title: Surface water disinfection by chlorination and advanced oxidation processes: Inactivation of an antibiotic resistant E. coli strain and cytotoxicity evaluation.
abstract: The release of antibiotics into the environment can result in antibiotic resistance (AR) spread, which in turn can seriously affect human health. Antibiotic resistant bacteria have been detected in different aquatic environments used as drinking water source. Water disinfection may be a possible solution to minimize AR spread but conventional processes, such as chlorination, result in the formation of dangerous disinfection by-products. In this study advanced oxidation processes (AOPs), namely H2O2/UV, TiO2/UV and N-TiO2/UV, have been compared with chlorination in the inactivation of an AR Escherichia coli (E. coli) strain in surface water. TiO2 P25 and nitrogen doped TiO2 (N-TiO2), prepared by sol-gel method at two different synthesis temperatures (0 and -20°C), were investigated in heterogeneous photocatalysis experiments. Under the investigated conditions, chlorination (1.0 mg L(-1)) was the faster process (2.5 min) to achieve total inactivation (6 Log). Among AOPs, H2O2/UV resulted in the best inactivation rate: total inactivation (6 Log) was achieved in 45 min treatment. Total inactivation was not observed (4.5 Log), also after 120 min treatment, only for N-doped TiO2 synthesized at 0°C. Moreover, H2O2/UV and chlorination processes were evaluated in terms of cytotoxicity potential by means of 3-(4,5-dime-thylthiazol-2-yl)-2,5-diphenylte-trazolium colorimetric test on a human-derived cell line and they similarly affected HepG2 cells viability.
authors.affiliation: Department of Sanitary and Environmental Engineering, Universidade Estadual da Paraíba - UEPB, Brazil.
authors.forename: Andreza Costa
authors.initials: AC
authors.lastname: Miranda
authors.affiliation: Department of Chemistry and Biology, European Laboratory for the Investigation of Food-Induced Diseases (ELFID), University of Salerno, Via Giovanni Paolo II, 132, 84084 Fisciano, SA, Italy.
authors.forename: Marilena
authors.initials: M
authors.lastname: Lepretti
authors.affiliation: Department of Civil Engineering, University of Salerno, Via Giovanni Paolo II, 132, 84084 Fisciano, SA, Italy. Electronic address: l.rizzo@unisa.it.
authors.forename: Luigi
authors.initials: L
authors.lastname: Rizzo
authors.affiliation: Department of Chemistry and Biology, European Laboratory for the Investigation of Food-Induced Diseases (ELFID), University of Salerno, Via Giovanni Paolo II, 132, 84084 Fisciano, SA, Italy.
authors.forename: Ivana
authors.initials: I
authors.lastname: Caputo
authors.affiliation: Department of Industrial Engineering, University of Salerno, Via Giovanni Paolo II, 132, 84084 Fisciano, SA, Italy.
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Vaiano
authors.affiliation: Department of Industrial Engineering, University of Salerno, Via Giovanni Paolo II, 132, 84084 Fisciano, SA, Italy.
authors.forename: Olga
authors.initials: O
authors.lastname: Sacco
authors.affiliation: Department of Sanitary and Environmental Engineering, Universidade Estadual da Paraíba - UEPB, Brazil.
authors.forename: Wilton Silva
authors.initials: WS
authors.lastname: Lopes
authors.affiliation: Department of Industrial Engineering, University of Salerno, Via Giovanni Paolo II, 132, 84084 Fisciano, SA, Italy.
authors.forename: Diana
authors.initials: D
authors.lastname: Sannino
mesh_terms: D004203:Disinfection / Q000379:methods*; D004352:Drug Resistance, Microbial; D004926:Escherichia coli / Q000502:physiology*; D054879:Halogenation; D006861:Hydrogen Peroxide; D010084:Oxidation-Reduction; D014466:Ultraviolet Rays; D018508:Water Purification / Q000379:methods*
chemical_list: D006861:Hydrogen Peroxide
keywords: Antibiotic resistance; Cytotoxicity MTT assay; Drinking water; H(2)O(2)/UV; Photocatalysis