Effect of μM Fe addition, mild heat and solar UV on sulfate radical-mediated inactivation of bacteria, viruses, and micropollutant degradation in water. (1st September 2018)

• Record Type: Journal Article
• Authors: Marjanovic, Miloch; Giannakis, Stefanos; Grandjean, Dominique; de Alencastro, Luiz Felippe; Pulgarin, Cesar
• Is Part Of: Water research. Volume 140(2018)
• Page Start: 220
• Page End: 231
• Publication Date: 2018-09-01
• Subjects: Advanced oxidation process (AOPs) -- Sulfate radicals -- Photo-fenton -- E. coli -- MS2 bacteriophage -- Emerging contaminants; Water -- Pollution -- Research -- Periodicals; 363.7394
• DOI: 10.1016/j.watres.2018.04.054
• Languages: English
• ISSNs: 0043-1354

Abstract

Abstract: In this work, solar disinfection (SODIS) was enhanced by moderate addition of Fe and sodium peroxydisulfate (PDS), under solar light. A systematic assessment of the activating factors was performed, firstly isolated, then in pairs and concluded in the combined Fe/heat/solar UV-PDS activation process. Solar light was the most effective (single) activator, and its combination with Fe and heat (double activation) yielded high level of synergies (up to S = 2.13). The triple activation was able to reduce the bacterial load up to 6-log in less than 1 h, similarly to the photo-Fenton process done in comparison (SODIS alone: >5 h). Fe-oxides were suitable activators of PDS under the same conditions while the presence of organic matter enhanced bacterial inactivation by the triple activated PDS process. The degradation of a (selected) mixture of micropollutants (i.e. drugs, pesticides) was also achieved in similar order of magnitude, and faster than the photo-Fenton process. Finally, the removal of a viral pathogen indicator (MS2 bacteriophage) was attained at minute-range residence times. The aforementioned facts indicate the suitability of the mild, combined process, as a potential SODIS enhancement, producing safe drinking water for sunny and especially for developing countries. Highlights: Low Fe, mild heat and solar light were assessed as sulfate radical generators. Single, double and triple factor activation of peroxydisulfate was performed. Solar light and mild heat were the most efficient activators in the SODIS context. Benchmarking with the photo-Fenton process was performed in comparison. SO4 . - was more efficient than HO against micropollutants, while similar for microorganisms