A photoelectrocatalytic process that disinfects water contaminated with Mycobacterium kansasii and Mycobacterium avium.
Nontuberculous mycobacteria are resistant to conventional water treatment; indeed, they have been recovered from a wide variety of environmental sources. Here, we applied the photoelectrocatalytic technique using a Ti/TiO2-Ag photoanode to inactivate mycobacteria. For a mycobacteria population of 5 × 10(8) CFU mL(-1), we achieved 99.9 and 99.8% inactivation of Mycobacterium kansasii and Mycobacterium avium with rate constant of 6.2 × 10(-3) and 4.2 × 10(-3) min(-1), respectively, after 240 min. We compared the proposed method with the photolytic and photocatalytic methods. Using a mycobacteria population of 7.5 × 10(4) CFU mL(-1), the proposed Ti/TiO2-Ag photoanode elicited total mycobacteria inactivation within 3 min of treatment; the presence of Ag nanoparticles in the electrode provided 1.5 larger degradation rate constant as compared with the Ti/TiO2 anode (1.75 × 10(-2) for M. kansassi and 1.98 × 10(-2) for M. avium). We monitored the degradation of the metabolites released during cellular lysis by TOC removal, sugar release, chromatography, and mass spectrometry measurements; photoelectrocatalysis and Ti/TiO2-Ag photoanodes furnished the best results.
Department of Analytical Chemistry, Institute of Chemistry of Araraquara, UNESP, Rua Francisco Degni, 55 - Bairro Quitandinha, 14800-900 Araraquara, SP, Brazil. Electronic address: michellebrugnera@gmail.com.
Michelle Fernanda
MF
Brugnera
Marcelo
M
Miyata
Guilherme Julião
GJ
Zocolo
Clarice Queico Fujimura
CQ
Leite
Maria Valnice Boldrin
MV
Zanoni
D002241:Carbohydrates / Q000032:analysis; D002244:Carbon / Q000302:isolation & purification; D002384:Catalysis / Q000528:radiation effects; D004203:Disinfection / Q000379:methods*; D055664:Electrochemical Techniques / Q000379:methods*; D008027:Light; D013058:Mass Spectrometry; D050296:Microbial Viability / Q000528:radiation effects; D009162:Mycobacterium avium / Q000302:isolation & purification* / Q000528:radiation effects; D019909:Mycobacterium kansasii / Q000302:isolation & purification* / Q000528:radiation effects; D009171:Mycolic Acids / Q000378:metabolism; D013997:Time Factors; D014871:Water Microbiology; D018508:Water Purification / Q000379:methods*
D002241:Carbohydrates; D009171:Mycolic Acids; D002244:Carbon
Ag nanoparticles; Disinfection; Mycobacteria; Photoelectrocatalysis; TiO(2) nanotubes