abstract
Pathogens in drinking water remain a challenge for human health, photo-Fenton process is a promising technique for pathogen inactivation, herein, two common iron oxides, hematite and magnetite mediate persulfate (per-oxymonosulfate-PMS - and peroxydisulfate-PDS) involved photo-Fenton-like processes were constructed for E. coli inactivation, and the inactivation performance was investigated and compared with the photo-Fenton process under a low intensity UVA irradiation. Results indicated that with a low dose of iron oxides (1 mg/L) and inorganic peroxides (10 mg/L), PMS-involved photo-Fenton-like process is the best substitute for the photoFenton one over pH range of 5-8. In addition, humic acid (HA, one of the important components of natural organic matter) incorporated iron oxide-mediated photo-Fenton-like processes for bacteria inactivation was also studied, and facilitating effect was found in UVA/hematite/PMS and UVA/magnetite/PDS systems. Reactive oxygen species (ROS) exploration experiments revealed that & sdot;OH was the predominant radical in H2O2- and PDS- containing systems, whereas 1O2 was one of the principal reactive species in the PMS systems. In addition to the semiconductor photocatalysis of iron oxides and UVA-activated oxidants, iron-complexes (iron-oxidant com-plexes and iron-bacteria complexes) mediated ligand-to-metal charge transfer (LMCT) processes also made contribution to bacterial inactivation. Overall, this study demonstrates that it is feasible to replace H2O2 with PMS in a photo-Fenton-like process for water disinfection using a low dose of reagents, mediated by cheap catalysts, such as hematite and magnetite, it is also hoped to provide some insights to practical water treatment.
keywords
NATURAL ORGANIC-MATTER; HYDROGEN-PEROXIDE; WATER-TREATMENT; OXIDATION; DECOMPOSITION; POLLUTANTS; MECHANISM; KINETICS; REMOVAL; FE3+
subject category
Environmental Sciences & Ecology
authors
Jia, JL; Minella, M; González, ID; Lehmann, AH; Li, D; Gonçalves, NPF; Prevot, AB; Lin, T; Giannakis, S
our authors
