the byproducts and inorganic ions produced, and the possible regrowth of bacteria. Tests with scavengers and electronic paramagnetic resonance spectroscopy will be carried out to elucidate the radicals generated, e.g., HOÏ, SO4Ï- or ClÏ, and the main oxidation mechanisms. (AU)